Habets, Jesse; Budde, Ricardo P.; Symersky, Petr; van den Brink, Renee B.; de Mol, Bas A.; Mali, Willem P.; van Herwerden, Lex A.; Chamuleau, Steven A.
Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these
Habets, Jesse; Budde, Ricardo P.; Symersky, Petr; van den Brink, Renee B.; de Mol, Bas A.; Mali, Willem P.; van Herwerden, Lex A.; Chamuleau, Steven A.
Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these
Meguro, Kentaro; Lellouche, Nicolas; Teiger, Emmanuel
After transcatheter aortic valve implantation (TAVI) in a 75-year-old male, chronic wide left bundle branch block (LBBB) developed. He experienced repeated episodes of decompensated systolic heart failure with severe systolic left ventricular dysfunction. After cardiac resynchronization therapy, his heart function improved substantially and he had no further admissions for heart failure. Cardiac resynchronization therapy can be effective in systolic heart failure associated with LBBB developing after TAVI.
Full Text Available Abstract Background The West African sub-region has poor health infrastructure. Mechanical valve replacement in children from such regions raises important postoperative concerns; among these, valve-related morbidity and complications of lifelong anticoagulation are foremost. Little is known about the long-term outcome of mechanical valve replacement in West Africa. We sought to determine the outcome of mechanical valve replacement of the left heart in children from this sub-region. Method We conducted a retrospective review of all consecutive left heart valve replacements in children ( Results One hundred and fourteen patients underwent mitral valve replacement (MVR, aortic valve replacement (AVR or mitral and aortic valve replacements (MAVR. Their ages ranged from 6-18 years (13.3 ± 3.1 years. All patients were in NYHA class III or IV. Median follow up was 9.1 years. MVR was performed in 91 (79.8% patients, AVR in 13 (11.4% and MAVR in 10 (8.8% patients. Tricuspid valve repair was performed concomitantly in 45 (39.5% patients. There were 6 (5.3% early deaths and 6 (5.3% late deaths. Preoperative left ventricular dysfunction (ejection fraction Conclusion Mechanical valve replacement in West African children has excellent outcomes in terms of mortality, valve-related events, and reoperation rate. Preoperative left ventricular dysfunction is the primary determinant of mortality within the first 2 years of valve replacement. The risk of valve-related complications is acceptably low. Anticoagulation is well tolerated with a very low risk of bleeding even in this socioeconomic setting.
Jagdish C. Mohan
Full Text Available Hypoplastic right heart syndrome is a rare cyanotic congenital heart disease with under-development of the right ventricle, tricuspid, and pulmonary valves leading to right-to-left shunting of the blood through inter-atrial septal defect. Perinatal mortality is high with very few patients surviving to adulthood without corrective surgery. This report describes a 26-year-old young woman, who had recurrent abortions and stillbirths and detected to have marked cyanosis with hypoplastic right heart, sub-arterial ventricular septal defect, absent pulmonary valve, non-compaction of the left ventricle, and bicuspid aortic valve with aortic regurgitation. The patient died owing to progressive heart failure 4 years after the diagnosis was made.
Azarnoush, Kasra; Nadeemy, Ahmad S; Pereira, Bruno; Leesar, Massoud A; Lambert, Céline; Azhari, Alaa; Eljezi, Vedat; Dauphin, Nicolas; Geoffroy, Etienne; Camilleri, Lionel
AIM To determine whether the need for additional tricuspid valve repair is an independent risk factor when surgery is required for a left-sided heart disease. METHODS One hundred and eighty patients (68 ± 12 years, 79 males) underwent tricuspid annuoplasty. Cox proportional-hazards regression model for multivariate analysis was performed for variables found significant in univariate analyses. RESULTS Tricuspid regurgitation etiology was functional in 154 cases (86%), organic in 16 cases (9%),...
Azarnoush, Kasra; Nadeemy, Ahmad S; Pereira, Bruno; Leesar, Massoud A; Lambert, Céline; Azhari, Alaa; Eljezi, Vedat; Dauphin, Nicolas; Geoffroy, Etienne; Camilleri, Lionel
To determine whether the need for additional tricuspid valve repair is an independent risk factor when surgery is required for a left-sided heart disease. One hundred and eighty patients (68 ± 12 years, 79 males) underwent tricuspid annuoplasty. Cox proportional-hazards regression model for multivariate analysis was performed for variables found significant in univariate analyses. Tricuspid regurgitation etiology was functional in 154 cases (86%), organic in 16 cases (9%), and mixed in 10 cases (6%), respectively. Postoperative mortality at 30 days was 11.7%. Mean follow-up was 51.7 mo with survival at 5 years of 73.5%. Risk factors for mortality were acute endocarditis [hazard ratio (HR) = 9.22 (95%CI: 2.87-29.62), P disease requiring myocardial revascularization [HR = 2.79 (1.26-6.20), P = 0.012], and aortic valve stenosis [HR = 2.6 (1.15-5.85), P = 0.021]. Significant predictive factors from univariate analyses were double-valve replacement combined with tricuspid annuloplasty [HR = 2.21 (1.11-4.39), P = 0.003] and preoperatively impaired ejection fraction [HR = 1.98 (1.04-3.92), P = 0.044]. However, successful mitral valve repair showed a protective effect [HR = 0.32 (0.10-0.98), P = 0.046]. Additionally, in instances where tricuspid regurgitation required the need for concomitant tricuspid valve repair, mortality predictor scores such as Euroscore 2 could be shortened to a simple Euroscore-tricuspid comprised of only 7 inputs. The explanation may lie in the fact that significant tricuspid regurgitation following left-sided heart disease represents an independent risk factor encompassing several other factors such as pulmonary arterial hypertension and dyspnea. Tricuspid annuloplasty should be used more often as a concomitant procedure in the presence of relevant tricuspid regurgitation, although it usually reveals an overly delayed correction of a left-sided heart disease.
Chandrakasu, Arumugam; Jayachandran, Avinash; Gopinath Nayar, Pradeep; Meyyappan, Chokkalingam; Narayan, Ganesh; Basha Abdul Bari, Ahamed; Johnson Samuel, Prince
Thrombosis of a mechanical prosthetic heart valve is a potentially life-threatening complication associated with a high mortality. Although thrombolytic therapy has been considered highly beneficial in this situation, very few studies have been conducted to monitor the effectiveness of such thrombolytic therapy among Asian populations. Hence, the study aim was to evaluate the clinical profile, efficacy and safety of the thrombolytic agent streptokinase (SK) in patients with obstructive thrombosis of a left-sided mechanical heart valve. Patients (n = 30) with left-sided mechanical heart valve thrombosis (LSMHVT) who had been managed with SK during the past four years were included in this retrospective study. Clinical features such as presenting symptoms based on NYHA functional class, prosthetic valve position, oral anticoagulant compliance, International Normalized Ratio (INR) and imaging methods including fluoroscopy, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were evaluated. In addition, the effectiveness and complications of SK were analyzed. The majority of patients presented with advanced NYHA class (III and IV, each 40%). Obstructive thromboses were observed at the mitral prosthesis in 70% of cases, at the aortic prosthesis in 27%, and at both valves in 3%. All patients underwent TTE, but fluoroscopy was used more often than TEE. Despite compliance with oral anticoagulation therapy, a sub-therapeutic INR was observed in 40% of cases at the time of presentation. Overall, thrombolysis was successful in 80% of patients using intravenous SK, with 100% success in patients in NYHA classes I-III and 42% for NYHA class IV. Moreover, embolic complications occurred in only a small number of patients. In patients with obstructive thrombosis of LSMHVT, intravenous SK was effective and should be considered as first choice in patients in NYHA classes I-III, and as an acceptable alternative in those in NYHA class IV.
... Understanding Problems and Causes Heart Murmurs and Valve Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - Problem: Pulmonary Valve Stenosis Problem: Mitral ...
Roberts, William C; Hall, Shelley A; Ko, Jong M; McCullough, Peter A; Lima, Brian
Described are findings in a 70-year-old man who had heart transplantation 4 years after treatment with a left ventricular assist device, and surgical closure of his previously replaced aortic valve. The result was a totally nonfunctioning left ventricle resulting in severe atrophy. Copyright © 2016 Elsevier Inc. All rights reserved.
Sandeep, Nefthi; Punn, Rajesh; Balasubramanian, Sowmya; Smith, Shea N; Reinhartz, Olaf; Zhang, Yulin; Wright, Gail E; Peng, Lynn F; Wise-Faberowski, Lisa; Hanley, Frank L; McElhinney, Doff B
Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling. This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015. A composite valved conduit (cryopreserved homograft valve anastomosed to a polytetrafluoroethylene tube) was placed in 100 patients (47 aortic, 32 pulmonary, 13 femoral/saphenous vein, 8 unknown), and a nonvalved conduit was used in 30 patients. Echocardiographic functional parameters were evaluated before and after stage 1 palliation and before the bidirectional Glenn procedure, and interstage interventions were assessed. On competing risk analysis, survival over time was better in the valved conduit group (P = .040), but this difference was no longer significant after adjustment for surgical era. There was no significant difference between groups in the cumulative incidence of bidirectional Glenn completion (P = .15). Patients with a valved conduit underwent more interventions for conduit obstruction in the interstage period, but this difference did not reach significance (P = .16). There were no differences between groups in echocardiographic parameters of right ventricle function at baseline or pre-Glenn. In this cohort of patients with hypoplastic left heart syndrome, inclusion of a valved right ventricle to pulmonary artery conduit was not associated with any difference in survival on adjusted analysis and did not confer an identifiable benefit on right ventricle function. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier
Koizumi, Shigeki; Ehara, Natsuhiko; Nishiya, Kenta; Koyama, Tadaaki
Late transcatheter heart valve embolization is a rare but life-threatening complication of transcatheter aortic valve implantation. Surgical intervention is performed for most cases, but some cases were treated by valve-in-valve transcatheter aortic valve implantation. We describe a patient in whom a 29-mm Edwards SAPIEN XT valve migrated into the left ventricular outflow tract 41 days after the initial implantation. We tried to perform valve-in-valve transcatheter aortic valve implantation using a transfemoral approach. As soon as the second transcatheter heart valve touched the first implanted valve, it fell into the left ventricle. Immediate surgical intervention was required. The first valve was removed, and surgical aortic valve replacement was successfully performed. In conclusion, we should choose surgical aortic valve replacement for late transcatheter heart valve embolization. Even if we need to treat by catheter intervention, transapical approach may be better.
Your heart has four valves. Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing ... close tightly. It's one of the most common heart valve conditions. Sometimes it causes regurgitation. Stenosis - when ...
... Heart Valves Sometimes heart valves can’t be repaired and must be replaced. This surgery involves removing the faulty valve and replacing it with a man-made or biological valve. Biological valves are made ...
... is called a valve-in-valve procedure. Heart-Healthy Lifestyle Changes to Treat Other Related Heart Conditions To ... your doctor may advise you to make heart-healthy lifestyle changes, such as: Heart-healthy eating Aiming for ...
Ciubotaru, Anatol; Cebotari, Serghei; Tudorache, Igor; Beckmann, Erik; Hilfiker, Andres; Haverich, Axel
Cardiac valvular pathologies are often caused by rheumatic fever in young adults, atherosclerosis in elderly patients, or by congenital malformation of the heart in children, in effect affecting almost all population ages. Almost 300,000 heart valve operations are performed worldwide annually. Tissue valve prostheses have certain advantages over mechanical valves such as biocompatibility, more physiological hemodynamics, and no need for life-long systemic anticoagulation. However, the major disadvantage of biological valves is related to their durability. Nevertheless, during the last decade, the number of patients undergoing biological, rather than mechanical, valve replacement has increased from half to more than three-quarters for biological implants. Continuous improvement in valve fabrication includes development of new models and shapes, novel methods of tissue treatment, and preservation and implantation techniques. These efforts are focused not only on the improvement of morbidity and mortality of the patients but also on the improvement of their quality of life. Heart valve tissue engineering aims to provide durable, "autologous" valve prostheses. These valves demonstrate adaptive growth, which may avoid the need of repeated operations in growing patients.
Hubert, A; Galli, E; Bouzille, G; Samset, E; Donal, E
Aims. The Assessment of left ventricular (LV) function remains a clinical challenge especially in patients with preserved LV ejection fraction (EF) and valvular heart diseases (VHD). Mechanical dispersion is supposed to be a strong predictor of events and, to be related to the extent of fibrosis. Regional cardiac work is a new validated and very promising approach to quantify LV-function. We investigated the differences in mechanical dispersions and global LV work (totW) and wasted work fraction (WWF) in normal subjects and in patients with severe primary mitral regurgitation (MR) and severe aortic stenosis (AS). A complete transthoracic echocardiography was performed in 21 normal subject, 97 patients with severe valvulopathy (47 AS, 50 MR) and preserved LV EF. Segmental strain analysis was performed in all patients and the dispersion of regional LV strain curves was computed automatically considering peaks and integrals. The LV-pressure was estimated non-invasively using a standard waveform fitted to valvular events and scaled to systolic blood pressure. Using pressure-strain loops, regional cardiac work indices were computed. LVEF was 66±12 in controls, 65±9 in MR and 65±4% in AS (p=0.125). Global longitudinal strain was -23±2.7 in controls, -24±2.9 in MR and -18±3.2% in AS (p < 0.001). The mechanical dispersion was 38±7.9 in controls, 36±11 in MR, and much higher in the hypertrophied LV of the AS: 60±19ms (p < 0.001). Cardiac work was 2200±260 in controls, 2100±270 in MR, and much lower in AS: 1700±280 mmHg.% (p < 0.001). The wasted work fraction (WWF) was even more describing how different the LV systolic function is in the 3 groups (figure1). Longitudinal strain data are robusted and new indices might be calculated based on them. These seem especially promising for a more pathophysiological driven analyzing of LV-functions. Abstract P697 Figure. Abstract P697 Figure.
Heart valve replacements improve symptoms and life expectancy but may have potential problems. Biological replacements have limited durability but do not require anticoagulation and are usually used for the relatively elderly. Mechanical valves have a virtually zero primary failure rate but require anticoagulation and are usually used for the relatively younger patient. Transcatheter valves are used for patients in whom conventional surgery is not technically feasible or who have significant comorbidities. This article discusses the management of patients after valve replacement and discusses future developments. © 2014 John Wiley & Sons Ltd.
Pagnesi, Matteo; Montalto, Claudio; Mangieri, Antonio; Agricola, Eustachio; Puri, Rishi; Chiarito, Mauro; Ancona, Marco B; Regazzoli, Damiano; Testa, Luca; De Bonis, Michele; Moat, Neil E; Rodés-Cabau, Josep; Colombo, Antonio; Latib, Azeem
Tricuspid valve (TV) repair at the time of left-sided valve surgery is indicated in patients with either severe functional tricuspid regurgitation (TR) or mild-to-moderate TR with coexistent tricuspid annular dilation or right heart failure. We assessed the benefits of a concomitant TV repair strategy during left-sided surgical valve interventions, focusing on mortality and echocardiographic TR-related outcomes. A meta-analysis was performed of studies reporting outcomes of patients who underwent left-sided (mitral and/or aortic) valve surgery with or without concomitant TV repair. Primary endpoints were all-cause and cardiac-related mortality; secondary endpoints were the presence of more-than-moderate TR, TR progression, and TR severity grade. All endpoints were evaluated at the longest available follow-up. Fifteen studies were included for a total of 2840 patients. TV repair at the time of left-sided valve surgery was associated with a significantly lower risk of cardiac-related mortality (odds ratio [OR] 0.38; 95% confidence interval [CI]: 0.25-0.58; pvalve surgery is associated with a reduction in cardiac-related mortality and improved echocardiographic TR outcomes at follow-up. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.
Emmert, Maximilian Y; Weber, Benedikt; Falk, Volkmar; Hoerstrup, Simon P
Valvular heart disease represents a leading cause of mortality worldwide. Transcatheter heart valve replacement techniques have been recently introduced into the clinical routine expanding the treatment options for affected patients. However, despite this technical progress toward minimally invasive, transcatheter strategies, the available heart valve prostheses for these techniques are bioprosthetic and associated with progressive degeneration. To overcome such limitations, the concept of heart valve tissue engineering has been repeatedly suggested for future therapy concepts. Ideally, a clinically relevant heart valve tissue engineering concept would combine minimally invasive strategies for both, living autologous valve generation as well as valve implantation. Therefore, merging transcatheter techniques with living tissue engineered heart valves into a trascatheter tissue engineered heart valve concept could significantly improve current treatment options for patients suffering from valvular heart disease. This report provides an overview on transcatheter tissue engineered heart valves and summarizes available pre-clinical data.
... Understanding Problems and Causes Heart Murmurs and Valve Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - Problem: Pulmonary Valve Stenosis Problem: Mitral ...
Catheterization - left heart ... to help guide the catheters up into your heart and arteries. Dye (sometimes called "contrast") will be ... in the blood vessels that lead to your heart. The catheter is then moved through the aortic ...
Gatti, Giuseppe; Dell'Angela, Luca; Morosin, Marco; Maschietto, Luca; Pinamonti, Bruno; Forti, Gabriella; Benussi, Bernardo; Nicolosi, Gian Luigi; Sinagra, Gianfranco; Pappalardo, Aniello
Tricuspid valve annuloplasty is the treatment of choice for tricuspid regurgitation (TR) secondary to left-sided heart valve disease (functional TR). Between 1999 and 2014, 527 consecutive patients (mean age, 69.6 ± 9.5 years) with grade ≥ 1+ functional TR (graded from 0-3+) underwent tricuspid annuloplasty in addition to left-sided heart valve operations at the authors' institution. The operative risk (by the European System for Cardiac Operative Risk Evaluation II [EuroSCORE II]) was 10.4% ± 12.2%. Clinical data and echocardiographic studies were reviewed retrospectively during a mean follow-up of 5.2 ± 3.5 years. Risk factors for late repair failure were identified by multivariable analysis. Either suture (De Vega) or device annuloplasty was used in 14.8% and 85.2% of patients, respectively. Concomitant mitral or aortic valve surgery was performed in 92.6% and 35.9% of cases, respectively. There were 48 (9.1%) hospital deaths. The 10-year nonparametric estimates of freedom from all-cause death, cardiac and cerebrovascular deaths, and grade ≥ 2+ TR were 51.2% (95% confidence interval [CI], 47.8%-54.6%) 69.9% (95% CI, 67%-72.8%), and 77.8% (95% CI, 74.2%-81.4%), respectively. A left ventricular ejection fraction tricuspid annular diameter > 40 mm (P = 0.001), and use of De Vega annuloplasty (P = 0.019) were predictors of grade ≥ 2+ TR during the follow-up period. There was a strong link between grade ≥ 2+ TR and new left-sided valvular lesions (odds ratio, 5.3; P tricuspid annular dilatation, functional TR is generally controlled within grade 1+ during the follow-up period. Recurrent TR is associated with new left-sided valvular lesions. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Dasi, Lakshmi P; Simon, Helene A; Sucosky, Philippe; Yoganathan, Ajit P
1. Artificial heart valves have been in use for over five decades to replace diseased heart valves. Since the first heart valve replacement performed with a caged-ball valve, more than 50 valve designs have been developed, differing principally in valve geometry, number of leaflets and material. To date, all artificial heart valves are plagued with complications associated with haemolysis, coagulation for mechanical heart valves and leaflet tearing for tissue-based valve prosthesis. For mecha...
Jordan, James E; Williams, J Koudy; Lee, Sang-Jin; Raghavan, Devanathan; Atala, Anthony; Yoo, James J
Mechanical and biological prostheses are used to replace damaged heart valves but are associated with significant morbidities. Although there is increased interest in bioengineering cell-seeded heart valve scaffolds, it is a time-consuming and technically difficult process. The goal of this project was to engineer self-seeding heart valves that mature quickly in vivo and have a shorter preparation time. Porcine pulmonary valves were decellularized using detergent methods and then either (1) left untreated (unconjugated, n = 6), (2) reseeded with autologous endothelial progenitor cell-derived endothelial cells (cell-seeded, n = 4), or (3) conjugated with CD133 antibodies (conjugated, n = 8). The valve constructs were transplanted into the pulmonary position of sheep using standard surgical techniques. After 1 or 3 months, the implants were removed and assessed for cell and matrix content as well as biomechanical properties. Endothelial cells expressing von Willebrand factor lined the entire length of both ventricular and arterial surfaces of conjugated valves by 1 month after implantation. Interstitial cell and structural protein content of conjugated valves increased from 1 month to 3 months with interstitial expression of metalloproteinase-9 and new collagen formation. In contrast, there were few endothelial or interstitial cells associated with unconjugated, or cell-seeded valves at any time point. No calcification or thrombi were noted on any of the valves. Young's modulus and tensile strength was greater in the conjugated valves versus unconjugated or cell-seeded valves. Results indicate that tissue-engineered heart valve replacement constructs can be made quickly and therefore may be a clinically relevant option for patients needing heart valve surgery in a timely fashion. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
Pierlot, Caitlin M; Moeller, Andrew D; Lee, J Michael; Wells, Sarah M
Recent studies have demonstrated remodeling of aortic and mitral valves leaflets under the volume loading and cardiac expansion of pregnancy. Those valves' leaflets enlarge with altered collagen fiber architecture, content, and cross-linking and biphasic changes (decreases, then increases) in extensibility during gestation. This study extends our analyses to right-sided valves, with additional compositional measurements for all valves. Valve leaflets were harvested from nonpregnant heifers and pregnant cows. Leaflet structure was characterized by leaflet dimensions, and ECM composition was determined using standard biochemical assays. Histological studies assessed changes in cellular and ECM components. Leaflet mechanical properties were assessed using equibiaxial mechanical testing. Collagen thermal stability and cross-linking were assessed using denaturation and hydrothermal isometric tension tests. Pulmonary and tricuspid leaflet areas increased during pregnancy by 35 and 55%, respectively. Leaflet thickness increased by 20% only in the pulmonary valve and largely in the fibrosa (30% thickening). Collagen crimp length was reduced in both the tricuspid (61%) and pulmonary (42%) valves, with loss of crimped area in the pulmonary valve. Thermomechanics showed decreased collagen thermal stability with surprisingly maintained cross-link maturity. The pulmonary leaflet exhibited the biphasic change in extensibility seen in left side valves, whereas the tricuspid leaflet mechanics remained largely unchanged throughout pregnancy. The tricuspid valve exhibits a remodeling response during pregnancy that is significantly diminished from the other three valves. All valves of the heart remodel in pregnancy in a manner distinct from cardiac pathology, with much similarity valve to valve, but with interesting valve-specific responses in the aortic and tricuspid valves. Copyright © 2015 the American Physiological Society.
Yang, Yang; Sun, Wei; Wu, Sean M; Xiao, Junjie; Kong, Xiangqing
Valve interstitial cells (VICs) are responsible for maintaining the structural integrity and dynamic behaviour of the valve. Telocytes (TCs), a peculiar type of interstitial cells, have been recently identified by Popescu's group in epicardium, myocardium and endocardium (visit www.telocytes.com). The presence of TCs has been identified in atria, ventricles and many other tissues and organ, but not yet in heart valves. We used transmission electron microscopy and immunofluorescence methods (double labelling for CD34 and c-kit, or vimentin, or PDGF Receptor-β) to provide evidence for the existence of TCs in human heart valves, including mitral valve, tricuspid valve and aortic valve. TCs are found in both apex and base of heart valves, with a similar density of 27-28 cells/mm(2) in mitral valve, tricuspid valve and aortic valve. Since TCs are known for the participation in regeneration or repair biological processes, it remains to be determined how TCs contributes to the valve attempts to re-establish normal structure and function following injury, especially a complex junction was found between TCs and a putative stem (progenitor) cell. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.
Killu, Ammar M; Newman, Darrell B; Miranda, William R; Maleszewski, Joseph J; Pellikka, Patricia; Schaff, Hartzell V; Connolly, Heidi M
Carcinoid syndrome causes a rare form of acquired valvular heart disease which typically occurs in the setting of liver metastases. In carcinoid-induced valvular heart disease, the tricuspid valve is almost universally affected; left-sided valve disease occurs infrequently in affected patients. Herein, we report 2 cases of carcinoid-induced valvular heart disease; one case had no evidence of tricuspid valve involvement despite severe involvement of all other valves, while the other case was without severe tricuspid valve involvement. © 2015 S. Karger AG, Basel.
Full Text Available Abstract Hypoplastic left heart syndrome(HLHS refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch. Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision
Most commonly used for replacement are mechanical heart valves and biological valves. This paper brieﬂy outlines the evolution, designs employed, materials being used,. and important factors that affect the performance of mechanical heart valves. The clinical performance of mechanical heart valves is also addressed.
Artiﬁcial heart valves are engineered devices used for replacing diseased or damaged natural valves of the heart. Most commonly used for replacement are mechanical heart valves and biological valves. This paper brieﬂy outlines the evolution, designs employed, materials being used,. and important factors that affect the ...
Toeg, Hadi Daood; Abessi, Ovais; Al-Atassi, Talal; de Kerchove, Laurent; El-Khoury, Gebrine; Labrosse, Michel; Boodhwani, Munir
Aortic valve (AV) repair (AVr) has become an attractive alternative to AV replacement for the correction of aortic insufficiency; however, little clinical evidence exists in determining which biomaterial at AVr would be optimal. Cusp replacement in AVr has been associated with increased long-term AVr failure. We measured the hemodynamic and biomaterial properties using an ex vivo porcine AVr model with clinically relevant biomaterials and generated a finite element model to ascertain which materials would be best suited for valve repair. Porcine aortic roots with intact AVs were placed in a left heart simulator mounted with a high-speed camera for baseline valve assessment. The noncoronary cusp was excised and replaced with autologous porcine pericardium, glutaraldehyde-fixed bovine pericardial patch (Synovis), extracelluar matrix scaffold (CorMatrix), or collagen-impregnated Dacron (Hemashield). The hemodynamic parameters were measured for a range of cardiac outputs (2.5-6.5 L/min) after repair. The biomaterial properties and St Jude Medical pericardial patch were determined using pressurization experiments. Finite element models of the AV and root complex were constructed to determine the hemodynamic characteristics and leaflet stresses. The geometric orifice areas after repair were significantly reduced in the Hemashield (Pbiomaterial groups. Finite element modeling of the biomaterials displayed differences in the percentage of changes in total Von Mises stress for both replaced (noncoronary cusp) and nonreplaced left and right cusps with the St Jude Medical pericardial patch (+4%, +24%) and autologous porcine pericardium (+5, +26%), with a lower percentage of changes than for the bovine pericardial patch (+12%, +27%), Hemashield (+30%, +9%), and CorMatrix (+13%, +32%). The present study has shown that postrepair left ventricular work did not increase despite a decrease in geometric orifice areas in the Hemashield and CorMatrix groups. The autologous porcine
Christopher Robin Mart
We have proposed a systematic method for evaluating and displaying the TV using 3DE which can provide significant insight into the mechanisms causing TVI in HLHS. This has the potential to improve both the surgical approach to repairing the valve and, ultimately, patient outcomes.
Filová, Elena; Straka, František; Miřejovský, T.; Mašín, J.; Bačáková, Lucie
Roč. 58, Suppl.2 (2009), S141-S158 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA AV ČR(CZ) 1QS500110564 Institutional research plan: CEZ:AV0Z50110509 Keywords : bioarteficial heart valve * valve interstitial cells * pulse flow bioreactor Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.430, year: 2009
M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22
Mechanical heart valves; biological valves; valve design; valve performance. 1. Introduction. The human heart can be considered a twin positive displacement pump working in tandem for supporting the systemic and pulmonary circulation of blood. Each pump comprises of a receiving chamber called atrium and a pumping ...
Cheema, Faisal H; Hussain, Nasir; Kossar, Alexander P; Polvani, Gianluca
Valvular heart disease, inherited or acquired, affects more than 5 million Americans yearly. Whereas medical treatment is beneficial in the initial stages of valvular heart disease, surgical correction provides symptomatic relief and long-term survival benefits. Surgical options include either repair or replacement using mechanical or bio-prosthetic valves. Patient age and the post-operative need for anticoagulation therapy are major determinants of the choice between use of mechanical or bio-prosthetic valves. Since the first mechanical valves were made available several decades ago, the incorporation of increasingly sophisticated materials and methodologies has led to substantial improvements in the valve design, and has catalyzed a parallel increase in the amount of patents issued for these emerging technologies. In this paper, we have chronologically reviewed such patents, briefly discussed various challenges that mechanical heart valve implementation is faced with and finally reviewed some of the strategies employed to overcome such obstacles. An ideal prosthetic heart valve would comprehensively mimic the natural hemodynamics and physiology of the native heart valve. Additionally, such a valve would be easily implantable, associated with a minimal risk of thrombosis and thus need for anti-coagulation, and with a proven long-term durability. With cutting edge technological advancements in the recent times, the ongoing innovative and collaborative efforts of physicians, scientists, and engineers will not seize until an ideal mechanical heart valve becomes a reality.
Mokadam, Nahush A; Stout, Karen K; Verrier, Edward D
The management of acute, severe cardiac valvular regurgitation requires expeditious multidisciplinary care. Although acute, severe valvular regurgitation can be a true surgical emergency, accurate diagnosis and subsequent treatment decisions require clinical acumen, appropriate imaging, and sound judgment. An accurate and timely diagnosis is essential for successful outcomes and requires appropriate expertise and a sufficiently high degree of suspicion in a variety of settings. Whereas cardiovascular collapse is the most obvious and common presentation of acute cardiac valvular regurgitation, findings may be subtle, and the clinical presentation can often be nonspecific. Consequently, other acute conditions such as sepsis, pneumonia, or nonvalvular heart failure may be mistaken for acute valvular regurgitation. In comparison with that of the right-sided valves, regurgitation of the left-sided valves is more common and has greater clinical impact. Therefore, this review focuses on acute regurgitation of the aortic and mitral valves.
... working correctly. Most valve replacements involve the aortic Tricuspid valve and mitral valves. The aortic valve separates the ... in life and cause problems. •Aging can make valves weaken or harden. • Certain diseases can scar or destroy a valve. What can ...
Prosthetic heart valve (PHV) dysfunction is an infrequent but potentially life-threatening disease with a heterogeneous clinical presentation. Patients with PHV dysfunction clinically can present with symptoms of congestive heart failure (dyspnea, fatigue, edema), fever, angina pectoris, dizziness
Filová, E; Straka, F; Mirejovský, T; Masín, J; Bacáková, L
Currently-used mechanical and biological heart valve prostheses have several disadvantages. Mechanical prostheses, based on carbon, metallic and polymeric components, require permanent anticoagulation treatment, and their usage often leads to adverse reactions, e.g. thromboembolic complications and endocarditis. Xenogenous and allogenous biological prostheses are associated with immune reaction, thrombosis and degeneration, and thus they have a high rate of reoperation. Biological prostheses of autologous origin, such as pulmonary autografts, often burden the patient with a complicated surgery and the risk of reoperation. Therefore, efforts are being made to prepare bioartificial heart valves with an autologous biological component by methods of tissue engineering. They should be biocompatible, durable, endowed with appropriate mechanical properties and able to grow with a child. For this purpose, scaffolds composed of synthetic materials, such as poly(lactic acid), poly(caprolactone), poly(4-hydroxybutyrate), hydrogels or natural polymers, e.g. collagen, elastin, fibrin or hyaluronic acid, have been seeded with autologous differentiated, progenitor or stem cells. Promising results have been obtained with nanostructured scaffolds, and also with cultivation in special dynamic bioreactors prior to implantation of the bioartificial grafts into an animal organism.
Steffensen, Maria Charlotte; Maegbaek, Merete Lund; Laurberg, Peter
Increased risk of heart valve disease during treatment with certain dopamine agonists, such as cabergoline, has been observed in patients with Parkinson's disease. The same compound is used to treat hyperprolactinemia, but it is unknown whether this also associates with heart valve disease....
Issa, Issa Farah; Poulsen, Steen Hvitfeldt; Waziri, Farhad
OBJECTIVES: Concern has been raised regarding the long-term durability of the Mitroflow biological heart valve prosthesis. Our aim was to assess the incidence of structural valve degeneration (SVD) for the Mitroflow bioprosthesis in a nationwide study in Denmark including all patients alive in De...
Full Text Available Abstract A 54 years old male with undiagnosed chronic calcific degenerative aortic valve incompetence presented with acute left anterior chordae tendinae rupture resulting in severe left heart failure and cardiogenic shock. He was successfully treated with emergency double valve replacement using mechanical valves. The pathogenesis of acute rupture of the anterior chordae tendinae, without any evidence of infective endocarditis or ischemic heart disease seems to have been attrition of the subvalvular mitral apparatus by the chronic regurgitant jet of aortic incompetence with chronic volume overload. We review the literature with specific focus on the occurrence of this unusual event.
... are the most commonly replaced valves. Pulmonary and tricuspid valve replacements are fairly uncommon in adults. Replacing a ... Problems and Causes • Risks, Signs and Symptoms • Accurate Diagnosis • Treatment Options ... Repair Valve Replacement - Ross Procedure - Newer Surgery Options - ...
Webb, John G; Wood, David A; Ye, Jian; Gurvitch, Ronen; Masson, Jean-Bernard; Rodés-Cabau, Josep; Osten, Mark; Horlick, Eric; Wendler, O; Dumont, Eric; Carere, Ronald G; Wijesinghe, Namal; Nietlispach, Fabian; Johnson, Mark; Thompson, Chrisopher R; Moss, Robert; Leipsic, Jonathon; Munt, Brad; Lichtenstein, Samuel V; Cheung, Anson
The majority of prosthetic heart valves currently implanted are tissue valves that can be expected to degenerate with time and eventually fail. Repeat cardiac surgery to replace these valves is associated with significant morbidity and mortality. Transcatheter heart valve implantation within a failed bioprosthesis, a "valve-in-valve" procedure, may offer a less invasive alternative. Valve-in-valve implantations were performed in 24 high-risk patients. Failed valves were aortic (n=10), mitral (n=7), pulmonary (n=6), or tricuspid (n=1) bioprostheses. Implantation was successful with immediate restoration of satisfactory valve function in all but 1 patient. No patient had more than mild regurgitation after implantation. No patients died during the procedure. Thirty-day mortality was 4.2%. Mortality was related primarily to learning-curve issues early in this high-risk experience. At baseline, 88% of patients were in New York Heart Association functional class III or IV; at the last follow-up, 88% of patients were in class I or II. At a median follow-up of 135 days (interquartile range, 46 to 254 days) and a maximum follow-up of 1045 days, 91.7% of patients remained alive with satisfactory valve function. Transcatheter valve-in-valve implantation is a reproducible option for the management of bioprosthetic valve failure. Aortic, pulmonary, mitral, and tricuspid tissue valves were amenable to this approach. This finding may have important implications with regard to valve replacement in high-risk patients.
Steiner, R.M.; Flicker, S.
The development of prosthetic heart valves in the late 1950s ushered in a new era in the treatment of heart disease. The radiologist has an important role to play preoperatively in the diagnosis of valvular heart disease. Radiology is valuable in identification of the implanted prosthetic valve and recognition of complications associated with valve implantation. Radiologists must be familiar with the imaging techniques best suited to evaluate the function of the valve prosthesis in question. In this chapter the authors discuss the radiographic approach to the evaluation of the status of patients for valve replacement and the imaging problems peculiar to the types of valves in current use. The relative value of plain-film radiography, fluoroscopy, videorecording and cinerecording, and aortography is addressed, as well as the potential value of magnetic resonance imaging and subsecond dynamic computed tomography
Manji, Rizwan A; Ekser, Burcin; Menkis, Alan H; Cooper, David K C
Glutaraldehyde-fixed bioprosthetic heart valves (GBHVs), derived from pigs or cows, undergo structural valve deterioration (SVD) over time, with calcification and eventual failure. It is generally accepted that SVD is due to chemical processes between glutaraldehyde and free calcium ions in the blood. Valve companies have made significant progress in decreasing SVD from calcification through various valve chemical treatments. However, there are still groups of patients (e.g., children and young adults) that have accelerated SVD of GBHV. Unfortunately, these patients are not ideal patients for valve replacement with mechanical heart valve prostheses as they are at high long-term risk from complications of the mandatory anticoagulation that is required. Thus, there is no "ideal" heart valve replacement for children and young adults. GBHVs represent a form of xenotransplantation, and there is increasing evidence that SVD seen in these valves is at least in part associated with xenograft rejection. We review the evidence that suggests that xenograft rejection of GBHVs is occurring, and that calcification of the valve may be related to this rejection. Furthermore, we review recent research into the transplantation of live porcine organs in non-human primates that may be applicable to GBHVs and consider the potential use of genetically modified pigs as sources of bioprosthetic heart valves. © 2014 John Wiley & Sons A/S.
The total right/left-volume index: a new and simplified cardiac magnetic resonance measure to evaluate the severity of Ebstein anomaly of the tricuspid valve: a comparison with heart failure markers from various modalities.
Hösch, Olga; Sohns, Jan Martin; Nguyen, Thuy-Trang; Lauerer, Peter; Rosenberg, Christina; Kowallick, Johannes Tammo; Kutty, Shelby; Unterberg, Christina; Schuster, Andreas; Faßhauer, Martin; Staab, Wieland; Paul, Thomas; Lotz, Joachim; Steinmetz, Michael
The classification of clinical severity of Ebstein anomaly still remains a challenge. The aim of this study was to focus on the interaction of the pathologically altered right heart with the anatomically-supposedly-normal left heart and to derive from cardiac magnetic resonance (CMR) a simple imaging measure for the clinical severity of Ebstein anomaly. Twenty-five patients at a mean age of 26±14 years with unrepaired Ebstein anomaly were examined in a prospective study. Disease severity was classified using CMR volumes and functional measurements in comparison with heart failure markers from clinical data, ECG, laboratory and cardiopulmonary exercise testing, and echocardiography. All examinations were completed within 24 hours. A total right/left-volume index was defined from end-diastolic volume measurements in CMR: total right/left-volume index=(RA+aRV+fRV)/(LA+LV). Mean total right/left-volume index was 2.6±1.7 (normal values: 1.1±0.1). This new total right/left-volume index correlated with almost all clinically used biomarkers of heart failure: brain natriuretic peptide (r=0.691; P=0.0003), QRS (r=0.432; P=0.039), peak oxygen consumption/kg (r=-0.479; P=0.024), ventilatory response to carbon dioxide production at anaerobic threshold (r=0.426; P=0.048), the severity of tricuspid regurgitation (r=0.692; P=0.009), tricuspid valve offset (r=0.583; P=0.004), and tricuspid annular plane systolic excursion (r=0.554; P=0.006). Previously described severity indices ([RA+aRV]/[fRV+LA+LV]) and fRV/LV end-diastolic volume corresponded only to some parameters. In patients with Ebstein anomaly, the easily acquired index of right-sided to left-sided heart volumes from CMR correlated well with established heart failure markers. Our data suggest that the total right/left-volume index should be used as a new and simplified CMR measure, allowing more accurate assessment of disease severity than previously described scoring systems. © 2014 American Heart Association, Inc.
Kockova, Radka; Kacer, Petr; Pirk, Jan; Maly, Jiri; Sukupova, Lucie; Sikula, Viktor; Kotrc, Martin; Barciakova, Lucia; Honsova, Eva; Maly, Marek; Kautzner, Josef; Sedmera, David; Penicka, Martin
The aim of our study was to investigate the relationship between the cardiac magnetic resonance (CMR)-derived native T1 relaxation time and myocardial extracellular volume (ECV) fraction and the extent of diffuse myocardial fibrosis (DMF) on targeted myocardial left ventricular (LV) biopsy. The study population consisted of 40 patients (age 63±8 years, 65% male) undergoing valve and/or ascending aorta surgery for severe aortic stenosis (77.5%), root dilatation (7.5%) or valve regurgitation (15%). The T1 relaxation time was assessed in the basal interventricular septum pre- and 10-min post-contrast administration using the modified Look-Locker Inversion recovery sequence prior to surgery. LV myocardial biopsy specimen was obtained during surgery from the basal interventricular septal segment matched with the T1 mapping assessment. The percentage of myocardial collagen was quantified using picrosirius red staining. The average percentage of myocardial collagen was 22.0±14.8%. Both native T1 relaxation time with cutoff value ≥1,010 ms (sensitivity=90%, specificity=73%, area under the curve=0.82) and ECV with cutoff value ≥0.32 (sensitivity=80%, specificity=90%, area under the curve=0.85) showed high accuracy to identify severe (>30%) DMF. The native T1 relaxation time showed significant correlation with LV mass (Pmarkers of DMF. (Circ J 2016; 80: 1202-1209).
Chivukula, V. Keshav; McGah, Patrick; Prisco, Anthony; Beckman, Jennifer; Mokadam, Nanush; Mahr, Claudius; Aliseda, Alberto
Flow in the aortic vasculature may impact stroke risk in patients with left ventricular assist devices (LVAD) due to severely altered hemodynamics. Patient-specific 3D models of the aortic arch and great vessels were created with an LVAD outflow graft at 45, 60 and 90° from centerline of the ascending aorta, in order to understand the effect of surgical placement on hemodynamics and thrombotic risk. Intermittent aortic valve opening (once every five cardiac cycles) was simulated and the impact of this residual native output investigated for the potential to wash out stagnant flow in the aortic root region. Unsteady CFD simulations with patient-specific boundary conditions were performed. Particle tracking for 10 cardiac cycles was used to determine platelet residence times and shear stress histories. Thrombosis risk was assessed by a combination of Eulerian and Lagrangian metrics and a newly developed thrombogenic potential metric. Results show a strong influence of LVAD outflow graft angle on hemodynamics in the ascending aorta and consequently on stroke risk, with a highly positive impact of aortic valve opening, even at low frequencies. Optimization of LVAD implantation and management strategies based on patient-specific simulations to minimize stroke risk will be presented
Ayoub, Salma; Ferrari, Giovanni; Gorman, Robert C.; Gorman, Joseph H.; Schoen, Frederick J.; Sacks, Michael S.
Heart valves control unidirectional blood flow within the heart during the cardiac cycle. They have a remarkable ability to withstand the demanding mechanical environment of the heart, achieving lifetime durability by processes involving the ongoing remodeling of the extracellular matrix. The focus of this review is on heart valve functional physiology, with insights into the link between disease-induced alterations in valve geometry, tissue stress, and the subsequent cell mechanobiological responses and tissue remodeling. We begin with an overview of the fundamentals of heart valve physiology and the characteristics and functions of valve interstitial cells (VICs). We then provide an overview of current experimental and computational approaches that connect VIC mechanobiological response to organ- and tissue-level deformations and improve our understanding of the underlying functional physiology of heart valves. We conclude with a summary of future trends and offer an outlook for the future of heart valve mechanobiology, specifically, multiscale modeling approaches, and the potential directions and possible challenges of research development. PMID:27783858
Dahl, Jordi S; Christensen, Nicolaj L; Videbæk, Lars
BACKGROUND: In aortic valve stenosis (AS), the occurrence of heart failure symptoms does not always correlate with severity of valve stenosis and left ventricular (LV) function. Therefore, we tested the hypothesis that symptomatic patients with AS have impaired diastolic, longitudinal systolic...... atrial volume index, and deceleration time were still associated with the presence of symptoms. CONCLUSIONS: The present study demonstrates that symptomatic status in severe AS is associated with impaired diastolic function, LV hypertrophy, concentric remodeling, and left atrial dilatation when corrected...
Schoenaker, Michiel H; van Wetten, Herbert B; Morshuis, Wim J
In the 1960s, the Starr-Edwards valve was the first artificial heart valve to be successfully implanted in humans. This valve has now been in use for decades with outstanding results: patients whose life expectancy had previously been short acquired a good prognosis with this development. Nowadays the Starr-Edwards valve is not used anymore, but patients are being described today in whom these valves are still functioning well after more than 40 years.
Lytzen, Rebekka; Helvind, Morten; Jørgensen, Finn Stener
In-utero treatment of fetal aortic stenosis (AS) may prevent hypoplastic left heart syndrome. A girl was diagnosed prenatally with severe AS and was referred to the Women's and Children's Hospital in Linz, Austria, where she underwent an intrauterine valvuloplasty of the aortic valve. Postnatally...
Cheema, Faisal H; Kossar, Alexander P; Rehman, Atiq; Younas, Fahad; Polvani, Gianluca
Valvular heart disease affects millions of Americans yearly and currently requires surgical intervention to repair or replace the defective valves. Through a close-knit collaboration between physicians, scientists and biomedical engineers, a vast degree of research and development has been aimed towards the optimization of prosthetic heart valves. Although various methods have made fantastic strides in producing durable prostheses, the therapeutic efficacy of prosthetic valves is inherently limited by a dependency upon lifelong anticoagulant regimens for recipients - a difficult challenge for many in clinical setting. Thus, biological tissue valves have been developed to circumvent vascular and immunemediated complications by incorporating biological materials to mimic native valves while still maintaining a necessary level of structural integrity. Over the past decade, a multitude of patents pertaining to the refinement of designs as well as the advancement in methodologies and technologies associated with biological tissue valves have been issued. This review seeks to chronicle and characterize such patents in an effort to track the past, present, and future progress as well as project the trajectory of tissue valves in the years to come.
Gavin, Caroline; Coblentz, John; Acsell, Jeffrey R.; Shackelford, Anthony G.; Sistino, Joseph J.
Vent vacuum relief valves (VRVs) are used to limit the negative pressure at the ventricular vent catheter tip as well as prevent reversal of blood flow and prevention of air embolism. The purpose of this study was to evaluate the performance of three commercially available ventricular vent valves. The negative pressure at which the vent valve opened was measured at the valve inlet using high-fidelity pressure transducers. Also, the flow rate at which air entrainment occurred due to valve open...
Full Text Available The historical evolution of the prosthetic heart valves from the first attempts with the Hufnagel′s valve in the treatment of the aortic insufficiency to the Starr-Edwards′ ball valve and later the tilting disc valves (Bjork-Shiley etc., and finally the bileaflet valves (St. Jude are discussed. The Indian contribution with Chitra valve is also described.
Stassen, O M J A; Muylaert, D E P; Bouten, Carlijn V. C.; Hjortnaes, J; Hjortnaes, J
OPINION STATEMENT: Heart valve disease is a major health burden, treated by either valve repair or valve replacement, depending on the affected valve. Nearly 300,000 valve replacements are performed worldwide per year. Valve replacement is lifesaving, but not without complications. The in situ
Habets, Jesse; Mali, Willem P.T.M.; Budde, Ricardo P.J.; Brink, Renee B.A. van den; Uijlings, Ruben; Spijkerboer, Anje M.; Chamuleau, Steven A.J.
Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers. Eighty-two CT angiograms were performed on a 64-slice (n = 27) or 256-slice (n = 55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types. Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts. circle Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment circle Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts circle Bjoerk-Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessment. (orig.)
Habets, Jesse; van den Brink, Renee B A; Uijlings, Ruben; Spijkerboer, Anje M; Mali, Willem P Th M; Chamuleau, Steven A J; Budde, Ricardo P J
Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers. Eighty-two CT angiograms were performed on a 64-slice (n = 27) or 256-slice (n = 55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types. Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts. • Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment • Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts • Björk-Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessment.
Ilina, Anna; Lasso, Andras; Jolley, Matthew A.; Wohler, Brittany; Nguyen, Alex; Scanlan, Adam; Baum, Zachary; McGowan, Frank; Fichtinger, Gabor
PURPOSE: Patient-specific heart and valve models have shown promise as training and planning tools for heart surgery, but physically realistic valve models remain elusive. Available proprietary, simulation-focused heart valve models are generic adult mitral valves and do not allow for patient-specific modeling as may be needed for rare diseases such as congenitally abnormal valves. We propose creating silicone valve models from a 3D-printed plastic mold as a solution that can be adapted to any individual patient and heart valve at a fraction of the cost of direct 3D-printing using soft materials. METHODS: Leaflets of a pediatric mitral valve, a tricuspid valve in a patient with hypoplastic left heart syndrome, and a complete atrioventricular canal valve were segmented from ultrasound images. A custom software was developed to automatically generate molds for each valve based on the segmentation. These molds were 3D-printed and used to make silicone valve models. The models were designed with cylindrical rims of different sizes surrounding the leaflets, to show the outline of the valve and add rigidity. Pediatric cardiac surgeons practiced suturing on the models and evaluated them for use as surgical planning and training tools. RESULTS: Five out of six surgeons reported that the valve models would be very useful as training tools for cardiac surgery. In this first iteration of valve models, leaflets were felt to be unrealistically thick or stiff compared to real pediatric leaflets. A thin tube rim was preferred for valve flexibility. CONCLUSION: The valve models were well received and considered to be valuable and accessible tools for heart valve surgery training. Further improvements will be made based on surgeons' feedback.
Infectious endocarditis (IE), a complication that is both cardiac and infectious, occurs frequently and is associated with a heavy burden of morbidity and mortality in chronic hemodialysis patients (CHD). About 2-6% of chronic hemodialysis patients develop IE and the incidence is 50-60 times higher among CHD patients than in the general population. The left heart is the most frequent location of IE in CHD and the different published series report a prevalence of left valve involvement varying from 80% to 100%. Valvular and perivalvular abnormalities, alteration of the immune system, and bacteremia associated with repeated manipulation of the vascular access, particularly central venous catheters, comprise the main factors explaining the left heart IE in CHD patients. While left-sided IE develops in altered valves in a high-pressure system, right-sided IE on the contrary, generally develops in healthy valves in a low-pressure system. Right-sided IE is rare, with its incidence varying from 0% to 26% depending on the study, and the tricuspid valve is the main location. Might the massive influx of pathogenic and virulent germs via the central venous catheter to the right heart, with the tricuspid being the first contact valve, have a role in the physiopathology of IE in CHD, thus facilitating bacterial adhesion? While the physiopathology of left-sided IE entails multiple and convincing mechanisms, it is not the case for right-sided IE, for which the physiopathological mechanism is only partially understood and remains shrouded in mystery.
Vukicevic, M.; Fortini, S.; Querzoli, G.; Cenedese, A.; Pedrizzetti, G.
The mechanical heart valves (MHVs) are extremely important medical devices, commonly used for diseased heart valves replacement. Despite the long term of use and constant design refinement, the MHVs are very far from ideal and their performance is very diverse from that of the native ones. It has been approved that small variations in geometry of valvular leaflets influence the significant change in the intraventricular vortical flow, known as one of the most important factors for the overall functionality of the heart. We have experimentally examined the home-made heart valve prototypes, exclusively modeled for the mitral valve replacement. The performance and energetic properties of the prototypes have been compared with those in the presence of standard MHVs. The analysis was based on the testing of intraventricular fluid dynamics, usually missing criteria for the quality of the valve performance. It has been shown that the asymmetric prototype, with unequal leaflets and D-shaped orifice produces flow patterns and energetic properties close to those found in the healthy subjects. Thus, the break of symmetry in the standard bi-leaflet MHV prosthesis, at least from the fluid dynamics point of view, is worthwhile to be considered for the design of MHVs for the mitral valve replacement.
Alavi, S Hamed; Kheradvar, Arash
This study describes the efforts to develop and test the first hybrid tissue-engineered heart valve whose leaflets are composed of an extra-thin superelastic Nitinol mesh tightly enclosed by uniform tissue layers composed of multiple cell types. The trileaflet Nitinol mesh scaffolds underwent three-dimensional cell culture with smooth muscle and fibroblast/myofibroblast cells enclosing the mesh, which were finally covered by an endothelial cell layer. Quantitative and qualitative assays were performed to analyze the microstructure of the tissues. A tissue composition almost similar to that of natural heart valve leaflets was observed. The function of the valves and their Nitinol scaffolds were tested in a heart flow simulator that confirmed the trileaflet valves open and close robustly under physiologic flow conditions with an effective orifice area of 75%. The tissue-metal attachment of the leaflets once exposed to physiologic flow rates was tested and approved. Our preliminary results indicate that the novel hybrid approach with nondegradable scaffold for engineering heart valves is viable and may address the issues associated with current tissue-engineered valves developed with degradable scaffolds. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
Gavin, Caroline; Coblentz, John; Acsell, Jeffrey R; Shackelford, Anthony G; Sistino, Joseph J
Vent vacuum relief valves (VRVs) are used to limit the negative pressure at the ventricular vent catheter tip as well as prevent reversal of blood flow and prevention of air embolism. The purpose of this study was to evaluate the performance of three commercially available ventricular vent valves. The negative pressure at which the vent valve opened was measured at the valve inlet using high-fidelity pressure transducers. Also, the flow rate at which air entrainment occurred due to valve opening was recorded. Using a 51.5 cm column of saline, the resistance for each valve was calculated. The mean ± SD opening negative pressures were -231.3 ± 35.2 mmHg for the Quest Medical valve, -219.8 mmHg ± 17.2 for the Sorin valve, and -329.6 · 38.0 mmHg for the Terumo valve. The red Quest Medical valve opened at a lower flow (1.44 ± .03 L/min) than the dark blue Sorin valve (2.93 ± .01 L/min) and light blue LH130 Terumo valve (2.36 ± .02 L/min). The Sorin valve had the least resistance of 34.1 dyn-s/cm, followed by the Terumo LH130 valve resistance of 58.1 dyn·s/cm5, and the Quest Medical VRV-II valve with a resistance of 66.5 dyn·s/cm. We found that the valves are significantly different in the negative pressure generated. Understanding the limitations of these devices is important to reduce the occurrence of adverse events associated with venting and to select the best device for a specific clinical application.
Severe tricuspid regurgitation may often appear and progress late after left-sided valve surgery without left-sided valve dysfunction, significant left heart failure, and pulmonary hypertension. The clinical features, echocardiographic evaluation, treatment, and prognosis of this disease entity have been discussed, but data is limited compared with left-sided valve diseases. Tricuspid annular dilatation associated with atrial fibrillation and right ventricular dysfunction strongly relate to development of isolated tricuspid regurgitation late after left-sided valve surgery. Three-dimensional evaluation may be useful in evaluating tricuspid valve anatomy in more detail. Better prognosis in patients undergoing surgical treatment for severe isolated tricuspid regurgitation than those who were treated medically has been reported; however, the timing of isolated tricuspid valve surgery is often too late. Right ventricular function is a key word for determining the timing of isolated tricuspid valve surgery; however, it is difficult to evaluate by conventional echocardiography. One of the serious issues in the future will be how to accurately evaluate right ventricular function.
VeDepo, Mitchell C; Detamore, Michael S; Hopkins, Richard A; Converse, Gabriel L
The tissue-engineered heart valve portends a new era in the field of valve replacement. Decellularized heart valves are of great interest as a scaffold for the tissue-engineered heart valve due to their naturally bioactive composition, clinical relevance as a stand-alone implant, and partial recellularization in vivo. However, a significant challenge remains in realizing the tissue-engineered heart valve: assuring consistent recellularization of the entire valve leaflets by phenotypically appropriate cells. Many creative strategies have pursued complete biological valve recellularization; however, identifying the optimal recellularization method, including in situ or in vitro recellularization and chemical and/or mechanical conditioning, has proven difficult. Furthermore, while many studies have focused on individual parameters for increasing valve interstitial recellularization, a general understanding of the interacting dynamics is likely necessary to achieve success. Therefore, the purpose of this review is to explore and compare the various processing strategies used for the decellularization and subsequent recellularization of tissue-engineered heart valves.
Johansen, Peter; Andersen, Tina S; Hasenkam, J Michael; Nygaard, Hans; Paulsen, Peter K
Today, the quality of mechanical heart valves is quite high, and implantation has become a routine clinical procedure with a low operative mortality (mechanism found to be a possible contributor to these adverse effects is cavitation. In vitro, cavitation has been directly demonstrated by visualization and indirectly in vivo by registering of high frequency pressure fluctuations (HFPF). Tilting disc valves are thought of having higher cavitation potential than bileaflet valves due to higher closing velocities. However, the thromboembolic potential seems to be the same. Further studies are therefore needed to investigate the cavitation potential of bileaflet valves in vivo. The post processing of HFPF have shown difficulties when applied on bileaflet vavles due to asynchronous closure of the two leaflets. The aim of this study was therefore to isolate the pressure signature from each leaflet closure and perform cavitation analyses on each component. Six patients were included in the study (St. Jude Medical (n=3) and CarboMedics (n=3); all aortic bileaflet mechanical heart valves). HFPFs were recorded intraoperatively through a hydrophone at the aortic root. The pressure signature relating to the first and second leaflet closure was isolated and cavitation parameters were calculated (RMS after 50 kHz highpass filtering and signal energy). Data were averaged over 30 heart cycles. For all patients both the RMS value and signal energy of the second leaflet closure were higher than for the first leaflet closure. This indicates that the second leaflet closure is most prone to cause cavitation. Therefore, quantifying cavitation based on the HFPF related to the second leaflet closure may suggest that the cavitation potential for bileaflet valves in vivo may be higher than previous studies have suggested.
Soulen, R L; Budinger, T F; Higgins, C B
To evaluate the safety of magnetic resonance (MR) imaging of prosthetic heart valves, nine different synthetic and tissue valves were studied ex vivo. Deflection was measured in 0.35-tesla (T) and 1.5-T superconducting magnets and at the edge of the bore of a 2.35-T electromagnet in field gradients of 5, 1.1, and 6.3 mT/cm, respectively. No valve deflected in the 0.35-T magnet; six synthetic valves deflected 0.25 degrees-3 degrees in the 1.5-T magnet; all valves deflected 1 degree-27 degrees at the edge of the 2.35-T magnet. Each valve was then submerged in a vial of water and the temperature was measured immediately before and after each of two spin-echo imaging sequences in the two superconducting magnets. No significant temperature rise followed exposure in either magnet. Image distortion varied from negligible to severe in both imagers; magnitude of distortion paralleled magnitude of deflection. These data suggest that patients with present-day prosthetic heart valves can be safely imaged in present-day MR imagers and that prosthesis-induced artifacts will not interfere with interpretation in most instances.
Pigula, Frank A; Mettler, Bret
Tricuspid valve (TV) performance is critical for palliation of hypoplastic left heart syndrome. We will review current TV repair techniques, outcomes, and novel approaches. Copyright © 2017 Elsevier Inc. All rights reserved.
Rajani, Ronak, E-mail: Dr.R.Rajani@gmail.com [Department of Cardiology, St. Thomas’ Hospital, London (United Kingdom); Khattar, Rajdeep [Department of Cardiology, Royal Brompton Hospital, London (United Kingdom); Chiribiri, Amedeo [Divisions of Imaging Sciences, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Victor, Kelly; Chambers, John [Department of Cardiology, St. Thomas’ Hospital, London (United Kingdom)
Unidentified heart valve disease is associated with a significant morbidity and mortality. It has therefore become important to accurately identify, assess and monitor patients with this condition in order that appropriate and timely intervention can occur. Although echocardiography has emerged as the predominant imaging modality for this purpose, recent advances in cardiac magnetic resonance and cardiac computed tomography indicate that they may have an important contribution to make. The current review describes the assessment of regurgitant and stenotic heart valves by multimodality imaging (echocardiography, cardiac computed tomography and cardiac magnetic resonance) and discusses their relative strengths and weaknesses.
Arakawa, Mamoru; Yamaguchi, Atsushi; Nishimura, Takashi; Itoh, Satoshi; Yuri, Koichi; Kyo, Shunei; Adachi, Hideo
Both left ventricular assist device and left ventricular reconstruction are treatment choices for severe heart failure conditions. Our institution performed a left ventricular assist device installation following a left ventricular reconstruction procedure on a 42-year-old male patient who presented with dilated cardiomyopathy and low cardiac output syndrome. A mitral valve plasty was used to correct the acute mitral valve regurgitation and we performed a Nipro extra-corporeal left ventricular assist device installation on post-operative day 14. Due to the left ventricular reconstruction that the patient had in a previous operation, we needed to attach an apical cuff on posterior apex, insert the inflow cannula with a large curve, and shift the skin insertion site laterally to the left. We assessed the angle between the cardiac longitudinal axis and the inflow cannula using computed tomography. The patient did not complain of any subjective symptoms of heart failure. Although Nipro extra-corporeal left ventricular assist device installation after left ventricular reconstruction has several difficulties historically, we have experienced a successful case.
Meschini, Valentina; De Tullio, M.D.; Querzoli, Giorgio; Verzicco, R.
In this paper, the structure and the dynamics of the flow in the left heart ventricle are studied for different pumping efficiencies and mitral valve types (natural, biological and mechanical prosthetic). The problem is investigated by direct numerical simulation of the Navier-Stokes equations,
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of the...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve holder. 870.3935 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3935 Prosthetic heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a...
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
variability (HRV). Reduced HRV is seen in dogs with heart failure secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease progression in dogs with early stages of MMVD. Comparable results are found in people with primary mitral valve prolapse, a disease......dogs; even prior to the development of overt congestive heart failure....... into 4 groups: 1) no or minimal mitral regurgitation (MR) (MR jet=15% of the left atrial area) and no murmur, 2) mild MR (20%50%) and no clinical signs of heart failure, 4) left atrium to aortic root ratio >1.5, clinical signs of heart failure and furosemide...
Wang, JiangSheng; Gao, Qi; Wei, RunJie; Wang, JinJun
The use of artificial valves to replace diseased human heart valves is currently the main solution to address the malfunctioning of these valves. However, the effect of artificial valves on the ventricular flow still needs to be understood in flow physics. The left ventricular flow downstream of a St. Jude Medical (SJM) bileaflet mechanical heart valve (BMHV), which is a widely implanted mechanical bileaflet valve, is investigated with time-resolved particle image velocimetry in the current work. A tilting-disk valve is installed on the aortic orifice to guarantee unidirectional flow. Several post-processing tools are applied to provide combined analyses of the physics involved in the ventricular flow. The triple jet pattern that is closely related to the characteristics of the bileaflet valve is discussed in detail from both Eulerian and Lagrangian views. The effects of large-scale vortices on the transportation of blood are revealed by the combined analysis of the tracking of Lagrangian coherent structures, the Eulerian monitoring of the shear stresses, and virtual dye visualization. It is found that the utilization of the SJM BMHV complicates the ventricular flow and could reduce the efficiency of blood transportation. In addition, the kinematics of the bileaflets is presented to explore the effects of flow structures on their motion. These combined analyses could elucidate the properties of SJM BMHV. Furthermore, they could provide new insights into the understanding of other complex blood flows.
Pollmann, Agathe Gerwina Elena; Frederiksen, Marianne; Prescott, Eva
PURPOSE: Evidence of the effect of cardiac rehabilitation (CR) after heart valve surgery is scarce, but nevertheless CR is recommended for this group of patients. Therefore, this study assessed the effect of CR on exercise capacity, cardiovascular risk factors, and long-term mortality and morbidity......, as well as predictors for enrolment in or failing to complete CR. METHODS: A review of medical records identified 250 patients who underwent heart valve surgery between January 2009 and August 2013. Of these, 211 patients eligible for CR were identified. Effect of CR was assessed by peak oxygen uptake...... ((Equation is included in full-text article.)O2peak) or 6-minute walk test (6MWT). A composite endpoint of all-cause mortality and hospital admission due to myocardial infarction, stroke, heart failure, endocarditis, revascularization, or reoperation was used to assess the hazard ratio between CR attenders...
Sorrentino, Sabato; Giustino, Gennaro; Moalem, Kamilia; Indolfi, Ciro; Mehran, Roxana; Dangas, George D
Transcatheter heart valve replacement technology was introduced as alternative to surgery for the growing high-risk profile population. Developed first, aortic valve replacement (TAVR) became a standard of care for patients with severe aortic stenosis at high operative risk, with a potential future use also for low-risk subjects. In the last decade, a multitude of transcatheter mitral valve replacement (TMVR) devices have been developed for the treatment of severe mitral regurgitation, with encouraging results coming from first-in-man and feasibility studies. As for biological surgical-type valves, transcatheter implanted valves still preserve the risk of thrombosis and embolic events and anticoagulation- or antiplatelet-based strategies are the most widely used options. Unfortunately, these last remain recommended on the basis of empirical or not widely validated evidence. Therefore, given the exponential rise of TAVR and TMVR procedures, it is important to identify the optimal antithrombotic strategies that best fit the risk of thromboembolic and bleeding events. Hereafter, this review evaluates the current guidelines, trials, and observational data discussing antithrombotic strategy after transcatheter aortic or mitral valve replacement. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Preetham R Muskula
Full Text Available An 84-year-old man presented 5 years after bioprosthetic mitral valve replacement with three months of worsening dyspnea on exertion. A new mitral stenosis murmur was noted on physical examination, and an electrocardiogram revealed newly recognized atrial fibrillation. Severe mitral stenosis (mean gradient = 13 mmHg was confirmed by transthoracic echocardiography. Transesophageal echocardiography revealed markedly thickened mitral bioprosthetic leaflets with limited mobility, and a massive left atrial thrombus (>4 cm in diameter (Fig. 1A, B, C, D and Videos 1, 2, 3 and 4. Intravenous heparin was initiated, and 5 days later, he was taken to the operating room for planned redo mitral valve replacement and left atrial thrombus extraction. Intraoperative transesophageal echocardiography revealed near-complete resolution of the bioprosthetic leaflet thickening, and a mean mitral gradient of only 3 mmHg (Fig. 2A, B, C and Videos 5, 6 and 7. The patient underwent resection of the massive left atrial thrombus (Fig. 2D but did not require redo mitral valve replacement. He was initiated on heparin (and transitioned to warfarin early in the post-operative period, with complete resolution of dyspnea on exertion at 3-month follow-up. Bioprosthetic valve thrombosis is increasingly recognized as a cause of early prosthetic valve dysfunction (1, 2. This case illustrates that bioprosthetic valve thrombosis may occur years after valve replacement; therefore, any deterioration in a patient’s clinical status (new-onset dyspnea, heart failure or atrial fibrillation warrants a thorough evaluation of the bioprosthetic valve with transesophageal echocardiography. In this case, initiation of anticoagulation obviated the need for redo mitral valve replacement.
Buse, Eric E; Hilbert, Stephen L; Hopkins, Richard A; Converse, Gabriel L
There are many heart valve replacements currently available on the market; however, these devices are not ideal for pediatric patients with congenital heart valve defects. Decellularized valve substitutes offer potential for improved clinical outcomes and require pre-clinical testing guidelines and testing systems suitable for non-crosslinked, biological heart valves. The objective of this study was to assess the hydrodynamic performance of intact, bioengineered pulmonary valves using a custom pulse duplicator capable of testing intact biological valved conduits. The mechanical behavior of valve associated sinus and arterial tissue was also evaluated under biaxial loading. Cryopreserved, decellularized, extracellular matrix (ECM) conditioned and glutaraldehyde fixed valves showed reduced pressure gradients and increased effective orifice area for decellularized and ECM conditioned valves. ECM conditioning resulted in increased elastic modulus but decreased stretch in circumferential and longitudinal directions under biaxial loading. Overall, decellularization and ECM conditioning did not compromise the scaffolds, which exhibited satisfactory bench top performance.
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).......Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD)....
Full Text Available The use of a rotary Left Ventricular Assist Device (LVAD as a bridge-to-recovery treatment is gaining considerable attention in the LVAD research community. Using a mathematical model of the cardiovascular-LVAD system, this paper intends to define the critical control parameters in terms of power and rotational speed of the LVAD to ensure normal dynamics of the aortic valve for different levels of patient's activity and severity of heart failure. The effects of permanent closure of the aortic valve on the hemodynamics of the patient and the pump flow characteristics, if the critical control values are exceeded, are also examined. Additionally, LVAD power and speed control parameters that yield a given percentage of the cardiac cycle during which the aortic valve remains open are examined indicating that the severity of the heart failure is a very important factor in deciding the appropriateness of the LVAD as a bridge-to recovery treatment.
Pistecky, P.; Havlik, P.; Van Kasteren, J.
The action of any pump will start to decline when the valves no longer close properly. The same goes for the heart, the pump that maintains the circulation in our vascular system. Consequently, a major field of focus of open heart surgery is the repair or replacement of heart valves. Petr Havl a
Kwon, Murray H.
Tricuspid valve regurgitation (TVR) in the orthotopic heart transplant (OHT) recipient is quite common and has varied clinical sequelae. In its severest forms, it can lead to right-sided failure symptoms indistinguishable from that seen in native heart TVR disease. While certain implantation techniques are widely recognized to reduce the risk of TVR in the cardiac allograft, concomitant tricuspid annuloplasty, while having advocates, is not currently accepted as a routinely established adjunct. Decisions to surgically correct TVR in the OHT recipient must be made carefully, as certain clinical scenarios have high risk of failure. Like in the native heart, anatomic etiologies typically have the greatest chances for success compared to functional etiologies. While repair options have been utilized, there is emerging data to support replacement as the more durable option. While mechanical prostheses are impractical in the heart transplant recipient, biologic valves offer the advantage of continued access to the right ventricle for biopsies in addition to acceptable durability in the low pressure system of the right side. PMID:28706871
Kamioka, Norihiko; Caughron, Hope; Corrigan, Frank; Block, Peter; Babaliaros, Vasilis
Currently, there are no recommendations regarding the selection of valve type for a transcatheter heart valve (THV)-in-THV procedure. A supra-annular valve design may be superior in that it results in a larger effective orifice area and may have a lower chance of valve thrombosis after THV-in-THV. In this report, we describe the use of a supra-annular valve strategy for an early degenerated THV. © 2018 Wiley Periodicals, Inc.
Syedain, Zeeshan H; Meier, Lee A; Reimer, Jay M; Tranquillo, Robert T
A novel tissue-engineered heart valve (TEHV) was fabricated from a decellularized tissue tube mounted on a frame with three struts, which upon back-pressure cause the tube to collapse into three coapting "leaflets." The tissue was completely biological, fabricated from ovine fibroblasts dispersed within a fibrin gel, compacted into a circumferentially aligned tube on a mandrel, and matured using a bioreactor system that applied cyclic distension. Following decellularization, the resulting tissue possessed tensile mechanical properties, mechanical anisotropy, and collagen content that were comparable to native pulmonary valve leaflets. When mounted on a custom frame and tested within a pulse duplicator system, the tubular TEHV displayed excellent function under both aortic and pulmonary conditions, with minimal regurgitant fractions and transvalvular pressure gradients at peak systole, as well as well as effective orifice areas exceeding those of current commercially available valve replacements. Short-term fatigue testing of one million cycles with pulmonary pressure gradients was conducted without significant change in mechanical properties and no observable macroscopic tissue deterioration. This study presents an attractive potential alternative to current tissue valve replacements due to its avoidance of chemical fixation and utilization of a tissue conducive to recellularization by host cell infiltration.
Sibilitz, K L; Berg, S K; Thygesen, L C
investigated. RESULTS: After valve surgery, the self-reported health was lower (Short Form-36 (SF-36) Physical Component Scale (PCS): 44.5 vs. 50.6 and Mental Component Scale (MCS): 51.9 vs. 55.0, pClinical signs......BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... of anxiety and depression were present in 13.6% and 13.8%, respectively (Hospital Anxiety and Depression Scale score≥8). Twelve months following discharge, 483 persons (56%) were readmitted. Readmission was associated with lower self-reported health (SF-36 PCS: 46.5 vs. 43.9, and MCS 52.2 vs. 50.7). Higher...
Surgical treatment for transvenous tumor extension into the heart: four cases. J Vasc Surg (1998) 27(4): 740 – 744. 7. Daneman A, Martin DJ, Chan HSL. Cardiac metastasis from osteosarcoma. A report of two cases. JCAT (1983);7:41 – 43. 8. Petropoulakis PN,Steriotis JD,Melanidis JG, Metastatic malignant melanoma as ...
Weitsman, Tatyana; Weisz, Giora; Farkash, Rivka; Klutstein, Marc; Butnaru, Adi; Rosenmann, David; Hasin, Tal
Pulmonary hypertension has many causes. While it is conventionally thought that the most prevalent is left heart disease, little information about its proportion, causes, and implications on outcome is available. Between 1993 and 2015, 12,115 of 66,949 (18%) first adult transthoracic echocardiograms were found to have tricuspid incompetence gradient ≥40 mm Hg, a pulmonary hypertension surrogate. Left heart disease was identified in 8306 (69%) and included valve malfunction in 4115 (49%), left ventricular systolic dysfunction in 2557 (31%), and diastolic dysfunction in 1776 (21%). Patients with left heart disease, as compared with those without left heart disease, were of similar age, fewer were females (50% vs 63% P pulmonary hypertension with left heart disease. Independent predictors of mortality were age (hazard ratio [HR] 1.05; 95% CI, 1.04-1.05; P pulmonary hypertension but without left heart disease (HR 1.30; 95% CI, 1.20-1.42 and HR 1.44; 95% CI, 1.33-1.55, respectively; P Pulmonary hypertension was found to be associated with left heart disease in 69% of patients. Among these patients, valve malfunction and diastolic dysfunction emerged as prominent causes. Left ventricular dysfunction carries additional risk to patients with pulmonary hypertension. Copyright © 2017 Elsevier Inc. All rights reserved.
Yinon, Yoav; Siu, Samuel C; Warshafsky, Chelsie; Maxwell, Cynthia; McLeod, Anne; Colman, Jack M; Sermer, Mathew; Silversides, Candice K
There are a number of different anticoagulation options for pregnant women with mechanical heart valves. The purpose of this study was to examine maternal thromboembolic complications in women with mechanical valves treated with low-molecular weight heparin (LMWH) throughout pregnancy. This was a substudy of a larger prospective cohort study of pregnant women with heart disease followed from 1998 to 2008. All pregnant women with mechanical left-sided valves who were treated with LMWH throughout pregnancy were included. Maternal thromboembolic events were defined as valve thrombosis, need for valve replacement, or stroke during pregnancy or postpartum (up to 6 months). Twenty-three pregnancies (17 women) occurred in women treated with LMWH and low-dose aspirin: 15 in women with mechanical mitral valves, 9 in women with mechanical aortic valves, and 1 in a woman with both. There was 1 maternal thromboembolic event (4%), which resulted in maternal and fetal death. Five women (22%) developed other adverse cardiac events during pregnancy. Nine pregnancies (43%) had fetal or neonatal adverse events, 5 of which had favorable outcomes. Three pregnancies were complicated by postpartum hemorrhage. In conclusion, carefully monitored LMWH may be a suitable anticoagulation strategy in pregnant women with mechanical heart valves who are unwilling to use warfarin. However, this group of women remains at risk for maternal cardiac and fetal complications. The occurrence of valve thrombosis resulting in maternal death despite therapeutic anti-Xa levels highlights current limitations with anticoagulation in this population.
Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman
Since the advent of heart valve, several valve types such as mechanical and bio-prosthetic valves have been designed. Mechanical Heart Valves (MHV) are durable but suffer from thromboembolic complications that caused by shear-induced platelet activation near the valve region. Bio-prosthetic Heart Valves (BHV) are known for better hemodynamics. However, they usually have a short average life time. Realistic simulations of heart valves in combination with platelet activation models can lead to a better understanding of the potential risk of thrombus formation in such devices. In this study, an Eulerian approach is developed to calculate the platelet activation in three-dimensional simulations of flow through MHV and BHV using a parallel overset-curvilinear immersed boundary technique. A curvilinear body-fitted grid is used for the flow simulation through the anatomic aorta, while the sharp-interface immersed boundary method is used for simulation of the Left Ventricle (LV) with prescribed motion. In addition, dynamics of valves were calculated numerically using under-relaxed strong-coupling algorithm. Finally, the platelet activation results for BMV and MHV are compared with each other.
Jan 27, 1973 ... find a pathologic cause for some of the unexplained sudden deaths which occur following heart valve replace- ment. In our local cardiac surgery unit at Groote Schuur. Hospital, the hospital mortality rate for aortic valve replacement with the University of Cape Town (VeT) aortic valve prosthesis between ...
Payanam Ramachandra, Umashankar; Shenoy, Sachin J; Arumugham, Sabareeswaran
Although the sheep is the most acceptable animal model for heart valve evaluation, it has severe limitations for detecting heart valve thrombosis during preclinical studies. While the pig offers an alternative model and is better for detecting prosthetic valve thrombogenicity, it is not often used because of inadvertent valve thrombosis or bleeding complications. The study aim was to develop an improved pig model which can be used reliably to evaluate mechanical heart valve thrombogenicity. Mechanical heart valves were implanted in the mitral position of indigenous pigs administered aspirin-clopidogrel, and compared with similar valves implanted in control pigs to which no antiplatelet therapy had been administered. The pigs were observed for six months to study their overall survivability, inadvertent bleeding/valve thrombosis and pannus formation. The efficacy of aspirinclopidogrel on platelet aggregation and blood coagulation was also recorded and compared between test and control animals. In comparison to controls, pigs receiving anti-platelet therapy showed an overall better survivability, an absence of inadvertent valve thrombosis/ bleeding, and less obstructive pannus formation. Previously unreported inhibitory effects of aspirin-clopidogrel on the intrinsic pathway of blood coagulation were also observed in the pig model. Notably, with aspirin-clopidogrel therapy inadvertent thrombus formation or bleeding can be prevented. The newly developed pig model can be successfully used to evaluate heart valve thrombosis following chronic orthotopic valve implantation. The model may also be utilized to evaluate other bloodcontacting implantable devices.
Stassen, O M J A; Muylaert, D E P; Bouten, C V C; Hjortnaes, J
Heart valve disease is a major health burden, treated by either valve repair or valve replacement, depending on the affected valve. Nearly 300,000 valve replacements are performed worldwide per year. Valve replacement is lifesaving, but not without complications. The in situ tissue-engineered heart valve is a promising alternative to current treatments, but the translation of this novel technology to the clinic still faces several challenges. These challenges originate from the variety encountered in the patient population, the conversion of an implant into a living tissue, the highly mechanical nature of the heart valve, the complex homeostatic tissue that has to be reached at the end stage of the regenerating heart valve, and all the biomaterial properties that can be controlled to obtain this tissue. Many of these challenges are multidimensional and multiscalar, and both the macroscopic properties of the complete heart valve and the microscopic properties of the patient's cells interacting with the materials have to be optimal. Using newly developed in vitro models, or bioreactors, where variables of interest can be controlled tightly and complex mixtures of cell populations similar to those encountered in the regenerating valve can be cultured, it is likely that the challenges can be overcome.
Maggie N Tillquist
Full Text Available Maggie N Tillquist1, Thomas M Maddox21School of Medicine, University of Colorado Denver, Denver, CO, USA; 2VA Eastern Colorado Health Care System, and Department of Medicine (Cardiology, University of Colorado Denver, Denver, CO, USAAbstract: Nearly 15 million people in the United States suffer from either aortic or mitral valvular disease. For patients with severe and symptomatic valvular heart disease, valve replacement surgery improves morbidity and mortality outcomes. In 2009, 90,000 valve replacement surgeries were performed in the United States. This review evaluates the advantages and disadvantages of mechanical and bioprosthetic prosthetic heart valves as well as the factors for consideration in deciding the appropriate valve type for an individual patient. Although many caveats exist, the general recommendation is for patients younger than 60 to 65 years to receive mechanical valves due to the valve's longer durability and for patients older than 60 to 65 years to receive a bioprosthetic valve to avoid complications with anticoagulants. Situations that warrant special consideration include patient co-morbidities, the need for anticoagulation, and the potential for pregnancy. Once these characteristics have been considered, patients' values, anxieties, and expectations for their lifestyle and quality of life should be incorporated into final valve selection. Decision aids can be useful in integrating preferences in the valve decision. Finally, future directions in valve technology, anticoagulation, and medical decision-making are discussed.Keywords: prosthetic heart valves, patient preference, valve type, anticoagulant, structural valve deterioration
Suboh, Mohd Zubir; Mansor, Muhammad Naufal; Junoh, Ahmad Kadri; Daud, Wan Suhana Wan; Muhamad, Wan Zuki Azman Wan; Idris, Azrini
Heart valve disease affects a large number of patients. During the past decade, major advances have occurred in diagnostic techniques of heart valve disease. In this paper, we present an alternative method in classifying heart valve disease using correlation analysis and neural network classifier based on heart sound signal. The heart sound signals used in this study were taken from heart sound manipulator software. First, the signal was converted into frequency domain. Then, power spectrum of the sample is determined and cross-correlated with a reference sample (also in power spectrum form) to get different pattern of correlation plot. Seven different heart sounds of normal and other abnormal sounds from heart valve disease were classified into their classes. The result shows that 98.70% of the samples had been correctly classified by the system.
Ginns, Jonathan; Ammash, Naser; Bernier, Pierre-Luc
The tricuspid valve is frequently affected in adults with congenital heart disease but is also frequently overlooked. Disease of this valve can occur primarily or develop secondary to changes in the right ventricle caused by other disease states. The embryology and anatomy of the tricuspid valve are important to understanding pathogenesis of valve dysfunction in congenital heart disease. Clinical findings can be subtle. Multimodality imaging may be necessary to fully assess the cause and impact of tricuspid valve lesions. More research is needed in pathophysiology, imaging, and treatment in this area. Copyright © 2014 Elsevier Inc. All rights reserved.
Rashid, M B; Parvin, T; Ahmed, C M; Islam, M J; Monwar, M M; Karmoker, K K; Parveen, R; Shakil, S S; Hasan, M N
Rheumatic heart disease causes a significant number of morbidity and mortality in Bangladesh. Although the mitral and the aortic valve are the two most involved valves in rheumatic heart disease, the tricuspid valve disease is not uncommon secondary to, or in association with, mitral or aortic valve disease, but receives less attention as compared to the primary left-sided valve disease. Appropriate treatment of the tricuspid valve disease may improve long-term functional outcome. But the pattern and extent of the tricuspid valve involvement was not studied recently. This study was carried out to observe the pattern and extent of tricuspid valve involvement in Rheumatic Heart Disease patients. This observational analytical study was undertaken in the department of Cardiology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from December 2010 to September 2011. Considering all ethical issues, data were collected from 173 subjects who underwent Echocardiography for their Chronic Rheumatic heart disease. Pattern of tricuspid valve involvement was observed by using Transthoracic Echocardiography by 2D, M mode and Doppler assessment. One hundred seventy three (173) patients with Rheumatic Heart disease was studied, out of these, 36 patients had evidence of tricuspid valve involvement based on echocardiographic findings. Fifteen (15) patients had Tricuspid stenosis and 36 patients had Tricuspid Regurgitation in the patients with TV involvement. All the patients with TV involvement had thickened leaflets. Doming, restriction of motion and calcification were present in different proportions. From this study, it can be concluded that organic tricuspid valve involvement in RHD is not uncommon in our country.
Rippel, Radoslaw A; Ghanbari, Hossein; Seifalian, Alexander M
Heart valve disease is currently a growing problem, and demand for heart valve replacement is predicted to increase significantly in the future. Existing "gold standard" mechanical and biological prosthesis offers survival at a cost of significantly increased risks of complications. Mechanical valves may cause hemorrhage and thromboembolism, whereas biologic valves are prone to fibrosis, calcification, degeneration, and immunogenic complications. A literature search was performed to identify all relevant studies relating to tissue-engineered heart valve in life sciences using the PubMed and ISI Web of Knowledge databases. Tissue engineering is a new, emerging alternative, which is reviewed in this paper. To produce a fully functional heart valve using tissue engineering, an appropriate scaffold needs to be seeded using carefully selected cells and proliferated under conditions that resemble the environment of a natural human heart valve. Bioscaffold, synthetic materials, and preseeded composites are three common approaches of scaffold formation. All available evidence suggests that synthetic scaffolds are the most suitable material for valve scaffold formation. Different cell sources of stem cells were used with variable results. Mesenchymal stem cells, fibroblasts, myofibroblasts, and umbilical blood stem cells are used in vitro tissue engineering of heart valve. Alternatively scaffold may be implanted and then autoseeded in vivo by circulating endothelial progenitor cells or primitive circulating cells from patient's blood. For that purpose, synthetic heart valves were developed. Tissue engineering is currently the only technology in the field with the potential for the creation of tissues analogous to a native human heart valve, with longer sustainability, and fever side effects. Although there is still a long way to go, tissue-engineered heart valves have the capability to revolutionize cardiac surgery of the future.
Le Huu, Alice; Shum-Tim, Dominique
The prevalence of valvular heart disease is expected to increase in the coming decades, with an associated rise in valve-related surgeries. Current options for valve prostheses remain limited, essentially confined to mechanical or biological valves. Neither selection provides an optimal balance between structural integrity and associated morbidity. Mechanical valves offer exceptional durability coupled with a considerable risk of thrombogenesis. Conversely, a biological prosthesis affords freedom from anticoagulation, but with a truncated valve lifespan. Tissue-engineered heart valves have been touted as a solution to this dilemma, by offering an immunopriviledged prosthesis combined with resistance from degeneration and the potential to grow. Although the reality of commercially available tissue-engineered heart valves remains distant, this article will highlight the cellular and clinical advancements in recent years.
Kane, Colin; Kogon, Brian; Pernetz, Maria; McConnell, Michael; Kirshbom, Paul; Rodby, Katherine; Book, Wendy M
Congenital heart defects that have a component of right ventricular outflow tract obstruction, such as tetralogy of Fallot, are frequently palliated in childhood by disruption of the pulmonary valve. Although this can provide an initial improvement in quality of life, these patients are often left with severe pulmonary valve insufficiency. Over time, this insufficiency can lead to enlargement of the right ventricle and to the deterioration of right ventricular systolic and diastolic function. Pulmonary valve replacement in these patients decreases right ventricular volume overload and improves right ventricular performance. To date, few studies have examined the effects of pulmonary valve replacement on left ventricular function in patients with biventricular dysfunction. We sought to perform such an evaluation.Records of adult patients who had undergone pulmonary valve replacement from January 2003 through November 2006 were analyzed retrospectively. We reviewed preoperative and postoperative echocardiograms and calculated left ventricular function in 38 patients.In the entire cohort, the mean left ventricular ejection fraction increased by a mean of 0.07 after pulmonary valve replacement, which was a statistically significant change (P < 0.01). In patients with preoperative ejection fractions of less than 0.50, mean ejection fractions increased by 0.10.We conclude that pulmonary valve replacement in patients with biventricular dysfunction arising from severe pulmonary insufficiency and right ventricular enlargement can improve left ventricular function. Prospective studies are needed to verify this finding.
Kane, Colin; Kogon, Brian; Pernetz, Maria; McConnell, Michael; Kirshbom, Paul; Rodby, Katherine; Book, Wendy M.
Congenital heart defects that have a component of right ventricular outflow tract obstruction, such as tetralogy of Fallot, are frequently palliated in childhood by disruption of the pulmonary valve. Although this can provide an initial improvement in quality of life, these patients are often left with severe pulmonary valve insufficiency. Over time, this insufficiency can lead to enlargement of the right ventricle and to the deterioration of right ventricular systolic and diastolic function. Pulmonary valve replacement in these patients decreases right ventricular volume overload and improves right ventricular performance. To date, few studies have examined the effects of pulmonary valve replacement on left ventricular function in patients with biventricular dysfunction. We sought to perform such an evaluation. Records of adult patients who had undergone pulmonary valve replacement from January 2003 through November 2006 were analyzed retrospectively. We reviewed preoperative and postoperative echocardiograms and calculated left ventricular function in 38 patients. In the entire cohort, the mean left ventricular ejection fraction increased by a mean of 0.07 after pulmonary valve replacement, which was a statistically significant change (P < 0.01). In patients with preoperative ejection fractions of less than 0.50, mean ejection fractions increased by 0.10. We conclude that pulmonary valve replacement in patients with biventricular dysfunction arising from severe pulmonary insufficiency and right ventricular enlargement can improve left ventricular function. Prospective studies are needed to verify this finding. PMID:21720459
Bobylev, D O; Chebotar', S; Tudorake, I; Khaverikh, A
Replacement of heart valves appears to be prevailing method of surgical correction of end stage valvular heart defects. Main drawback of contemporary artificial valves is lack of growth, potential for remodeling, and inclination to degeneration. To overcome these limitations the modern science in the last decade focuses on tissue engineering of valves as an alternative to their prostheses. Basic idea of the technique is the use of decellularized xenogenic allogenic matrix or biopolymers seeded with autologous cells under special conditions created in bioreactor. This literature review is devoted to a novel direction in experimental cardiosurgery - tissue engineering of heart valves which in a unique way combines biological, engineering, and technological achievements.
Jian, Bo; Xu, Jie; Connolly, Jeanne; Savani, Rashmin C.; Narula, Navneet; Liang, Bruce; Levy, Robert J.
Clinical disorders associated with increased serotonin [5-hydroxytryptamine (5-HT)] levels, such as carcinoid syndrome, and the use of serotonin agonists, such as fenfluoramine have been associated with a valvulopathy characterized by hyperplastic valvular and endocardial lesions with increased extracellular matrix. Furthermore, 5-HT has been demonstrated to up-regulate transforming growth factor (TGF)-β in mesangial cells via G-protein signal transduction. We investigated the hypothesis that increased exposure of heart valve interstitial cells to 5-HT may result in increased TGF-β1 expression and activity because of serotonin receptor-mediated signal transduction with activation of Gαq, and subsequently up-regulation of phospholipase C. Thus, in the present study we performed a clinical-pathological investigation of retrieved carcinoid and normal valve cusps using immunohistochemical techniques to detect the presence of TGF-β1 and other proteins associated with TGF-β expression, including TGF-β receptors I and II, latent TGF-β-associated peptide (LAP), and α-smooth muscle actin. Carcinoid valve cusps demonstrated the unusual finding of widespread smooth muscle actin involving the interstitial cells in the periphery of carcinoid nodules; these same cells were also positive for LAP. Normal valve cusps were only focally positive for smooth muscle actin and LAP. In sheep aortic valve interstitial cell cultures 5-HT induced TGF-β1 mRNA production and increased TGF-β1 activity. 5-HT also increased collagen biosynthesis at the dosages studied. Furthermore, TGF-β1 added to SAVIC cultures increased the production of sulfated glycan and hyaluronic acid. In addition, overexpression of Gαq using an adenoviral expression vector for a constitutively active Gαq mutant (Q209L-Gαq) resulted in increased phospholipase C activity as well as up-regulation of TGF-β expression and activity. These results strongly support the view that G-protein-related signal
Cremer, Signe Emilie; Singletary, G.E.; Olsen, Lisbeth Høier
[5HT] in platelet-rich plasma (PRP), platelet-poor plasma (PPP), mitral valve leaflets (MV), and left ventricular myocardium (LV). ANIMALS: Forty-five dogs comprised 4 plasma groups of Cavalier King Charles Spaniels (CKCS) or non-CKCS, either healthy (CON) or MMVD affected: CKCS CON (n = 12); non......-CKCS CON (n = 8); CKCS MMVD (n = 14); non-CKCS MMVD (n = 11). Twenty-four dogs comprised 3 tissue groups: MMVD (n = 8); other-HD (heart disease) (n = 7); non-HD, extracardiac disease (n = 9). METHODS: High-performance liquid chromatography measured PRP, PPP, MV, and LV [5HT]. RESULTS: Platelet-rich plasma......HYPOTHESIS/OBJECTIVES: Altered serotonin (5-hydroxytryptamine, 5HT) signaling is postulated in development and progression of canine myxomatous mitral valve disease (MMVD). Little is known regarding platelet, plasma, valvular, or myocardial 5HT concentration ([5HT]) in affected dogs. We quantified...
Sibilitz, Kirstine Laerum; Berg, Selina Kikkenborg; Hansen, Tina Birgitte
Heart valve diseases are common with an estimated prevalence of 2.5% in the Western world. The number is rising due to an ageing population. Once symptomatic, heart valve diseases are potentially lethal, and heavily influence daily living and quality of life. Surgical treatment, either valve repl...
Bapat, Vinnie; Pirone, Francesco; Kapetanakis, Stam; Rajani, Ronak; Niederer, Steven
To determine the factors influencing left ventricular outflow tract (LVOT) area reduction after a mitral valve-in-valve (VIV) or a valve-in-ring (VIR) procedure. Transcatheter heart valves (THVs) are increasingly used in performing a VIV or a VIR procedure in high-risk patients. Although less invasive, a potential complication is LVOT obstruction. However, the factors predisposing to LVOT obstruction are ill defined. To understand the effects of the various factors, the study was carried out in three parts: To understand the effect of VIV and VIR on reduction in LVOT area with special attention to different surgical heart valve (SHV) orientations and depth of THV implant. This was carried out in porcine and cadaver hearts. To quantify aorto-mitral-annular (AMA) angle in 20 patients with or without mitral disease and to derive a static computational model to predict LVOT obstruction. To study the effect of SHV design on LVOT obstruction after VIV. This was carried out as a bench test. LVOT area reduction was similar after VIV irrespective of orientation of the mitral SHV implantation as it pinned open the SHV leaflets. Similar effect was seen after VIR. The degree of LVOT obstruction was partly determined by AMAangle and was inversely proportional. SHV design, ring design, and depth of SPAIEN XT implantation also had effect on LVOT obstruction. A possibility of LVOT obstruction should be considered when performing a VIV and VIR procedure. Type of SHV, flexible ring, less obtuse AMA angle, and depth of SAPIEN XT implant can influence the risk. © 2015 Wiley Periodicals, Inc.
Full Text Available Patients with mechanical valve prostheses require a lifelong anticoagulant treatment. The combined use of Warfarin and low-dose aspirin appears to reduce the risk of valve thrombosis and systemic embolism at a low risk of bleeding. The management of women with prosthetic heart valves during pregnancy poses a particular challenge, as there are no available controlled clinical trials to provide guidelines for effective antithrombotic therapy. Oral anticoagulants, such as Warfarin, cause foetal embryopathy; unfractionated heparin and low-molecular-weight heparin have been reported to be ineffective in preventing thromboembolic complications.This article discusses the available data and the most recent guidelines in the antithrombotic management of patients with prosthetic valves, and antithrombotic therapy in various clinical situations such as pregnant women with prosthetic heart valves, and patients with prosthetic heart valves undergoing noncardiac surgery.
Berry, Joel L; Steen, Julie A; Koudy Williams, J; Jordan, James E; Atala, Anthony; Yoo, James J
Millions of people worldwide are diagnosed each year with valvular heart disease, resulting in hundreds of thousands of valve replacement operations. Prosthetic valve replacements are designed to correct narrowing or backflow through the valvular orifice. Although commonly used, these therapies have serious disadvantages including morbidity associated with long-term anticoagulation and limited durability necessitating repeat operations. The ideal substitute would be widely available and technically implantable for most cardiac surgeons, have normal hemodynamic performance, low risk for structural degeneration, thrombo-embolism and endocarditis, and growth potential for pediatric patients. Tissue engineered heart valves hold promise as a viable substitute to outperform existing valve replacements. An essential component to the development of tissue engineered heart valves is a bioreactor. It is inside the bioreactor that the scaffold and cells are gradually conditioned to the biochemical and mechanical environment of the valve to be replaced.
Hasan, Anwarul; Ragaert, Kim; Swieszkowski, Wojciech; Selimović, Seila; Paul, Arghya; Camci-Unal, Gulden; Mofrad, Mohammad R K; Khademhosseini, Ali
Due to the increasing number of heart valve diseases, there is an urgent clinical need for off-the-shelf tissue engineered heart valves. While significant progress has been made toward improving the design and performance of both mechanical and tissue engineered heart valves (TEHVs), a human implantable, functional, and viable TEHV has remained elusive. In animal studies so far, the implanted TEHVs have failed to survive more than a few months after transplantation due to insufficient mechanical properties. Therefore, the success of future heart valve tissue engineering approaches depends on the ability of the TEHV to mimic and maintain the functional and mechanical properties of the native heart valves. However, aside from some tensile quasistatic data and flexural or bending properties, detailed mechanical properties such as dynamic fatigue, creep behavior, and viscoelastic properties of heart valves are still poorly understood. The need for better understanding and more detailed characterization of mechanical properties of tissue engineered, as well as native heart valve constructs is thus evident. In the current review we aim to present an overview of the current understanding of the mechanical properties of human and common animal model heart valves. The relevant data on both native and tissue engineered heart valve constructs have been compiled and analyzed to help in defining the target ranges for mechanical properties of TEHV constructs, particularly for the aortic and the pulmonary valves. We conclude with a summary of perspectives on the future work on better understanding of the mechanical properties of TEHV constructs. © 2013 Published by Elsevier Ltd.
Amstrup Funder, Jonas; Christian Danielsen, Carl; Baandrup, Ulrik; Martin Bibby, Bo; Carl Andelius, Ted; Toft Brøndum, Emil; Wang, Tobias; Michael Hasenkam, J
Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid in developing techniques to design improved pressure-resistant biological heart valves. Heart valves from 12 giraffes and 10 calves were explanted and subjected to either biomechanical or morphological examinations. Strips from the heart valves were subjected to cyclic loading tests, followed by failure tests. Thickness measurements and analyses of elastin and collagen content were also made. Valve specimens were stained with hematoxylin and eosin, elastic van Gieson stain, Masson's trichrome and Fraser-Lendrum stain, as well as immunohistochemical reactions for morphological examinations. The aortic valve was shown to be 70% (95% CI 42-103%) stronger in the giraffe than in its bovine counterpart (p giraffe aortic valve was found to be significantly stiffer than the bovine aortic valve (p giraffes contained significantly more collagen than those of calves. The elastin contents of the pulmonary valves (2.5%) and aortic valves (1.5%) were also higher in giraffes. The greater strength of the giraffe aortic valve is most likely due to a compact collagen construction. Both, collagen and elastin contents were higher in giraffes than in calves, which would make giraffe valves more resistant to the high-pressure forces. However, collagen also stiffens and thickens the valves. The mitral leaflets showed similar (but mostly insignificant) trends in strength, stiffness, and collagen content.
Hansen, T B; Zwisler, A D; Berg, S K
BACKGROUND: Owing to a lack of evidence, patients undergoing heart valve surgery have been offered exercise-based cardiac rehabilitation (CR) since 2009 based on recommendations for patients with ischaemic heart disease in Denmark. The aim of this study was to investigate the impact of CR...... expensive outpatient visits. Further studies should investigate the benefits of CR to heart valve surgery patients as part of a formal cost-utility analysis....
Condurache, Alexandru Paul; Hahn, Tobias; Hofmann, Ulrich G.; Scharfschwerdt, Michael; Misfeld, Martin; Aach, Til
Patients suffering from a heart valve deficiency are often treated by replacing the valve with an artificial or biological implant. In case of biological implants, the use of porcine heart valves is common. Quality assessment and inspection methods are mandatory to supply the patients (and also medical research) with only the best such xenograft implants thus reducing the number of follow-up surgeries to replace worn-up valves. We describe an approach for automatic in-vitro evaluation of prosthetic heart valves in an artificial circulation system. We show how to measure the orifice area during a heart cycle to obtain an orifice curve. Different quality parameters are then estimated on such curves.
Kabbach, Ghazal; Mukherjee, Debabrata
Pulmonary hypertension (PH) related to left heart disease (LHD) is the most common form of PH, accounting for more than two third of all PH cases. The hemodynamic abnormalities seen in PH-LHD are complex, and there are currently minimal evidence-based recommendations for the management of PH-LHD. While it is accepted that PH in the context of left heart disease is a marker of worse prognosis, it remains unclear whether its primary treatment is beneficial or harmful. In this article, we discuss the prevalence and significance of PH in patients with heart failure (HF) with reduced ejection fraction (HFrEF) as well as HF with preserved ejection fraction (HFpEF), and those with valvular heart disease and provide insights into the complex pathophysiology of cardiopulmonary interrelationship in individuals with PH due to left heart disease. Furthermore, we provide a framework for diagnostic testing and an approach to optimal management of these complex patients based on current European Society of Cardiology (ESC) guidelines. Copyright© Bentham Science Publishers; For any queries, please email at email@example.com.
Full Text Available The effects of cryopreservation on the biological tissue mechanics are still largely unknown. Generalized Maxwell model was applied to characterize quantitatively the viscoelastic behavior of sheep mitral heart valve tissue. Three different groups of specimens are supposed to be tested: fresh tissue specimens (control group, cryopreserved allografts from tissue bank and allografts already used as tissue replacements taken from the animals approximately one year after the surgery. Specific aim of this study is to determine whether or not the treatment used for storage in tissue bank influences significantly the mechanical properties and behavior of the tissue. At the moment, only the first group of specimens was examined. The methodology presented in this paper proved suitable to complete the study.
Full Text Available Tissue engineering is a new field of knowledge which creates the possibilities for producing bioactive cardiac prostheses that will characterize by biomechanical and morphological properties similar to native tissue. It is expected that it will be characterized by high durability, which is very important from the social and clinical point of view. The aim of the study was to compare the cytotoxic effect of enzymatic and detergent acellularization methods commonly used for the biological scaffold preparation. It seems that the use of enzymatic methods, allows efficient donor cells removal while maintaining the ability to autologous cell seeding. Heart valves bioprosthesis created using these techniques, may be a good alternative to the currently used prostheses.
Voldstedlund, Marianne; Fuursted, Kurt; Bruun, Niels Eske
The degree to which the results of valve culture depend on different laboratory procedures as well as other factors is unknown. The aim of this study was to compare the results of heart valve culture at 2 different endocarditis centres in order to clarify this.......The degree to which the results of valve culture depend on different laboratory procedures as well as other factors is unknown. The aim of this study was to compare the results of heart valve culture at 2 different endocarditis centres in order to clarify this....
Full Text Available Infective endocarditis (IE of the left heart is the most frequent type of IE in chronic hemodialysis (CHD (in 90% of cases whereas involvement of the right heart is rare. The aim of this study was to determine the clinical, biological, and echocardiographic characteristics, as well as the prognosis of IE in CHD. This is a retrospective study conducted at the Center of Nephrology and Hemodialysis in Oujda, Morocco. Over a period of 56 months, we compiled data on a series of 11 CHD patients with IE. Their mean age was 40.5 ± 14 years, 72% were male and 27.3% had diabetes. All patients had native valve. All patients had bacteremia preceding the episode of IE. The tricuspid valve was the site of IE in 45% of the cases. Cardiac complications were observed in 72% of the patients and mortality was observed in 72% of cases. The period from IE diagnosis to death was 9 ± 6 days. In our study, the tricuspid valve was the most affected valve of IE in CHD.
Sasaki, Norihito; Kinugawa, Toru; Yamawaki, Masahiro; Furuse, Yoshiyuki; Shimoyama, Masaki; Ogino, Kazuhide; Igawa, Osamu; Hisatome, Ichiro; Shigemasa, Chiaki
A 44-year-old woman had tako-tsubo-like ventricular dysfunction with chest pain and ST segment elevation on the ECG. Echocardiography revealed a bicuspid aortic valve with moderate to severe aortic regurgitation. She developed mild heart failure during the clinical course, but the medication (furosemide, enalapril, and asprin) had to be stopped because of skin eruptions. Four weeks after ceasing the antiplatelet agent, she was re-admitted with acute renal infarction. Enhanced chest computed tomography revealed a filling defect in the left ventricle and echocardiography showed a high echogenic mass in the left ventricular apical wall. These findings strongly suggested that the renal infarction was caused by an embolism derived from a left ventricular thrombus that formed during the clinical course of the transient left ventricular apical ballooning. Anticoagulation therapy with urokinase and warfarin successfully lysed the thrombus. Left ventricular thrombus should be considered a complication of transient left ventricular apical ballooning, especially in patients with organic heart disease.
Berthelot, Emmanuelle; Bailly, Minh Tam; Hatimi, Safwane El; Robard, Ingrid; Rezgui, Hatem; Bouchachi, Amir; Montani, David; Sitbon, Olivier; Chemla, Denis; Assayag, Patrick
Pulmonary hypertension due to left heart disease, also known as group 2 pulmonary hypertension according to the European Society of Cardiology/European Respiratory Society classification, is the most common cause of pulmonary hypertension. In patients with left heart disease, the development of pulmonary hypertension favours right heart dysfunction, which has a major impact on disease severity and outcome. Over the past few years, this condition has been considered more frequently. However, epidemiological studies of group 2 pulmonary hypertension are less exhaustive than studies of other causes of pulmonary hypertension. In group 2 patients, pulmonary hypertension may be caused by an isolated increase in left-sided filling pressures or by a combination of this condition with increased pulmonary vascular resistance, with an abnormally high pressure gradient between arteries and pulmonary veins. A better understanding of the conditions underlying pulmonary hypertension is of key importance to establish a comprehensive diagnosis, leading to an adapted treatment to reduce heart failure morbidity and mortality. In this review, epidemiology, mechanisms and diagnostic approaches are reviewed; then, treatment options and future approaches are considered. Copyright © 2017. Published by Elsevier Masson SAS.
Kuan, Yee Han; Nguyen, Vinh-Tan; Kabinejadian, Foad; Leo, Hwa Liang
The trileaflet heart valve is a more desirable mechanical heart valve due to its similarity to native heart valves, which produce a central blood flow with decreased blood flow disturbance. There are, however, many challenges and difficulties in designing a trileaflet valve, mainly due to a greater number of moving mechanical parts. The flow profiles through a bileaflet mechanical heart valve (BMHV) and a trileaflet mechanical heart valve (TMHV) were compared at downstream regions. Geometric models of a 29 mm St. Jude Medical BMHV and a TMHV were used and positioned at the anatomic position in a curved aortic downstream geometry. Three-dimensional numerical simulations for both types of mechanical heart valve were performed under normal physiological pulsatile flow conditions. Flow profiles were studied under three different implantation locations at Z = 1D (D = 29 mm inlet diameter), 2D and 4D along the aorta centerline during peak systole. The simulation results showed different flow fields at the downstream positions at Z = 1D and 2D. The leaflets of the BMHV obstructed the flow, while the TMHV allowed a central orifice flow which resulted in a more physiological flow profile. Further downstream, at Z = 4D, the flow fields shared similarities in terms of the flow profile and velocity magnitude. The findings of this study may help to further improve the development of the TMHV.
Querzoli, G.; Fortini, S.; Cenedese, A.
Mechanical heart valves implanted in mitral position have a great effect on the ventricular flow. Changes include alteration of the dynamics of the vortical structures generated during the diastole and the onset of turbulence, possibly affecting the efficiency of the heart pump or causing blood cell damage. Modifications to the hemodynamics in the left ventricle, when the inflow through the mitral orifice is altered, were investigated in vitro using a silicone rubber, flexible ventricle model. Velocity fields were measured in space and time by means of an image analysis technique: feature tracking. Three series of experiments were performed: one with a top hat inflow velocity profile (schematically resembling physiological conditions), and two with mechanical prosthetic valves of different design, mounted in mitral position—one monoleaflet and the other bileaflet. In each series of runs, two different cardiac outputs have been examined by changing the stroke volume. The flow was investigated in terms of phase averaged velocity field and second order moments of turbulent fluctuations. Results show that the modifications in the transmitral flow change deeply the interaction between the coherent structures generated during the first phase of the diastole and the incoming jet during the second diastolic phase. Top hat inflow gives the coherent structures which are optimal, among the compared cases, for the systolic function. The flow generated by the bileaflet valve preserves most of the beneficial features of the top hat inflow, whereas the monoleaflet valve generates a strong jet which discourages the permanence of large coherent structures at the end of the diastole. Moreover, the average shear rate magnitudes induced by the smoother flow pattern of the case of top hat inflow are nearly halved in comparison with the values measured with the mechanical valves. Finally, analysis of the turbulence statistics shows that the monoleaflet valves yield higher turbulence
Durmaz, Tahir; Ayhan, Huseyin; Keles, Telat; Aslan, Abdullah Nabi; Erdogan, Kemal Esref; Sari, Cenk; Bilen, Emine; Akcay, Murat; Bozkurt, Engin
Transcatheter aortic valve replacement can be an effective, reliable treatment for severe aortic stenosis in surgically high-risk or ineligible patients. However, various sequelae like coronary artery obstruction can occur, not only in the long term, but also immediately after the procedure. We present the case of a 78-year-old woman whose left main coronary artery became obstructed with calculus 2 hours after the transfemoral implantation of an Edwards Sapien XT aortic valve. Despite percutaneous coronary intervention in that artery, the patient died. This case reminds us that early recognition of acute coronary obstruction and prompt intervention are crucial in patients with aortic stenosis who have undergone transcatheter aortic valve replacement.
Hasenkam, J. Michael; Ringgaard, Steffen; Houlind, Kim; Botnar, René M.; Stødkilde-Jørgensen, Hans; Boesiger, Peter; Pedersen, Erik Morre
Objective: To evaluate the potential of magnetic resonance imaging (MRI) for evaluation of velocity fields downstream of prosthetic aortic valves. Furthermore, to provide comparative data from bileaflet aortic valve prostheses in vitro and in patients. Methods: A pulsatile flow loop was set up in a 7.0 Tesla MRI scanner to study fluid velocity data downstream of a 25 mm aortic bileaflet heart valve prosthesis. Three dimensional surface plots of velocity fields were displayed. In six NYHA clas...
Rieck, Ashild E; Cramariuc, Dana; Staal, Eva M
Both hypertension and aortic valve stenosis induce left ventricular hypertrophy. However, less is known about the influence of concomitant hypertension on left ventricular structure in patients with aortic valve stenosis.......Both hypertension and aortic valve stenosis induce left ventricular hypertrophy. However, less is known about the influence of concomitant hypertension on left ventricular structure in patients with aortic valve stenosis....
Hasbun, Rodrigo; Vikram, Holenarasipur R; Barakat, Lydia A; Buenconsejo, Joan; Quagliarello, Vincent J
Complicated left-sided native valve endocarditis causes significant morbidity and mortality in adults. Lack of valid data regarding estimation of prognosis makes management of this condition difficult. To derive and externally validate a prognostic classification system for adults with complicated left-sided native valve endocarditis. Retrospective observational cohort study conducted from January 1990 to January 2000 at 7 Connecticut hospitals among 513 patients older than 16 years who experienced complicated left-sided native valve endocarditis and who were divided into derivation (n = 259) and validation (n = 254) cohorts. All-cause mortality at 6 months after baseline. In the derivation and validation cohorts, the 6-month mortality rates were 25% and 26%, respectively. Five baseline features were independently associated with 6-month mortality (comorbidity [P =.03], abnormal mental status [P =.02], moderate to severe congestive heart failure [P =.01], bacterial etiology other than viridans streptococci [Pclassification system. In the derivation cohort, patients were classified into 4 groups with increasing risk for 6-month mortality: 5%, 15%, 31%, and 59% (Pendocarditis can be accurately risk stratified using baseline features into 4 groups of prognostic severity. This prognostic classification system might be useful for facilitating management decisions.
Jan 27, 1973 ... could be found, even at autopsy. These latter deaths were regarded as being due to arrhythmia. The hospital mortality rate was 14% for mitral valve replacement with the vcr mitral valve prosthesis.' The major comp- lication was systemic embolism. A frequent autopsy finding in hearts which have recently ...
Clark, G. [Lawrence Livermore National Lab., CA (United States)
Prosthetic heart valves and the many great strides in valve design have been responsible for extending the life spans of many people with serious heart conditions. Even though the prosthetic valves are extremely reliable, they are eventually susceptible to long-term fatigue and structural failure effects expected from mechanical devices operating over long periods of time. The purpose of our work is to classify the condition of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of heart valve sounds. The structural failures of interest for Bscc valves is called single leg separation (SLS). SLS can occur if the outlet strut cracks and separates from the main structure of the valve. We measure acoustic opening and closing sounds (waveforms) using high sensitivity contact microphones on the patient`s thorax. For our analysis, we focus our processing and classification efforts on the opening sounds because they yield direct information about outlet strut condition with minimal distortion caused by energy radiated from the valve disc.
... become short of breath? Is it walking three miles? Or has that three mile distance gotten shorter and shorter over time so ... her life depended on it. This content was last reviewed May 2016. Heart Valve Problems and Disease • ...
Schipke, Kimberly J; To, S D Filip; Warnock, James N
The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic valve leaflets are composed of interstitial cells suspended within an extracellular matrix (ECM) and are lined with an endothelial cell monolayer. The valve withstands a harsh, dynamic environment and is constantly exposed to shear, flexion, tension, and compression. Research has shown calcific lesions in diseased valves occur in areas of high mechanical stress as a result of endothelial disruption or interstitial matrix damage(1-3). Hence, it is not surprising that epidemiological studies have shown high blood pressure to be a leading risk factor in the onset of aortic valve disease(4). The only treatment option currently available for valve disease is surgical replacement of the diseased valve with a bioprosthetic or mechanical valve(5). Improved understanding of valve biology in response to physical stresses would help elucidate the mechanisms of valve pathogenesis. In turn, this could help in the development of non-invasive therapies such as pharmaceutical intervention or prevention. Several bioreactors have been previously developed to study the mechanobiology of native or engineered heart valves(6-9). Pulsatile bioreactors have also been developed to study a range of tissues including cartilage(10), bone(11) and bladder(12). The aim of this work was to develop a cyclic pressure system that could be used to elucidate the biological response of aortic valve leaflets to increased pressure loads. The system consisted of an acrylic chamber in which to place samples and produce cyclic pressure, viton diaphragm solenoid valves to control the timing of the pressure cycle, and a computer to control electrical devices. The pressure was monitored using a pressure transducer, and the signal was conditioned using a load cell conditioner. A LabVIEW program regulated the pressure using an analog device to pump compressed
Tarasov, D G; Chernov, I I; Gordeev, M L; Pavlov, A V
The results of plasty (124 patients) of postinfarction left ventricular aneurysm performed on the working heart are presented in this article. It is shown, that the upgrade of existing surgical techniques, which are directed to the creation of the optimal left ventricle shape, could improve the clinical results after plasty of postinfarction left ventricular aneurysm. It's important to arrange the conditions, which allow avoiding a negative influence on contractility function of the myocardium. The desired conditions could be obtained, if the plasty is performed on the working or fibrillating heart provided that the patient has a consistent aortic valve.
Gallo, Michele; Bianco, Roberto; Bottio, Tomaso; Naso, Filippo; Franci, Paolo; Zanella, Fabio; Perona, Giovanni; Busetto, Roberto; Spina, Michele; Gandaglia, Alessandro; Gerosa, Gino
Tissue engineering of heart valves investigates the possibility to create a fully compatible and biomimetic graft able to provide host cell repopulation like the native living valve. Decellularized aortic and pulmonary valves and synthetic polymers have been used to promote the creation of a native-like scaffold suitable to be colonized by cells either in vitro, in dynamic bioreactors or in vivo using different animal models. The herein presented research provides the intra-operative protocol and details of surgical technique. Porcine aortic valve conduits were decellularized and implanted in the right ventricular outflow tract of Vietnamese pigs.
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University......-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS......) and 2) to compare HR and HRV between CKCS and other dog breeds in a group of dogs in HF secondary to MMVD. One-hundred dogs were examined by echocardiography and 24-hour electrocardiography. The dogs were divided into five groups: 1) CKCS with no/minimal mitral regurgitation (MR) (MR jet=15% of the left...
Karavolias, George K; Georgiadou, Panagiota; Houri, Mazen; Sbarouni, Eftihia; Thomopoulou, Sofia; Tsiapras, Dimitrios; Smirli, Anna; Balanika, Marina; Voudris, Vassilis
This case report describes a percutaneous aortic valve implantation with the Medtronic CoreValve selfexpanding valve prosthesis in a patient with severe aortic stenosis. The approach was made via the left subclavian artery because of the lack of femoral vessel access. The patient was a 78-year-old female with breathlessness on minimal effort, a recent hospitalisation due to pulmonary oedema, and frequent episodes of pre-syncope; surgical valve replacement had been ruled out. The prosthetic valve was successfully implanted with mild paravalvular aortic regurgitation. At 30 days, the patient's clinical condition had significantly improved, with excellent functioning of the aortic valve prosthesis.
Alfonso, Abraham R; Rath, Sasmita; Rafiee, Parvin; Hernandez-Espino, Mario; Din, Mahreen; George, Florence; Ramaswamy, Sharan
Tissue engineered heart valves (TEHVs) may provide a permanent solution to congenital heart valve disease by permitting somatic valve growth in the pediatric patient. However, to date, TEHV studies have focused primarily on collagen, the dominant component of valve extracellular matrix (ECM). Temporal decreases in other ECM components, such as the glycosaminoglycans (GAGs), generally decrease as cells produce more collagen under mechanically loaded states; nevertheless, GAGs represent a key component of the valve ECM, providing structural stability and hydration to the leaflets. In an effort to retain GAGs within the engineered constructs, here we investigated the utility of the protein fibrin in combination with a valve-like, cyclic flexure and steady flow (flex-flow) mechanical conditioning culture process using adult human periodontal ligament cells (PLCs). We found both fibrin and flex-flow mechanical components to be independently significant (pengineered tissues. In addition, the interaction of fibrin with flex-flow was found to be significant in the case of collagen; specifically, the combination of these environments promoted PLC collagen production resulting in a significant difference compared to dynamic and statically cultured specimens without fibrin. Histological examination revealed that the GAGs were retained by fibrin entrapment and adhesion, which were subsequently confirmed by additional experiments on native valve tissues. We conclude that fibrin in the flex-flow culture of engineered heart valve tissues: (i) augments PLC-derived collagen production; and (ii) enhances retention of GAGs within the developing ECM. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Troolin, Daniel; Amatya, Devesh; Longmire, Ellen
Volumetric velocity fields inside two types of artificial heart valves were obtained experimentally through the use of volumetric 3-component velocimetry (V3V). Index matching was used to mitigate the effects of optical distortions due to interfaces between the fluid and curved walls. The steady flow downstream of a mechanical valve was measured and the results matched well with previously obtained 2D PIV results, such as those of Shipkowitz et al. (2002). Measurements upstream and downstream of a deformable silicone valve in a pulsatile flow were obtained and reveal significant three-dimensional features of the flow. Plots and movies will be shown, and a detailed discussion of the flow and various experimental considerations will be included. Reference: Shipkowitz, T, Ambrus J, Kurk J, Wickramasinghe K (2002) Evaluation technique for bileaflet mechanical valves. J. Heart Valve Disease. 11(2) pp. 275-282.
De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D.; Costantino, Maria Laura
Introduction Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy, the latter display better fluid dynamic behaviour but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the haemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of two groups of newly developed supra-annular tri-leaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. Methods Two types of Poli-Valves made of SBC differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. An ad - hoc designed pulse duplicator allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the valve’s behaviour. Results Both types Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by ISO 5840 Standard. Results were compared with five mechanical heart valves (MHVs) and five tissue heart valves (THVs), currently available on the market. Conclusion Based on these results, polymeric heart valves based on styrenic block copolymers, as Poli-Valves are, can be considered as promising alternative for heart valve replacement in near future. PMID:26689146
Tillquist, Maggie N; Maddox, Thomas M
Nearly 15 million people in the United States suffer from either aortic or mitral valvular disease. For patients with severe and symptomatic valvular heart disease, valve replacement surgery improves morbidity and mortality outcomes. In 2009, 90,000 valve replacement surgeries were performed in the United States. This review evaluates the advantages and disadvantages of mechanical and bioprosthetic prosthetic heart valves as well as the factors for consideration in deciding the appropriate valve type for an individual patient. Although many caveats exist, the general recommendation is for patients younger than 60 to 65 years to receive mechanical valves due to the valve’s longer durability and for patients older than 60 to 65 years to receive a bioprosthetic valve to avoid complications with anticoagulants. Situations that warrant special consideration include patient co-morbidities, the need for anticoagulation, and the potential for pregnancy. Once these characteristics have been considered, patients’ values, anxieties, and expectations for their lifestyle and quality of life should be incorporated into final valve selection. Decision aids can be useful in integrating preferences in the valve decision. Finally, future directions in valve technology, anticoagulation, and medical decision-making are discussed. PMID:21448466
Erdoğan, Serkan; Lima, Martin; Pérez, William
In this study, we describe the internal structures of both ventricles and the valvular apparatus of the heart of the white rhino. In the right of the heart, three papillary muscles were found in septal and marginal walls and m. papillaris magnus was the biggest. There was only one m. papillaris parvus in the right ventricle. The right atrioventricular valve was tricuspid, and the parietal cusp was longest. In the left of the heart, two papillary muscles were found on the septal wall and the subauricular was the biggest. The left atrioventricular valve was bicuspid and the parietal cusp was longest. There were no nodules in the valves of the pulmonary trunk and aorta, and the semilunar valves had many fibrous folds and transparent parts. Within the cardiac skeleton there was a cartilago cordis which occupied a small part of the right fibrous trigone. While the right ventricle included only one septomarginal trabecula, there were many trabeculae in the left ventricle. In both ventricles, the endocardium was thin and the subendocardial network was visible, also their continuation with the septomarginal trabeculae. We also found many trabeculae carneae in the dorsal part of the ventricles.
Peskin, Charles S.
The fluid dynamics of the heart involve the interaction of blood, a viscous incompressible fluid, with the flexible, elastic, fiber-reinforced heart valve leaflets that are immersed in that fluid. Neither the fluid motion nor the valve leaflet motion are known in advance: both must be computed simultaneously by solving their coupled equations of motion. This can be done by the immersed boundary method(Peskin CS and McQueen DM: A general method for the computer simulation of biological systems interacting with fluids. In: Biological Fluid Dynamics (Ellington CP and Pedley TJ, eds.), The Company of Biologists Limited, Cambridge UK, 1995, pp. 265-276.), which can be extended to incorporate the contractile fiber architecture of the muscular heart walls as well as the valve leaflets and the blood. In this way we arrive at a three-dimensional computer model of the heart(Peskin CS and McQueen DM: Fluid dynamics of the heart and its valves. In: Case Studies in Mathematical Modeling: Ecology, Physiology, and Cell Biology (Othmer HG, Adler FR, Lewis MA, and Dallon JC, eds.), Prentice-Hall, Englewood Cliffs NJ, 1996, pp. 309-337.), which can be used as a test chamber for the design of prosthetic cardiac valves, and also to study the function of the heart in health and in disease. Numerical solutions of the equations of cardiac fluid dynamics obtained by the immersed boundary method will be presented in the form of a video animation of the beating heart.
Hinton, Robert B.; Yutzey, Katherine E.
The mature heart valves are made up of highly organized extracellular matrix (ECM) and valve interstitial cells (VIC) surrounded by an endothelial cell layer. The ECM of the valves is stratified into elastin-, proteoglycan- and collagen-rich layers that confer distinct biomechanical properties to the leaflets and supporting structures. Signaling pathways have critical functions in primary valvulogenesis as well as maintenance of valve structure and function over time. Animal models provide powerful tools to study valve development and disease processes. Valve disease is a significant public health problem and increasing evidence implicates aberrant developmental mechanisms underlying pathogenesis. Further studies are necessary to determine regulatory pathway interactions underlying pathogenesis in order to generate new avenues for novel therapeutics. PMID:20809794
Sotiropoulos, Fotis; Le, Trung Bao; Gilmanov, Anvar
As the pulsatile cardiac blood flow drives the heart valve leaflets to open and close, the flow in the vicinity of the valve resembles a pulsed jet through a nonaxisymmetric orifice with a dynamically changing area. As a result, three-dimensional vortex rings with intricate topology emerge that interact with the complex cardiac anatomy and give rise to shear layers, regions of recirculation, and flow instabilities that could ultimately lead to transition to turbulence. Such complex flow patterns, which are inherently valve- and patient-specific, lead to mechanical forces at scales that can cause blood cell damage and thrombosis, increasing the likelihood of stroke, and can trigger the pathogenesis of various life-threatening valvular heart diseases. We summarize the current understanding of flow phenomena induced by heart valves, discuss their linkage with disease pathways, and emphasize the research advances required to translate in-depth understanding of valvular hemodynamics into effective patient therapies.
Trujillo, John F; Hollenberg, Steven M
Patients undergoing cardiac valve replacement may receive mechanical or bioprosthetic valves. Mechanical valves require lifelong anticoagulation but are durable and the need for a second surgery is up to eightfold times less than with bioprosthetic valves. Bioprosthetic valves do not require lifelong anticoagulation and thus are associated with fewer bleeding complications but they are less durable and associated with higher morbidity and mortality rates, particularly in younger patients. Anticoagulation with mechanical valves is achieved using warfarin; use of direct-acting oral anticoagulants is not indicated. Concomitant low-dose aspirin is recommended for patients with mechanical valves and as sole thromboembolism prophylaxis for patients receiving aortic or mitral bioprosthetic valves. If a patient taking warfarin is to undergo a surgical procedure that requires interruption of anticoagulation, bridging therapy with heparin is indicated if the patient has a mechanical aortic valve and any risk of thromboembolism, an older-generation mechanical aortic valve, or a mechanical mitral valve. Warfarin is teratogenic; pregnant women should take heparin. Patients with mechanical or bioprosthetic valves should receive antibiotic prophylaxis before some dental and surgical procedures to prevent endocarditis. Thrombolytic therapy should be considered in patients who develop a thrombus on a valve that does not resolve with heparin. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.
De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D; Costantino, Maria Laura
Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. 2 types of Poli-Valves made of SBC and differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. A pulse duplicator designed ad hoc allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the behavior of the valve. Both types of Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by the ISO 5840 Standard. Results were compared with 5 mechanical heart valves (MHVs) and 5 tissue heart valves (THVs), currently available on the market. Based on these results, PHVs based on styrenic block copolymers, as are Poli-Valves, can be considered a promising alternative for heart valve replacement in the near future.
Valvular heart disease accounts for a substantial part of the cardiovascular disease worldwide with an estimated prevalence of 2.5% in the Western population aged <65 years and over 13% in the population aged >75 years. Surgical prosthetic heart valve (PHV) replacement is the indicated therapy for
Reimer, Jay M; Syedain, Zeeshan H; Haynie, Bee H T; Tranquillo, Robert T
Pediatric patients account for a small portion of the heart valve replacements performed, but a pediatric pulmonary valve replacement with growth potential remains an unmet clinical need. Herein we report the first tubular heart valve made from two decellularized, engineered tissue tubes attached with absorbable sutures, which can meet this need, in principle. Engineered tissue tubes were fabricated by allowing ovine dermal fibroblasts to replace a sacrificial fibrin gel with an aligned, cell-produced collagenous matrix, which was subsequently decellularized. Previously, these engineered tubes became extensively recellularized following implantation into the sheep femoral artery. Thus, a tubular valve made from these tubes may be amenable to recellularization and, ideally, somatic growth. The suture line pattern generated three equi-spaced leaflets in the inner tube, which collapsed inward when exposed to back pressure, per tubular valve design. Valve testing was performed in a pulse duplicator system equipped with a secondary flow loop to allow for root distention. All tissue-engineered valves exhibited full leaflet opening and closing, minimal regurgitation (Valve performance was maintained under various trans-root pressure gradients and no tissue damage was evident after 2 million cycles of fatigue testing. Copyright © 2015 Elsevier Ltd. All rights reserved.
Blum, Kevin M; Drews, Joseph D; Breuer, Christopher K
Heart valve disease carries a substantial risk of morbidity and mortality. Outcomes are significantly improved by valve replacement, but currently available mechanical and biological replacement valves are associated with complications of their own. Mechanical valves have a high rate of thromboembolism and require lifelong anticoagulation. Biological prosthetic valves have a much shorter lifespan, and they are prone to tearing and degradation. Both types of valves lack the capacity for growth, making them particularly problematic in pediatric patients. Tissue engineering has the potential to overcome these challenges by creating a neovalve composed of native tissue that is capable of growth and remodeling. The first tissue-engineered heart valve (TEHV) was created more than 20 years ago in an ovine model, and the technology has been advanced to clinical trials in the intervening decades. Some TEHVs have had clinical success, whereas others have failed, with structural degeneration resulting in patient deaths. The etiologies of these complications are poorly understood because much of the research in this field has been performed in large animals and humans, and, therefore, there are few studies of the mechanisms of neotissue formation. This review examines the need for a TEHV to treat pediatric patients with valve disease, the history of TEHVs, and a future that would benefit from extension of the reverse translational trend in this field to include small animal studies.
Brown, Morgan L; Schaff, Hartzell V; Suri, Rakesh M; Li, Zhuo; Sundt, Thoralf M; Dearani, Joseph A; Enriquez-Sarano, Maurice
We examined the role of prosthesis-patient mismatch on left ventricular mass regression after aortic valve replacement for chronic aortic valve regurgitation. We selected patients who had complete preoperative and follow-up echocardiograms with measurement of left ventricular mass. Patients were excluded who had moderate or greater aortic valve stenosis, concomitant coronary artery bypass grafting, or mitral valve procedures. Patients' mean age was 55 ± 17 years; 21% were female. The mean preoperative indexed left ventricular mass was 150 ± 45 g/m(2). Patients with mildly (n = 44; mean indexed mass, 126 ± 15 g/m(2)), moderately (n = 31; mean indexed mass, 168 ± 11 g/m(2)), or severely (n = 15; mean indexed mass, 241 ± 34 g/m(2)) increased preoperative indexed left ventricular mass, were similar, except for lower ejection fractions, larger end-diastolic dimensions, and larger ventricular wall thicknesses in the severely enlarged group (P regression was unrelated to labeled valve size, prosthesis-patient mismatch, or measured indexed effective aortic valve area. A greater preoperative indexed left ventricular mass (P regression. Despite having greater left ventricular mass regression, patients with severe preoperative indexed left ventricular mass did not return to normal values (mean, 142 ± 25 g/m(2)). Left ventricular mass regression after aortic valve replacement for chronic aortic regurgitation is unrelated to indexed prosthetic valve area. Although incomplete, regression is greatest in patients with the largest preoperative indexed left ventricular mass. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
Takizawa, Kenji; Tezduyar, Tayfun E.; Buscher, Austin; Asada, Shohei
Fluid mechanics computation of heart valves with an interface-tracking (moving-mesh) method was one of the classes of computations targeted in introducing the space-time (ST) interface tracking method with topology change (ST-TC). The ST-TC method is a new version of the Deforming-Spatial-Domain/Stabilized ST (DSD/SST) method. It can deal with an actual contact between solid surfaces in flow problems with moving interfaces, while still possessing the desirable features of interface-tracking methods, such as better resolution of the boundary layers. The DSD/SST method with effective mesh update can already handle moving-interface problems when the solid surfaces are in near contact or create near TC, if the "nearness" is sufficiently "near" for the purpose of solving the problem. That, however, is not the case in fluid mechanics of heart valves, as the solid surfaces need to be brought into an actual contact when the flow has to be completely blocked. Here we extend the ST-TC method to 3D fluid mechanics computation of heart valve models. We present computations for two models: an aortic valve with coronary arteries and a mechanical aortic valve. These computations demonstrate that the ST-TC method can bring interface-tracking accuracy to fluid mechanics of heart valves, and can do that with computational practicality.
Hasenkam, J M; Ringgaard, S; Houlind, K; Botnar, R M; Stødkilde-Jørgensen, H; Boesiger, P; Pedersen, E M
To evaluate the potential of magnetic resonance imaging (MRI) for evaluation of velocity fields downstream of prosthetic aortic valves. Furthermore, to provide comparative data from bileaflet aortic valve prostheses in vitro and in patients. A pulsatile flow loop was set up in a 7.0 Tesla MRI scanner to study fluid velocity data downstream of a 25 mm aortic bileaflet heart valve prosthesis. Three dimensional surface plots of velocity fields were displayed. In six NYHA class I patients blood velocity profiles were studied downstream of their St. Jude Medical aortic valves using a 1.5 Tesla MRI whole-body scanner. Blood velocity data were displayed as mentioned above. Fluid velocity profiles obtained from in vitro studies 0.25 valve diameter downstream of the valve exhibited significant details about the cross sectional distribution of fluid velocities. This distribution completely reflected the valve design. Blood velocity profiles in humans were considerably smoother and in some cases skewed with the highest velocities toward the anterior-right ascending aortic wall. Display and interpretation of fluid and blood velocity data obtained downstream of prosthetic valves is feasible both in vitro and in vivo using the MRI technique. An in vitro model with a straight tube and the test valve oriented orthogonally to the long axis of the test tube does not entail fluid velocity profiles which are compatible to those obtained from humans, probably due to the much more complex human geometry, and variable alignment of the valve with the ascending aorta. With the steadily improving quality of MRI scanners this technique has significant potential for comparative in vitro and in vivo hemodynamic evaluation of heart valves.
Zheng, Xudong; Mittal, Rajat; Abraham, Theodore; Pinheiro, Aurelio
Hypertrophic Cardiomyopathy (HCM) is a cardiovascular disease manifested by the thickening of the ventricular wall and often leads to a partial obstruction to the blood flow out of the left ventricle. HCM is recognized as one of the most common causes of sudden cardiac death in athletes. In a heart with HCM, the hypertrophy usually narrows the blood flow pathway to the aorta and produces a low pressure zone between the mitral valve and the hypertrophy during systole. This low pressure can suck the mitral valve leaflet back and completely block the blood flow into the aorta. In the current study, a sharp interface immersed boundary method flow solver is employed to study the hemodynamics and valve dynamics inside a heart with HCM. The three-dimensional motion and configuration of the left ventricle including mitral valve leaflets and aortic valves are reconstructed based on echo-cardio data sets. The mechanisms of aortic obstruction associated with HCM are investigated. The long term objective of this study is to develop a computational tool to aid in the assessment and surgical management of HCM.
Tori E. Horne
Full Text Available The heart valve interstitial cell (VIC population is dynamic and thought to mediate lay down and maintenance of the tri-laminar extracellular matrix (ECM structure within the developing and mature valve throughout life. Disturbances in the contribution and distribution of valve ECM components are detrimental to biomechanical function and associated with disease. This pathological process is associated with activation of resident VICs that in the absence of disease reside as quiescent cells. While these paradigms have been long standing, characterization of this abundant and ever-changing valve cell population is incomplete. Here we examine the expression pattern of Smooth muscle α-actin, Periostin, Twist1 and Vimentin in cultured VICs, heart valves from healthy embryonic, postnatal and adult mice, as well as mature valves from human patients and established mouse models of disease. We show that the VIC population is highly heterogeneous and phenotypes are dependent on age, species, location, and disease state. Furthermore, we identify phenotypic diversity across common models of mitral valve disease. These studies significantly contribute to characterizing the VIC population in health and disease and provide insights into the cellular dynamics that maintain valve structure in healthy adults and mediate pathologic remodeling in disease states.
John B Chambers
Full Text Available This is a practical description of how replacement valves are assessed using echocardiography. Normal transthoracic appearances including normal variants are described. The problem of differentiating normal function, patient–prosthesis mismatch and pathological obstruction in aortic replacement valves with high gradients is discussed. Obstruction and abnormal regurgitation is described for valves in the aortic, mitral and right-sided positions and when to use echocardiography in suspected infective endocarditis. The roles of transoesophageal and stress echocardiography are described and finally when other imaging techniques may be useful.
Chambers, John B
This is a practical description of how replacement valves are assessed using echocardiography. Normal transthoracic appearances including normal variants are described. The problem of differentiating normal function, patient-prosthesis mismatch and pathological obstruction in aortic replacement valves with high gradients is discussed. Obstruction and abnormal regurgitation is described for valves in the aortic, mitral and right-sided positions and when to use echocardiography in suspected infective endocarditis. The roles of transoesophageal and stress echocardiography are described and finally when other imaging techniques may be useful. © 2016 The authors.
Haji-Esmaeili, Farida; Oshkai, Peter
Turbulent flow trough a model of a mechanical heart valve is investigated using digital particle image velocimetry. The valve leaflets are represented by flat plates mounted in a duct. The emphasis is on the effect of the valve design on the platelet activation state associated with the resulting flow field. Global quantitative images corresponding to multiple planes of data acquisition provide insight into the three-dimensional nature of the flow. Turbulent flow structures including jet-like regions and shed vortices are characterized in terms of patterns of instantaneous and time-averaged velocity, vorticity, and streamline topology. Potential of bileaflet heart valves for being thrombogenic is assessed by quantitative comparison of the associated flow fields in terms of maximum values of turbulent stresses and platelet activation states.
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Rosenkranz, Stephan; Gibbs, J. Simon R.; Wachter, Rolf; De Marco, Teresa; Vonk-Noordegraaf, Anton; Vachiéry, Jean-Luc
Abstract In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65–80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a ‘left ventricular phenotype’ to a ‘right ventricular phenotype’ across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context. PMID:26508169
Wei, Wei; Dong, Taiming; Zheng, Zhichao; Huang, Shuping
To evaluate the curative effects and risks of a medical therapy with combined anti-thrombotic agents for thrombosis on prosthetic heart valves. Twenty-two patients who suffered from thrombosis on prosthetic valves with stable hemodynamics were divided into the inpatient group and the outpatient group. Thrombosis on the valves were demonstrated by transesophageal echocardiographies (TEE). A combined anti-thrombotic therapy with clopidogrel and warfarin were prescribed for all the patients during the whole treatment. Low molecular weight heparin (LMWH) was given twice daily during the first 5 days for the inpatients. The patients accepted regular follow-ups for observation of the functions of prosthetic valves, changes of thrombi, coagulation status and general clinical status. There were 5 men and 17 women. Thirteen patients suffered from thrombosis on the mechanical mitral valves (MVs), five on the mechanical tricuspid valves (TVs), one on the mechanical aortic valve and tricuspid bio-prosthetic valve, one on the mechanical aortic valve, one on the mitral bio-prosthetic valve, and one on the tricuspid bio-prosthetic valve. After an average of 36.4±23.1 days' observation, 16 (73%) patients' valvular function recovered normal without TTE detectable thrombi, 6 (27%) patients' valvular function remained abnormal including three patients without TTE detectable thrombi during follow-ups. No significant differences of thrombi changes and period of thrombi disappearance were observed between the inpatient group and the outpatient group. For patients with mitral thrombosis, sizes of the left atriums (LAs) decreased an average of 4.1 mm after treatment (95% CI, 1.2-6.9 mm). No significant changes of other chambers and left ventricular ejection fractions (LVEF) were observed. For patients with tricuspid thrombosis, LVEF improved an average of 10.5% after treatment (95% CI, 0.1-17.9%). No significant changes of chambers were observed. None experienced major bleedings except
Dobrova, N B; Zaretskiĭ, Iu V
Bench tests for 38 models of artificial heart valves (AHV) with different design parameters allowed us to decide in favour of the valves with reduced eccentricity (compared to the serial AHV of the EMAHV type) according to its resistance in the constant flow. Out of the compatibility checks of the design parameters tested it was concluded that the disk did not make the complete calculated angle when rotated. The dependence of AHV resistance on the disk rotation angle showed that there is no necessity to increase that angle more than 70 degrees for the mitral valve and more than 75 degrees for the aortic AHV.
Haya, Laura; Tavoularis, Stavros
The aortic sinus is approximately tri-radially symmetric, but bileaflet mechanical heart valves (BMHVs), which are commonly used to replace diseased aortic valves, are bilaterally symmetric. This mismatch in symmetry suggests that the orientation in which a BMHV is implanted within the aortic sinus affects the flow characteristics downstream of it. This study examines the effect of BMHV orientation on the flow in the coronary arteries, which originate in the aortic sinus and supply the heart tissue with blood. Planar particle image velocimetry measurements were made past a BMHV mounted at the inlet of an anatomical aorta model under physiological flow conditions. The complex interactions between the valve jets, the sinus vortex and the flow in the right coronary artery were elucidated for three valve orientations. The coronary flow rate was directly affected by the size, orientation, and time evolution of the vortex in the sinus, all of which were sensitive to the valve's orientation. The total flow through the artery was highest when the valve was oriented with its axis of symmetry intersecting the artery's opening. The findings of this research may assist surgeons in choosing the best orientation for BMHV implantation. The bileaflet valve was donated by St. Jude Medical. Financial support was provided by the Natural Sciences and Engineering Research Council of Canada.
Gelsomino, Sandro; Lucà, Fabiana; Parise, Orlando; Lorusso, Roberto; Rao, Carmelo Massimiliano; Vizzardi, Enrico; Gensini, Gian Franco; Maessen, Jos G
We explored the influence of global longitudinal strain (GLS) measured with two-dimensional speckle-tracking echocardiography on left ventricular mass regression (LVMR) in patients with pure aortic stenosis (AS) and normal left ventricular function undergoing aortic valve replacement (AVR). The study population included 83 patients with severe AS (aortic valve area regression (all P regression in patients with pure AS undergoing AVR. Our findings must be confirmed by further larger studies.
Bark, David; Vahabi, Hamed; Movafaghi, Sanli; Popat, Ketul; Kota, Arun K.; Dasi, Lakshmi Prasad
A large number of prosthetic heart valves are implanted each year to treat heart valve disease, where half of the surgically replaced valves are mechanical heart valves (MHV)s. MHVs are at high risk for thrombosis and therefore require lifelong antithrombotic therapies, causing an increased bleeding risk that can lead to death. To alleviate this need, we investigate the potential of superhydrophobic surfaces in reducing the thrombotic risk. Particle imaging velocimetry and computational fluid dynamics are used to quantify shear stress in the presence of potential slip on the surface. Coagulation and cell adhesion are quantified by incubating blood under static conditions. We further evaluate a dynamic blood response in polydimethylsiloxane channels under complex shear conditions that mimic the hinge region of bileaflet mechanical heart valves, a region known to exhibit thrombosis. Overall, Shear stress is not reduced on a superhydrophobic bileaflet MHV. However, superhydrophobic surfaces significantly reduce the potential for platelet responses under static and dynamic blood flow conditions, a counterintuitive result when considering that hydrophobic surfaces are prone to protein and cell adhesion. The authors gratefully acknowledge funding from National Institutes of Health (NIH) under Award Number R01HL119824 and F32HL129730. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
Ujjwal Kumar Chowdhury
Full Text Available A 50-year-old woman with rheumatic heart disease, mitral stenosis, and critical isolated left main ostial stenosis was successfully treated by mitral valve replacement, tricuspid annuloplasty, and surgery of left main osteoplasty and is reported for its rarity. Notable clinical findings included an intermittently irregular pulse, blood pressure of 100/70 mmHg, cardiomegaly, a diastolic precordial thrill, a mid-diastolic murmur without presystolic accentuation that was loudest at the mitral area. Chest radiograph revealed cardiomegaly with a cardiothoracic ratio of 0.7 due to enlarged right atrium, right ventricle with a straightened left heart border and evidence of pulmonary hypertension. The investigation shows that surgical reconstruction of the left main coronary artery is safe and effective for the treatment.
Bloch, Oliver; Golde, Pia; Dohmen, Pascal M; Posner, Steffen; Konertz, Wolfgang; Erdbrügger, Wilhelm
Conventional biological heart valves treated with glutaraldehyde (GA) reveal a limited lifespan due to calcification. This is assumed to be an immune response initiated process, which is not seen with decellularized valves. However, their immunological potential is still a matter of debate. Therefore, serum samples from patients undergoing heart valve surgery were obtained before (Pre), after (Post), and 9-12 months after operation (Follow Up). Immunoglobulin G (IgG) and M (IgM) antibodies against porcine collagen I and α-Gal (Gal-alpha1,3-Gal-beta1,4-GlcNac-R) were determined for decellularized and GA treated valves. Antibody titers for collagen type I revealed no significant alteration for both types of valves. However, a considerable anti-α-Gal antibody response was observed in patients with GA-treated porcine valves. In detail, IgM antibodies were increased during follow up (pvalves revealed a minor decrease in the IgM response (pvalves. This indicates that GA treatment is not sufficient to eliminate immune response to the α-Gal epitope completely. Future investigations will have to verify whether immune response to α-Gal can be linked to the limited durability of conventional valves. © Mary Ann Liebert, Inc.
Aguiari, Paola; Fiorese, Michele; Iop, Laura; Gerosa, Gino; Bagno, Andrea
Mammalian pericardia are currently used for the production of percutaneous prosthetic heart valves. The characteristics of biological tissues largely influence the durability of prosthetic devices used in the percutaneous approach and in traditional surgery, too. This paper reviews methodologies employed to assess and compare mechanical properties of pericardial patches from different mammalian species in order to identify the biomaterials adequate for manufacturing prosthetic heart valves. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Mol, Anita; Rutten, Marcel C M; Driessen, Niels J B; Bouten, Carlijn V C; Zünd, Gregor; Baaijens, Frank P T; Hoerstrup, Simon P
Tissue engineering represents a promising approach for the development of living heart valve replacements. In vivo animal studies of tissue-engineered autologous heart valves have focused on pulmonary valve replacements, leaving the challenge to tissue engineer heart valves suitable for systemic application using human cells. Tissue-engineered human heart valves were analyzed up to 4 weeks and conditioning using bioreactors was compared with static culturing. Tissue formation and mechanical properties increased with time and when using conditioning. Organization of the tissue, in terms of anisotropic properties, increased when conditioning was dynamic in nature. Exposure of the valves to physiological aortic valve flow demonstrated proper opening motion. Closure dynamics were suboptimal, most likely caused by the lower degree of anisotropy when compared with native aortic valve leaflets. This study presents autologous tissue-engineered heart valves based on human saphenous vein cells and a rapid degrading synthetic scaffold. Tissue properties and mechanical behavior might allow for use as living aortic valve replacements.
Kikkenborg Berg, Selina; Zwisler, Ann-Dorthe; Pedersen, Birthe D.
Heart valve disease is becoming a public health problem due to increasing life expectancy and new treatment methods. Patients are at risk of developing depression, anxiety or post-traumatic stress disorder after heart valve surgery. To better plan proper care, describing and understanding patient......' perception of recovery after heart valve replacement is essential. The objective was to describe the experience of recovery at home after heart valve replacement....
Weber Moritz; Hoheisel Anna L.; Glasmacher Birgit
Using the electrospinning process the geometry of a heart valve is not replicable by just one manufacturing process. To produce heart valve scaffolds the heart valve leaflets and the vessel have to be produced in separated spinning processes. For the final product of a heart valve they have to be mated afterwards. In this work an already existing three-axes laser was enhanced to laser weld those scaffolds. The automation control software is based on the robot operating system (ROS). The mecha...
The aim of this study was to examine the side effect mechanisms of cabergoline and other ergoline compounds that cause fibrotic changes in heart valves. Heart valve fibrosis occurs during treatment of Parkinson’s disease and may cause regurgitation and even heart failure. To this date, surgical replacement with artificial valves is the only long term treatment option for patients with diseased heart valves. These pathological changes were observed in association with other influences on the s...
Zhang, Di; Wu, Yuequan; Yao, Jianping; Yang, Song; Du, Minghui
Auscultation, the act of listening for heart sounds to aid in the diagnosis of various heart diseases, is a widely used efficient technique by cardiologists. Since the mechanical prosthetic heart valves are widely used today, it is important to develop a simple and efficient method to detect abnormal mechanical valves. The study on five different mechanical valves showed that only the case of perivalvular leakage could be detected by spectral estimation. Though it is possible to classify different mechanical valves by using time-frequency components of the signal directly, the recognition rate is merely 84%. However, with the improved local discriminant bases (LDB) algorithm to extract features from heart sounds, the recognition rate is 97.3%. Experimental results demonstrated that the improved LDB algorithm could improve classification rate and reduce computational complexity in comparison with original LDB algorithm.
Everaerts, Fransiscus Joannes Leonardus
Due to some form of heart valve disease, approximately 250000 patients worldwide undergo surgery to receive a new heart-valve each year. In about 70% of the cases a mechanical heart valve is used despite the fact that permanent anticoagulant therapy for the patient is required. The remaining 30% of
Yang, Min; Lin, Yang-Hua; Shi, Wei-Ping; Shi, Hong-Can; Gu, Y. John; Shu, Yu-Sheng
Tissue calcification is a major cause of failure of bioprosthetic heart valves. Aim of this study was to examine whether surface heparin treatment of the decellularized porcine heart valve reduces tissue calcification. Fresh porcine aortic heart valves were dissected as tissue discs and divided into
Raghav, Vrishank; Clifford, Christopher; Midha, Prem; Okafor, Ikechukwu; Thurow, Brian; Yoganathan, Ajit; Auburn University Collaboration; Georgia Institute of Technology Collaboration
Transcatheter aortic valve replacement has emerged as a safe and effective treatment for severe, symptomatic aortic stenosis in intermediate or greater surgical risk patients. However, despite excellent short-term outcomes, improved imaging and awareness has led to the identification of leaflet thrombosis on the aortic side of the prosthesis. Upon implantation, the transcatheter heart valve (THV) becomes enclosed in the native aortic valve leaflet tissue dividing the native sinus into two regions - a smaller anatomical sinus and a neo-sinus. To understand the causes for thrombosis, plenoptic Particle Image Velocimetry (PIV) is used to investigate the pulsatile three-dimensional flow in the sinus and neo-sinus region of the THV. Experiments are conducted on both a real and a transparent THV model in a pulsatile flow loop capable of replicating physiological hemodynamics. Comparisons with planar PIV results demonstrate the feasibility of using Plenoptic PIV to study heart valve fluid dynamics. Large three-dimensional regions of low velocity magnitude and low viscous shear stress were observed near the heart valve which could increase particle residence time potentially leading to formation of clots the THV leaflet.
Yang, Ji Yeon; Kim, Dong Hun; Seo, Hye Sun; Her, Keun; Kim, Hee Kyung
We report multidetector row CT (MDCT) findings of two left atrial myxomas causing mitral valve obstruction and dyspnea of patients. Cardiac MDCT showed well-defined left atrial masses attached to the interatrial septum and shifting of tumors into the left ventricle causing mitral valve obstruction during diastole in a 37-year-old male and in a 69-year-old female. Also, we observed intratumoral hemorrhage in the second case. Myxomas were resected and the patients were discharged without dyspnea.
Orban, Mathias; Orban, Martin; Braun, Daniel; Nabauer, Michael; Massberg, Steffen; Hausleiter, Jörg
Heart failure and severe mitral regurgitation (MR) are mutually dependent. Secondary MR is a consequence of chronic heart failure in patients with severely depressed left ventricular ejection fraction (LV-EF) and LV dilatation. Severe MR in heart failure patients worsens prognosis and accelerates LV dilatation and decline in LV-EF. Interventional therapies have changed clinical practice for heart failure patients with secondary MR. In this review we summarize the available data of patients with chronic heart failure undergoing transcatheter edge-to-edge mitral valve repair (TMVR) with the MitraClip® system for severe secondary mitral regurgitation. TMVR could be a therapeutic option with a favorable long-term outcome even in patients with severely depressed LV-EF. Selection criteria predicting mortality in patients undergoing TMVR comprise clinical, laboratory and echocardiographic parameters and can help for clinical decision-making. Ongoing randomized trials will influence the use of interventional treatment of MR in these high-risk patients.
N. A. Shostak
Full Text Available Cardiac surgery is the only radical method of treatment of valvular defects (congenital or acquired: valve preservation procedures or prosthetics operations. 250 000 – 280 000 valve prostheses are implanted every year worldwide, while the number of prosthetic valves operation increases by an average of 5–7 % per year (biological prostheses – 8–11 %, mechanical prostheses – 3–5 %. Selection of biological or mechanical types of prosthesis, its location, the presence of associated risk factors for embolic events, such as atrial fibrillation, previous embolism, left ventricular dysfunction, hypercoagulable states determine patient management tactics. Particularly high risk of prosthetic thrombosis and thromboembolic complications can be seen in case of mechanical prosthesis implantation. Numerous prospective and retrospective clinical studies have proven high effectiveness of anticoagulants for reduction the risk of cardioembolic complications. The degree of anticoagulation (optimal international normalized ratio (INR is determined by risk factors for prosthetic thrombosis and thromboembolic complications in a patient, as well as thrombogenicity of the prosthesis by itself; INR may range from 2.5 to 4.0. International recommendations take into account the presence/absence of additional risk factors for thromboembolism, and based on warfarin administration with the achievement of target INR values combined with low-dose aspirin. Administration of novel direct oral anticoagulation remedies in patients with prosthetic heart valves has not been studied sufficiently up to date and is contraindicated. Thus, warfarin currently is a drug of choice for the prevention of thromboembolic complications in patients with prosthetic heart valves.
Adlparvar, Payam; Guo, George; Kingsbury, Chris
The Edwards-Duromedics (ED) mechanical heart valve prosthesis is of a bileaflet design, incorporating unique design features that distinguish its performance with respect to other mechanical valves of similar type. Leaflet motion of mechanical heart valves, particularly during closure, is related to valve durability, valve sounds and the efficiency of the cardiac output. Modifications to the ED valve have resulted in significant improvements with respect to leaflet motion. In this study a high-speed video system was used to monitor the leaflet motion of the valve, and to compare the performance of the Modified Specification to that of the Original Specification using a St. Jude Medical as a control valve.
Munk, Kim; Sørensen, Stine Heidenheim; Andersen, Niels Holmark
We report a case of a 70-year-old female with considerable co-morbidities (Type 2 diabetes, Leiden factor V mutation, mild to moderate chronic obstructive pulmonary disease) and a recent biological aortic valve substitution, who was admitted due to circulatory collapse caused by severe heart...
Koyama, Terumasa; Okura, Hiroyuki; Kume, Teruyoshi; Fukuhara, Kenzo; Imai, Koichiro; Hayashida, Akihiro; Neishi, Yoji; Kawamoto, Takahiro; Tanemoto, Kazuo; Yoshida, Kiyoshi
Recently, the energy loss index (ELI) has been proposed as a new functional index to assess the severity of aortic stenosis (AS). The aim of this study was to investigate the impact of the ELI on left ventricular mass (LVM) regression in patients after aortic valve replacement (AVR) with mechanical valves. A total of 30 patients with severe AS who underwent AVR with mechanical valves was studied. Echocardiography was performed to measure the LVM before AVR (pre-LVM) (n = 30) and repeated 12 months later (post-LVM) (n = 19). The ELI was calculated as [effective orifice area (EOA) × aortic cross sectional area]/(aortic cross sectional area - EOA) divided by the body surface area. The LVM regression rate (%) was calculated as 100 × (post-LVM - pre-LVM)/(pre-LVM). A cardiac event was defined as a composite of cardiac death and heart failure requiring hospitalization. LVM regressed significantly (245.1 ± 84.3 to 173.4 ± 62.6 g, P regression rate negatively correlated with the ELI (R = -0.67, P regression rates (area under the curve = 0.825; P = 0.030). Patients with ELI regression after AVR with mechanical valves. Whether the ELI is a stronger predictor of clinical events than EOAI is still unclear, and further large-scale study is necessary to elucidate the clinical impact of the ELI in patients with AVR.
Jung, Young mee; Kim, Soo Hyun [Korea Institute of Science and Technology, Daejeon (Korea, Republic of)
Artificial heart valves are used in valvular heart diseases, but these valves have disadvantages that they cannot grow, repair and remodel. In current study, the strategies to development of in vitro cultured functional tissue by tissue engineering is available to heart valve disease. In the point of using viable autolougous cells, tissue engineered heart valves have some advantage to include that they can repair, remodel, and grow. Because heart valve is placed under the strong shear stress condition by pumping of heart, the durability of tissue-engineered heart valves is now questionable. The purpose of the study is to evaluate of the durability of tissue engineered heart valve with surface modified scaffolds under hemodynamic conditions
Full Text Available Abstract Objective: This work describes the experimental validation of a cardiac simulator for three heart rates (60, 80 and 100 beats per minute, under physiological conditions, as a suitable environment for prosthetic heart valves testing in the mitral or aortic position. Methods: In the experiment, an aortic bileaflet mechanical valve and a mitral bioprosthesis were employed in the left ventricular model. A test fluid of 47.6% by volume of glycerin solution in water at 36.5ºC was used as blood analogue fluid. A supervisory control and data acquisition system implemented previously in LabVIEW was applied to induce the ventricular operation and to acquire the ventricular signals. The parameters of the left ventricular model operation were based on in vivo and in vitro data. The waves of ventricular and systemic pressures, aortic flow, stroke volume, among others, were acquired while manual adjustments in the arterial impedance model were also established. Results: The acquired waves showed good results concerning some in vivo data and requirements from the ISO 5840 standard. Conclusion: The experimental validation was performed, allowing, in future studies, characterizing the hydrodynamic performance of prosthetic heart valves.
... Tetralogy of Fallot Total Anomalous Pulmonary Venous Return Tricuspid Atresia Truncus Arteriosus Ventricular Septal Defect Living With ... ventricle is underdeveloped and too small. The mitral valves is not formed or is very small. The ...
McKellar, Stephen H; Abel, Stuart; Camp, Christopher L; Suri, Rakesh M; Ereth, Mark H; Schaff, Hartzell V
Warfarin reduces risk of stroke in patients with mechanical heart valves but increases risk of hemorrhage and is difficult to use. Dabigatran etexilate, a new oral direct thrombin inhibitor, is safe and effective in reducing risk of stroke among patients with atrial fibrillation. No data exist in the setting of mechanical heart valves. We tested the hypothesis that dabigatran etexilate is as effective as heparin for thromboprophylaxis of mechanical valves in a porcine heterotopic aortic valve model. Thirty swine underwent implantation of modified bileaflet mechanical valved conduit bypassing the ligated, native descending thoracic aorta. Animals randomly received no anticoagulation (n = 10), enoxaparin 2 mg/kg subcutaneously twice daily (n = 10), or dabigatran etexilate 20 mg/kg orally twice daily. Primary end point was amount of valve thrombus at 30 days. Secondary end points included quantitative measurement of platelet deposition on valve prosthesis, thromboelastography, and hemorrhagic and embolic events. At 30 days, we observed 638 ± 895 mg thrombus in no anticoagulation group, 121 ± 128 mg in enoxaparin group, and 19 ± 31 mg in dabigatran etexilate group (P = .01 enoxaparin vs dabigatran etexilate). Fewer platelets were deposited on valves in dabigatran etexilate group (2.7 × 10(8)) than in enoxaparin group (1.8 × 10(9), P = .03). No major or occult hemorrhagic or embolic events were observed. By thromboelastographic analysis, dabigatran etexilate produced less prolongation of K value (P = .01) and less decreases in angle (P = .01) and maximum amplitude (P = .001) than enoxaparin. Dabigatran etexilate is as effective as enoxaparin for short-term thromboprophylaxis of mechanical valves. It prevents valve thrombus and platelet deposition at 30 days without increased adverse events. These promising results serve as a foundation for prospective clinical trials with dabigatran etexilate as an alternative to warfarin in patients with bileaflet
Lund, K.; Sibilitz, Kirstine Lærum; Kikkenborg Berg, Selina
physical activity levels 6-12 months after heart valve surgery and (1) survival, (2) hospital readmission 18-24 months after surgery and (3) participation in exercise-based cardiac rehabilitation. METHODS: Prospective cohort study with registry data from The CopenHeart survey, The Danish National Patient...... readmission. Patients who participated in exercise-based cardiac rehabilitation (n=297) were more likely than the non-participants (n=200) to have a moderate or high physical activity level than a low physical activity level (fully adjusted OR: 1.52, 95% CI 1.03 to 2.24). CONCLUSIONS: Moderate to high levels...... of physical activity after heart valve surgery are positively associated with higher survival rates and participation in cardiac rehabilitation....
Pablo M. A Pomerantzeff
Full Text Available A reoperação de próteses valvulares tem sido realizada, com freqüência cada vez maior, nos vários Serviços de cirurgia cardíaca. Os detalhes do tratamento, a indicação e a técnica operatória melhoraram os resultados. No período de janeiro de 1984 a junho de 1986, no Instituto do Coração, foram submetidos a retroca valvular 145 pacientes, num total de 157 próteses, e 4 trocas da bola de válvula de Starr-Edwards. Em posição mitral, 6 pacientes foram submetidos a terceira troca valvular, sem óbito imediato. A insuficiência valvular e a calcificação do tecido biológico de dura-máter foram as principais causas de indicação da reoperação. Quarenta e um pacientes apresentavam roturas e 19 pacientes, calcificação de bioprótese em posição mitral; em posição aórtica, 32 pacientes tinham rotura e 12, calcificação de bioprótese. Quanto à prótese implantada, foram utilizadas principalmente as biopróteses, sendo 63 porcinas e 35 de pericárdio bovino. A mortalidade imediata global foi de 8,3% (12 pacientes, sendo a principal causa de óbito o baixo débito cardíaco. As principais complicações imediats foram: baixo débito cardíaco, arritmias e sangramento. Noventa por cento dos pacientes encontravam-se em classe funcional (NYHA III e IV no pré-operatório, evoluindo para as classes funcionais I e II em 89% das trocas aórticas de 82% das trocas mitrais. A curva atuarial de sobrevida.em 5 semestres, foi, para a posição mitral, de 85,7% e, para a aórtica, de 91,3%. Os autores concluem que os cuidados de técnica, a proteção miocárdica e o tipo de prótese utilizada foram os responsáveis pelos resultados bastante satisfatórios.Replacement of valvular prosthesis is an increasingly frequent procedure in heart surgery. Better results are attained with the observation of correct indication and improved surgical technique. In the period of January 1984 to June 1986, 145 patients were submitted to prosthesis
Edwards, Maria-Benedicta; Taylor, Kenneth M
Changes in the age profile of the United Kingdom population and improvements in preoperative and postoperative care have resulted in increasing numbers of very elderly patients undergoing heart valve replacement (HVR) operations. Although HVR operations in nonagenarians are relatively uncommon, the demand for cardiac operations in this age group may increase over time. Outcomes after HVR operations in nonagenarians have not been well described yet. Therefore, the aim of this study was to determine outcomes in terms of early mortality and long-term survival in 35 nonagenarians after HVR operation. Data from the United Kingdom Heart Valve Registry were analyzed and nonagenarian patients were identified. Additional analyzed data include gender, valve position, valve type, valve size, operative priority, follow-up time, and date and cause of death. Kaplan-Meier actuarial curves were calculated to determine accurate 30-day mortality and long-term survival. On average five HVR operations are performed annually in the United Kingdom in nonagenarians with equal numbers of males and females. Aortic valve replacement with a bioprosthetic valve was the most common operation and 86% were elective admissions. Fourteen patients died within the review period; mean time to death was 402 days. Overall 30-day mortality was 17%, which was higher for males compared with females; females also displayed better long-term survival. HVR operations in nonagenarians carry a significantly higher risk of early mortality and reduced long-term survival. Despite increases in the age profile of the population, elective HVR operation with patients aged 90 years or older is likely to remain an infrequent surgical procedure reserved for very carefully selected patients.
Haya, Laura; Tavoularis, Stavros
A bileaflet mechanical heart valve has been inserted in an axisymmetric model of the aorta within a mock circulation apparatus with physiological pressure and flow variations. The velocity field behind the valve has been measured with laser Doppler velocimetry and particle image velocimetry. The results closely match those reported by similar studies. A triple jet emanated from the valve's orifices and regions of reverse flow formed in the sinus region. Velocity fluctuations were greatest in the shear layers of the jets. The average r.m.s. streamwise velocity fluctuation over the turbulent period was 0.22 m/s; its maximum value was 0.53 m/s and occurred at the onset of deceleration. Measurements with the valve inserted in an anatomical model of the aorta are planned for the near future. The present and future measurements will be compared to determine the effects of the aorta anatomy on the characteristics of flow through bileaflet valves. In particular, measurements of the viscous and turbulent shear stresses will be analyzed to identify possible locations of blood element damage, and regions of recirculation and stagnation will be identified as locations favourable to thrombus growth. The effects of flows in branching arteries and valve orientation will also be investigated. Supported by NSERC.
Sündermann, Simon H; Reser, Diana; Czerny, Martin; Falk, Volkmar
Most common heart valve diseases in western industrialized nations are the aortic valve stenosis and the mitral valve regurgitation. More seldom are a regurgitation of the aortic valve and mitral valve stenosis. Even more seldom are heart valve diseases of the Tricuspid and the pulmonary valve. The only curative therapy in severe heart valve disease is a surgical intervention. The timing is crucial for the outcome. Especially in asymptomatic patients it's difficult to find the right point of time for intervention due to missing realization of the health status. In 2013, the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC) published guidelines according to the therapy in heart valve disease. Here we want to summarize the recommendations of these guidelines in regards of timing of the surgical intervention.
Kandler, Kristian; Møller, Christian H; Hassager, Christian
The presence of patient-prosthesis mismatch (PPM) after aortic valve replacement may influence patient survival. We examined the relationship between PPM and changes in left ventricular mass index at 3 months follow-up and also overall survival.......The presence of patient-prosthesis mismatch (PPM) after aortic valve replacement may influence patient survival. We examined the relationship between PPM and changes in left ventricular mass index at 3 months follow-up and also overall survival....
Gomes Walter J.
Full Text Available Rupture of the left ventricle following mitral valve replacement is a catastrophic complication with deadly consequences. We report here the case of a 75-year-old man who underwent elective mitral valve replacement for severe mitral regurgitation. Delayed type 1 rupture of the left ventricle developed 3 hours postoperatively in the intensive care unit. A salvaging maneuver was used, which gained time, allowing reoperation and successful intraventricular repair.
Harpa Marius Mihai
Full Text Available Background: We hypothesized that an ideal heart valve replacement would be acellular valve root scaffolds seeded with autologous stem cells. To test this hypothesis, we prepared porcine acellular pulmonary valves, seeded them with autologous adipose derived stem cells (ADSCs and implanted them in sheep and compared them to acellular valves.
van Wachem, Pauline B.; Brouwer, Linda A.; Zeeman, R.; Dijkstra, Pieter J.; Feijen, Jan; Hendriks, Marc; Cahalan, Patrick T.; van Luyn, Marja J.A.
Calcification limits the long-term durability of xenograft glutaraldehyde-crosslinked heart valves. In this study, epoxy-crosslinked porcine aortic valve tissue was evaluated after subcutaneous implantation in weanling rats. Non-crosslinked valves and valves crosslinked with glutaraldehyde or
van Wachem, PB; Brouwer, LA; Zeeman, R; Dijkstra, PJ; Feijen, J; Hendriks, M; Cahalan, PT; van Luyn, MJA
Calcification limits the long-term durability of xenograft glutaraldehyde-crosslinked heart valves. In this study, epoxy-crosslinked porcine aortic valve tissue was evaluated after subcutaneous implantation in weanling rats, Non-crosslinked valves and valves crosslinked with glutaraldehyde or
Louw, J W; Kinsley, R H; Dion, R A; Colsen, P R; Girdwood, R W
The results of 170 emergency heart valve procedures performed during a 4 1/2-year period were analyzed. Five pathological groups of patients were recognized: those with infective endocarditis (Group 1, 28 patients); acute rheumatic carditis (Group 2, 43 patients); previous valve operation (Group 3, 29 patients); acute-on-chronic cardiac disease (Group 4, 67 patients); and miscellaneous conditions (Group 5, 3 patients). Mitral, aortic, and multiple valve procedures were performed on 58, 65, and 44 patients, respectively. The most common functional lesion was regurgitation. Hospital mortality was highest in Groups 3 (34%) and 4 (31%). By contrast, among the hospital survivors, the highest rate of attrition was in Group 2. Myocardial failure was the predominat cause of death. In view of the hopeless prognosis without operation, the 52% overall 3-year actuarial survival is a gratifying salvage. Unnecessary procrastination can only jeopardize the prospects for surgical cure.
Sibilitz, Kirstine L; Berg, Selina K; Tang, Lars H; Risom, Signe S; Gluud, Christian; Lindschou, Jane; Kober, Lars; Hassager, Christian; Taylor, Rod S; Zwisler, Ann-Dorthe
at 3 to 6 months follow-up to judge the effect of exercise-based cardiac rehabilitation compared to no exercise on mortality (RR 4.46 (95% confidence interval (CI) 0.22 to 90.78); participants = 104; studies = 1; quality of evidence: very low) and on serious adverse events (RR 1.15 (95% CI 0.37 to 3.62); participants = 148; studies = 2; quality of evidence: very low). Included trials did not report on health-related quality of life (HRQoL), and the secondary outcomes of New York Heart Association class, left ventricular ejection fraction and cost. We did find that, compared with control (no exercise), exercise-based rehabilitation may increase exercise capacity (SMD -0.47, 95% CI -0.81 to -0.13; participants = 140; studies = 2, quality of evidence: moderate). There was insufficient evidence at 12 months follow-up for the return to work outcome (RR 0.55 (95% CI 0.19 to 1.56); participants = 44; studies = 1; quality of evidence: low). Due to limited information, trial sequential analysis could not be performed as planned. Our findings suggest that exercise-based rehabilitation for adults after heart valve surgery, compared with no exercise, may improve exercise capacity. Due to a lack of evidence, we cannot evaluate the impact on other outcomes. Further high-quality randomised clinical trials are needed in order to assess the impact of exercise-based rehabilitation on patient-relevant outcomes, including mortality and quality of life.
Massel, David R; Little, Stephen H
Patients with prosthetic heart valves are at increased risk for valve thrombosis and arterial thromboembolism. Oral anticoagulation alone, or the addition of antiplatelet drugs, has been used to minimise this risk. An important issue is the effectiveness and safety of the latter strategy. This is an update of our previous review; the goal was to create a valid synthesis of all available, methodologically sound data to further assess the safety and efficacy of combined oral anticoagulant and antiplatelet therapy versus oral anticoagulant monotherapy in patients with prosthetic heart valves. We updated the previous searches from 2003 and 2010 on 16 January 2013 and searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (2012, Issue 12), MEDLINE (OVID, 1946 to January Week 1 2013), and EMBASE (OVID, 1980 to 2013 Week 02). We have also looked at reference lists of individual reports, review articles, meta-analyses, and consensus statements. We included reports published in any language or in abstract form. All reports of randomised controlled trials comparing standard-dose oral anticoagulation to standard-dose oral anticoagulation and antiplatelet therapy in patients with one or more prosthetic heart valves. Two review authors independently performed the search strategy, assessed trials for inclusion and study quality, and extracted data. We collected adverse effects information from the trials. One new study has been identified and included in this update. In total, 13 studies involving 4122 participants were included in this review update. Years of publication ranged from 1971 to 2011. Compared with anticoagulation alone, the addition of an antiplatelet agent reduced the risk of thromboembolic events (odds ratio (OR) 0.43, 95% confidence interval (CI) 0.32 to 0.59; P heart valves. The risk of major bleeding is increased with antiplatelet therapy. These results apply to patients with mechanical prosthetic valves or those with
... health are a good diet and a regular exercise routine. If your doctor has recommended a particular diet, it's important that you follow it. If a special diet has not been recommended, balanced, heart-healthy nutrition can speed healing and lessen fatigue. Weight ...
Schmidt, Dörthe; Stock, Ulrich A; Hoerstrup, Simon P
Heart valve replacement represents the most common surgical therapy for end-stage valvular heart diseases. A major drawback that all contemporary heart valve replacements have in common is the lack of growth, repair and remodelling capability. In order to overcome these limitations, the emerging new field of tissue engineering is focusing on the in vitro generation of functional, living heart valve replacements. The basic approach uses starter matrices either of decellularized xenogeneic or p...
Zhang, Xing; Xu, Bin; Puperi, Daniel S.; Wu, Yan; West, Jennifer L.; Grande-Allen, K. Jane
With an increasing number of patients requiring valve replacement, there is heightened interest in advancing heart valve tissue engineering (HVTE) to provide solutions to the many limitations of current surgical treatments. A variety of materials have been developed as scaffolds for HVTE including natural polymers, synthetic polymers, and decellularized valvular matrices. Among them, biocompatible hydrogels are generating growing interest. Natural hydrogels, such as collagen and fibrin, generally show good bioactivity, but poor mechanical durability. Synthetic hydrogels, on the other hand, have tunable mechanical properties; however, appropriate cell-matrix interactions are difficult to obtain. Moreover, hydrogels can be used as cell carriers when the cellular component is seeded into the polymer meshes or decellularized valve scaffolds. In this review, we discuss current research strategies for HVTE with an emphasis on hydrogel applications. The physicochemical properties and fabrication methods of these hydrogels, as well as their mechanical properties and bioactivities are described. Performance of some hydrogels including in vitro evaluation using bioreactors and in vivo tests in different animal models are also discussed. For future HVTE, it will be compelling to examine how hydrogels can be constructed from composite materials to replicate mechanical properties and mimic biological functions of the native heart valve. PMID:25955010
Suri, Rakesh M; Thalji, Nassir M
Cardiac surgical procedures via traditional sternotomy are safe and effective operations performed by cardiothoracic surgeons worldwide. However, postoperative limitations in upper extremity activity during bone healing are seen as undesirable by some. Percutaneous catheter-based attempts to emulate the outcomes of traditional cardiac surgical procedures have largely fallen short of established standards of efficacy and durability. The field of minimally invasive heart valve surgery thus developed out of a need to offer smaller, better-tolerated incisions to patients while maintaining high-quality clinical outcomes. These operations are safe and effective when performed by proficient surgical teams, allowing patients to resume normal activities more rapidly. We explore current evidence supporting the practice of minimally invasive heart valve surgery in 2012 and analyze the clinical impact of these nascent surgical platforms.
Forsberg, Peter; DeSancho, Maria T
The introduction of the target-specific oral anticoagulants (TSOACs) has led to a major shift in the management of patients at risk for thrombosis. The landscape continues to evolve as the evidence regarding their efficacy and safety in various clinical situations emerges. Antithrombotic therapy for thromboprophylaxis in patients with mechanical heart valves is challenging. To date, the RE-ALIGN trial comparing dabigatran etexilate to warfarin is the only randomized controlled study in this patient population. The higher risk of thromboembolic and bleeding events in the group of patients who received dabigatran compared with warfarin reinforced current guidelines recommending against the use of TSOACs in patients with mechanical heart valves. However, additional studies are needed to find suitable alternatives to vitamin K antagonists in this unique patient population.
Vignesh Vellayappan, Muthu; Balaji, Arunpandian; Priyadarshini Subramanian, Aruna; Aruna John, Agnes; Jaganathan, Saravana Kumar; Murugesan, Selvakumar; Mohandas, Hemanth; Supriyanto, Eko; Yusof, Mustafa
Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases.
Li, Weidong; Zheng, Junnan; Zhao, Hengchi; Xu, Hongfei; Ni, Yiming
Abstract Background: Cardiac papillary fibroelastomas are rare. And only 15% of the papillary fibroelastomas are located on tricuspid valve. However, the treatment of papillary fibroelastomas varies. Case summary: We report a 75-year-old Chinese male who was hospitalized because of a right atrial mass found by echocardiography. Complete tumor excision along with Kay's tricuspid valvuloplasty surgery on beating heart under cardiopulmonary bypass was performed to the patient. Pathologic examina...
Juaneda, Ignacio; Rychik, Jack; Fuller, Stephanie; Weinberg, Paul M; Rome, Jonathan J; Mahle, William T; Gaynor, J William
We describe management of a patient with a prenatal diagnosis of absent pulmonary valve, tricuspid atresia, ventricular septal defect, and congenital heart block. Initial treatment consisted of temporary pacemaker implantation, and subsequent palliation included a central shunt during the neonatal period and placement of a permanent pacemaker. At seven months of age, a bidirectional Glenn anastomosis was performed. Cardiac catheterization revealed high cavopulmonary pressures and ventricular dysfunction precluding Fontan completion. Heart transplantation was performed at 3.75 years of age. The patient is alive and well 26 months posttransplantation. © The Author(s) 2014.
Hedayat, Mohammadali; Borazjani, Iman
Platelet activation is one of the major drawbacks of the Mechanical Heart Valves (MHVs) which can increase the risk of thrombus formation in patients. The platelet activation in MHVs can be due to the abnormal shear stress during the systole, the backward leakage flow during the diastole, and the flow through the hinge region. We investigate the contribution of each of the above mechanism to the activation of platelets in MHVs by performing simulations of the flow through the MHV and in the hinge region. The large scale heart valve simulations are performed in a straight aorta using a sharp interface curvilinear immersed boundary method along with a strong-coupling algorithm under physiological flow conditions. In addition, in order to perform the simulation of hinge region the flow field boundary conditions are obtained from the largescale simulations during a whole cardiac cycle. In order to investigate the role of hinge flow on platelet activation in MHVs, a 23mm St. Jude Medical Regent valve hinge with three different gap sizes is tested along with different platelet activation models to ensure the consistency of our results with different activation models. We compare the platelet activation of the hinge region against the bulk of the flow during one cardiac cycle. This work is supported by the American Heart Association Grant 13SDG17220022, and the computational resources were partly provided by Center for Computational Research (CCR) at University at Buffalo.
Dohmen, P M
Since the first heterotopic implantation of a biological heart valve in 1955 by Murray, bioprostheses have been steadily improved. For allografts different methods have been evaluated and modified to stabilize and preserve the available tissue. Xenografts were fixed to cross-link the connective tissue as well as prevent immunogenic reactions. Nevertheless, gluteraldehyde fixation leads to structural deterioration, which could only be partially reduced by different kinds of anti-mineralization treatment. Due to preservation and fixation, allografts and xenografts become non-viable bioprostheses with a lack of remodelling, regeneration and growth. Tissue engineering is a possible key to overcome these disadvantages as it will provide living tissue with remodelling, regeneration and growth potential. This overview will look at the key points to provide such tissue engineered heart valves by creating an appropriate scaffold where cells can grow, either in vitro or in vivo and remodel a neo-scaffold which will lead to a functional autologous heart valve, and show initial clinical results.
Full Text Available Introduction: In patients who underwent surgery to repair Tetralogy of Fallot, right ventricular dilation from pulmonary regurgitation may be result in right ventricular failure, arrhythmias and cardiac arrest. Hence, pulmonary valve replacement may be necessary to reduce right ventricular volume overload. The aim of present study was to assess the effects of pulmonary valve replacement on right ventricular function after repair of Tetralogy of Fallot. Materials and Method: This retrospective study was carried out between July 2011 and October 2013 on 21 consecutive patients in Chamran Heart Center (Esfahan. The study included 13 male (61.9% and 8 female (38.1%. Cardiac magnetic resonance was performed before, 6 and 12 months after pulmonary valve replacement in all patients (Babak Imaging Center, Tehran with the 1.5 Tesla system. The main reason for surgery at Tetralogy of Fallot repaired time was Tetralogy of Fallot + Pulmonary insufficiency (17 cases and Tetralogy of Fallot + Pulmonary atresia (4 cases. Right ventricular function was assessed before and after pulmonary valve replacement with Two-dimensional echocardiography and ttest was used to evaluate follow-up data. Results: Right ventricular end-diastolic volume, right ventricular end- systolic volume significantly decreased (P value ˂ 0.05.Right ventricular ejection fraction had a significant increase (P value ˂ 0.05. Right ventricular mass substantially shrank after pulmonary valve replacement. Moreover, pulmonary regurgitation noticeably decreased in patients. The other hemodynamic parameter such as left ventricular ejection fraction improved but was not significant (P value= 0.79. Conclusion: Pulmonary valve replacement can successfully restores the impaired hemodynamic function of right ventricle which is caused by direct consequence of volume unloading in patient. Pulmonary valve surgery in children with Tetralogy of Fallot who have moderate to severe pulmonary
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University...... of Copenhagen, Frederiksberg, Denmark. 2. Novo Nordic A/S, Maaloev, Denmark. 3. Department of Clinical Sciences, Swedish University of Agricultural Science, Uppsala, Sweden. Heart rate variability (HRV) is an indirect measurement of the autonomic modulation of heart rate (HR). Reduced HRV measured from short......-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS...
K. Yu. Klyshnikov
Full Text Available The aim of the study was to perform a series of in vitro tests of a prototype of the developing heart valve prosthesis to evaluate its functional characteristics. Materials and methods. In this work we have used the frames and full prototypes of the prosthesis, consisting of a stent-like stainless steel support frame with mounted biological leaflets and cover. The authors evaluated the calculated and experimental forces necessary for the displacement of the sutureless implanted prosthesis using the test machine under uniaxial tension. The risk of defects and damages to the supporting framework as a result of implantation was evaluated by scanning electron microscopy. The hydrodynamic characteristics of the prosthesis were investigated under physiological conditions and «valvein-valve» implantation. Evaluation of the ergonomics and applicability of the proposed construction on the cadaver heart model of cattle was carried out. Results. As a result of the forces assessment, it was found that the force required to shear the prosthesis was 3.12 ± 0.37 N, while the calculated value was 1.7 N, which is significantly lower than the obtained value. The comparison of the images obtained with small and large magnifications demonstrated the absence of critical surface defects. Additional analysis under the super-large magnifications also did not reveal problem areas. During the hydrodynamic study, it was shown that the average transplant gradient increased slightly from 2.8–3.4 to 3.2–4.5 mm Hg for the initial prosthesis and the «valve-in-valve» complex, respectively. The decrease of the effective orifice area was 6–9% relative to the initial one. Evaluation of the implantation technique demonstrated the consistency of the approach: the use of the developed holder in combination with the balloon implantation system made it possible to position the prosthesis throughout the procedure. Conclusion. The series of tests demonstrates the consistency
Habets, Jesse; van den Brink, Renee B. A.; Uijlings, Ruben; Spijkerboer, Anje M.; Mali, Willem P. Th. M.; Chamuleau, Steven A. J.; Budde, Ricardo P. J.
Objectives Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. Methods ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artef...
Hasegawa, Jun; Kobayashi, Kenji
A new in vitro experimental tool was developed to study the mechanism of the ultrasonic closing clicks' genesis of mechanical heart valves. Since the newly developed tester adopted compressed air flow directly instead of the blood analog fluid to drive the mechanical heart valve, it is not possibe to generate any cavitation. Closing clicks were measured with a small accelerometer at the surface of the valve holder made of silicone rubber. Ultrasonic closing clicks as well as audible closing clicks, similar to those measured clinically, could be observed using this setup. Thus, it was confirmed that the ultrasonic closing clicks can be generated without the existence of cavitation. Simultaneous measurements of the valve motion were made with a high-speed video camera, and the analysis of the video frames and clicks showed that higher frequency signal components of more than 50kHz could be generated only at the instant of the closure, which means the collision of the occluder with the housing. Eighteen miniature accelerometers with an area of one square millimeter were developed and stuck on the housing to monitor the distribution of the housing vibrations in detail, and it was found that the vibrations correspond to the ultrasonic closing clicks propagated from the valve stop: the collision point of the occluder with the housing. This fact indicated that the generation of ultrasonic closing clicks are limited to the small area of the collision. From those results, it was concluded that the major origin of the ultrasonic closing clicks' genesis should be the collision of the occluder with the housing.
Helder, Meghana R K; Ugur, Murat; Bavaria, Joseph E; Kshettry, Vibhu R; Groh, Mark A; Petracek, Michael R; Jones, Kent W; Suri, Rakesh M; Schaff, Hartzell V
The study objective was to analyze factors associated with left ventricular mass regression in patients undergoing aortic valve replacement with a newer bioprosthesis, the Trifecta valve pericardial bioprosthesis (St Jude Medical Inc, St Paul, Minn). A total of 444 patients underwent aortic valve replacement with the Trifecta bioprosthesis from 2007 to 2009 at 6 US institutions. The clinical and echocardiographic data of 200 of these patients who had left ventricular hypertrophy and follow-up studies 1 year postoperatively were reviewed and compared to analyze factors affecting left ventricular mass regression. Mean (standard deviation) age of the 200 study patients was 73 (9) years, 66% were men, and 92% had pure or predominant aortic valve stenosis. Complete left ventricular mass regression was observed in 102 patients (51%) by 1 year postoperatively. In univariate analysis, male sex, implantation of larger valves, larger left ventricular end-diastolic volume, and beta-blocker or calcium-channel blocker treatment at dismissal were significantly associated with complete mass regression. In the multivariate model, odds ratios (95% confidence intervals) indicated that male sex (3.38 [1.39-8.26]) and beta-blocker or calcium-channel blocker treatment at dismissal (3.41 [1.40-8.34]) were associated with increased probability of complete left ventricular mass regression. Patients with higher preoperative systolic blood pressure were less likely to have complete left ventricular mass regression (0.98 [0.97-0.99]). Among patients with left ventricular hypertrophy, postoperative treatment with beta-blockers or calcium-channel blockers may enhance mass regression. This highlights the need for close medical follow-up after operation. Labeled valve size was not predictive of left ventricular mass regression. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Lee, Whayoung; Long, Cassandra; Ramsoondar, Jagdeece; Ayares, David; Cooper, David K C; Manji, Rizwan A; Hara, Hidetaka
Glutaraldehyde-fixed bioprosthetic heart valves (GBHVs) derived from wild-type (WT, genetically unmodified) pigs are widely used clinically for heart valve replacement. There is evidence that their failure is related to an immune response. The use of valves from genetically engineered pigs that do not express specific pig antigens may prolong GBHV survival. Our aims were to determine (i) expression of Gal and NeuGc on heart (aortic and pulmonary) valves and pericardium of WT, α1,3-galactosyltransferase gene knockout (GTKO) and GTKO/N-glycolylneuraminic acid gene-knockout (GTKO/NeuGcKO) pigs in comparison with three different commercially available GBHVs and (ii) to determine human antibody binding to these tissues. Wild-type, GTKO/CD46, and GTKO/CD46/NeuGcKO pig valves and pericardium were tested (i) fresh and (ii) after fixation with glutaraldehyde (0.02%, 0.2%, 2%). Sections of GBHVs, fresh and fixed valves, and pericardium were stained for Gal and NeuGc expression, and for human IgM and IgG antibody binding. Gal and NeuGc expression was high on all GBHVs and WT pig valves/pericardium, but was absent after antigen-specific-knockout. There was no difference in antigen expression or antibody binding among WT aortic, pulmonary valves, and pericardium as well as GBHVs. Glutaraldehyde fixation did not alter expression of Gal or NeuGc. After incubation with human serum, human IgM and IgG bound to all GBHVs and WT pig valves/pericardium. Valves from GTKO/CD46 pigs and, particularly, GTKO/CD46/NeuGcKO pigs (with/without glutaraldehyde fixation) showed less IgM and IgG binding. Compared to WT pigs, GTKO/CD46/NeuGcKO pigs would be preferable sources of GBHVs, because the absence of Gal/NeuGc expression reduces human antibody binding. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Hillebrand, Julia; Hoffmeier, Andreas; Djie Tiong Tjan, Tonny; Sindermann, Juergen R; Schmidt, Christoph; Martens, Sven; Scherer, Mirela
Left ventricular assist device (LVAD) implantation is a well-established therapy to support patients with end-stage heart failure. However, the operative procedure is associated with severe trauma. Third generation LVADs like the HeartWare assist device (HeartWare, Inc., Framingham, MA, USA) are characterized by enhanced technology despite smaller size. These devices offer new minimally invasive surgical options. Tricuspid regurgitation requiring valve repair is frequent in patients with the need for mechanical circulatory support as it is strongly associated with ischemic and nonischemic cardiomyopathy. We report on HeartWare LVAD implantation and simultaneous tricuspid valve reconstruction through minimally invasive access by partial upper sternotomy to the fifth left intercostal space. Four male patients (mean age 51.72 ± 11.95 years) suffering from chronic heart failure due to dilative (three patients) and ischemic (one patient) cardiomyopathy and also exhibiting concomitant tricuspid valve insufficiency due to annular dilation underwent VAD implantation and tricuspid valve annuloplasty. Extracorporeal circulation was established via the ascending aorta, superior vena cava, and right atrium. In all four cases the LVAD implantation and tricuspid valve repair via partial median sternotomy was successful. During the operative procedure, no conversion to full sternotomy was necessary. One patient needed postoperative re-exploration because of pericardial effusion. No postoperative focal neurologic injury was observed. New generation VADs are advantageous because of the possibility of minimally invasive implantation procedure which can therefore minimize surgical trauma. Concomitant tricuspid valve reconstruction can also be performed simultaneously through partial upper sternotomy. Nevertheless, minimally invasive LVAD implantation is a challenging operative technique. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals
Full Text Available Research on prosthesis to replace diseased heart valves began almost simultaneously with mechanical valves which aredurable but with inherent thromboembolic complication requiring life-long anticoagulant therapy and tissue valves whichare more prone to structural failure but free from thromboembolic complication. Tissue valves are more useful in females ofreproductive age desiring a child, male patients older than 60 years of age and female patients over 55 years of age, patientshaving chronic liver disease, history of stroke, bleeding disorder and in presence of infective endocarditis. Gluteraldehydefixation at low pressure with removal of maximal amount of phospholipid have increased the durability of tissue valves inrecent years. Considering the better quality of life with tissue valve the trend is shifting towards using it more frequentlyaround the world. Recently two heart valve replacement operations using bovine perimount pericardial valve were done inthe department of cardiac surgery, BSMMU, one in aortic position another in mitral position, both in females of reproductiveage desiring children.The operations were technically demanding but the outcomes were uneventful. Tissue heart valvereplacement is a safe procedure and can be useful in female of child bearing age desiring children.Key Words: Tissue heart valve replacement; Aortic valve; Mitral valve; Bioprosthetic heart valves; Bovine perimountpericardial valve.DOI: 10.3329/bsmmuj.v3i1.5511BSMMU J 2010; 3(1: 27-30
Deklunder, Ghislaine; Lecroart, Jean-Louis; Conger, Jeff L.; Lapeyre, Didier; Gregoric, Igor; Rose, Harris; Tamez, Daniel; Frazier, O. H.
Microemboli caused by mechanical heart valves have the potential to cause cerebrovascular events. We investigated the effects of myocardial contractility and heart rate on microemboli production in association with conventional and experimental mechanical heart valves implanted in the mitral position in a bovine model.
Sewell-Loftin, M.K.; Chun, Young Wook; Khademhosseini, Ali; Merryman, W. David
Although artificial prostheses for diseased heart valves have been around for several decades, viable heart valve replacements have yet to be developed due to their complicated nature. The majority of research in heart valve replacement technology seeks to improve decellularization techniques for porcine valves or bovine pericardium as an effort to improve current clinically used valves. The drawback of clinically used valves is that they are nonviable and thus do not grow or remodel once implanted inside patients. This is particularly detrimental for pediatric patients, who will likely need several reoperations over the course of their lifetimes to implant larger valves as the patient grows. Due to this limitation, additional biomaterials, both synthetic and natural in origin, are also being investigated as novel scaffolds for tissue engineered heart valves, specifically for the pediatric population. Here, we provide a brief overview of valves in clinical use as well as of the materials being investigated as novel tissue engineered heart valve scaffolds. Additionally, we focus on natural-based biomaterials for promoting cell behavior that is indicative of the developmental biology process that occurs in the formation of heart valves in utero, such as epithelial-to-mesenchymal transition or transformation (EMT). By engineering materials that promote native developmental biology cues and signaling, while also providing mechanical integrity once implanted, a viable tissue engineered heart valve may one day be realized. A viable tissue engineered heart valve, capable of growing and remodeling actively inside a patient, could reduce risks and complications associated with current valve replacement options and improve overall quality of life in the thousands of patients who received such valves each year, particularly for children. PMID:21751069
Sewell-Loftin, M K; Chun, Young Wook; Khademhosseini, Ali; Merryman, W David
Although artificial prostheses for diseased heart valves have been around for several decades, viable heart valve replacements have yet to be developed due to their complicated nature. The majority of research in heart valve replacement technology seeks to improve decellularization techniques for porcine valves or bovine pericardium as an effort to improve current clinically used valves. The drawback of clinically used valves is that they are nonviable and thus do not grow or remodel once implanted inside patients. This is particularly detrimental for pediatric patients, who will likely need several reoperations over the course of their lifetimes to implant larger valves as the patient grows. Due to this limitation, additional biomaterials, both synthetic and natural in origin, are also being investigated as novel scaffolds for tissue-engineered heart valves, specifically for the pediatric population. Here, we provide a brief overview of valves in clinical use as well as of the materials being investigated as novel tissue-engineered heart valve scaffolds. Additionally, we focus on natural-based biomaterials for promoting cell behavior that is indicative of the developmental biology process that occurs in the formation of heart valves in utero, such as epithelial-to-mesenchymal transition or transformation. By engineering materials that promote native developmental biology cues and signaling, while also providing mechanical integrity once implanted, a viable tissue-engineered heart valve may one day be realized. A viable tissue-engineered heart valve, capable of growing and remodeling actively inside a patient, could reduce risks and complications associated with current valve replacement options and improve overall quality of life in the thousands of patients who received such valves each year, particularly for children.
Syedain, Zeeshan H; Tranquillo, Robert T
A tissue-engineered heart valve (TEHV) represents the ultimate valve replacement, especially for juvenile patients given its growth potential. To date, most TEHV bioreactors have been developed based on pulsed flow of culture medium through the valve lumen to induce strain in the leaflets. Using a strategy for controlled cyclic stretching of tubular constructs reported previously, we developed a controlled cyclic stretch bioreactor for TEHVs that leads to improved tensile and compositional properties. The TEHV is mounted inside a latex tube, which is then cyclically pressurized with culture medium. The root and leaflets stretch commensurately with the latex, the stretching being dictated by the stiffer latex and thus controllable. Medium is also perfused through the lumen at a slow rate in a flow loop to provide nutrient delivery. Fibrin-based TEHVs prepared with human dermal fibroblasts were subjected to three weeks of cyclic stretching with incrementally increasing strain amplitude. The TEHV possessed the tensile stiffness and stiffness anisotropy of leaflets from sheep pulmonary valves and could withstand cyclic pulmonary pressures with similar distension as for a sheep pulmonary artery.
Sibilitz, Kirstine L; Berg, Selina K; Tang, Lars H; Risom, Signe S; Gluud, Christian; Lindschou, Jane; Kober, Lars; Hassager, Christian; Taylor, Rod S; Zwisler, Ann-Dorthe
BACKGROUND: Exercise-based cardiac rehabilitation may benefit heart valve surgery patients. We conducted a systematic review to assess the evidence for the use of exercise-based intervention programmes following heart valve surgery.OBJECTIVES: To assess the benefits and harms of exercise-based cardiac rehabilitation compared with no exercise training intervention, or treatment as usual, in adults following heart valve surgery. We considered programmes including exercise training with or witho...
Shafique, H.; Chaudhry, A.; Ayyub, M.
To evaluate the complications and outcome of anticoagulation therapy in pregnant females with valvular heart diseases. All pregnant females with prosthetic heart valves admitted in Armed Forces Institute of Cardiology from Jan 2004 to Dec 2004 were included in this study Basic demographic data including age, duration of pregnancy and complications observed were recorded. Warfarin was replaced with un-fractionated heparin (UFH) in first trimester and after that warfarin was continued with a targeted INR between 2.0-3.0. At 36 weeks warfarin was stopped and UFH was added; however, if patient went into spontaneous labour before this then immediate caesarian section was performed and UFH was restarted 4-6 hours after delivery along with oral warfarin. Out of 21 patients, sixteen (76.1%) had mitral valve diseases and five (23.9%) had both mitral and atrial. Majority (42.3%)of patients were in age group 26-30 years. Eleven (52.2%) reported in 9th month of gestation. Complications observed were hypertension (1), transient ischaemic attacks (1), pulmonary embolism (1), haemoptysis (1) and abortion (1). All patients, except one had successful completion of pregnancy. No case of foetal abnormality was seen. In 76% patients, daily dose of warfarin was <5 mg. Thrombo-prophylaxis in pregnancy with warfarin and UFH with an INR of 2.0-3.0 is effective in preventing thrombotic complications in females with mechanical valves without resulting in increase hemorrhagic complications. (author)
Szymanski, Catherine; Andréjak, Michel; Peltier, Marcel; Maréchaux, Sylvestre; Tribouilloy, Christophe
Benfluorex is responsible for the development of restrictive valvular regurgitation due to one of its metabolites, norfenfluramine. The 5-HT2B receptor, expressed on heart valves, acts as culprit receptor for drug-induced valvular heart disease (VHD). Stimulation of this receptor leads to the upregulation of target genes involved in the proliferation and stimulation of valvular interstitial cells through different intracellular pathways. Valve lesions essentially involve the mitral and/or aortic valves. The randomised prospective REGULATE trial shows a threefold increase in the incidence of valvular regurgitation in patients exposed to benfluorex. A cross-sectional trial shows that about 7% of patients without a history of VHD previously exposed to benfluorex present echocardiographic features of drug-induced VHD. The excess risks of hospitalisation for cardiac valvular insufficiency and of valvular replacement surgery were respectively estimated to 0.5 per 1000 and 0.2 per 1000 exposed patients per year. Recent data strongly suggest an aetiological link between benfluorex exposure and pulmonary arterial hypertension (PAH). The PAH development may be explained by serotonin, which creates a pulmonary vasoconstriction through potassium-channel blockade. Further studies should be conducted to determine the subsequent course of benfluorex-induced VHD and PAH, and to identify genetic, biological and clinical factors that determine individual susceptibility to developing such adverse effects. Copyright © 2014 John Wiley & Sons, Ltd.
Askov, Jesper B; Honge, Jesper L; Jensen, Morten O; Nygaard, Hans; Hasenkam, J Michael; Nielsen, Sten L
The objective of this study was to assess the combined force transfer from the papillary muscle tips to the mitral valve through the chordae tendineae in vivo, and thereby quantify the force transmitted through the papillary-chordal complex to augment left ventricular ejection. In an acute porcine model (n = 8), force transfer between papillary muscles and the mitral valve was recorded on the anterior and posterior papillary muscle tip using dedicated force transducers. Ultrasound sonomicrometry was utilized to record and calculate left ventricular long-axis shortening and mitral annular geometry. The closing force acting on the mitral valve leaflets was calculated as mitral annular area multiplied by the transmitral pressure difference throughout systole. Mitral valve competence was verified before measurements with color Doppler ultrasound. Peak force in the anterior and posterior papillary muscle was 5.9 ± 0.6 N and 5.8 ± 0.7 N (mean ± standard error of the mean), respectively, and peak closing force was 6.8 ± 0.3 N all at a transmitral pressure of 90 mm Hg. Peak rate of left ventricular contraction coincided with peak papillary muscle force. This study is the first to assess the magnitude and time course of the longitudinal force transmitted through the papillary-chordal complex to the left ventricular wall during ejection. The study also demonstrates a significant force transfer to the closing force acting on the mitral valve leaflets that constitutes an essential component of valvular-ventricular interaction to enhance left ventricular systolic pump performance. The magnitude of the combined papillary muscle force component emphasizes the crucial role of preserving mitral valve-left ventricular continuity in mitral valve surgery. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
Valdes Martin, Alexander
The case of a 26 year-old patient with diagnosis of heart failure and presence of a mobile echogenic mass without calcification attached to the posterolateral area of the left atrium was reported. She underwent surgery and tissue examination evidenced a high-grade heart leiomyosarcoma. Postoperative course was satisfactory and her clinical state was rigorously monitored by oncology and heart specialists in the institution
Dahl, Jordi S; Videbæk, Lars; Poulsen, Mikael K
One of the hemodynamic consequences of aortic valve stenosis is pressure overload leading to left atrial dilatation. Left atrial size is a known risk factor providing prognostic information in several cardiac conditions. It is not known if this is also the case in patients with aortic valve...
Bezuidenhout, Deon; Williams, David F; Zilla, Peter
Efficient function and long-term durability without the need for anticoagulation, coupled with the ability to be accommodated in many different types of patient, are the principal requirements of replacement heart valves. Although the clinical use of valves appeared to have remained steady for several decades, the evolving demands for the elderly and frail patients typically encountered in the developed world, and the needs of much younger and poorer rheumatic heart disease patients in the developing world have now necessitated new paradigms for heart valve technologies and associated materials. This includes further consideration of durable elastomeric materials. The use of polymers to produce flexible leaflet valves that have the benefits of current commercial bioprosthetic and mechanical valves without any of their deficiencies has been held desirable since the mid 1950s. Much attention has been focused on thermoplastic polyurethanes in view of their generally good physico-chemical properties and versatility in processing, coupled with the improving biocompatibility and stability of recent formulations. Accelerated in vitro durability of between 600 and 1000 million cycles has been achieved using polycarbonate urethanes, and good resistance to degradation, calcification and thrombosis in vivo has been shown with some polysiloxane-based polyurethanes. Nevertheless, polymeric valves have remained relegated to use in temporary ventricular assist devices for bridging heart failure patients to transplantation. Some recent studies suggest that there is a greater degree of instability in thermoplastic materials than hitherto believed so that significant challenges remain in the search for the combination of durability and biocompatibility that would allow polymeric valves to become a clinical reality for surgical implantation. Perhaps more importantly, they could become candidates for use in situations where minimally invasive transcatheter procedures are used to
Habets, Jesse; Symersky, Petr; van Herwerden, Lex A.; de Mol, Bas A. J. M.; Spijkerboer, Anje M.; Mali, Willem P. Th M.; Budde, Ricardo P. J.
Multidetector CT (MDCT) has shown potential for prosthetic heart valve (PHV) assessment. We assessed the image quality of different PHV types to determine which valves are suitable for MDCT evaluation. All ECG-gated CTs performed in our institutions since 2003 were reviewed for the presence of PHVs.
Falk, Bo Torkel; Jönsson, Lennart; Olsen, Lisbeth Høier
Background: The occurrence of small vessel arteriosclerosis in the myocardium, kidney, and lung in dogs with naturally occurring myxomatous mitral valve disease has not been previously investigated systematically. Methods: Twenty-one dogs with naturally occurring congestive heart failure and 21 age...... and pulmonary artery. Results: Dogs with congestive heart failure had significantly more arterial narrowing in the left ventricle (Pdogs. However......, they did not have more plaque formation or intimal-medial thickening in the aorta than controls. There was significantly more arterial narrowing in papillary muscles than in all other locations in dogs with congestive heart failure (Pdogs, arterial changes were less pronounced and did...
Yaghoubi, A.R.; Raeesi, K.
Assessment of surgical pathology of excised heart valves in a referral hospital in Iran in a five years period. This retrospective descriptive study was done from 2002 to 2005 in Rajaie heart center in Tehran, Iran. Surgery and pathology records of patients who underwent valve replacement or repair surgery were reviewed. Of 1563 patients 738 (47.2%) underwent mitral, 565 (36.1%) aortic, and 215 (14%) multivalve operation. Most common pathology of mitral valve was rheumatic (68%), while degenerative calcific pathology was dominant in aortic valve (52%). Rheumatic involvement was 46%, and degenerative pathology was common in tricuspid and pulmonary valves (50% and 67%, respectively). Time trend analysis shows no significant variation in excised valves pathology or pattern from 2002 to 2005 (p=0.112). Rheumatic pathology in excised heart valves is still common in this referral heart center in Iran, and no obvious change in this pattern was found during a 5 years period. (author)
Madias, John E
A case is presented revealing the common phenomenon of heart rate-dependent diagnosis of electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH), which consists of satisfaction of LVH criteria only at faster rates whereas ECGs with a slow heart rate do not satisfy such criteria. The mechanism of the phenomenon has been attributed to the tachycardia-mediated underfilling of the left ventricle bringing the electrical "centroid" of the heart closer to the recording electrodes, which results in augmentation of the amplitude of QRS complexes, particularly in leads V2-V4. ©2012, The Author. Journal compilation ©2012 Wiley Periodicals, Inc.
Full Text Available Using the electrospinning process the geometry of a heart valve is not replicable by just one manufacturing process. To produce heart valve scaffolds the heart valve leaflets and the vessel have to be produced in separated spinning processes. For the final product of a heart valve they have to be mated afterwards. In this work an already existing three-axes laser was enhanced to laser weld those scaffolds. The automation control software is based on the robot operating system (ROS. The mechatronically control is done by an Arduino Mega. A graphical user interface (GUI is written with Python and Kivy.
Lieber, Samuel C; Kruithof, Boudewijn P T; Aubry, Nadine; Vatner, Stephen F; Gaussin, Vinciane
Valvular heart disease is a leading cause of morbidity and mortality in adults but little is known about the underlying etiology. A better understanding of the genetic and hemodynamic mechanisms involved in growth and remodeling of heart valves during physiological and pathological conditions is needed for a better understanding of valvular heart disease. Here, we report the design of a miniature tissue culture system (MTCS) that allows the culture of mitral valves from perinatal to adult mice. The design of the MTCS is novel in that fine positioning and cannulation can be conducted with hearts of different sizes (perinatal to adult). Perfusion of the heart and hence, culture of the mitral valve in its natural position, occurs in a hydraulically sealed culture bath environment. Using the MTCS, we successfully cultured the mitral valve of adult mouse hearts for 3 days. Histological analysis indicated that the cultured valves remained viable and their extracellular matrix organization was similar to age-matched native valves. Gene expression could also be modified in cultured valves by perfusion with medium containing beta-galactosidase-expressing adenovirus. Thus, the MTCS is a new tool to study the genetic and hemodynamic mechanisms underlying the three-dimensional organization of the heart valves, which could provide insights in the pathology of valvular heart disease and be used in animal models for the development of tissue-engineered heart valves.
Loerakker, S; Argento, G; Oomens, C W J; Baaijens, F P T
Tissue engineering represents a promising technique to overcome the limitations of the current valve replacements, since it allows for creating living autologous heart valves that have the potential to grow and remodel. However, also this approach still faces a number of challenges. One particular problem is regurgitation, caused by cell-mediated tissue retraction or the mismatch in geometrical and material properties between tissue-engineered heart valves (TEHVs) and their native counterparts. The goal of the present study was to assess the influence of valve geometry and tissue anisotropy on the deformation profile and closed configuration of TEHVs. To achieve this aim, a range of finite element models incorporating different valve shapes was developed, and the constitutive behavior of the tissue was modeled using an established computational framework, where the degree of anisotropy was varied between values representative of TEHVs and native valves. The results of this study suggest that valve geometry and tissue anisotropy are both important to maximize the radial strains and thereby the coaptation area. Additionally, the minimum degree of anisotropy that is required to obtain positive radial strains was shown to depend on the valve shape and the pressure to which the valves are exposed. Exposure to pulmonary diastolic pressure only yielded positive radial strains if the anisotropy was comparable to the native situation, whereas considerably less anisotropy was required if the valves were exposed to aortic diastolic pressure. Copyright © 2013 Elsevier Ltd. All rights reserved.
Kaasi, Andreas; Cestari, Idágene A.; Stolf, Noedir A G.
the cell-scaffold constructs to a wider array of mechanical forces. The pump of the VAD has two chambers: a blood and a pneumatic chamber, separated by an elastic membrane. Pulsatile air-pressure is generated by a piston-type actuator and delivered to the pneumatic chamber, ejecting the fluid in the blood...... chamber. Subsequently, applied vacuum to the pneumatic chamber causes the blood chamber to fill. A mechanical heart valve was placed in the VAD's inflow position. The tissue engineered (TE) valve was placed in the outflow position. The VAD was coupled in series with a Windkessel compliance chamber......, variable throttle and reservoir, connected by silicone tubings. The reservoir sat on an elevated platform, allowing adjustment of ventricular preload between 0 and 11 mmHg. To allow for sterile gaseous exchange between the circuit interior and exterior, a 0.2 µm filter was placed at the reservoir. Pressure...
Apte, Sameer S; Paul, Arghya; Prakash, Satya; Shum-Tim, Dominique
The use of tissue-engineering methods to create autologous heart valve constructs has the potential to overcome the fundamental drawbacks of more traditional valve prostheses. Traditional mechanical valves, while durable, increase the risk for endocarditis and thrombogenesis, and require the recipient to continue lifelong anticoagulant therapy. Homograft or xenograft heart valve prostheses are associated with immune reaction and progressive deterioration with limited durability. Most importantly, neither option is capable of growth and remodeling in vivo and both options place the patient at risk for valve-related complications and reoperation. These shortcomings have prompted the application of tissue-engineering techniques to create fully autologous heart valve replacements. Future clinically efficacious tissue-engineered autologous valves should be nonthrombogenic, biocompatible, capable of growth and remodeling in vivo, implantable with current surgical techniques, hemodynamically perfect, durable for the patient's life and most importantly, significantly improve quality of life for the patient. In order to meet these expectations, the nature of the ideal biochemical milieu for conditioning an autologous heart valve will need to be elucidated. In addition, standardized criteria by which to quantitatively evaluate a tissue-engineered heart valve, as well as noninvasive analytical techniques for use in long-term animal models, will be required. This article highlights the advances, challenges and future clinical prospects in the field of tissue engineering of autologous heart valves, focusing on progress made by studies that have investigated a fully autologous, tissue-engineered pulmonary valve replacement in vivo.
Kostrzewa, Benita; Rybak, Zbigniew
Artificial heart valves can be classified into mechanical and biological. We have three types of mechanical heart valves: caged ball, tilting disc and bileaflet. Mechanical heart valves are made from various materials. They may be produced from metals, ceramics and polymers, e.g.: stainless steel, titanium, silicone, pyrolytic carbon. Biological valves are made from synthetic components (e.g.: PTFE, Dacron) and materials of biological origin (e.g.: cow pericardium, pig heart valve). We have also identified transcatheter aortic valve implantation (TAVI). TAVI may be produced from metals, ceramics and polymers (e.g.: stainless steel, titanium, Dacron) and biological material (e.g.: pig heart valve). This paper describes advantages and disadvantages of different types of artificial heart valves. The lifespan of mechanical valves is 20-30 years and they can be used for patients of any age. Mechanical valves have also disadvantages--anticoagulants are required to prevent thrombosis. Biological valves are made from natural materials, so they do not require prolonged anticoagulation. Their lifetime is 10-15 years, so they are offered to patients over 40 years. Another problem is the occurrence of calcification.
Aydin, Ebuzer; Arslan, Akin; Ozkokeli, Mehmet
Objective: In this study, we aimed to compare clinical outcomes of superior transseptal approach with the conventional left atriotomy in patients undergoing mitral valve surgery. Methods: Between January 2010 and November 2012, a total of 91 consecutive adult patients (39 males, 52 females; mean age: 54.0±15.4 years; range, 16 to 82 years) who underwent mitral valve surgery in the Division of Cardiovascular Surgery at Koşuyolu Training Hospital were included. The patients were randomized ...
... correct direction. These valves include the mitral valve, tricuspid valve, pulmonary valve and aortic valve. Each valve has ... Causes of aortic valve regurgitation include: Congenital heart valve disease. You may have been born with an aortic ...
Murphy, David; Dasi, Lakshmi; Yoganathan, Ajit; Glezer, Ari
The time-periodic closing of bileaflet mechanical heart valves is accompanied by a strong flow transient that is associated with the formation of a counter-rotating vortex pair near the b-datum line of leaflet edges. The strong transitory shear that is generated by these vortices may be damaging to blood elements and may result in platelet activation. In the present work, these flow transients are mitigated using miniature vortex generator arrays that are embedded on the surface of the leaflets. Two vortex generator designs were investigated: one design comprised staggered rectangular fins and the other one staggered hemispheres. The closing transients in the absence and presence of the passive vortex generators are characterized using phase locked PIV measurements. The study utilizes a 25 mm St. Jude Medical valve placed in the aortic position of the Georgia Tech left heart simulator. Measurements of the velocity field in the center plane of the leaflets demonstrate that the dynamics of the transient vortices that precede the formation of the leakage jets can be significantly altered and controlled by relatively simple passive modifications of existing valve designs. Human blood experiments validated the effectiveness of miniature vortex generators in reducing thrombus formation by over 42 percent.
Chen, Jing; Yang, Zhi-Gang; Ma, En-Sen; Zhang, Qin; Liu, Xi; Guo, Ying-Kun
Background To retrospectively evaluate mitral valve abnormality in left atrial myxoma patients by using cardiac computed tomography (CT). Material and methods Cardiac CT was performed in 56 patients with left atrial myxoma and 50 controls. Tumor and mitral valve characteristics were analyzed. The mitral valve parameters differences were compared between patients with myxoma and controls, myxoma with or without mitral valve obstruction, different obstruction degrees, respectively. Receiver operating characteristic analysis was performed to determine the cut-off values of abnormal mitral valve parameters for myxoma patients. Multiple linear regression, logistic regression models and cox regression analysis were used to determine factors associated with mitral valve abnormalities, mitral obstruction, mitral regurgitation and postoperative recovery, respectively. Results Myxoma induced the dilation of mitral valve, with different results among different degrees of obstruction (pmyxoma parameters. The cut-off values for discriminating mitral valve abnormalities in myxoma patients were found. Some significant predictors for mitral obstruction were tumor pedicle-tumor volume and patient age (HR, 0.886-30.811; p = 0.011-0.043). Moreover, the predictor for mitral regurgitation was mitral annulus diameter in diastolic phase (HR, 20.862; 95%CI,1.331-327.100; p = 0.031). Some predictors associated with postoperative recovery of mitral regurgitation were age, mitral annulus area, mitral annulus diameter and mitral valve diameter cutoff value for diastolic phase (HR, 0.001-119.160; p = 0.012-0.028). Conclusion Cardiac CT is capable of quantitatively assessing myxoma characteristic and mitral valve abnormality induced by myxoma, thus providing guidance of operative management and postoperative evaluation. PMID:28915697
Gössl, Mario; Johnson, Jonathan N; Hagler, Donald J
We present the case of a 36-year-old woman with increasing shortness of breath, a new 3/4 diastolic murmur, and a complex history of LV outflow tract obstruction. She has undergone multiple surgeries including the replacement of her old LV apex to ascending aorta conduit with a 20-mm Gore-Tex tube graft, addition of a 24-mm homograft sutured between the conduit and the LV apex, and insertion of a 21-mm Freestyle porcine valve conduit between the Gore-Tex tube graft and allograft at age 23. The current assessment showed a failing Freestyle conduit prosthesis leading to left heart decompensation. Due to substantial surgical risk, the patient underwent successful implantation of a Melody valve into the Gore-Tex tube and exclusion of the failing Freestyle bioprosthesis with a NuMed CP stent in a hybrid procedure. The case nicely illustrates the collaborative potential of cardiovascular surgeons and interventional cardiologists in the new arena of a hybrid operating room. Complex hybrid procedures like the current one, especially those including percutaneous placements of valves, offer therapeutic options for patients that are otherwise too high risk for conventional open heart surgery. Copyright © 2013 Wiley Periodicals, Inc.
Wuliya, Mijiti; Peyrot, Sandrine; Radu, Costin; Deux, Jean-François; Ben Elhaj, Habib; Lellouche, Nicolas; Damy, Thibaud; Guendouz, Soulef; Gellen, Barnabas
An aortic valve thrombus (AVT) is a rare complication after HeartMate II implantation. In a 44-year-old man, a large AVT was discovered 6 weeks after implantation of a HeartMate II for severe dilated cardiomyopathy. The aortic valve was permanently closed. After a followup of 3 months without embolic events, the patient started a cardiac rehabilitation (CR) program involving aerobic exercise, resistance exercises, group gymnastics, and relaxation exercise, and completed the program without any complications, resulting in a significant functional benefit. CR might not be systematically contraindicated in patients with HeartMate II and an AVT, in particular, if there is no opening of the aortic valve at rest.
Jose, John; Sulimov, Dmitriy S; El-Mawardy, Mohamed; Sato, Takao; Allali, Abdelhakim; Holy, Erik W; Becker, Björn; Landt, Martin; Kebernik, Julia; Schwarz, Bettina; Richardt, Gert; Abdel-Wahab, Mohamed
The aim of this study was to determine the incidence, characteristics, and treatment outcomes of patients diagnosed with clinical transcatheter heart valve thrombosis. Limited data exists on clinical or manifest transcatheter heart valve thrombosis. Prior studies have focused on subclinical thrombosis. A retrospective analysis was conducted of prospectively collected data from a single-center registry that included 642 consecutive patients who underwent transcatheter aortic valve replacement between 2007 and 2015 (305 patients had self-expanding valves; balloon-expandable, n = 281; mechanically expanding, n = 56). Long-term oral anticoagulation (OAC) was indicated in 261 patients, while 377 patients received dual-antiplatelet therapy post-procedure. All patients underwent scheduled clinical and echocardiographic follow-up. The overall incidence of clinical valve thrombosis was 2.8% (n = 18). No patient on OAC developed thrombosis. Of the detected thrombosis cases, 13 patients had balloon-expandable, 3 had self-expanding, and 2 had mechanically expanding valves. Thrombosis occurred significantly more often with balloon-expandable valves (odds ratio: 3.45; 95% confidence interval: 1.22 to 9.81; p = 0.01) and following valve-in-valve procedures (odds ratio: 5.93; 95% confidence interval: 2.01 to 17.51; p = 0.005). Median time to diagnosis of valve thrombosis was 181 days. The median N-terminal pro-brain natriuretic peptide level was 1,318 pg/ml (interquartile range: 606 to 1,676 pg/ml). The mean transvalvular gradient and valve area were 34 ± 14 mm Hg and 1.0 ± 0.46 cm 2 , respectively. Computed tomography showed hypoattenuating areas with reduced leaflet motion. Initiation of OAC resulted in significant reduction of transvalvular gradient and clinical improvement. No deaths were related to valve thrombosis. Clinical transcatheter heart valve thrombosis is more common than previously considered, characterized by imaging abnormalities and increased gradients
Kaminsky, Radoslav; Kallweit, Stephan; Rossi, Massimiliano; Morbiducci, Umberto; Scalise, Lorenzo; Verdonck, Pascal; Tomasini, Enrico Primo
Through several decades many different models of prosthetic artificial heart valves (PHV) have been designed and optimized in order to enhance hemodynamic properties. These properties are not only material dependent but the major influence results from the mechanical assembly of the particular PHV. For the experimental assessment of the flow through such PHVs particle image velocimetry (PIV) is already an accepted method  due to its noninvasive optical approach and accuracy. Here, we present various modifications of PIV in order to explain, compare and realize which method is the most suitable for the quantification of such flows. The choice of the experimental procedure for testing the PHVs is strongly dependent on the optical access of the designed in-vitro testing loops simulating the human heart and vascular system. The hardware demand and its configuration for, e.g., stereoscopic PIV is much more complex than standard 2D PIV, therefore the conditions and design of the testing loop have to be realized to allow the desired flow measurement. The flow in heart valves as an unsteady periodically generated flow, can be obtained by averaged phaselocked or measurements with high temporal. The properties, advantages and drawbacks of specific PIV techniques to visualize the flow behind a PHV will be discussed.
Le, Trung; Borazjani, Iman; Sotiropoulos, Fotis
In order to test and optimize heart valve prosthesis and enable virtual implantation of other biomedical devices it is essential to develop and validate high-resolution FSI-CFD codes for carrying out simulations in patient-specific geometries. We have developed a powerful numerical methodology for carrying out FSI simulations of cardiovascular flows based on the CURVIB approach (Borazjani, L. Ge, and F. Sotiropoulos, Journal of Computational physics, vol. 227, pp. 7587-7620 2008). We have extended our FSI method to overset grids to handle efficiently more complicated geometries e.g. simulating an MHV implanted in an anatomically realistic aorta and left-ventricle. A compliant, anatomic left-ventricle is modeled using prescribed motion in one domain. The mechanical heart valve is placed inside the second domain i.e. the body-fitted curvilinear mesh of the anatomic aorta. The simulations of an MHV with a left-ventricle model underscore the importance of inflow conditions and ventricular compliance for such simulations and demonstrate the potential of our method as a powerful tool for patient-specific simulations.
Tamborini, Gloria; Fusini, Laura; Muratori, Manuela; Gripari, Paola; Ghulam Ali, Sarah; Fiorentini, Cesare; Pepi, Mauro
According to current recommendations, patients could benefit from tricuspid valve (TV) annuloplasty at the time mitral valve (MV) surgery if tricuspid regurgitation is severe or if tricuspid annulus (TA) dilatation is present. Therefore, an accurate pre-operative echocardiographic study is mandatory for left but also for right cardiac structures. Aims of this study are to assess right atrial (RA), right ventricular (RV) and TA geometry and function in patients undergoing MV repair without or with TV annuloplasty. We studied 103 patients undergoing MV surgery without (G1: 54 cases) or with (G2: 49 cases) concomitant TV annuloplasty and 40 healthy subjects (NL) as controls. RA, RV and TA were evaluated by three-dimensional (3D) transthoracic echocardiography. Comparing the pathological to the NL group, TA parameters and 3D right chamber volumes were significantly larger. RA and RV ejection fraction and TA% reduction were lower in pathological versus NL, and in G2 versus G1. In pathological patients, TA area positively correlated to systolic pulmonary pressure and negatively with RV and RA ejection fraction. Patients undergoing MV surgery and TV annuloplasty had an increased TA dimensions and a more advanced remodeling of right heart chambers probably reflecting an advanced stage of the disease.
Hyde, Annastasia S.; Farmer, Erin L.; Easley, Katherine E.; van Lammeren, Kristy; Christoffels, Vincent M.; Barycki, Joseph J.; Bakkers, Jeroen; Simpson, Melanie A.
Cardiac valve defects are a common congenital heart malformation and a significant clinical problem. Defining molecular factors in cardiac valve development has facilitated identification of underlying causes of valve malformation. Gene disruption in zebrafish revealed a critical role for
Hyde, A.S.; Farmer, E.L.; Easley, K.E.; van Lammeren, K.; Christoffels, V.M.; Barycki, J.J.; Bakkers, J.; Simpson, M.A.
Cardiac valve defects are a common congenital heart malformation and a significant clinical problem. Defining molecular factors in cardiac valve development has facilitated identification of underlying causes of valve malformation. Gene disruption in zebrafish revealed a critical role for
Haas, Nikolaus A; Carere, Ronald Giacomo; Kretschmar, Oliver; Horlick, Eric; Rodés-Cabau, Josep; de Wolf, Daniël; Gewillig, Marc; Mullen, Michael; Lehner, Anja; Deutsch, Cornelia; Bramlage, Peter; Ewert, Peter
Patients with congenital or acquired heart defects affecting the pulmonary valve and right ventricular outflow tract (RVOT) commonly require multiple surgical interventions, resulting in significant morbidity. A less invasive alternative is percutaneous pulmonary valve implantation (PPVI). Though studies have previously reported the safety and efficacy of the early generation transcatheter heart valves (THVs), data on more recent devices are severely lacking. We performed a multinational, multicentre, retrospective, observational registry analysis of patients who underwent PPVI using the Edwards SAPIEN XT THV. Of the 46 patients that were enrolled, the majority had tetralogy of Fallot as the underlying diagnosis (58.7%), and stentless xenograft as the most common RVOT anatomy (34.8%). Procedural success rate was high (93.5%), with a low frequency of periprocedural complications and adverse events (6.5% and 10.9%, respectively). At 30days post-procedure, NYHA class had improved significantly (90.6% were at NYHA I or II). The rate of moderate/severe pulmonary regurgitation had decreased from 76.1% at baseline to 5.0% at 30days, and the calculated peak systolic gradient had decreased from 45.2 (SD±21.3) mmHg to 16.4 (SD±8.0) mmHg, with these values remaining low up to 2years. The data suggest the efficacy and safety of the SAPIEN XT THV in PPVI in common anatomies in patients with conduits, as well as those with native pulmonary valves or transannular patches. Continued data collection is necessary to verify long-term findings. CLINICALTRIALS. NCT02302131. Copyright © 2017 Elsevier B.V. All rights reserved.
Suri, Rakesh M; Zehr, Kenton J; Sundt, Thoralf M; Dearani, Joseph A; Daly, Richard C; Oh, Jae K; Schaff, Hartzell V
It is unclear whether small differences in transprosthetic gradient between porcine and bovine biologic aortic valves translate into improved regression of left ventricular (LV) hypertrophy after aortic valve replacement. We investigated transprosthetic gradient, aortic valve orifice area, and LV mass in patients randomized to aortic valve replacement with either the Medtronic Mosaic (MM) porcine or an Edwards Perimount (EP) bovine pericardial bioprosthesis. One hundred fifty-two patients with aortic valve disease were randomly assigned to receive either the MM (n = 76) or an EP prosthesis. There were 89 men (59%), and the mean age was 76 years. Echocardiograms from preoperative, postoperative, predismissal, and 1-year time points were analyzed. Baseline characteristics and preoperative echocardiograms were similar between the two groups. The median implant size was 23 mm for both. There were no early deaths, and 10 patients (7%) died after dismissal. One hundred seven of 137 patients (78%) had a 1-year echocardiogram, and none required aortic valve reoperation. The mean aortic valve gradient at dismissal was 19.4 mm Hg (MM) versus13.5 mm Hg (EP; p regression of LV mass index (MM, -32.4 g/m(2) versus EP, -27.0 g/m(2); p = 0.40). Greater preoperative LV mass index was the sole independent predictor of greater LV mass regression after surgery (p regression of LV mass during the first year after aortic valve replacement.
Dobrova, N B; Agafonov, A V; Barbarash, L S; Zavalishin, N N; Neniukov, A K
Hydraulic characteristics of heart valve bioprostheses mounted on supporting structures of various rigidity have been studied under physiologic conditions. An actual mobility of the supporting structures made of different polymers is determined. Static and dynamic components of the support displacements have been shown to develop as the bioprosthesis is under the load, the dynamic component being strongly dependent upon the rigidity of fastening the bioprosthesis on the axis. It is noted that considerable improvements in hydraulic characteristics of bioprostheses are achieved through the use of flexible supporting structures.
Cromheecke, M. E.; Overkamp, P. J.; de Mol, B. A.; van Gaalen, G. L.; Becker, A. E.
Explanted mechanical heart valves were examined nondestructively, and the findings were related to guidelines, technical reports, and other information to judge the risk of failure and its possible impact on valve design and clinical practice. Diagnoses for single valves could be made, but risks and
Puperi, Daniel S; O'Connell, Ronan W; Punske, Zoe E; Wu, Yan; West, Jennifer L; Grande-Allen, K Jane
Advanced tissue engineered heart valves must be constructed from multiple materials to better mimic the heterogeneity found in the native valve. The trilayered structure of aortic valves provides the ability to open and close consistently over a full human lifetime, with each layer performing specific mechanical functions. The middle spongiosa layer consists primarily of proteoglycans and glycosaminoglycans, providing lubrication and dampening functions as the valve leaflet flexes open and closed. In this study, hyaluronan hydrogels were tuned to perform the mechanical functions of the spongiosa layer, provide a biomimetic scaffold in which valve cells were encapsulated in 3D for tissue engineering applications, and gain insight into how valve cells maintain hyaluronan homeostasis within heart valves. Expression of the HAS1 isoform of hyaluronan synthase was significantly higher in hyaluronan hydrogels compared to blank-slate poly(ethylene glycol) diacrylate (PEGDA) hydrogels. Hyaluronidase and matrix metalloproteinase enzyme activity was similar between hyaluronan and PEGDA hydrogels, even though these scaffold materials were each specifically susceptible to degradation by different enzyme types. KIAA1199 was expressed by valve cells and may play a role in the regulation of hyaluronan in heart valves. Cross-linked hyaluronan hydrogels maintained healthy phenotype of valve cells in 3D culture and were tuned to approximate the mechanical properties of the valve spongiosa layer. Therefore, hyaluronan can be used as an appropriate material for the spongiosa layer of a proposed laminate tissue engineered heart valve scaffold.
Salah E. Altarabsheh
Full Text Available Aortic valve replacement in patients with dextrocardia and situs inversus totalis is technically challenging due to anatomical considerations. Modifications of the cannulation strategy and operative tool sets are helpful. We report a 47-year-old man who had dextrocardia with situs inversus totalis with severe aortic regurgitation. Our approach was precisely planned depending on the clear anatomy outlined by preoperative contrast-enhanced computed tomography of the chest. We used a surgical approach in which the main surgeon was standing on the left side of the patient. Left sided approach provided excellent exposure for aortic valve replacement in this case scenario.
Schlegel, Franziska; Salameh, Aida; Oelmann, Katja; Halling, Michelle; Dhein, Stefan; Mohr, Friedrich W; Dohmen, Pascal M
Transcatheter pulmonary valve replacement is currently performed in clinical trials, however limited by the use of glutaraldehyde treated bioprostheses. This feasibility study was performed to evaluate delivery-related tissue distortion during implantation of a tissue engineered (TE) heart valves. The injectable TE heart valve was mounted on a self-expanding nitinol stent (n=7) and delivered into the pulmonary position of seven pigs, (weight 26 to 31 kg), performing a sternotomy or limited lateral thoracotomy. Prior to implantation, the injectable TE heart valve was crimped and inserted into an applicator. Positioning of the implants was guided by fluoroscopy and after carefully deployment angiographic examination was performed to evaluate the correct delivered position. Hemodynamic measurements were performed by epicardial echocardiography. Finally, the animals were sacrificed and the injectable TE heart valves were inspected by gross examination and histological examination. Orthotopic delivery of the injectable TE heart valves were all successful performed, expect in one were the valve migrated due to a discrepancy of pulmonary and injectable TE valve size. Angiographic evaluation (n=6) showed normal valve function, supported by epicardial echocardiography in which no increase flow velocity was measured, neither trans- nor paravalvular regurgitation. Histological evaluation demonstrated absence of tissue damage due to the delivery process. Transcatheter implantation of an injectable TE heart valve seems to be possible without tissue distortion due to the delivery system.
Erica D. Wittwer
Full Text Available The purpose of this case is to describe the complex perioperative management of a 30-year-old woman with congenital heart disease and multiple resternotomies presenting with pulmonary homograft dysfunction and evaluation for percutaneous pulmonary valve replacement. Transvenous, transcatheter Melody valve placement caused left main coronary artery occlusion and cardiogenic shock. An Impella ventricular assist device (VAD provided rescue therapy during operating room transport for valve removal and pulmonary homograft replacement. ECMO support was required following surgery. Several days later during an attempted ECMO wean, her hemodynamics deteriorated abruptly. Transesophageal and epicardial echocardiography identified pulmonary graft obstruction, requiring homograft revision due to large thrombosis. This case illustrates a role for Impella VAD as bridge to definitive procedure after left coronary occlusion and describes management of complex perioperative ECMO support challenges.
Kaminsky, R; Dumont, K; Weber, H; Schroll, M; Verdonck, P
The aim of this study was to validate the 2D computational fluid dynamics (CFD) results of a moving heart valve based on a fluid-structure interaction (FSI) algorithm with experimental measurements. Firstly, a pulsatile laminar flow through a monoleaflet valve model with a stiff leaflet was visualized by means of Particle Image Velocimetry (PIV). The inflow data sets were applied to a CFD simulation including blood-leaflet interaction. The measurement section with a fixed leaflet was enclosed into a standard mock loop in series with a Harvard Apparatus Pulsatile Blood Pump, a compliance chamber and a reservoir. Standard 2D PIV measurements were made at a frequency of 60 bpm. Average velocity magnitude results of 36 phase-locked measurements were evaluated at every 10 degrees of the pump cycle. For the CFD flow simulation, a commercially available package from Fluent Inc. was used in combination with inhouse developed FSI code based on the Arbitrary Lagrangian-Eulerian (ALE) method. Then the CFD code was applied to the leaflet to quantify the shear stress on it. Generally, the CFD results are in agreement with the PIV evaluated data in major flow regions, thereby validating the FSI simulation of a monoleaflet valve with a flexible leaflet. The applicability of the new CFD code for quantifying the shear stress on a flexible leaflet is thus demonstrated.
Theis, Jeanne L; Hrstka, Sybil C L; Evans, Jared M; O'Byrne, Megan M; de Andrade, Mariza; O'Leary, Patrick W; Nelson, Timothy J; Olson, Timothy M
Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect (CHD) that necessitates staged, single ventricle surgical palliation. An increased frequency of bicuspid aortic valve (BAV) has been observed among relatives. We postulated number of mutant alleles as a molecular basis for variable CHD expression in an extended family comprised of an HLHS proband and four family members who underwent echocardiography and whole-genome sequencing (WGS). Dermal fibroblast-derived induced pluripotent stem cells (iPSC) were procured from the proband-parent trio and bioengineered into cardiomyocytes. Cardiac phenotyping revealed aortic valve atresia and a slit-like left ventricular cavity in the HLHS proband, isolated bicuspid pulmonary valve in his mother, BAV in a maternal 4° relative, and no CHD in his father or sister. Filtering of WGS for rare, functional variants that segregated with CHD and were compound heterozygous in the HLHS proband identified NOTCH1 as the sole candidate gene. An unreported missense mutation (P1964L) in the cytoplasmic domain, segregating with semilunar valve malformation, was maternally inherited and a rare missense mutation (P1256L) in the extracellular domain, clinically silent in the heterozygous state, was paternally inherited. Patient-specific iPSCs exhibited diminished transcript levels of NOTCH1 signaling pathway components, impaired myocardiogenesis, and a higher prevalence of heterogeneous myofilament organization. Extended, phenotypically characterized families enable WGS-derived variant filtering for plausible Mendelian modes of inheritance, a powerful strategy to discover molecular underpinnings of CHD. Identification of compound heterozygous NOTCH1 mutations and iPSC-based functional modeling implicate mutant allele burden and impaired myogenic potential as mechanisms for HLHS.
Full Text Available Objective: The relationship of mitral annular (MA kinetics to left ventricular (LV and left atrial (LA function before and after mitral valve repair has not been well studied. Here we sought to provide comprehensive analysis that relates to MA motions, LA and LV diastolic function post mitral valve repair. Methods: Three-dimensional analyses of mitral annular motion, LA function and LV volumetric and diastolic strain rates were performed on 35 degenerative mitral regurgitation (MR patients at baseline and 1-year post mitral valve repair, and 51 normal controls, utilizing cardiac magnetic resonance imaging with tissue tagging. Results: All had normal LV ejection fraction (EF at baseline. LV and LA EFs decreased 1-year post-surgery vs. controls. LV early-diastolic myocardial strain rates decreased post-surgery along with decreases in normalized early-diastolic filling rate, E/A ratio and early-diastolic MA relaxation rates. Post-surgical LA late active kick remained higher in MR patients vs. control. LV and LA EFs were significantly associated with peak MA centroid to apex shortening. Furthermore, during LV systolic phase, peak LV ejection and LA filling rates were significantly correlated with peak MA centroid to apex shortening rate, respectively. While during LV diastolic phase, both peak early diastolic MA centroid to apex relaxation rate and LA ejection rate were positively significantly associated with LV peak early diastolic filling rate. Conclusions— MA motion is significantly associated with LA and LV function. Mitral annular motion, left atrial function and left ventricular diastolic strain rates are still impaired one year post mitral valve repair. Long term effects of these impairments should be prospectively evaluated.
Scarsoglio, Stefania; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca; Anselmino, Matteo
Although atrial fibrillation (AF), a common arrhythmia, frequently presents in patients with underlying valvular disease, its hemodynamic contributions are not fully understood. The present work aimed to computationally study how physical conditions imposed by pathologic valvular anatomy act on AF hemodynamics. We simulated AF with different severity grades of left-sided valvular diseases and compared the cardiovascular effects that they exert during AF, compared to lone AF. The fluid dynamics model used here has been recently validated for lone AF and relies on a lumped parameterization of the four heart chambers, together with the systemic and pulmonary circulation. The AF modelling involves: (i) irregular, uncorrelated and faster heart rate; (ii) atrial contractility dysfunction. Three different grades of severity (mild, moderate, severe) were analyzed for each of the four valvulopathies (AS, aortic stenosis, MS, mitral stenosis, AR, aortic regurgitation, MR, mitral regurgitation), by varying-through the valve opening angle-the valve area. Regurgitation was hemodynamically more relevant than stenosis, as the latter led to inefficient cardiac flow, while the former introduced more drastic fluid dynamics variation. Moreover, mitral valvulopathies were more significant than aortic ones. In case of aortic valve diseases, proper mitral functioning damps out changes at atrial and pulmonary levels. In the case of mitral valvulopathy, the mitral valve lost its regulating capability, thus hemodynamic variations almost equally affected regions upstream and downstream of the valve. In particular, the present study revealed that both mitral and aortic regurgitation strongly affect hemodynamics, followed by mitral stenosis, while aortic stenosis has the least impact among the analyzed valvular diseases. The proposed approach can provide new mechanistic insights as to which valvular pathologies merit more aggressive treatment of AF. Present findings, if clinically confirmed
Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca; Anselmino, Matteo
Background: Although atrial fibrillation (AF), a common arrhythmia, frequently presents in patients with underlying valvular disease, its hemodynamic contributions are not fully understood. The present work aimed to computationally study how physical conditions imposed by pathologic valvular anatomy act on AF hemodynamics. Methods: We simulated AF with different severity grades of left-sided valvular diseases and compared the cardiovascular effects that they exert during AF, compared to lone AF. The fluid dynamics model used here has been recently validated for lone AF and relies on a lumped parameterization of the four heart chambers, together with the systemic and pulmonary circulation. The AF modelling involves: (i) irregular, uncorrelated and faster heart rate; (ii) atrial contractility dysfunction. Three different grades of severity (mild, moderate, severe) were analyzed for each of the four valvulopathies (AS, aortic stenosis, MS, mitral stenosis, AR, aortic regurgitation, MR, mitral regurgitation), by varying–through the valve opening angle–the valve area. Results: Regurgitation was hemodynamically more relevant than stenosis, as the latter led to inefficient cardiac flow, while the former introduced more drastic fluid dynamics variation. Moreover, mitral valvulopathies were more significant than aortic ones. In case of aortic valve diseases, proper mitral functioning damps out changes at atrial and pulmonary levels. In the case of mitral valvulopathy, the mitral valve lost its regulating capability, thus hemodynamic variations almost equally affected regions upstream and downstream of the valve. In particular, the present study revealed that both mitral and aortic regurgitation strongly affect hemodynamics, followed by mitral stenosis, while aortic stenosis has the least impact among the analyzed valvular diseases. Discussion: The proposed approach can provide new mechanistic insights as to which valvular pathologies merit more aggressive treatment of
Full Text Available Background: Although atrial fibrillation (AF, a common arrhythmia, frequently presents in patients with underlying valvular disease, its hemodynamic contributions are not fully understood. The present work aimed to computationally study how physical conditions imposed by pathologic valvular anatomy act on AF hemodynamics. Methods: We simulated AF with different severity grades of left-sided valvular diseases and compared the cardiovascular effects that they exert during AF, compared to lone AF. The fluid dynamics model used here has been recently validated for lone AF and relies on a lumped parameterization of the four heart chambers, together with the systemic and pulmonary circulation. The AF modelling involves: (i irregular, uncorrelated and faster heart rate; (ii atrial contractility dysfunction. Three different grades of severity (mild, moderate, severe were analyzed for each of the four valvulopathies (AS, aortic stenosis, MS, mitral stenosis, AR, aortic regurgitation, MR, mitral regurgitation, by varying–through the valve opening angle–the valve area. Results: Regurgitation was hemodynamically more relevant than stenosis, as the latter led to inefficient cardiac flow, while the former introduced more drastic fluid dynamics variation. Moreover, mitral valvulopathies were more significant than aortic ones. In case of aortic valve diseases, proper mitral functioning damps out changes at atrial and pulmonary levels. In the case of mitral valvulopathy, the mitral valve lost its regulating capability, thus hemodynamic variations almost equally affected regions upstream and downstream of the valve. In particular, the present study revealed that both mitral and aortic regurgitation strongly affect hemodynamics, followed by mitral stenosis, while aortic stenosis has the least impact among the analyzed valvular diseases. Discussion: The proposed approach can provide new mechanistic insights as to which valvular pathologies merit more aggressive
Full Text Available We report a 42-year-old lady on combined oral contraceptive pills with deep venous thrombosis and mild pulmonary embolism, who developed shock, while being treated with heparin. On auscultation, there was an unexpected loud, superficial, squeaky, triphasic friction rub over the left lower parasternal area. Simultaneous echocardiogram revealed a large serpiginous, freely floating mass in right atrium, prolapsing freely to right ventricular inlet across the tricuspid valve. The endocardial friction rub persisted for about 24 h as long as the thrombus was intracardiac and disappeared when the thrombus disappeared from right heart, occluding the proximal left pulmonary artery. She died due to shock awaiting surgery. We highlight that such a rub in a patient with deep venous thrombosis, though rare, may be an important clue to impending pulmonary embolism.
Ramu, Bhavadharini; Thenappan, Thenappan
Pulmonary hypertension associated with left heart disease is the most common form of pulmonary hypertension. Although its pathophysiology remains incompletely understood, it is now well recognized that the presence of pulmonary hypertension is associated with a worse prognosis. Right ventricular failure has independent and additive prognostic value over pulmonary hypertension for adverse outcomes in left heart disease. Recently, several new terminologies have been introduced to better define and characterize the nature and severity of pulmonary hypertension. Several new treatment options including the use of pulmonary arterial hypertension specific therapies are being considered, but there is lack of evidence. Here, we review the recent advances in this field and summarize the diagnostic and therapeutic modalities of use in the management of pulmonary hypertension associated with left heart disease.
Beyerbacht, Hugo P.; Bax, Jeroen J.; Lamb, Hildo J.; van der Laarse, Arnoud; Vliegen, Hubert W.; de Roos, Albert; Zwinderman, Aeilko H.; van der Wall, Ernst E.
PURPOSE: Evaluation of different electrocardiographic criteria for left ventricular hypertrophy (ECG-LVH criteria) using left ventricular mass index (LVMI) determined by magnetic resonance imaging (MRI). In addition, the relation between LVMI regression after aortic valve replacement and
Ernest W. Lau
Full Text Available Multi-site multi-polar left ventricular pacing through the coronary sinus (CS may be preferred over endocardial right ventricular or surgical epicardial pacing in the presence of tricuspid valve disease. However, the required lead placement can be difficult through a persistent left superior vena cava (PLSVC, as the CS tends to be hugely dilated and side branches tend to have sharp angulations (>90° when approached from the PLSVC. Pre-shaped angiography catheters and techniques used for finding venous grafts from the ascending aorta post coronary bypass surgery may help with lead placement in such a situation.
Reuven, Eliran Moshe; Leviatan Ben-Arye, Shani; Marshanski, Tal; Breimer, Michael E; Yu, Hai; Fellah-Hebia, Imen; Roussel, Jean-Christian; Costa, Cristina; Galiñanes, Manuel; Mañez, Rafael; Le Tourneau, Thierry; Soulillou, Jean-Paul; Cozzi, Emanuele; Chen, Xi; Padler-Karavani, Vered
The two common sialic acids (Sias) in mammals are N-acetylneuraminic acid (Neu5Ac) and its hydroxylated form N-glycolylneuraminic acid (Neu5Gc). Unlike most mammals, humans cannot synthesize Neu5Gc that is considered foreign and recognized by circulating antibodies. Thus, Neu5Gc is a potential xenogenic carbohydrate antigen in bioprosthetic heart valves (BHV) that tend to deteriorate in time within human patients. We investigated Neu5Gc expression in non-engineered animal-derived cardiac tissues and in clinically used commercial BHV, and evaluated Neu5Gc immunogenicity on BHV through recognition by human anti-Neu5Gc IgG. Neu5Gc was detected by immunohistochemistry in porcine aortic valves and in porcine and bovine pericardium. Qualitative analysis of Sia linkages revealed Siaα2-3>Siaα2-6 on porcine/bovine pericardium while the opposite in porcine aortic/pulmonary valve cusps. Similarly, six commercial BHV containing either porcine aortic valve or porcine/bovine/equine pericardium revealed Siaα2-3>Siaα2-6 expression. Quantitative analysis of Sia by HPLC showed porcine/bovine pericardium express 4-fold higher Neu5Gc levels compared to the porcine aortic/pulmonary valves, with Neu5Ac at 6-fold over Neu5Gc. Likewise, Neu5Gc was expressed on commercial BHV (186.3±16.9 pmol Sia/μg protein), with Neu5Ac at 8-fold over Neu5Gc. Affinity-purified human anti-Neu5Gc IgG showing high specificity toward Neu5Gc-glycans (with no binding to Neu5Ac-glycans) on a glycan microarray, strongly bound to all tested commercial BHV, demonstrating Neu5Gc immune recognition in cardiac xenografts. We conclusively demonstrated Neu5Gc expression in native cardiac tissues, as well as in six commercial BHV. These Neu5Gc xeno-antigens were recognized by human anti-Neu5Gc IgG, supporting their immunogenicity. Altogether, these findings suggest BHV-Neu5Gc/anti-Neu5Gc may play a role in valve deterioration warranting further investigation. © 2016 John Wiley & Sons A/S. Published by John Wiley
Vellayappan, Muthu Vignesh; Balaji, Arunpandian; Subramanian, Aruna Priyadarshini; John, Agnes Aruna; Jaganathan, Saravana Kumar; Supriyanto, Eko; Yusof, Mustafa; Murugesan, Selvakumar; Mohandas, Hemanth
Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases. (review)
Goth, Will; Yang, Bin; Lesicko, John; Allen, Alicia; Sacks, Michael S.; Tunnell, James W.
Our group previously introduced Polarized Spatial Frequency Domain Imaging (PSFDI), a wide-field, reflectance imaging technique which we used to empirically map fiber direction in porcine pulmonary heart valve leaflets (PHVL) without optical clearing or physical sectioning of the sample. Presented is an extended analysis of our PSFDI results using an inverse Mueller matrix model of polarized light scattering that allows additional maps of fiber orientation distribution, along with instrumentation permitting increased imaging speed for dynamic PHVL fiber measurements. We imaged electrospun fiber phantoms with PSFDI, and then compared these measurements to SEM data collected for the same phantoms. PHVL was then imaged and compared to results of the same leaflets optically cleared and imaged with small angle light scattering (SALS). The static PHVL images showed distinct regional variance of fiber orientation distribution, matching our SALS results. We used our improved imaging speed to observe bovine tendon subjected to dynamic loading using a biaxial stretching device. Our dynamic imaging experiment showed trackable changes in the fiber microstructure of biological tissue under loading. Our new PSFDI analysis model and instrumentation allows characterization of fiber structure within heart valve tissues (as validated with SALS measurements), along with imaging of dynamic fiber remodeling. The experimental data will be used as inputs to our constitutive models of PHVL tissue to fully characterize these tissues' elastic behavior, and has immediate application in determining the mechanisms of structural and functional failure in PHVLs used as bio-prosthetic implants.
van Slooten, Ymkje J.; Melle, van Joost P.; Freling, Hendrik G.; Bouma, Berto J.; van Dijk, Arie P. J.; Jongbloed, Monique R. M.; Post, Martijn C.; Sieswerda, Gertjan T.; in 't Veld, Anna Huis; Ebels, Tjark; Voors, Adriaan A.; Pieper, Petronella G.
Objectives To report the prevalence of aortic valve prosthesis patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis
van Slooten, Ymkje J.; van Melle, Joost P.; Freling, Hendrik G.; Bouma, Berto J.; van Dijk, Arie Pj; Jongbloed, Monique Rm; Post, Martijn C.; Sieswerda, Gertjan T.; Huis In 't Veld, Anna; Ebels, Tjark; Voors, Adriaan A.; Pieper, Petronella G.
To report the prevalence of aortic valve prosthesis-patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis later in
Marcelo Felipe Kozak
Full Text Available AbstractIntroduction:Left atrioventricular valve regurgitation is the most concerning residual lesion after surgical correction of atrioventricular septal defect.Objective:To determine factors associated with moderate or greater left atrioventricular valve regurgitation within 30 days of surgical repair of incomplete atrioventricular septal defect.Methods:We assessed the results of 51 consecutive patients 14 years-old and younger presenting with incomplete atrioventricular septal defect that were operated on at our practice between 2002 and 2010. The following variables were considered: age, weight, absence of Down syndrome, grade of preoperative left atrioventricular valve regurgitation, abnormalities on the left atrioventricular valve and the use of annuloplasty. The median age was 4.1 years; the median weight was 13.4 Kg; 37.2% had Down syndrome. At the time of preoperative evaluation, there were 23 cases with moderate or greater left atrioventricular valve regurgitation (45.1%. Abnormalities on the left atrioventricular valve were found in 17.6%; annuloplasty was performed in 21.6%.Results:At the time of postoperative evaluation, there were 12 cases with moderate or greater left atrioventricular valve regurgitation (23.5%. The variation between pre- and postoperative grades of left atrioventricular valve regurgitation of patients with atrioventricular valve malformation did not reach significance (P=0.26, unlike patients without such abnormalities (P=0.016. During univariate analysis, only absence of Down syndrome was statistically significant (P=0.02. However, after a multivariate analysis, none of the factors reached significance.Conclusion:None of the factors studied was determinant of a moderate or greater left atrioventricular valve regurgitation within the first 30 days of repair of incomplete atrioventricular septal defect in the sample. Patients without abnormalities on the left atrioventricular valve benefit more of the operation.
Sigvardsen, Per Ejlstrup; Larsen, Linnea Hornbech; Carstensen, Helle Gervig
by multi-detector computed tomography according to previous definitions. Follow-up was conducted using electronic health records. Event-free survival was assessed using Cox proportional hazards models. Patients were followed for a median of 2.2 years (interquartile range 1.6-3.6). Indication for AVR......Aims: Left ventricular (LV) regional hypertrophy in the form of LV asymmetry is a common finding in patients with aortic valve stenosis. The aim of this study was to test the hypothesis that LV asymmetry predicts future symptomatic status and indication for aortic valve replacement (AVR......) in patients with asymptomatic aortic valve stenosis. Methods and results: In total, 114 patients with asymptomatic aortic valve stenosis (peak velocity > 2.5 m/s assessed by echocardiographic screening and LV ejection fraction > 50%) were enrolled in the study. LV asymmetry and LV geometry was assessed...
Kalejs, Martins; Stradins, Peteris; Lacis, Romans; Ozolanta, Iveta; Pavars, Janis; Kasyanov, Vladimir
The major problem with heart valve bioprostheses made from chemically treated porcine aortic valves is their limited longevity caused by gradual deterioration, which has a causal link with valve tissue mechanical properties. To our best knowledge, there are no published studies on the mechanical properties of modern, commercially available bioprostheses comparing them to native human valves. The objective of this study is to determine the mechanical properties of St Jude Epic bioprostheses and to compare them with native human and porcine aortic valves. Leaflets from eight porcine aortic valves and six Epic bioprostheses were analyzed using uni-axial tensile tests in radial and circumferential directions. Mechanical properties of human valves have been previously published by our group. Results are represented as mean values+/-S.D. Circumferential direction. Modulus of elasticity of Epic bioprostheses in circumferential direction at the level of stress 1.0 MPa is 101.99+/-58.24 MPa, 42.3+/-4.96 MPa for native porcine and 15.34+/-3.84 MPa for human aortic valves. Ultimate stress is highest for Epic bioprostheses 5.77+/-1.94 MPa, human valves have ultimate stress of 1.74+/-0.29 MPa and porcine 1.58+/-0.26 MPa. Ultimate strain in circumferential direction is highest for human valves 18.35+/-7.61% followed by 7.26+/-0.69% for porcine valves and 5.95+/-1.54% for Epic bioprostheses. Radial direction. Modulus of elasticity in radial direction is 9.18+/-1.81 MPa for Epic bioprostheses, 5.33+/-0.61 MPa for native porcine, and 1.98+/-0.15 MPa for human aortic valve leaflets. In the radial direction ultimate stress is highest for Epic bioprostheses 0.7+/-0.21 MPa followed by native porcine valves 0.55+/-0.11 MPa and 0.32+/-0.04 MPa for human valves. For human valves ultimate strain is 23.92+/-4.87%, for native porcine valves 8.57+/-0.8% and 7.92+/-1.74% for Epic bioprostheses. Epic bioprostheses have non-linear stress-strain behavior similar to native valve tissue, but they
Dalsgaard, Morten; Egstrup, Kenneth; Wachtell, Kristian
Left atrial (LA) size is known to increase with chronically increased left ventricular (LV) filling pressure. We hypothesized that LA volume was predictive of aortic valve replacement (AVR) and cardiovascular events in a large cohort of patients with asymptomatic mild to moderate aortic valve...
Stephen P. Juraschek
Full Text Available Coronary arterial fistulas are rare communications between vessels or chambers of the heart. Although cardiac symptoms associated with fistulas are well described, fistulas are seldom considered in the differential diagnosis of acute myocardial ischemia. We describe the case of a 64-year-old man who presented with left shoulder pain, signs of heart failure, and a new left bundle branch block (LBBB. Cardiac catheterization revealed a small left anterior descending (LAD-to-pulmonary artery (PA fistula. Diuresis led to subjective improvement of the patient's symptoms and within several days the LBBB resolved. We hypothesize that the coronary fistula in this patient contributed to transient ischemia of the LAD territory through a coronary steal mechanism. We elected to observe rather than repair the fistula, as his symptoms and ECG changes resolved with treatment of his heart failure.
Dahl, Jordi S; Videbaek, Lars; Poulsen, Mikael K
In hypertension, angiotensin receptor blockers can augment regression of left ventricular (LV) hypertrophy. It is not known whether this also is the case after aortic valve replacement (AVR) for severe aortic stenosis (AS). To test the hypothesis that treatment with candesartan in addition...
Snygg-Martin, U; Rasmussen, Rasmus Vedby; Hassager, C
Anticoagulant therapy has been anticipated to increase the risk of cerebrovascular complications (CVC) in native valve endocarditis (NVE). This study investigates the relationship between ongoing oral anticoagulant therapy and the incidence of symptomatic CVC in left-sided NVE. In a prospective...
Castilla, Elena; Gato, Manuel; Ruiz, José Ramón
Pseudoaneurysm of the left ventricle (LV) is a rare cardiac disease that occurs after myocardial infarction or cardiac surgery. Because patients frequently present with nonspecific symptoms, a high index of suspicion is needed to make the diagnosis. This report describes an unusual case demonstrating a large LV pseudoaneurysm after mitral valve replacement performed 30 years earlier.
Her, Keun; Ahn, Chi Bum; Park, Sung Min; Choi, Seong Wook
Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle. To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs. In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 - 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices. The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.
Amstrup Funder, Jonas; Christian Danielsen, Carl; Baandrup, Ulrik
BACKGROUND: Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid in develop......BACKGROUND: Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid...... in developing techniques to design improved pressure-resistant biological heart valves. METHODS: Heart valves from 12 giraffes and 10 calves were explanted and subjected to either biomechanical or morphological examinations. Strips from the heart valves were subjected to cyclic loading tests, followed...... by failure tests. Thickness measurements and analyses of elastin and collagen content were also made. Valve specimens were stained with hematoxylin and eosin, elastic van Gieson stain, Masson's trichrome and Fraser-Lendrum stain, as well as immunohistochemical reactions for morphological examinations...
Balguid, A.; Rubbens, M.P.; Mol, A.; Bank, R.A.; Bogers, A.J.J.C.; Kats, J.P. van; Mol, B.A.J.M. de; Baaijens, F.P.T.; Bouten, C.V.C.
A major challenge in tissue engineering of functional heart valves is to determine and mimic the dominant tissue structures that regulate heart valve function and in vivo survival. In native heart valves, the anisotropic matrix architecture assures sustained and adequate functioning under
Forleo, Marcio; Dasi, Lakshmi
Bileaflet mechanical heart valves are widely used to replace diseased aortic heart valves. The stresses induced by the rich and unsteady non-physiological flow structures have been the focus to evaluate red blood cells damage and platelet activation, develop flow control strategies, or improve valve designs. In this study, we analyzed the flow fields obtained downstream of a bileaflet mechanical heart valve using time-resolved particle image velocimetry under pulsatile and steady flow conditions. Our study demonstrates the rich dynamics downstream of the valve and weighs the relevance of unsteady effects vs inertia effects on the different flow structures. Power spectrum analyses of the turbulent fluctuations highlight the highly anisotropic influence and the limited applicability of classical self-similar turbulence theory in describing the small-scale structures in the immediate vicinity of the valve.
Full Text Available Atrial fibrillation increases the risk of thrombus formation. It is commonly responsible for cerebral stroke whereas less frequently for pulmonary embolism. The aim of the study was to describe the morphology of the left atrial appendage in the human heart with respect to sex, age and weight. Macroscopic examination was carried out on 100 left appendages taken from the hearts of the patients aged 18-77, both sexes. All hearts preserved in 4% water solution of formaldehyde carried neither marks of coronary artery disease nor congenital abnormalities. Three axes of appendage orientation were performed. After the appendage had been cut off, morphological examination was performed in long and perpendicular axes. Measurements of the appendages were taken from anatomical specimens and their silicone casts. We classified the left atrial appendage into 4 morphological groups according to the number of lobes. Most left atrial appendages in female population were composed of 2 lobes. In the male group typically 2 or 3-lobed appendages were observed. The mean left atrial appendage orifice ranged from 12.0 to 16.0 mm and the most significant difference in the orifices between males and females was observed in LAA type 2 (about 3.3 mm. A smaller orifice and narrower, tubular shape of the LAA lobes could explain a higher risk of thrombus formation during nonvalvular atrial fibrillation in women. Knowledge of anatomical variability of the LAA helps diagnose some undefined echoes in the appendage during transesophageal echocardiographic examination.
A. V. Bogachev-Prokophiev
Full Text Available Aim. Persistence or appearance of atrial fibrillation (AF after mitral valve surgery significantly reduces the number of excellent and good results in the long-term period. AF leads to heart failure and pulmonary hypertension and increases the risk of thromboembolic events and stroke. Drug strategies for prevention of new-onset AF in the postoperative period are well developed, while invasive methods are still under development and clinical trials. This study aims to evaluate the safety and efficacy of surgical prevention of atrial fibrillation in patients with left atrium enlargement and mitral valve (MV lesion at 3-month follow-up.Methods. Forty patients operated in our clinic over a period of 2015–2017 were included in the study. All patients had MV lesion and left atrial dilatation greater than 60 mm. All patients had a sinus rhythm at the time of the operation and no documented AF in the history. The mean age of the patients was 48.9±10.1 (23-69 years. All patients had indications for mitral valve surgery and were randomized into two groups. The first group included patients who underwent a concomitant preventive ablation procedure (n = 20. The second group included patients with isolated MV surgery (n = 20. Complications and heart rhythm were evaluated within 3 months after surgery.Results. Patients who underwent preventive ablation within 3 months after the surgery did not differ significantly in the number of complications as compared with the control. In the group of patients with preventive ablation, a higher freedom from AF in comparison with the group of patients with isolated MV surgery was observed: 95 vs. 40%, respectively. Conclusion. Preventive atrial fibrillation ablation in patients with mitral valve lesion and left atrium enlargement is a safe and effective procedure. Preventive ablation reduces the risk of atrial fibrillation by 1.6 times within 3-month follow-up.Received 24 April 2017. Accepted 28 June 2017.Funding: The
Dysfunctional natural heart valves are replaced with prosthetic heart valves through surgery. However, prosthetic valves are far from ideal. Bioprosthetic heart valves (BHVs) suffer from early calcification and structural damages. Mechanical heart valves (MHVs) are durable but highly thrombogenic and require lifelong anticoagulant treatment. These complications are believed to be related to nonphysiologic flow patterns created by these valves. Fluid-structure interaction (FSI) simulations are essential in revealing the hemodynamics of these valves. By combining the three-dimensional (3D) flow field obtained from realistic FSI simulations with platelet activation models, nonphysiologic flow patterns can be identified. In this review paper, state-of-the-art methods for simulating FSI in heart valves are reviewed, and the flow physics uncovered by FSI simulations are discussed. Finally, the limitations of current methods are discussed, and future research directions are proposed as follows: (1) incorporation of realistic, image-based ventricle and atrium geometries; (2) comparing MHV and BHV under similar conditions to identify nonphysiologic flow patterns; (3) developing better models to estimate platelet activation potential to be incorporated into the simulations; and (4) identifying the optimum placement of the valves in both mitral and aortic positions.
Garside, Victoria C.; Chang, Alex C.; Karsan, Aly; Hoodless, Pamela A.
Congenital heart defects affect approximately 1–5% of human newborns each year and of these cardiac defects, 20–30% are due to heart valve abnormalities. Recent literature indicates that key factors and pathways that regulate valve development are also implicated in congenital heart defects and valve disease. Currently, there are limited options for treatment of valve disease and therefore, having a better understanding of valve development can contribute critical insight into congenital valve defects and disease. There are three major signalling pathways required for early specification and initiation of Endothelial-to-Mesenchymal Transformation (EMT) in the cardiac cushions: BMP, TGFβ, and Notch signalling. BMPs secreted from the myocardium setup the environment for the overlying endocardium to become activated, Notch signalling initiates EMT, and both BMP and TGFβ signalling synergizes with Notch to promote the transition of endothelia to mesenchyme and to promote mesenchymal cell invasiveness. Together, these three essential signalling pathways help to form the cardiac cushions and populate them with mesenchyme and, consequently, set off the cascade of events required to develop mature heart valves. Furthermore, integration and cross-talk between these pathways generate highly stratified and delicate valve leaflets and septa of the heart. Here, we discuss BMP, TGFβ, and Notch signalling pathways during mouse cardiac cushion formation and how they together produce a coordinated EMT response in the developing mouse valves. PMID:23161060
Ali, Ayyaz; Patel, Amit; Ali, Ziad; Abu-Omar, Yasir; Saeed, Amber; Athanasiou, Thanos; Pepper, John
Aortic valve replacement in patients with aortic stenosis is usually followed by regression of left ventricular hypertrophy. More complete resolution of left ventricular hypertrophy is suggested to be associated with superior clinical outcomes; however, its translational impact on long-term survival after aortic valve replacement has not been investigated. Demographic, operative, and clinical data were obtained retrospectively through case note review. Transthoracic echocardiography was used to measure left ventricular mass preoperatively and at annual follow-up visits. Patients were classified according to their reduction in left ventricular mass at 1 year after the operation: group 1, less than 25 g; group 2, 25 to 150 g; and group 3, more than 150 g. Kaplan-Meier and multivariable Cox regression were used. A total of 147 patients were discharged from the hospital after aortic valve replacement for aortic stenosis between 1991 and 2001. Preoperative left ventricular mass was 279 ± 98 g in group 1 (n = 47), 347 ± 104 g in group 2 (n = 62), and 491 ± 183 g in group 3 (n = 38) (P regression such as ischemic heart disease or hypertension, valve type, or valve size used. Ten-year actuarial survival was not statistically different in patients with enhanced left ventricular mass regression when compared with the log-rank test (group 1, 51% ± 9%; group 2, 54% ± 8%; and group 3, 72% ± 10%) (P = .26). After adjustment, left ventricular mass reduction of more than 150 g was demonstrated as an independent predictor of improved long-term survival on multivariate analysis (P = .02). Our study is the first to suggest that enhanced postoperative left ventricular mass regression, specifically in patients undergoing aortic valve replacement for aortic stenosis, may be associated with improved long-term survival. In view of these findings, strategies purported to be associated with superior left ventricular mass regression should be considered when undertaking
Endocarditis has been reported in patients with valvular heart disease who have undergone acupuncture treatment, although most have been associated with the use of semi-permanent needles. This has led reviewers to suggest that acupuncture may not only be contraindicated in such patients but that prophylactic antibiotics should be given. This study investigated the use of acupuncture treatment in patients with proven valvular heart disease and observed whether endocarditis developed in such patients. All patients in a single-handed GP practice with proven valvular heart disease, including those with prosthetic valves, were identified over a ten-year period. Those who had undergone acupuncture treatment underwent a clinical examination and diagnostic tests, which focused on the signs, symptoms and laboratory criteria for the diagnosis of endocarditis and included a transthoracic echocardiogram. Autopsy findings were reviewed in any patient who died. Based on these clinical and laboratory data, using the modified Duke's criteria for the diagnosis of endocarditis, patients were identified as having definite or possible endocarditis, or the diagnosis was rejected. All patients underwent brief acupuncture with no skin disinfectant and no prophylactic antibiotics were given. Semi-permanent needles were avoided. Thirty-six patients with valvular heart disease underwent a total of 479 acupuncture treatments over a ten-year period. The median number of treatments was 9 (range 1-72), with a follow-up after treatment of 5.75 years (range 0.5-10 years). Definite endocarditis was not found in any patient, but two patients had possible endocarditis, eventually discounted by both negative blood cultures and echocardiography. In conclusion, brief acupuncture was safe in this small cohort of valvular heart disease patients and no case of endocarditis was detected over a ten-year period.
Full Text Available Since 2000, transcatheter pulmonary valve replacement has steadily advanced. However, the available prosthetic valves are restricted to bioprosthesis which have defects like poor durability. Polymeric heart valve is thought as a promising alternative to bioprosthesis. In this study, we introduced a novel polymeric transcatheter pulmonary valve and evaluated its feasibility and safety in sheep by a hybrid approach.We designed a novel polymeric trileaflet transcatheter pulmonary valve with a balloon-expandable stent, and the valve leaflets were made of 0.1-mm expanded polytetrafluoroethylene (ePTFE coated with phosphorylcholine. We chose glutaraldehyde-treated bovine pericardium valves as control. Pulmonary valve stents were implanted in situ by a hybrid transapical approach in 10 healthy sheep (8 for polymeric valve and 2 for bovine pericardium valve, weighing an average of 22.5±2.0 kg. Angiography and cardiac catheter examination were performed after implantation to assess immediate valvular functionality. After 4-week follow-up, angiography, echocardiography, computed tomography, and cardiac catheter examination were used to assess early valvular function. One randomly selected sheep with polymeric valve was euthanized and the explanted valved stent was analyzed macroscopically and microscopically.Implantation was successful in 9 sheep. Angiography at implantation showed all 9 prosthetic valves demonstrated orthotopic position and normal functionality. All 9 sheep survived at 4-week follow-up. Four-week follow-up revealed no evidence of valve stent dislocation or deformation and normal valvular and cardiac functionality. The cardiac catheter examination showed the peak-peak transvalvular pressure gradient of the polymeric valves was 11.9±5.0 mmHg, while that of two bovine pericardium valves were 11 and 17 mmHg. Gross morphology demonstrated good opening and closure characteristics. No thrombus or calcification was seen macroscopically
Prifti, Edvin; Ademaj, Fadil; Kajo, Efrosina; Baboci, Arben
The left ventricular localization of a myxoma is very rare, usually arising from the interventricular septum close to the left ventricular outflow tract, the mitral valve, the ventricular wall and extremely rarely the aortic valve. A 13-year-old male was admitted due to dyspnea and angina. Transesophageal echocardiography revealed left ventricular outflow tract obstruction with a mean gradient of 58 mmHg, and a mobile mass measuring 65×25 mm originating from the ventricular surface of the aortic valve was identified. The patient underwent urgent surgical excision and aortic valve replacement. Histopathological examination of the mass confirmed the diagnosis of a myxoma. In conclusion, a myxoma originating from the aortic valve remains a very rare localization. Total resection associated with aortic valve replacement seems to offer an excellent outcome.
Kurian, Mathew V; Umasankar, Payanam R; Sabareeswaran, Arumugam; Shenoy, Sachin J; Subban, Vijayakumar; Joseph, Mathew K
Valve-associated complications challenge the quality of life and longevity after heart valve replacement. Inappropriate healing may be a contributing factor. To evaluate a new design mechanical heart valve in an animal model. The new valve was fabricated by substituting the sewing ring with an inbuilt suture ridge and an overlying fabric flap. It improved the effective orifice area. Animal experiments were performed on pigs to compare this valve with standard valve models. The animals were kept on dual antiplatelet drugs. Six of the 8 test animals survived the observation period of 140 days compared to 2 of the 6 controls. Among the test valves, one had thrombosis and 3 had significant tissue hyperplasia, whereas 5 control valves had thrombosis associated with significant tissue hyperplasia. Three test valves had paravalvular defects compared to none in the control group. Histology showed good tissue incorporation of the fabric flap of the test valves, whereas the control valves had tissue infiltration limited to the peripheral fabric layer of the sewing ring. The new valve has improved effective orifice area, and the animal study showed better survival, good healing, and a lower incidence of thrombosis and tissue hyperplasia.
Sillesen, Martin; Hjortdal, Vibeke; Vejlstrup, Niels
Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves.......Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves....
Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman
Thrombus formation is a major concern for recipients of mechanical heart valves (MHVs), which requires them to take anticoagulant drugs for the rest of their lives. Bioprosthetic heart valves (BHVs) do not require life-long anticoagulant therapy but deteriorate after 10-15years. The thrombus formation is initiated by the platelet activation which is thought to be mainly generated in MHVs by the flow through the hinge and the leakage flow during the diastole. However, our results show that the activation in the bulk flow during the systole phase might play an essential role as well. This is based on our results obtained by comparing the thrombogenic performance of a MHV and a BHV (as control) in terms of shear induced platelet activation under exactly the same conditions. Three different mathematical activation models including linear level of activation, damage accumulation, and Soares model are tested to quantify the platelet activation during systole using the previous simulations of the flow through MHV and BHV in a straight aorta under the same physiologic flow conditions. Results indicate that the platelet activation in the MHV at the beginning of the systole phase is slightly less than the BHV. However, at the end of the systole phase the platelet activation by the bulk flow for the MHV is several folds (1.41, 5.12, and 2.81 for linear level of activation, damage accumulation, and Soares model, respectively) higher than the BHV for all tested platelet activation models. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Severe aortic valve stenosis (AVS can cause an exercise-induced reflex syncope (RS. The precise mechanism of this syncope is not known. The changes in hemodynamics are variable, including arrhythmias and myocardial ischemia, and one of the few consistent changes is a sudden fall in systemic and pulmonary arterial pressures (suggesting a reduced vascular resistance followed by a decline in heart rate. The contribution of the cardioinhibitory and vasodepressor components of the RS to hemodynamics was evaluated by a computer model. This lumped-parameter computer simulation was based on equivalent electronic circuits (EECs that reflect the hemodynamic conditions of a heart with severe AVS and a concomitantly decreased contractility as a long-term detrimental consequence of compensatory left ventricular hypertrophy. In addition, the EECs model simulated the resetting of the sympathetic nervous tone in the heart and systemic circuit during exercise and exercise-induced syncope, the fluctuating intra-thoracic pressure during respiration, and the passive relaxation of ventricle during diastole. The results of this simulation were consistent with the published case reports of exertional syncope in patients with AVS. The value of the EEC model is its ability to quantify the effect of a selective and gradable change in heart rate, ventricular contractility, or systemic vascular resistance on the hemodynamics during an exertional syncope in patients with severe AVS.
Preetham R Muskala
Full Text Available A 68-year-old man with a severe ischemic cardiomyopathy underwent left ventricular assist device (LVAD implantation (Heart Mate II device for destination therapy. He presented 49 months after LVAD implantation with worsening heart failure symptoms and new severe aortic regurgitation. Given high risk for both surgical and transcatheter aortic valve replacement, he was admitted for transcatheter closure of the aortic valve under transesophageal echocardiographic (TEE guidance. TEE imaging revealed severe aortic regurgitation (Fig. 1A and B and Videos 1 and 2. Under TEE and fluoroscopic guidance, a 25 mm Amplatzer cribriform atrial septal defect closure device was advanced across the aortic valve (Fig. 1C and D and Videos 3 and 4. Immediately after device deployment, TEE revealed a well-seated device with complete aortic valve closure and trivial aortic regurgitation (Fig. 2A, B, C and D and Videos 5, 6, 7 and 8. Subsequent transthoracic echocardiograms obtained from 74 to 172 days after the procedure revealed no residual aortic regurgitation. The patient awoke with diffuse urticaria 244 days after the procedure and died en route to the emergency department, presumably secondary to a systemic allergic reaction. De novo aortic regurgitation is increasingly recognized in patients with LVADs (1. TEE-guided transcatheter aortic valve closure is an option in these high-risk patients (2.
Hansen, Tina B; Berg, Selina K; Sibilitz, Kirstine L
BACKGROUND: As with ischaemic heart disease, cardiac rehabilitation (CR) is recommended for patients undergoing heart valve surgery; recommendations are based on limited evidence. The organization of CR programmes and factors associated with uptake among patients undergoing heart valve surgery have......, with patients in the capital region less likely to be referred (0.22 (0.08-0.57)). Patients with TAVI were less likely to participate (0.29 (0.12-0.70)). CONCLUSIONS: Despite high national programme coverage, only half the patients post heart valve surgery received CR. Both factors identified at provider......- and patient-level influenced uptake and included significant regional variation in referral pattern. Further research into the effect and organization of CR post heart valve surgery is needed....
Eren, Esin; Ellidag, Hamit Yasar; Cekin, Yesim; Ayoglu, Raif Umut; Sekercioglu, Ali Osman; Yılmaz, Necat
Endothelia, intima, and connective tissues comprise the heart valves, but the relationship between heart valve damage, the pathogenesis of valve degeneration, and vitamin D, oxidative stress remains unclear. Here, we assessed serum 25(OH) vitamin D (calcidiol), parathormone (PTH), and redox balance in patients with mitral valve regurgitation (MR) and aortic valve regurgitation (AR). This study includes 56 chronic heart valve disease (HVD) patients. Patients were diagnosed with MR or AR depending on the echocardiographic findings. Also, 40 sex-matched healthy control participants were enrolled for comparison. Serum calcidiol, PTH, total oxidative status (TOS), and total antioxidative capacity were measured, and the oxidative stress index (OSI) was calculated. Patients with HVD demonstrated significantly higher PTH, increased TOS and OSI, and a higher frequency of calcidiol deficiency than the control participants. Calcidiol and TOS were negatively correlated (r = -0.29; P Heart valve regurgitation (AR and MR) is correlated to oxidative stress and hypovitaminosis D.
Kim, Sang Soo; Lim, Sang Hyun; Cho, Seung Woo; Gwak, So Jung; Hong, Yoo Sun; Chang, Byung Chul; Park, Moon Hyang; Song, Kang Won; Choi, Cha Yong; Kim, Byung Soo
To increase the biocompatibility and durability of glutaraldehyde (GA)-fixed valves, a biological coating with viable endothelial cells (ECs) has been proposed. However, stable EC layers have not been formed successfully on GA-fixed valves due to their inability to repopulate. In this study, to improve cellular adhesion and proliferation, the GA-fixed prostheses were detoxified by treatment with citric acid to remove free aldehyde groups. Canine bone marrow mononuclear cells (MNCs) were differentiated into EC-like cells and myofibroblast-like cells in vitro. Detoxified prostheses were seeded and recellularized with differentiated bone marrow- derived cells (BMCs) for seven days. Untreated GA-fixed prostheses were used as controls. Cell attachment, proliferation, metabolic activity, and viability were investigated and cell-seeded leaflets were histologically analyzed. On detoxified GA-fixed prostheses, BMC seeding resulted in uninhibited cell proliferation after seven days. In contrast, on untreated GA-fixed prostheses, cell attachment was poor and no viable cells were observed. Positive staining for smooth muscle a-actin, CD31, and proliferating cell nuclear antigen was observed on the luminal side of the detoxified valve leaflets, indicating differentiation and proliferation of the seeded BMCs. These results demonstrate that the treatment of GA-fixed valves with citric acid established a surface more suitable for cellular attachment and proliferation. Engineering heart valves by seeding detoxified GA-fixed biological valve prostheses with BMCs may increase biocompatibility and durability of the prostheses. This method could be utilized as a new approach for the restoration of heart valve structure and function in the treatment of end-stage heart valve disease.
Sievers, Hans-Hinrich; Schubert, Kathrin; Jamali, Ashkan; Scharfschwerdt, Michael
A novel mechanical heart valve was developed with a special focus on avoiding anticoagulation. Computational fluid dynamics were used for the research design. Here, the effect of different anatomical inflow geometries on flow characteristics is evaluated. Flow and pressure simulations were performed on a novel 3-leaflet mechanical heart valve in a fully open position at 2 flow rates related to the peak and end-systolic flow. The computational fluid dynamics model was designed according to 4 different (1 cylindrical, 3 conical with increasing diameter) anatomical configurations of the left ventricular outflow tract derived from an inverse heart model. With increasing inflow diameter, the flow velocity decreased for both flow rates, from 1543 mm/s in cylindrical configuration to 1475 mm/s in conical configuration for a flow rate of 18 l/min. However, there was no further decrease for the inflow diameters 38 and 48 mm. The velocity profile became broader with increasing inflow diameter and the maximal pressure decreased. At the leading edge, velocity almost stagnated, while the pressure increased and the reflection point moved downstream. No occurrence of dead space was observed with the different configurations and flow rates. An analysis of different anatomical inflow configurations by computational fluid dynamic simulations showed a more homogenous velocity profile and lower flow velocity values with increasing inflow diameter up to 38 mm in this novel 3-leaflet mechanical heart valve.
Simionescu, Dan T.; Chen, Joseph; Jaeggli, Michael; Wang, Bo; Liao, Jun
Tissue engineering the aortic heart valve is a challenging endeavor because of the particular hemodynamic and biologic conditions present in the native aortic heart valve. The backbone of an ideal valve substitute should be a scaffold that is strong enough to withstand billions of repetitive bending, flexing and stretching cycles, while also being slowly degradable to allow for remodeling. In this review we highlight three overlooked aspects that might influence the long term durability of tissue engineered valves: replication of the native valve trilayered histoarchitecture, duplication of the three-dimensional shape of the valve and cell integration efforts focused on getting the right number and type of cells to the right place within the valve structure and driving them towards homeostatic maintenance of the valve matrix. We propose that the trilayered structure in the native aortic valve that includes a middle spongiosa layer cushioning the motions of the two external fibrous layers should be our template for creation of novel scaffolds with improved mechanical durability. Furthermore, since cells adapt to micro-loads within the valve structure, we believe that interstitial cell remodeling of the valvular matrix will depend on the accurate replication of the structures and loads, resulting in successful regeneration of the valve tissue and extended durability. PMID:23355946
Dan T. Simionescu
Full Text Available Tissue engineering the aortic heart valve is a challenging endeavor because of the particular hemodynamic and biologic conditions present in the native aortic heart valve. The backbone of an ideal valve substitute should be a scaffold that is strong enough to withstand billions of repetitive bending, flexing and stretching cycles, while also being slowly degradable to allow for remodeling. In this review, we highlight three overlooked aspects that might influence the long term durability of tissue engineered valves: (i replication of the native valve trilayered histoarchitecture, (ii duplication of the three-dimensional shape of the valve, (iii and cell integration efforts focused on getting the right number and type of cells to the right place within the valve structure and driving them towards homeostatic maintenance of the valve matrix. We propose that the trilayered structure in the native aortic valve that includes a middle spongiosa layer cushioning the motions of the two external fibrous layers should be our template for creation of novel scaffolds with improved mechanical durability. Furthermore, since cells adapt to micro-loads within the valve structure, we believe that interstitial cell remodeling of the valvular matrix will depend on the accurate replication of the structures and loads, resulting in successful regeneration of the valve tissue and extended durability.
Full Text Available Introduction: Takotsubo cardiomyopathy (TCM can be complicated by left ventricular outflow tract (LVOT obstruction and severe acute mitral regurgitation (MR, leading to hemodynamic instability in an otherwise benign disorder. Despite the severity of these complications, there is a paucity of literature on the matter. Because up to 20–25% of TCM patients develop LVOT obstruction and/or MR, it is important to recognize the clinical manifestations of these complications and to adhere to specific management in order to reduce patient morbidity and mortality. We report the clinical history, imaging, treatment strategy, and clinical outcome of a patient with TCM that was complicated with severe MR and LVOT obstruction. We then discuss the pathophysiology, characteristic imaging, key clinical features, and current treatment strategy for this unique patient population. Case report: A postmenopausal woman with no clear risk factor for coronary artery disease (CAD presented to the emergency department with chest pain after an episode of mental/physical stress. Physical examination revealed MR, mild hypotension, and pulmonary vascular congestion. Her troponins were mildly elevated. Cardiac catheterization excluded obstructive CAD, but revealed severe apical hypokinesia and ballooning. Notably, multiple diagnostic tests revealed the presence of severe acute MR and LVOT obstruction. The patient was diagnosed with TCM complicated by underlying MR and LVOT obstruction, and mild hemodynamic instability. The mechanism of her LVOT and MR was attributed to systolic anterior motion of the mitral valve (SAM, which the transesophageal echocardiogram clearly showed during workup. She was treated with beta-blocker, aspirin, and ACE-I with good outcome. Nitroglycerin and inotropes were discontinued and further avoided. Conclusions: Our case illustrated LVOT obstruction and MR associated with underlying SAM in a patient with TCM. LVOT obstruction and MR are severe
Antunes, Manuel J; Rodríguez-Palomares, José; Prendergast, Bernard; De Bonis, Michele; Rosenhek, Raphael; Al-Attar, Nawwar; Barili, Fabio; Casselman, Filip; Folliguet, Thierry; Iung, Bernard; Lancellotti, Patrizio; Muneretto, Claudio; Obadia, Jean-François; Pierard, Luc; Suwalski, Piotr; Zamorano, Pepe
Tricuspid regurgitation (TR) is a very frequent manifestation of valvular heart disease. It may be due to the primary involvement of the valve or secondary to pulmonary hypertension or to the left-sided heart valve disease (most commonly rheumatic and involving the mitral valve). The pathophysiology of secondary TR is complex and is intrinsically connected to the anatomy and function of the right ventricle. A systematic multimodality approach to diagnosis and assessment (based not only on the severity of the TR but also on the assessment of annular size, RV function and degree of pulmonary hypertension) is, therefore, essential. Once considered non-important, treatment of secondary TR is currently viewed as an essential concomitant procedure at the time of mitral (and, less frequently, aortic valve) surgery. Although the indications for surgical management of severe TR are now generally accepted (Class I), controversy persists concerning the role of intervention for moderate TR. However, there is a trend for intervention in this setting, especially at the time of surgery for left-sided heart valve disease and/or in patients with significant tricuspid annular dilatation (Class IIa). Currently, surgery remains the best approach for the interventional treatment of TR. Percutaneous tricuspid valve intervention (both repair and replacement) is still in its infancy but may become a reliable option in future, especially for high-risk patients with isolated primary TR or with secondary TR related to advanced left-sided heart valve disease. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Schoen, Frederick J
Over the past several decades, there has been substantial progress toward understanding the mechanisms of heart valve function and dysfunction. This review summarizes an evolving conceptual framework of heart valve functional structure, developmental biology, and pathobiology and explores the implications of key insights. I emphasize: (a) valve cell and extracellular matrix biology and the impact of biomechanical factors on function, homeostasis, environmental adaptation, and key pathological processes; (b) the role of developmental processes, valvular cell behavior, and extracellular matrix remodeling in congenital and acquired valve abnormalities; and (c) the cell/matrix biology of degeneration in replacement tissue valves. I also summarize how these considerations may ultimately inform the potential for prevention and treatment of major diseases and potentially therapeutic regeneration of the cardiac valves. Recent advances and opportunities for research and clinical translation are highlighted.
Quintana, Eduard; Suri, Rakesh M; Thalji, Nassir M; Daly, Richard C; Dearani, Joseph A; Burkhart, Harold M; Li, Zhuo; Enriquez-Sarano, Maurice; Schaff, Hartzell V
A proportion of patients experience a decrease in left ventricular (LV) ejection fraction (EF) after mitral valve repair; however, predictors and long-term consequences remain unclear. A study of 1705 patients with severe, degenerative mitral valve regurgitation and normal preoperative EF (>60%) undergoing mitral valve repair from 1993 to 2012 was performed. Multivariate logistic regression and Cox proportional hazards models were used to determine the predictors of early postoperative LV dysfunction (EF 60%) in only one third of patients with postrepair EF 49 mm Hg and left ventricular end-systolic diameter >36 mm were independently associated with a 4.4- and 6.5-fold increased risk of developing a postoperative EF < 40% (P < .001, for both). De novo postoperative LV dysfunction is not uncommon in patients with "normal" preoperative EF undergoing mitral valve repair. LV dysfunction can persist, impairing recovery of LV size, function, and survival. The consideration of mitral repair before the onset of excessive LV dilation or pulmonary hypertension, even in those with preserved EF, seems warranted. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Chen, Yan; Seto, Wai-Kay; Ho, Lai-Ming; Fung, James; Jim, Man-Hong; Yip, Gabriel; Fan, Katherine; Zhen, Zhe; Liu, Ju-Hua; Yuen, Man-Fung; Lau, Chu-Pak; Tse, Hung-Fat; Yiu, Kai-Hang
The aim of the study was to evaluate the relation between tricuspid regurgitation (TR) severity and liver stiffness (LS) in patients with TR. A total of 131 patients with various degrees of TR secondary to left-sided heart valve disease were enrolled. Severity of TR was quantitatively assessed by proximal isovelocity surface area-derived effective regurgitant orifice (ERO). Patients were divided into 2 groups: 48 with mild-moderate TR (ERO 2.15 cm(2)) provided a high specificity of 78% for significant LS. In conclusion, the present study demonstrates that TR-ERO, right atrial pressure, and IVC diameter are important parameters associated with LS in patients with TR. Copyright © 2016 Elsevier Inc. All rights reserved.
Full Text Available In this investigation, scanning electron microscopy was used to characterize the microstructure on the surfaces of animal heart valve cusps/leaflets. The results showed that though these surfaces appear smooth to the naked eye, they are actually comprised of a double hierarchical structure consisting of a cobblestone-like microstructure and nano-cilia along with mastoids with a directional arrangement. Such nanostructures could play a very important role in the hemocompatibility characteristics of heart valves. On this basis, the model of the microstructure was constructed and theoretical analysis was used to obtain optimal geometric parameters for the rough surface of artificial valve cusps/leaflets. This model may help improve reconstructive techniques and it may be beneficial in the design and fabrication of valve substitutes or partial substitutes. Namely, the model may help ameliorate heart valve replacement surgery.
Beltran, A.; Zenit, R.
We report experimental observations of the performance of mechanical and biological prosthetic heart valves. The valves are mounted in a test circular channel conected to a flow system that emulates accelerated human-like conditions. The flow is generated by a high frequencie pulsative pump (in the range of 7 to 18 Hz). The objective of the investigation is to find the treshold conditions for which the open/close performance fails. Preliminary results show that for the mechanical valve the failure starts at 436 pulses/min, while for the biological valve, it starts a failing performance is observed for frequencies higher that 462 pulses/min. Even though these values are far from the heart rate in the human body, we use these measurements to further understand the structure-fluid interaction mechanics of the flow through heart valves.
Ruhl, K M; Langebartels, G; Autschbach, R; Katoh, M; Günther, R W; Krombach, G A
To investigate the potential of ECG-triggered MRI for the evaluation of postoperative anatomy and function of the heart and conduit following implantation of a left-ventricular apico-aortic conduit. 5 patients (2 female, 3 male, mean age 72.5 years) were examined using a 1.5 Tesla whole-body MRI (Gyroscan Intera, Philips Medical Systems, Best, The Netherlands) following apico-aortic conduit surgery due to severe aortic valve stenosis. The reason for performing conduit implantation instead of aortic valve replacement was the risk of injuring a bypass graft from prior coronary artery bypass surgery. Cine steady-state-free-precession (SSFP) sequences were used to assess ventricular function, navigator-gated 3D-SSFP and breath-hold, time-resolved contrast-enhanced MR angiography was used to display the postoperative anatomy, and 2D-gradient echo sequences with an inversion pulse to suppress the signal of the healthy myocardium were used to evaluate potential myocardial scarring. Flow sensitive gradient echo sequences were performed to determine the blood flow in the conduit. In all patients the apico-aortic conduit proved to be open with a maximum flow velocity of 126 (+ 43) cm/s. The postoperative anatomy was able to be evaluated in all patients and perioperative myocardial infarction was able to be ruled out. The mean ejection fraction of the left ventricle was 44.2 + 6.2 % with a mean volume of 80 + 20.6 ml per heart beat. ECG-triggered MRI is a reliable method for the evaluation of postoperative anatomy and function following implantation of a left ventricular apico-aortic conduit.
Maeder, Micha Tobias; Schoch, Otto D; Kleiner, Rebekka; Joerg, Lucas; Weilenmann, Daniel; Swiss Society For Pulmonary Hypertension
Pulmonary hypertension associated with left-sided heart disease (PH-LHD) is the most common type of pulmonary hypertension. In patients with left-sided heart disease, the presence of pulmonary hypertension is typically a marker of more advanced disease, more severe symptoms, and worse prognosis. In contrast to pulmonary arterial hypertension, PH-LHD is characterised by an elevated pulmonary artery wedge pressure (postcapillary pulmonary hypertension) without or with an additional precapillary component (isolated postcapillary versus combined postcapillary and precapillary pulmonary hypertension). Transthoracic echocardiography is the primary nonin-vasive imaging tool to estimate the probability of pulmonary hypertension and to establish a working diagnosis on the mechanism of pulmonary hyperten-sion. However, right heart catheterisation is always required if significant pulmonary hypertension is sus-pected and exact knowledge of the haemodynamic constellation is necessary. The haemodynamic con-stellation (mean pulmonary artery pressure, mean pulmonary artery wedge pressure, left ventricular end-diastolic pressure) in combination with clinical infor-mation and imaging findings (mainly echocardiog-raphy, coronary angiography and cardiac magnetic resonance imaging) will usually allow the exact mech-anism underlying PH-LHD to be defined, which is a prerequisite for appropriate treatment. The general principle for the management of PH-LHD is to treat the underlying left-sided heart disease in an optimal man-ner using drugs and/or interventional or surgical ther-apy. There is currently no established indication for pulmonary arterial hypertension-specific therapies in PH-LHD, and specific therapies may even cause harm in patients with PH-LHD.
MacGrogan, Donal; Luxán, Guillermo; Driessen-Mol, Anita; Bouten, Carlijn; Baaijens, Frank; de la Pompa, José Luis
Cardiac valve disease is a significant cause of ill health and death worldwide, and valve replacement remains one of the most common cardiac interventions in high-income economies. Despite major advances in surgical treatment, long-term therapy remains inadequate because none of the current valve substitutes have the potential for remodeling, regeneration, and growth of native structures. Valve development is coordinated by a complex interplay of signaling pathways and environmental cues that cause disease when perturbed. Cardiac valves develop from endocardial cushions that become populated by valve precursor mesenchyme formed by an epithelial–mesenchymal transition (EMT). The mesenchymal precursors, subsequently, undergo directed growth, characterized by cellular compartmentalization and layering of a structured extracellular matrix (ECM). Knowledge gained from research into the development of cardiac valves is driving exploration into valve biomechanics and tissue engineering directed at creating novel valve substitutes endowed with native form and function. PMID:25368013
Full Text Available It is known that a dynamic left ventricular outflow tract (LVOT obstruction exists in patients, following aortic valve replacement (AVR and is usually considered to be benign. We present a patient with dynamic LVOT obstruction following AVR, who developed refractory cardiogenic shock and expired inspite of various treatment strategies. This phenomenon must be diagnosed early and should be considered as a serious and potentially fatal complication following AVR. The possible mechanisms and treatment options are reviewed.
Bazan, Ovandir; Ortiz, Jayme P; Fukumasu, Newton K; Pacifico, Antonio L; Yanagihara, Jurandir I
The flow patterns of a prosthetic heart valve in the aortic or mitral position can change according to its type and orientation. This work describes the use of 2D particle image velocimetry (PIV) applied to the in vitro flow fields characterization inside the upper part of a left ventricular model at various heart rates and as a function of two orientations of stented tricuspid mitral bioprostheses. In the ventricular model, each mitral bioprosthesis (27 and 31 mm diameter) was installed in two orientations, rotated by 180°, while the aortic bileaflet mechanical valve (27 mm diameter) remained in a fixed orientation. The results (N = 50) showed changes in the intraventricular flow fields according to the mitral bioprostheses positioning. Also, changes in the aortic upstream velocity profiles were noticed as a function of mitral orientations. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
Chaux, Aurelio; Gray, Richard J; Stupka, Jonathan C; Emken, Michael R; Scotten, Lawrence N; Siegel, Rolland
Valvular heart disease remains a large public health problem for all societies; it attracts the attention of public health organizations, researchers and governments. Valve substitution is an integral part of the treatment for this condition. At present, the choice of valve prosthesis is either tissue or mechanical. Tissue valves have become increasingly popular in spite of unresolved problems with durability, hemodynamics, cost and need for anticoagulation therapy. As a consequence, mechanical valve innovation has virtually ceased; the last successful mechanical design is 25 years old. We postulate that with improved technology, knowledge and experience gained over the last quarter century, the best possible solution to the problem of valve substitution can be achieved with a mechanical valve that is anticoagulant independent, durable, hemodynamically and cost efficient. At present, it is possible to design, test and produce a valve that can accomplish these goals.
Syedain, Zeeshan H; Bradee, Allison R; Kren, Stefan; Taylor, Doris A; Tranquillo, Robert T
Tissue-engineered heart valves (TEHV) have been proposed as a promising solution for the clinical needs of pediatric patients. In vivo studies have shown TEHV leaflet contraction and regurgitation after several months of implantation. This has been attributed to contractile cells utilized to produce the extracellular matrix (ECM) during TEHV culture. Here, we utilized such cells to develop a mature ECM in a fibrin-based scaffold that generates commissural alignment in TEHV leaflets and then removed these cells using detergents. Further, we evaluated recellularization with potentially noncontractile cells. A tissue-engineered leaflet model was developed with mechanical anisotropy and tensile properties comparable to an ovine pulmonary valve leaflet. No change in tensile properties occurred after decellularization using 1% sodium dodecyl sulfate and 1% Triton detergent treatment. Cell removal was verified by DNA quantitation and western blot analysis for cellular proteins. Histological and scanning electron microscope imaging showed no significant change in the ECM organization and microstructure. We further tested the recellularization potential of decellularized leaflets by seeding human mesenchymal stem cells (hMSC) on the surface of the leaflets and evaluated them at 1 and 3 weeks in two culture conditions. One medium (M1) was chosen to maintain the MSC phenotype while a second medium (M2) was used to potentially differentiate cells to an interstitial cell phenotype. Cellular quantitation showed that the engineered leaflets were recellularized to the highest concentration with M2 followed by M1, with minimum cell invasion of decellularized native leaflets. Histology showed cellular invasion throughout the thickness of the leaflets in M2 and partial invasion in M1. hMSC stained positive for MSC markers, but also for α-smooth muscle actin in both media at 1 week, with no presence of MSC markers at 3 weeks with the exception of CD90. These results show that
van den Brink, Renee B. A.
Transesophageal echocardiography (TEE) is especially suitable for examination of prosthetic valves because of the proximity of the esophagus to the heart and absence of interference with lungs and ribs. This article reviews normal and abnormal morphologic characteristics of prosthetic valves such as
Habets, Jesse; van den Brink, Renee B. A.; Uijlings, Ruben; Spijkerboer, Anje M.; Mali, Willem P. Th M.; Chamuleau, Steven A. J.; Budde, Ricardo P. J.
Objectives Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. Methods ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of
Strong, M.; O'Neal, P.D.; Gage, H.N.; Moogk, M.
The Northwest Tissue Center established a human heart valve program in 199 1. It is one of four non-profit tissue banks and one for-profit program that recover and process heart valves in the United States. During the eight years in which the Northwest Tissue Center has been involved in heart valve banking, there have been a total of 673 hearts procured for processing. The age of the donors ranged from <1 to 44 years with a mean of 26.2 years, 66% werw male,and 6.5% of the hearts procered were discarded due to a variety of medical and criteria reason. The primary reasons for differal were questions of possible cancer and questions of high risk behavior/social history. Of the 1,264 cardiovascular tissues processed, 6% were lost because of donor history, 17% were lost because of microbiology results, and 5% were lost because of donor serology . There were total a total of 190 aortic valves and 48 pulmonic conduits transplanted over this time period. The mean age of the recipients was 23.4 with a median or 23 years; 102 of the recipients were less than one year of age. Males comprised 62% of the recipients. Since 1993, there has been a clear shift towards more use of pulmonic valves over aortic valves as a results of the acceptance of the Ross procedure. Early in the program, reports were received from surgeons that some heart valves appeared to have cracks in the conduits. Experimentations in the laboratory led to the discovery that thawing too rapidly would result in cracking of these materials. Packaging was designed to reduce the rate of thawing and this has resolved the problem with cracking. The heart valve program at the Northwest Tissue Center has been very successful in providing the necessary valves for patients in the Northwest Region of the United States
Drury, P J; Olsen, E G; Ross, D N
Porcine aortic valves stored in various concentrations of sucrose (50-80%) for up to 52 weeks were examined both histologically and by electron microscopy. The valves were compared with porcine aortic valves stored in a nutrient and antibiotic medium for 12 weeks. Overall preservation was better in those porcine valves stored in sucrose solution than in nutrient and antibiotic medium, the best preservation being in 50% sucrose. Despite wide separation of collagen at that concentration seen on...
Yousefi, Atieh; Vaesken, Antoine; Amri, Amna; Dasi, Lakshmi Prasad; Heim, Frederic
Transcatheter aortic valve implantation (TAVI) has become a popular alternative technique to surgical valve replacement for critical patients. Biological valve tissue has been used in TAVI procedures for over a decade, with over 100,000 implantations to date. However, with only 6 years follow up, little is known about the long-term durability of biological tissue. Moreover, the high cost of tissue harvesting and chemical treatment procedures favor the development of alternative synthetic valve leaflet materials. Textile polyester is one such material which provides outstanding folding and strength properties combined with proven biocompatibility, and could therefore be considered as a candidate to replace the biological valve leaflets in TAVI procedures. For that purpose, in addition to the mechanical properties, the hemodynamic properties of the synthetic material should be comparable to the properties of biological tissue. An ideal replacement heart valve would provide low static and dynamic regurgitation, ensure laminar flow across the valve, and limit the turbidity of flow downstream of the valve. The purpose of the present work is to compare in vitro the mechanical and hemodynamic performances of textile woven polyester valves with biological ones. Testing results indicate that textile valves trade elasticity for superior mechanical strength, relative to biological tissue. Despite this, the dynamic flexibility of textile valve leaflets strongly resembled what was seen with biological leaflets. Regurgitation, as well as slightly modified turbulent patterns, in textile valves was higher than biological valves due to the increased porosity, but, rapid tissue ingrowth post-implantation would likely mitigate this effect. Together these findings provide additional evidence favoring the use of textile polyester as a synthetic heart valve leaflet material.
... Aortic Valve Regurgitation - Problem: Mitral Valve Regurgitation - Problem: Tricuspid Valve Regurgitation - Problem: Pulmonary ... Heart Valve Disease Symptoms Dr. Robert Bonow describes the symptoms that ...
Wessels, Maria W.; van de Laar, Ingrid M. B. H.; Roos-Hesselink, Jolien; Strikwerda, Sipke; Majoor-Krakauer, Danielle F.; de Vries, Bert B. A.; Kerstjens-Frederikse, Wilhelmina S.; Vos, Yvonne J.; de Graaf, Bianca M.; Bertoli-Avella, Aida M.; Willems, Patrick J.
Only a limited number of families with clear monogenic inheritance of nonsyndromic forms of congenital valve defects have been described. We describe two multiplex pedigrees with a similar nonsyndromic form of heart valve anomalies that segregate as an autosomal dominant condition. The first family
Kwon, Young Joo
This paper addresses the basic concept of MDO methodology and the structural analysis that should be performed in the design process of a mechanical heart valve prosthesis with flat leaflet using MDO methodology. In the structural design of the mechanical heart valve (MHV) prosthesis, the fluid mechanics analysis is executed for the blood flow passing through the leaflets of a mechanical heart valve prosthesis. Thereafter, the rigid body dynamics analysis of the leaflet motion is performed to obtain the structural condition for the structural mechanics analysis of the deformed leaflet. Then the structural mechanics analysis of the deformed leaflet follows to confirm the minimum thickness of the leaflet for the structural durability of the mechanical heart valve prosthesis. This paper shows that the minimum leaflet thickness can be evaluated to be 0.6mm among the suggested thicknesses.
Klimeš, František; Kořenář, Josef
Roč. 9, č. 4 (2002), s. 249-258 ISSN 1210-2717 Institutional research plan: CEZ:AV0Z2060917 Keywords : mechanical heart valve prostheses * flow visualization- steady and pulsatile flow Subject RIV: BO - Biophysics
Rubbens, M.P.; Mol, A.; Boerboom, R.A.; Bank, R.A.; Baaijens, F.P.T.; Bouten, C.V.C.
Tissue-engineered heart valves lack sufficient amounts of functionally organized structures and consequently do not meet in vivo mechanical demands. To optimize tissue architecture and hence improve mechanical properties, various in vitro mechanical conditioning protocols have been proposed, of
Zarubin, Alexander M.; von Bally, Gert; Deiwick, M.; Geiger, A. W.; Scheld, H. H.
A new application of holographic interferometry in biomedicine and bioengineering is presented. Holographic interferometry techniques for non-destructive testing and biomechanical evaluation of prosthetic heart valves are developed, and experimental results obtained with tissue and mechanical values are demonstrated.
Gilmanov, Anvar; Stolarski, Henryk; Sotiropoulos, Fotis
Hyperelastic material models have been incorporated in the rotation-free, large deformation, shell finite element (FE) formulation of (Stolarski et al., 2013) and applied to dynamic simulations of aortic heart valve. Two models used in the past in analysis of such problem i.e. the Saint-Venant and May-Newmann-Yin (MNY) material models have been considered and compared. Uniaxial tests for those constitutive equations were performed to verify the formulation and implementation of the models. The issue of leaflets interactions during the closing of the heart valve at the end of systole is considered. The critical role of using non-linear anisotropic model for proper dynamic response of the heart valve especially during the closing phase is demonstrated quantitatively. This work contributes an efficient FE framework for simulating biological tissues and paves the way for high-fidelity flow structure interaction simulations of native and bioprosthetic aortic heart valves. Copyright © 2016. Published by Elsevier Ltd.
Bagno, Andrea; Anzil, Federico; Buselli, Roberto; Pesavento, Elena; Tarzia, Vincenzo; Pengo, Vittorio; Bottio, Tomaso; Gerosa, Gino
Bileaflet mechanical heart valves, which exhibit hemodynamic performance fairly similar to that of native valves, can be investigated by the analysis of their closing sounds. Signal spectra calculated from the closing sounds are characterized by specific features that are suitable for the functional evaluation of the valves. Five commercial bileaflet mechanical heart valves were studied under different conditions that were simulated in vitro using a Sheffield pulse duplicator for the aortic position. The closing sounds were acquired by means of a phonocardiographic apparatus, analyzed by a specifically implemented algorithm, and were statistically compared. This article was aimed at classifying the investigated valves on the basis of their signal spectra: different profiles were identified, depending on the working conditions; moreover, closing sound reproducibility and intensity allowed the ranking of valve performances with respect to the "noise" produced by valve closure. In particular, results demonstrated which valves were characterized by the lowest noise (i.e., the Medtronic Advantage and St. Jude Regent valves) and which were characterized by the highest reproducibility (OnX, Medtronic Advantage, and St. Jude Regent valves) under the examined experimental conditions.
Cheung, Daniel Y; Duan, Bin; Butcher, Jonathan T
Heart valve disease is an increasingly prevalent and clinically serious condition. There are no clinically effective biological diagnostics or treatment strategies. The only recourse available is replacement with a prosthetic valve, but the inability of these devices to grow or respond biologically to their environments necessitates multiple resizing surgeries and life-long coagulation treatment, especially in children. Tissue engineering has a unique opportunity to impact heart valve disease by providing a living valve conduit, capable of growth and biological integration. This review will cover current tissue engineering strategies in fabricating heart valves and their progress towards the clinic, including molded scaffolds using naturally derived or synthetic polymers, decellularization, electrospinning, 3D bioprinting, hybrid techniques, and in vivo engineering. Whereas much progress has been made to create functional living heart valves, a clinically viable product is not yet realized. The next leap in engineered living heart valves will require a deeper understanding of how the natural multi-scale structural and biological heterogeneity of the tissue ensures its efficient function. Related, improved fabrication strategies must be developed that can replicate this de novo complexity, which is likely instructive for appropriate cell differentiation and remodeling whether seeded with autologous stem cells in vitro or endogenously recruited cells.
Hong, Hao; Dong, Nianguo; Shi, Jiawei; Chen, Si; Guo, Chao; Hu, Ping; Qi, Hongxu
The aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an electrospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells (MSCs) onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated. MSCs were obtained from rats. Porcine aortic heart valves were decellularized, coated with poly(3-hydroxybutyrate-co-4-hydroxybutyrate) using an electrospinning technique, and reseeded and cultured over a time period of 14 days. In control group, the decellularized valve scaffolds were reseeded and cultured over an equivalent time period. Specimens of each group were examined histologically (hematoxylin-eosin [HE] staining, immunohistostaining, and scanning electron microscopy), biochemically (DNA and 4-hydroxyproline) and mechanically. The results showed that recellularization was comparable to the specimens of hybrid scaffolds and controls. The specimens of hybrid scaffolds and controls revealed comparable amounts of cell mass and 4-hydroxyproline (P>0.05). However, the specimens of hybrid scaffolds showed a significant increase in mechanical strength, compared to the controls (Ptissue engineered heart valves. And compared to the decellularized valve scaffolds, the hybrid scaffolds showed similar effects on the proliferation of MSCs and formation of extracellular matrix. It was believed that the hybrid scaffolds could be used for the construction of tissue engineered heart valves.
Tavakoli, Reza; Auf der Maur, Christoph; Mueller, Xavier; Schläpfer, Reinhard; Jamshidi, Peiman; Daubeuf, François; Frossard, Nelly
Full-root aortic valve replacement with stentless xenografts has potentially superior hemodynamic performance compared to stented valves. However, a number of cardiac surgeons are reluctant to transform a classical stented aortic valve replacement into a technically more demanding full-root stentless aortic valve replacement. Here we describe our technique of full-root stentless aortic xenograft implantation and compare the early clinical and midterm hemodynamic outcomes to those after aortic valve replacement with stented valves. We retrospectively compared the pre-operative characteristics of 180 consecutive patients who underwent full-root replacement with stentless aortic xenografts with those of 80 patients undergoing aortic valve replacement with stented valves. In subgroups presenting with aortic stenosis, we further analyzed the intra-operative data, early postoperative outcomes and mid-term regression of left ventricular mass index. Patients in the stentless group were younger (62.6 ± 13 vs. 70.3 ± 11.8 years, p regression of the left ventricular mass index in the stentless (p replacement can be performed without adversely affecting the early morbidity or mortality in patients operated on for aortic valve stenosis provided that the coronary ostia are not heavily calcified. The additional time necessary for the full-root stentless compared to the classical stented aortic valve replacement is therefore not detrimental to the early clinical outcomes and is largely rewarded in patients with aortic stenosis by lower transvalvular gradients at mid-term and a better regression of their left ventricular mass index.
Choi, Sun-Young; Jeong, Hee-Jin; Lim, Hong-Gook; Park, Seong-Sik; Kim, Soo-Hwan; Kim, Yong Jin
Porcine heart valves are among the most widely used tissue valves in clinical heart valve implantation. However, immunologic responses have been implicated as potential causes of the limited durability of xenograft heart valves. The study aim was to determine the effectiveness of alpha-galactosidase treatment used to degrade the major xenoreactive antigens found in xenograft heart valves. Fresh porcine heart valves and pericardium treated with alpha-galactosidase were studied to evaluate the xenoreactive galactose (alpha1,3) galactose (alpha-gal) antigen. Removal of the alpha-gal epitope from the porcine heart valve was monitored via 3,3'-diaminobenzidine staining intensity, while the removal of alpha-gal from N-glycans on porcine heart valves treated with recombinant alpha-galactosidase was determined either qualitatively or quantitatively by mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The porcine pericardium was used for monitoring the change in mechanical properties after alpha-galactosidase treatment. In addition, the biomechanical modification property of collagen fiber rearrangement on tissue was assessed using transmission electron microscopy (TEM). Following a 24-h incubation at pH 7.2, 4 degrees C, employing 0.1 U/ml of Bacteroides thetaiotaomicron-derived recombinant alpha-galactosidase, the enzyme effectively removed the alpha-gal epitopes expressed on porcine heart valves. The identification type of alpha-gal N-glycan on fresh aortic valve, aortic wall, pulmonary valve, and pulmonary wall was 7.1%, 10.3%, 6% and 8%, respectively. In the presence of alpha-galactosidase treatment, alpha-gal-containing N-glycans were converted into alpha-gal-negative N-glycans. Likewise, alpha-gal-containing N-glycans were not detected when MALDI-TOF MS quantitative analysis was used. Furthermore, no significant difference was observed in the mechanical properties and findings from TEM in alpha
Matsuyama, S.; Watabe, T.; Kuribayashi, S.
Conventional posteroanterior chest radiographs of 42 patients with mitral valve disease who had had surgery were analyzed, and particular attention was directed to the presence or absence of the convexity of the left lower midcardiac border (left artrial segment). The flatness or concavity of this segment, despite other evidence of left atrial enlargement, was observed in six (60%) of 10 patients who had left atrial thrombosis, and in three (9%) of 32 patients who did not have thrombosis (false positive diagnosis). Four of the 10 patients who had left atrial thrombosis did not show this finding on the radiographs (false negative diagnosis). One of these four had a thrombus only against the posterior wall of the body of the left atrium. Therefore, the accuracy in the diagnosis of thrombosis of the left atrial appendage was 66.7% (six of nine) for patients who had thrombosis of the appendage. Standard chest radiographs are important in the evaluation of the patient with thrombosis of the left atrial appendage
Pavone, Luigi Michele; Spina, Anna; Lo Muto, Roberta; Santoro, Dionea; Mastellone, Vincenzo; Avallone, Luigi
Multiple evidence demonstrate a role for serotonin and its transporter SERT in heart valve development and disease. By utilizing a Cre/loxP system driven by SERT gene expression, we recently demonstrated a regionally restricted distribution of SERT-expressing cells in developing mouse heart. In order to characterize the cell types exhibiting SERT expression within the mouse heart valves at early developmental stages, in this study we performed immunohistochemistry for Islet1 (Isl1) and connexin-43 (Cx-43) on heart sections from SERT Cre/+ ;ROSA26R embryos previously stained with X-gal. We observed the co-localization of LacZ staining with Isl1 labelling in the outflow tract, the right ventricle and the conal region of E11.5 mouse heart. Cx-43 labelled cells co-localized with LacZ stained cells in the forming atrioventricular valves. These results demonstrate the cardiomyocyte phenotype of SERT-expressing cells in heart valves of the developing mouse heart, thus suggesting an active role of SERT in early heart valve development.
Panduranga, Prashanth; Al-Mukhaini, Mohammed; Al-Muslahi, Muhanna; Haque, Mohammed A; Shehab, Abdullah
Management of warfarin-induced major bleeding in patients with mechanical heart valves is challenging. There is vast controversy and confusion in the type of treatment required to reverse anticoagulation and stop bleeding as well as the ideal time to restart warfarin therapy safely without recurrence of bleeding and/or thromboembolism. Presently, the treatments available to reverse warfarin-induced bleeding are vitamin K, fresh frozen plasma, prothrombin complex concentrates and recombinant activated factor VIIa. Currently, vitamin K and fresh frozen plasma are the recommended treatments in patients with mechanical heart valves and warfarin-induced major bleeding. The safe use of prothrombin complex concentrates and recombinant activated factor VIIa in patients with mechanical heart valves is controversial and needs well-designed clinical studies. With regard to restarting anticoagulation in patients with warfarin-induced major bleeding and mechanical heart valves, the safe period varies from 7-14 d after the onset of bleeding for patients with intracranial bleed and 48-72 h for patients with extra-cranial bleed. In this review article, we present relevant literature about these controversies and suggest recommendations for management of patients with warfarin-induced bleeding and a mechanical heart valve. Furthermore, there is an urgent need for separate specific guidelines from major associations/ professional societies with regard to mechanical heart valves and warfarin-induced bleeding.
Nachlas, Aline L Y; Li, Siyi; Davis, Michael E
Tissue engineered heart valves (TEHVs) have the potential to address the shortcomings of current implants through the combination of cells and bioactive biomaterials that promote growth and proper mechanical function in physiological conditions. The ideal TEHV should be anti-thrombogenic, biocompatible, durable, and resistant to calcification, and should exhibit a physiological hemodynamic profile. In addition, TEHVs may possess the capability to integrate and grow with somatic growth, eliminating the need for multiple surgeries children must undergo. Thus, this review assesses clinically available heart valve prostheses, outlines the design criteria for developing a heart valve, and evaluates three types of biomaterials (decellularized, natural, and synthetic) for tissue engineering heart valves. While significant progress has been made in biomaterials and fabrication techniques, a viable tissue engineered heart valve has yet to be translated into a clinical product. Thus, current strategies and future perspectives are also discussed to facilitate the development of new approaches and considerations for heart valve tissue engineering. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Sündermann, Simon H; Cesarovic, Nikola; Falk, Volkmar; Bettex, Dominique
Swine models are widely used to develop new techniques and materials for the treatment of heart valve disease like aortic valve and mitral valve transcatheter interventions and to train physicians in these techniques. Transoesophageal echocardiography (TOE) is crucial in these models. We defined standard planes of 2D and 3D TOE in healthy pigs undergoing transcatheter heart valve interventions. Twenty healthy pigs (weight 56-106 kg) underwent different mitral and aortic valve interventions (transcatheter aortic valve implantations, implantations of a mitral band, bicuspidization of the aortic valve, trans-septal punctures). For image guidance of the procedures, an adult TOE probe was introduced under direct vision in the oesophagus. Before the procedure itself was performed, a standardized protocol was used to determine normal values for anatomical and functional echocardiographic parameters. Positioning of the probe was possible in all animals and ideal when achieving a distance from the front teeth (incisors) of 40-60 cm. Anteflexion and lateroflexion of the probe was necessary to achieve optimal imaging quality. 2D visualization of all relevant cardiac structures was possible. The aortic annulus diameter was 24.1 ± 2.5 mm, the sinus of valsalva diameter was 30.6 ± 4 mm and the sinotubular junction diameter was 25.2 ± 4 mm. The ascending aorta had a diameter of 24 ± 4 mm and the descending aorta a diameter of 16 ± 5 mm. The mitral valve anterior-posterior diameter was 31.8 ± 4 mm and the commissure to commissure diameter was 40.5 ± 5 mm resulting in a mitral valve area of 10.7 ± 1.5 cm(2). 3D visualization was possible for the aortic and the mitral valve. None of the animals showed any pathology except one that had a dilated left ventricle and moderate mitral valve insufficiency. Left and right ventricular dimensions and the anatomy of the aortic-, mitral-, tricuspid and pulmonary valve as well as of the aorta were comparable with those of the human
D'Souza, Rohan; Silversides, Candice K; McLintock, Claire
The prothrombotic state of pregnancy increases the risk of thromboembolic complications and death in women with mechanical heart valves (MHVs). Although it is accepted that these women must be on therapeutic anticoagulation throughout pregnancy, competing maternal and fetal risks, as well as the lack of high-quality data from prospective studies, make the choice of the optimal method of anticoagulation challenging. Vitamin K antagonists (VKAs) are associated with fewer maternal complications, but conversely also the lowest live birth rates as well as warfarin-related embryopathy and fetopathy. Low-molecular-weight heparin (LMWH) does not cross the placenta and is associated with fewer fetal risks but more maternal complications. Sequential treatment involving VKAs in the second and third trimesters and either low-molecular-weight or unfractionated heparin in the first trimester, although appealing is still associated with maternal complications, especially around the time of bridging. As absolute equipoise of maternal versus fetal wellbeing is unlikely, patient preferences should be considered in decision making. A multidisciplinary team including hematologists, cardiologists, obstetric physicians, and high-risk obstetricians with expertise in the management of pregnant women with cardiac disease is required to optimize outcomes. Prospective studies are needed to determine the anticoagulant regimen for women with MHVs that provides optimal and acceptable maternal and fetal outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Delate, Thomas; Meisinger, Stephanie M; Witt, Daniel M; Jenkins, Daniel; Douketis, James D; Clark, Nathan P
Bridge therapy is associated with an increased risk of major bleeding in patients with atrial fibrillation and venous thromboembolism (TE) without a corresponding reduction in TE. The benefits of bridge therapy in patients with mechanical heart valve (MHV) prostheses interrupting warfarin for invasive procedures are not well described. A retrospective cohort study was conducted at an integrated health-care delivery system. Anticoagulated patients with MHV interrupting warfarin for invasive diagnostic or surgical procedures between January 1, 2006, and March 31, 2012, were identified. Patients were categorized according to exposure to bridge therapy during the periprocedural period and TE risk (low, medium, and high). Outcomes validated via manual chart review included clinically relevant bleeding, TE, and all-cause mortality in the 30 days following the procedure. There were 547 procedures in 355 patients meeting inclusion criteria. Mean cohort age was 65.2 years, and 38% were female. Bridge therapy was utilized in 466 (85.2%) procedures (95.2%, 77.3%, and 65.8% of high, medium, and low TE risk category procedures, respectively). The 30-day rate of clinically relevant bleeding was numerically higher in bridged (5.8%; 95% confidence interval [CI], 3.9%-8.3%) versus not bridged procedures (1.2%; 95% CI, bridge therapy is common among patients with MHV and may be associated with increased bleeding risk. Further research is needed to determine whether bridge therapy reduces TE in patients with MHV interrupting warfarin for invasive procedures.
Zhu, Tie-Yuan; Wang, Jian-Gang; Meng, Xu
A best evidence topic in adult valvular surgery was written according to a structured protocol. The question addressed was 'Does concomitant tricuspid annuloplasty increase the perioperative mortality and morbidity when correcting left-sided valve disease?' A total of 561 papers were found using the reported search, of which 12 presented the best evidence to answer the clinical question. The authors, country, journal, date of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Among these 12 papers, there were nine retrospective studies, two cohort studies and one randomized controlled trial (RCT). Overall, additional tricuspid valve (TV) repair takes more time during operations, particularly with a ring annuloplasty method. The mean aortic cross-clamping times were 57-83 min without associated tricuspid repair and 62-100 min with, and cardiopulmonary bypass times without and with repair were 82-124 and 90-174 min, respectively. A study of 624 patients who had undergone isolated mitral valve (MV) surgery and MV surgery plus TV repair showed more female and atrial fibrillation patients in the tricuspid valve plasty (TVP) group, but no increase in the 30-day mortality was found. One RCT, presenting similar patient baseline characteristics, also found no difference in the hospital mortality rates between the TVP group and the non-TVP group. Another 10 studies also demonstrated no statistically significant differences in perioperative mortality. In a cohort study of 311 patients undergoing MV repair with or without tricuspid annuloplasty, postoperative complications, such as bleeding, stroke, pacemaker, haemofiltration and myocardial infarction, all showed no statistically significant differences in the two groups. One study retrospectively analysed a large number of patients undergoing either isolated left-sided valve surgery or a concomitant TV repair, and there were no statistically significant differences
Haupt, Jessica; Lutter, Georg; Gorb, Stanislav N; Simionescu, Dan T; Frank, Derk; Seiler, Jette; Paur, Alina; Haben, Irma
Biological tissue has great potential to function as bioprostheses in patients for heart valve replacement. As these matrices are mainly xenogenic, the immunogenicity needs to be reduced by decellularization steps. Reseeding of bioscaffolds has tremendous potential to prevent calcification upon implantation, so intact microstructure of the material is mandatory. An optimal decellularization protocol of heart valves resulting in adequate preservation of the extracellular architecture has still not been developed. Biological scaffolds must be decellularized to remove the antigenic potential while preserving the complex mixture of structural and functional proteins that constitute the extracellular matrix. Here, we compared 3 different decellularization strategies for their efficiency to remove cells completely while preserving the porcine heart valve ultrastructure. Porcine pulmonary heart valves were treated either with trypsin-ethylenediaminetetraacetic acid (TRP), a protocol using detergents in combination with nucleases (DET + ENZ), or with Accutase® solution followed by nuclease treatment (ACC + ENZ). The treated heart valves then were subjected to histological, DNA and scanning electron microscopic analyses. All DNA fragments were removed after ACC + ENZ treatment, whereas cellular removal was incomplete in the TRP group. TRP and ACC + ENZ-treated valves were enlarged and showed a disrupted architecture and degraded ultrastructure. In contrast, fully acellular heart valves with intact architecture, layer composition and surface topography were achieved with DET + ENZ treatment. DET + ENZ treatment yielded excellent results in terms of preservation of material architecture and removal of DNA content. Compared to TRP and ACC + ENZ procedures, DET + ENZ-treated porcine pulmonary heart valves demonstrated well-preserved macroscopic structures and microscopic matrix components and represent an excellent scaffold for further
Full Text Available Abstract Background Infective Endocarditis (IE is considered as a multifaceted problem in every aspect from etiology and presentation to diagnosis and management. Early recognition of this disease and especially its complications, remain a critical task for the cardiologist. Atrial endocarditis is a rare and sometimes unrecognized complication of mitral valve endocarditis. Case presentation We present a 48 year-old male patient who was admitted to our clinic because of recent onset of malaise, fever, jaundice and peripheral edema. Important physical findings were peripheral stigmata of IE in addition to holosystolic murmur over the left sternal border. Transthoracic and transesophageal echocardiophy revealed a severe eccentric MR due to a flailed posterior mitral valve caused by IE. The presence of atrial septal endocarditis caused by jet streaming was also observed. Blood culture was positive for streptococcus oralis and antibiotic therapy was immediately initiated. Considering the large burden of infective tissue, the patient was planned for an early surgical intervention. A minimally invasive resection of the atrial mass, direct closure of the defect, resection of the diseased portions of mitral leaflets and implantation of a biological mitral valve prosthesis was performed. Intra-operative and histological findings confirmed provisional diagnosis by echocardiography. Conclusions Together with comprehensive echocardiographic evaluation, attention should be placed on mural vegetations and excluded among all cases of mitral valve endocarditis, particularly those with severe eccentric regurgitant jets.
Claiborne, Thomas E; Slepian, Marvin J; Hossainy, Syed; Bluestein, Danny
Present prosthetic heart valves, while hemodynamically effective, remain limited by progressive structural deterioration of tissue valves or the burden of chronic anticoagulation for mechanical valves. An idealized valve prosthesis would eliminate these limitations. Polymeric heart valves (PHVs), fabricated from advanced polymeric materials, offer the potential of durability and hemocompatibility. Unfortunately, the clinical realization of PHVs to date has been hampered by findings of in vivo calcification, degradation and thrombosis. Here, the authors review the evolution of PHVs, evaluate the state of the art of this technology and propose a pathway towards clinical reality. In particular, the authors discuss the development of a novel aortic PHV that may be deployed via transcatheter implantation, as well as its optimization via device thrombogenicity emulation. PMID:23249154
Azhar, Mohamad; Brown, Kristen; Gard, Connie; Chen, Hwudaurw; Rajan, Sudarsan; Elliott, David A.; Stevens, Mark V.; Camenisch, Todd D.; Conway, Simon J.; Doetschman, Thomas
Although the function of transforming growth factor beta2 (TGFβ2) in epithelial mesenchymal transition (EMT) is well studied, its role in valve remodeling remains to be fully explored. Here, we used histological, morphometric, immunohistochemical and molecular approaches and showed that significant dysregulation of major extracellular matrix (ECM) components contributed to valve remodeling defects in Tgfb2-/- embryos. The data indicated that cushion mesenchymal cell differentiation was impaired in Tgfb2-/- embryos. Hyaluronan and cartilage link protein-1 (CRTL1) were increased in hyperplastic valves of Tgfb2-/- embryos, indicating increased expansion and diversification of cushion mesenchyme into the cartilage cell lineage during heart development. Finally, western blot and immunohistochemistry analyses indicate that the activation of SMAD2/3 was decreased in Tgfb2-/- embryos during valve remodeling. Collectively, the data indicate that TGFβ2 promotes valve remodeling and differentiation by inducing matrix organization and suppressing cushion mesenchyme differentiation into cartilage cell lineage during heart development. PMID:21780244
Alavi, S Hamed; Soriano Baliarda, Marc; Bonessio, Noemi; Valdevit, Lorenzo; Kheradvar, Arash
The epidemiology of valvular heart disease has significantly changed in the past few decades with aging as one of the main contributing factors. The available options for replacement of diseased valves are currently limited to mechanical and bioprosthetic valves, while the tissue engineered ones that are under study are currently far from clinical approval. The main problem with the tissue engineered heart valves is their progressive deterioration that leads to regurgitation and/or leaflet thickening a few months after implantation. The use of bioresorbable scaffolds is speculated to be one factor affecting these valves' failure. We have previously developed a non-degradable superelastic nitinol mesh scaffold concept that can be used for heart valve tissue engineering applications. It is hypothesized that the use of a non-degradable superelastic nitinol mesh may increase the durability of tissue engineered heart valves, avoid their shrinkage, and accordingly prevent regurgitation. The current work aims to study the effects of the design features on mechanical characteristics of this valve scaffold to attain proper function prior to in vivo implantation.
Tian, E; Stevens, Sharon R.; Guan, Yu; Springer, Danielle A.; Anderson, Stasia A.; Starost, Matthew F.; Patel, Vyomesh; Ten Hagen, Kelly G.; Tabak, Lawrence A.
Congenital heart valve defects in humans occur in approximately 2% of live births and are a major source of compromised cardiac function. In this study we demonstrate that normal heart valve development and cardiac function are dependent upon Galnt1, the gene that encodes a member of the family of glycosyltransferases (GalNAc-Ts) responsible for the initiation of mucin-type O-glycosylation. In the adult mouse, compromised cardiac function that mimics human congenital heart disease, including aortic and pulmonary valve stenosis and regurgitation; altered ejection fraction; and cardiac dilation, was observed in Galnt1 null animals. The underlying phenotype is aberrant valve formation caused by increased cell proliferation within the outflow tract cushion of developing hearts, which is first detected at developmental stage E11.5. Developing valves from Galnt1 deficient animals displayed reduced levels of the proteases ADAMTS1 and ADAMTS5, decreased cleavage of the proteoglycan versican and increased levels of other extracellular matrix proteins. We also observed increased BMP and MAPK signaling. Taken together, the ablation of Galnt1 appears to disrupt the formation/remodeling of the extracellular matrix and alters conserved signaling pathways that regulate cell proliferation. Our study provides insight into the role of this conserved protein modification in cardiac valve development and may represent a new model for idiopathic valve disease. PMID:25615642
Reimer, Jay; Syedain, Zeeshan; Haynie, Bee; Lahti, Matthew; Berry, James; Tranquillo, Robert
Current pediatric heart valve replacement options are suboptimal because they are incapable of somatic growth. Thus, children typically have multiple surgeries to replace outgrown valves. In this study, we present the in vivo function and growth potential of our tissue-engineered pediatric tubular valve. The valves were fabricated by sewing two decellularized engineered tissue tubes together in a prescribed pattern using degradable sutures and subsequently implanted into the main pulmonary artery of growing lambs. Valve function was monitored using periodic ultrasounds after implantation throughout the duration of the study. The valves functioned well up to 8 weeks, 4 weeks beyond the suture strength half-life, after which their insufficiency index worsened. Histology from the explanted valves revealed extensive host cell invasion within the engineered root and commencing from the leaflet surfaces. These cells expressed multiple phenotypes, including endothelial, and deposited elastin and collagen IV. Although the tubes fused together along the degradable suture line as designed, the leaflets shortened compared to their original height. This shortening is hypothesized to result from inadequate fusion at the commissures prior to suture degradation. With appropriate commissure reinforcement, this novel heart valve may provide the somatic growth potential desired for a pediatric valve replacement.
Jahnavi, S., E-mail: firstname.lastname@example.org [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India); Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Kumary, T.V., E-mail: email@example.com [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Bhuvaneshwar, G.S., E-mail: firstname.lastname@example.org [Trivitron Innovation Centre, Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, TN (India); Natarajan, T.S., E-mail: email@example.com [Conducting Polymer laboratory, Department of Physics, Indian Institute of Technology, Madras, Chennai 600036, TN (India); Verma, R.S., E-mail: firstname.lastname@example.org [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India)
Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential. - Highlights: • A Bio-Hybrid scaffold was fabricated with PCL-CH blend and DBPECM. • PCL-CH functionally interacted with decellularized matrix without cross linking. • Modified scaffold exhibited mechanical properties similar to native heart valve. • Supported better fibroblast and endothelial cell adhesion and proliferation. • The developed scaffold can be utilized for tissue engineering of heart valve.
Ryan S. Hennessy, MD
Full Text Available Summary: Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acidâ and supercritical carbon dioxideâtreated valves were found to be sterile using histology, microbe culture, and electron microscopy assays. The cusp tensile properties of supercritical carbon dioxideâtreated valves were higher compared with valves treated with other techniques. Superior sterility and integrity was found in the decellularized valves treated with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Key Words: decellularized, decontamination, heart valve, tensile properties, tissue engineering
Full Text Available Abstract A 24-year-old woman admitted with mild chest distress associated with activity without chest complaint for twenty days. Two orifices were visible at the level of the mitral valve with a transthoracic short-axis view of the two-dimensional and three-dimensional echocardiography. The left ventricle was mildly dilatated and the left ventricular wall was thickened, especially at the apex and anterolateral wall, and appeared sponge-like. There were numerous, excessively prominent trabeculations associated with intertrabecular recesses. Although the coexistence of NVM and DOMV could be a coincidence, we believe that both defects were probably caused by a developmental arrest of the left ventricular myocardium in the present case.
Lewis, Matthew; Rosenbaum, Marlon
Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the mitral valve, left ventricle, and aorta and is ultimately palliated with a single-ventricle repair. Universally fatal in infancy prior to the advent of modern surgical techniques, the majority of HLHS patients will now reach adulthood. However, despite improvements in early survival, the HLHS population continues to face significant morbidity and early mortality. This review delineates common sources of patient morbidity and highlights areas in need of additional research for this growing segment of the adult congenital heart disease population. It has become increasingly clear that palliated adult single ventricle patients, like those with HLHS, face significant life-long morbidity from elevated systemic venous pressures as a consequence of the Fontan procedure. Downstream organ dysfunction secondary to elevated Fontan pressures has the potential to significantly impact long-term management decisions, including strategies of organ allocation. Because of the presence of a morphologic systemic right ventricle, HLHS patients may be at even higher risk than other adult patients with a Fontan. Because the adult HLHS population continues to grow, recognition of common sources of patient morbidity and mortality is becoming increasingly important. A coordinated effort between patients and providers is necessary to address the many remaining areas of clinical uncertainty to help ensure continued improvement in patient prognosis and quality of life.
Weber, Benedikt; Emmert, Maximilian Y; Behr, Luc; Schoenauer, Roman; Brokopp, Chad; Drögemüller, Cord; Modregger, Peter; Stampanoni, Marco; Vats, Divya; Rudin, Markus; Bürzle, Wilfried; Farine, Marc; Mazza, Edoardo; Frauenfelder, Thomas; Zannettino, Andrew C; Zünd, Gregor; Kretschmar, Oliver; Falk, Volkmar; Hoerstrup, Simon P
Prenatal heart valve interventions aiming at the early and systematic correction of congenital cardiac malformations represent a promising treatment option in maternal-fetal care. However, definite fetal valve replacements require growing implants adaptive to fetal and postnatal development. The presented study investigates the fetal implantation of prenatally engineered living autologous cell-based heart valves. Autologous amniotic fluid cells (AFCs) were isolated from pregnant sheep between 122 and 128 days of gestation via transuterine sonographic sampling. Stented trileaflet heart valves were fabricated from biodegradable PGA-P4HB composite matrices (n = 9) and seeded with AFCs in vitro. Within the same intervention, tissue engineered heart valves (TEHVs) and unseeded controls were implanted orthotopically into the pulmonary position using an in-utero closed-heart hybrid approach. The transapical valve deployments were successful in all animals with acute survival of 77.8% of fetuses. TEHV in-vivo functionality was assessed using echocardiography as well as angiography. Fetuses were harvested up to 1 week after implantation representing a birth-relevant gestational age. TEHVs showed in vivo functionality with intact valvular integrity and absence of thrombus formation. The presented approach may serve as an experimental basis for future human prenatal cardiac interventions using fully biodegradable autologous cell-based living materials. Copyright Â© 2012 Elsevier Ltd. All rights reserved.
Cox, Martijn A J; Kortsmit, Jeroen; Driessen, Niels; Bouten, Carlijn V C; Baaijens, Frank P T
Creating autologous tissues with on-demand and native-like biomechanical properties is the ultimate challenge in functional heart valve tissue engineering. A promising approach toward this goal is to induce development of native-like tissue structure in vitro by mimicking the diastolic loading phase in a bioreactor. Heart valves cultured with this approach showed in vitro sufficient strength to withstand systemic pressures. This study aims to link global functioning of these valves to the development of a native-like fiber architecture induced by in vitro diastolic loading. It is hypothesized that increased loading magnitude during culture will lead to increased collagen fiber alignment. To test this hypothesis, 10 tissue-engineered heart valves were subjected to different loading protocols in vitro. Local fiber distribution and mechanics were determined in an inverse numerical-experimental approach, combining indentation tests with confocal imaging. Indentation tests on native ovine heart valves were used as a comparison. Although the effect of loading magnitude was small within the tested range, results indicated that the local fiber architecture indeed developed toward native structural properties for all loading protocols. However, apparent fiber mechanics were much stiffer compared with native. This confirms that in vitro mechanical conditioning induces development of a native-like tissue architecture, which underlines its importance for functional heart valve tissue engineering.
Pruefer, D; Kalden, P; Schreiber, W; Dahm, M; Buerke, M; Thelen, M; Oelert, H
Magnetic resonance (MR) imaging is used in an increasing number of patients, and not only after cardiac valve replacement. However, ferromagnetic biomedical implants are often considered a contraindication for MR imaging because of the potential hazards with respect to their movement, dislodgement, or heating effects during the procedure. The purpose of this study was to assess ferromagnetism, attraction forces, heating effects, and artifacts associated with prosthetic heart valve implants. Seventeen common heart valve prostheses (12 mechanical, five biological) were examined in vitro using a high-field-strength 1.5 Tesla (T) MR system. Attractive forces, temperature changes and the amount of artifacts were assessed by applying turbo-spin and gradient-echo sequences. The maximal calculated corresponding ferromagnetic force was (0.22 x 10(-3) N) in the static magnetic field. The temperature changes ranged from 0 to 0.5 degrees C maximum. Artifacts produced by the presence of the heart valve prostheses were less evident using a spin-echo sequence than a gradient-echo sequence. MR imaging exerted no significant force on the examined heart valve prostheses, and did not result in significant biological relevant temperature increase. None of the associated artifacts is considered to pose a substantial risk on MR imaging. MR procedures performed with a 1.5 T MR system can be applied safely in patients with heart valve prostheses evaluated in this study.
Fallahiarezoudar, Ehsan; Ahmadipourroudposht, Mohaddeseh; Idris, Ani; Mohd Yusof, Noordin
The four heart valves represented in the mammalian hearts are responsible for maintaining unidirectional, non-hinder blood flow. The heart valve leaflets synchronically open and close approximately 4 million times a year and more than 3 billion times during the life. Valvular heart dysfunction is a significant cause of morbidity and mortality around the world. When one of the valves malfunctions, the medical choice is may be to replace the original valves with an artificial one. Currently, the mechanical and biological artificial valves are clinically used with some drawbacks. Tissue engineering heart valve concept represents a new technique to enhance the current model. In tissue engineering method, a three-dimensional scaffold is fabricated as the template for neo-tissue development. Appropriate cells are seeded to the matrix in vitro. Various approaches have been investigated either in scaffold biomaterials and fabrication techniques or cell source and cultivation methods. The available results of ongoing experiments indicate a promising future in this area (particularly in combination of bone marrow stem cells with synthetic scaffold), which can eliminate the need for lifelong anti-coagulation medication, durability and reoperation problems. Copyright © 2014 Elsevier B.V. All rights reserved.
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Kawamori, Hiroyuki; Yoon, Sung-Han; Chakravarty, Tarun; Maeno, Yoshio; Kashif, Mohammad; Israr, Sharjeel; Abramowitz, Yigal; Mangat, Geeteshwar; Miyasaka, Masaki; Rami, Tanya; Kazuno, Yoshio; Takahashi, Nobuyuki; Jilaihawi, Hasan; Nakamura, Mamoo; Cheng, Wen; Friedman, John; Berman, Daniel; Sharma, Rahul; Makkar, Raj R
We assessed the geometry of transcatheter heart valve (THV) and valve function associated with SAPIEN 3 implantation in patients with bicuspid aortic valve (BAV) stenosis. We included 280 consecutive patients who had a contrast computed tomography (CT) before and after transcatheter aortic valve implantation (TAVI) in our institution. Each THV was assessed by CT at five cross-sectional levels: inflow, annulus, mid, sinus, and outflow. The geometry of THV was assessed for eccentricity (1 - minimum diameter/maximum diameter) and expansion (CT derived external valve area/nominal external valve area). CT measurements and transthoracic echocardiogram data were compared between BAV and tricuspid aortic valve (TAV). Among 280 patients, 41 patients were diagnosed as BAV. Compared to TAV, BAV was associated with lower expansion at mid-level, sinus-level, and outflow-level (mid 94.1 ± 6.8% vs. 98.1 ± 7.8%; P = 0.002, sinus 95.9 ± 7.2% vs. 101.6 ± 8.5%; P 4.0-11.4); P < 0.001, and outflow 2.5% (1.3-4.3) vs. 4.9% (2.2-7.5); P < 0.001]. There were no differences in frequency of paravalvular leak ≥ moderate and mean post-procedural gradient between BAV and TAV. BAV patients have greater THV eccentricity at all levels and lower THV expansion at mid, sinus, and outflow levels than the TAV patients. There were no differences in parameters of valve function between BAV and TAV patients. Despite the observed geometrical differences, TAVI with SAPIEN 3 in BAV patients allows for feasible valve function. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: email@example.com.
Ascione, Raimondo; Suleiman, Saadeh M; Angelini, Gianni D
Intermittent antegrade cold-blood cardioplegia followed by terminal warm-blood cardioplegic reperfusion or hot-shot is reported to reduce myocardial injury in the setting of coronary surgery. The efficacy of this cardioplegic technique in patients with left ventricular hypertrophy secondary to aortic stenosis remains uncertain. Thirty-six patients with left ventricular hypertrophy undergoing aortic valve replacement were prospectively randomized to cold-blood cardioplegia either alone (cold-blood cardioplegia group) or with retrograde hot-shot (hot-shot group). Reperfusion injury was assessed by measuring myocardial levels of adenosine triphosphate and lactate in left and right ventricular biopsies taken 5 minutes after institution of cardiopulmonary bypass and 20 minutes after removal of cross-clamp using high-performance liquid chromatography and enzymatic techniques. Myocardial injury was assessed by serial release of troponin I up to 48 hours postoperatively. Overall clinical outcome was prospectively collected. Baseline and intraoperative characteristics were similar between groups. In the hot-shot group, there were no significant changes in the myocardial concentration of adenosine triphosphate and lactate in both left and right ventricular biopsies after reperfusion. In the cold-blood cardioplegia group, there was a trend to a fall in adenosine triphosphate levels in the left and right ventricular biopsies after reperfusion, but this reached statistical significance only in the right ventricle. Troponin I release was raised in both groups at 4 and 12 hours after surgery (p < 0.05), but did not reach levels of myocardial infarction. The terminal retrograde hot-shot reperfusion does not add any extra benefit to antegrade cold-blood cardioplegia in preventing myocardial injury in patients with left ventricular hypertrophy undergoing aortic valve replacement. Nevertheless, it appears to reduce ischemic stress in the right ventricle. There was no difference in
D'Avenio, Giuseppe; Grigioni, Mauro; Daniele, Carla; Morbiducci, Umberto; Hamilton, Kathrin
Prosthetic heart valves can be associated to mechanical loading of blood, potentially linked to complications (hemolysis and thrombogenicity) which can be clinically relevant. In order to test such devices in pulsatile mode, pulse duplicators (PDs) have been designed and built according to different concepts. This study was carried out to compare anemometric measurements made on the same prosthetic device, with two widely used PDs. The valve (a 27-mm bileaflet valve) was mounted in the aortic section of the PD. The Sheffield University PD and the RWTH Aachen PD were selected as physical models of the circulation. These two PDs differ mainly in the vertical vs horizontal realization, and in the ventricular section, which in the RWTH PD allows for storage of potential energy in the elastic walls of the ventricle. A glassblown aorta, realized according to the geometric data of the same anatomical district in healthy individuals, was positioned downstream of the valve, obtaining 1:1 geometric similarity conditions. A NaI-glycerol-water solution of suitable kinematic viscosity and, at the same time, the proper refractive index, was selected. The flow field downstream of the valve was measured by means of the stereo-PIV (Particle Image Velocimetry) technique, capable of providing the complete 3D velocity field as well as the entire Reynolds stress tensor. The measurements were carried out at the plane intersecting the valve axis. A three-jet profile was clearly found in the plane crossing the leaflets, with both PDs. The extent of the typical recirculation zone in the Valsalva sinus was much larger in the RWTH PD, on account of the different duration of the swirling motion in the ventricular chamber, caused by the elasticity of the ventricle and its geometry. The comparison of the hemodynamical behaviour of the same bileaflet valve tested in two PDs demonstrated the role of the mock loop in affecting the valve performance.
Steffensen, Charlotte; Maegbaek, Merete Lund; Laurberg, Peter; Andersen, Marianne; Kistorp, Caroline Micheala Nervil; Norrelund, Helene; Sørensen, Henrik Toft; Jorgensen, Jens Otto Lunde
Increased risk of heart valve disease during treatment with certain dopamine agonists, such as cabergoline, has been observed in patients with Parkinson's disease. The same compound is used to treat hyperprolactinemia, but it is unknown whether this also associates with heart valve disease. The objective of the study was to assess the incidence of diagnosed heart valve disease and cardiac valve surgery among patients with hyperprolactinemia, compared with a general population cohort in Denmark. This was a nationwide, population-based, cohort study based on a nationwide hospital registry. We identified 2381 hyperprolactinemia patients with a first-time diagnosis recorded from 1994 through 2010 in the registry, with no previous hospital diagnosis of heart valve disease. Each patient was compared with 10 age- and gender-matched comparison cohort members from the general population. The association between hyperprolactinemia and heart valve disease was analyzed with Cox's proportional hazards regression, controlling for potential confounding factors. To assess the risk of cardiac valve surgery and avoid ascertainment bias, a subanalysis was made in a cohort of 2,387 hyperprolactinemia patients with no previous cardiac valve surgery and 23,870 comparison cohort members. Nineteen hyperprolactinemic patients (0.80%) were diagnosed with heart valve disease during a total of 17,759.8 yr of follow-up, compared with 75 persons (0.31%) in the comparison cohort during 179,940.6 yr of follow-up [adjusted hazard ratio 2.27 (95% confidence interval 1.35-3.82)]. Seven of the 10 patients treated with cabergoline and diagnosed with heart valve disease were asymptomatic and diagnosed on the basis of an echocardiography performed as a safety measure. However, only two patients with hyperprolactinemia (0.08%) underwent surgery, compared with 28 persons in the general population cohort (0.12%) [adjusted hazard ratio 0.55 (95% confidence interval 0.13-2.42)]. Data from the present
Full Text Available Objective: The aim of this study was to evaluate the effect of aortic valve replacement on left ventricular function and remodeling among patients with severe aortic stenosis and severe left ventricular dysfunction. Methods: In this retrospective bicentric study extended over a 15-year period, 61 consecutive patients underwent isolated AVR for severe AS associated to reduced LV function. The mean age was 58.21 ± 12.50 years and 83.60 % were men. 70.50% of patients were in class III or IV NYHA. The mean left ventricular ejection fraction (LVEF was 32.9 ± 5.6.The mean LVEDD and LVESD were respectively 63.6 ± 9.2 and 50.2 ± 8.8 mm. The mean calculated logistic EuroScore was 12.2 ±4.5. Results: The hospital mortality was 11.5%. Morbidity was marked mainly by low output syndrome in 40.8% of cases. After a median follow-up of 38 months we have recorded 3 deaths. Almost all survivors were in class I and II of NYHA. The mean LV end-diastolic and end-systolic diameters decreased significantly at late postoperative stage. The mean LV ejection fraction increased significantly from 32.9 ± 5.6 to 38.2 ± 9.3 and to 50.3 ± 9.6 in early and late postoperative stages, respectively. Multivariate linear regression analysis found that increased early postoperative LVEF (β= 0.44, 95% CI [0.14; 0.75], p=0.006 and low mean transprosthesis gradient (β=-0.72, 95% CI [-1.42; -0.02], p= 0.04 were the independent predictors of left ventricular systolic function recovery. Conclusion: Patients with aortic valve stenosis and impaired LV systolic function benefited from AVR as regard improvement of LV function parameters and regression of the LV diameters .This improvement depends mainly on early postoperative LVEF and mean transprosthesis gradient.
Le Quang, Khai; Bouchareb, Rihab; Lachance, Dominic; Laplante, Marc-André; El Husseini, Diala; Boulanger, Marie-Chloé; Fournier, Dominique; Fang, Xiang Ping; Avramoglu, Rita Kohen; Pibarot, Philippe; Deshaies, Yves; Sweeney, Gary; Mathieu, Patrick; Marette, André
This study aimed to determine the potential impact of type 2 diabetes mellitus on left ventricular dysfunction and the development of calcified aortic valve disease using a dyslipidemic mouse model prone to developing type 2 diabetes mellitus. When compared with nondiabetic LDLr(-/-)/ApoB(100/100), diabetic LDLr(-/-)/ApoB(100/100)/IGF-II mice exhibited similar dyslipidemia and obesity but developed type 2 diabetes mellitus when fed a high-fat/sucrose/cholesterol diet for 6 months. LDLr(-/-)/ApoB(100/100)/IGF-II mice showed left ventricular hypertrophy versus C57BL6 but not LDLr(-/-)/ApoB(100/100) mice. Transthoracic echocardiography revealed significant reductions in both left ventricular systolic fractional shortening and diastolic function in high-fat/sucrose/cholesterol fed LDLr(-/-)/ApoB(100/100)/IGF-II mice when compared with LDLr(-/-)/ApoB(100/100). Importantly, we found that peak aortic jet velocity was significantly increased in LDLr(-/-)/ApoB(100/100)/IGF-II mice versus LDLr(-/-)/ApoB(100/100) animals on the high-fat/sucrose/cholesterol diet. Microtomography scans and Alizarin red staining indicated calcification in the aortic valves, whereas electron microscopy and energy dispersive x-ray spectroscopy further revealed mineralization of the aortic leaflets and the presence of inflammatory infiltrates in diabetic mice. Studies showed upregulation of hypertrophic genes (anp, bnp, b-mhc) in myocardial tissues and of osteogenic genes (spp1, bglap, runx2) in aortic tissues of diabetic mice. We have established the diabetes mellitus -prone LDLr(-/-)/ApoB(100/100)/IGF-II mouse as a new model of calcified aortic valve disease. Our results are consistent with the growing body of clinical evidence that the dysmetabolic state of type 2 diabetes mellitus contributes to early mineralization of the aortic valve and calcified aortic valve disease pathogenesis. © 2014 American Heart Association, Inc.
Kiessling Arndt H
Full Text Available Abstract Background We assessed the hemodynamic performance of various prostheses and the clinical outcomes after aortic valve replacement, in different age groups. Methods One-hundred-and-twenty patients with isolated aortic valve stenosis were included in this prospective randomized randomised trial and allocated in three age-groups to receive either pulmonary autograft (PA, n = 20 or mechanical prosthesis (MP, Edwards Mira n = 20 in group 1 (age 75. Clinical outcomes and hemodynamic performance were evaluated at discharge, six months and one year. Results In group 1, patients with PA had significantly lower mean gradients than the MP (2.6 vs. 10.9 mmHg, p = 0.0005 with comparable left ventricular mass regression (LVMR. Morbidity included 1 stroke in the PA population and 1 gastrointestinal bleeding in the MP subgroup. In group 2, mean gradients did not differ significantly between both populations (7.0 vs. 8.9 mmHg, p = 0.81. The rate of LVMR and EF were comparable at 12 months; each group with one mortality. Morbidity included 1 stroke and 1 gastrointestinal bleeding in the stentless and 3 bleeding complications in the MP group. In group 3, mean gradients did not differ significantly (7.8 vs 6.5 mmHg, p = 0.06. Postoperative EF and LVMR were comparable. There were 3 deaths in the stented group and no mortality in the stentless group. Morbidity included 1 endocarditis and 1 stroke in the stentless compared to 1 endocarditis, 1 stroke and one pulmonary embolism in the stented group. Conclusions Clinical outcomes justify valve replacement with either valve substitute in the respective age groups. The PA hemodynamically outperformed the MPs. Stentless valves however, did not demonstrate significantly superior hemodynamics or outcomes in comparison to stented bioprosthesis or MPs.
Samad, Zainab; Sivak, Joseph A; Phelan, Matthew; Schulte, Phillip J; Patel, Uptal; Velazquez, Eric J
Chronic kidney disease (CKD) is an adverse prognostic marker for valve intervention patients; however, the prevalence and related outcomes of valvular heart disease in CKD patients is unknown. Included patients underwent echocardiography (1999-2013), had serum creatinine values within 6 months before index echocardiogram, and had no history of valve surgery. CKD was defined as diagnosis based on the International Classification of Diseases, Ninth Revision or an estimated glomerular filtration rate <60 mL/min per 1.73 m 2 . Qualitative assessment determined left heart stenotic and regurgitant valve lesions. Cox models assessed CKD and aortic stenosis (AS) interaction for subsequent mortality; analyses were repeated for mitral regurgitation (MR). Among 78 059 patients, 23 727 (30%) had CKD; of these, 1326 were on hemodialysis. CKD patients were older; female; had a higher prevalence of hypertension, hyperlipidemia, diabetes, history of coronary artery bypass grafting/percutaneous coronary intervention, atrial fibrillation, and heart failure ≥mild AS; and ≥mild MR (all P <0.001). Five-year survival estimates of mild, moderate, and severe AS for CKD patients were 40%, 34%, and 42%, respectively, and 69%, 54%, and 67% for non-CKD patients. Five-year survival estimates of mild, moderate, and severe MR for CKD patients were 51%, 38%, and 37%, respectively, and 75%, 66%, and 65% for non-CKD patients. Significant interaction occurred among CKD, AS/MR severity, and mortality in adjusted analyses; the CKD hazard ratio increased from 1.8 (non-AS patients) to 2.0 (severe AS) and from 1.7 (non-MR patients) to 2.6 (severe MR). Prevalence of at least mild AS and MR is substantially higher and is associated with significantly lower survival among patients with versus without CKD. There is significant interaction among CKD, AS/MR severity, and mortality, with increasingly worse outcomes for CKD patients with increasing AS/MR severity. © 2017 The Authors. Published on
Heikhmakhtiar, Aulia Khamas; Lim, Ki Moo
Mitral valve regurgitation (MR) causes blood to flow in two directions during contraction of the left ventricle (LV), that is, forward into the aorta and backward into the left atrium (LA). In aortic valve regurgitation (AR), leakage occurs from the aorta into the LV during diastole. Our objective is to analyze the contribution of a left ventricular assist device (LVAD) to MR and AR for the following two different cannulation sites: from the LA to the aorta (LAAO) and from the LV to the aorta (LVAO). Using a computational method, we simulated three ventricular conditions (normal [HF without valvular regurgitation], 5% MR, and 5% AR) in three groups (control [no LVAD], LAAO, and LVAO). The results showed that LVAD with LAAO cannulation is appropriate for recovery of the MR heart, and the LVAD with LVAO cannulation is appropriate for treating the AR heart.
Sodian, Ralf; Schaefermeier, Philipp; Abegg-Zips, Sybille; Kuebler, Wolfgang M; Shakibaei, Mehdi; Daebritz, Sabine; Ziegelmueller, Johannes; Schmitz, Christoph; Reichart, Bruno
Tissue engineering of autologous heart valves with the potential to grow and to remodel represents a promising concept. Here we describe the use of cryopreserved umbilical cord blood-derived CD133(+) cells as a single cell source for the tissue engineering of heart valves. After expansion and differentiation of CD133(+) cells, phenotypes were analyzed by immunohistochemistry and cryopreserved. Heart valve scaffolds fabricated from a biodegradable polymer (n = 8) were seeded with blood-derived myofibroblasts and subsequently coated with blood-derived endothelial cells. Afterward, the heart valve constructs were grown in a pulse duplicator system. Analysis of all heart valves, including histology, immunohistochemistry, electron microscopy, fluorescence imaging, and biochemical and biomechanical examination, was performed. The tissue-engineered heart valves showed endothelialized layered tissue formation including connective tissue between the inside and the outside of the scaffold. The notion of an intact endothelial phenotype was substantiated by fluorescence imaging studies of cellular nitric oxide production and Ca(2+) signaling. Electron microscopy showed that the cells had grown into the pores and formed a confluent tissue layer. Biochemical examination showed extracellular matrix formation (77% +/- 9% collagen of human pulmonary leaflet tissue [HPLT], 85% +/- 61% glycosaminoglycans of HPLT and 67% +/- 17% elastin of HPLT). Importantly, this study demonstrates in vitro generation of viable human heart valves based on CD133(+) cells derived from umbilical cord blood. These findings constitute a significant step forward in the development of new clinical strategies for the treatment of congenital defects. 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
E-R. Andrinopoulou (Eleni-Rosalina)
markdownabstract__Abstract__ The heart is one of the most important organs in the entire human body. Specifically, it is a pump composed of muscle which pumps blood throughout the blood vessels to various parts of the body by repeated rhythmic contractions. The four heart valves determine the
Grotenhuis, H.B.; Ottenkamp, J.; de Bruijn, L.; Westenberg, J.J.M.; Vliegen, H.W.; Kroft, L.J.M.; de Roos, A.
Background: Aortic wall pathology and concomitant aortic dilatation have been described in tetralogy of Fallot (TOF) patients, which may negatively affect aortic valve and left ventricular systolic function. Objective: To assess aortic dimensions, aortic elasticity, aortic valve competence and
Romata, Clemens; Susin, Francesca Maria; Cambi, Andrea; Tarzia, Vincenzo; Pengo, Vittorio; Gerosa, Gino; Bagno, Andrea
Haemodynamic performance of bileaflet mechanical heart valves can be severely affected by the formation of thrombotic deposits. Hence, early detection of thrombi is fundamental for a prompt diagnosis and adequate therapy. This article aims at designing a novel diagnostic and prognostic tool able to detect valvular thrombosis at early stages of formation, i.e., before the appearance of critical symptoms in patients who can be effectively treated by pharmacological therapy, preventing re-operation. This approach relies on the acquisition of the acoustic signals produced by mechanical heart valves in the closing phase; the corresponding power spectra are then analysed by means of artificial neural networks trained to identify the presence of thrombi and classify their occurrence. Five commercial bileaflet mechanical heart valves were investigated in vitro in a Sheffield Pulse Duplicator; for each valve six functional conditions were considered, each corresponding to a risk class for patients (one normofunctioning and five thrombosed): they have been simulated by placing artificial deposits of increasing weight and different shape on the valve leaflet and on the annular housing; the case of one completely blocked leaflet was also investigated. These six functional conditions represent risk classes: they were examined under various hydrodynamic regimes. The acoustic signals produced by the valves were acquired by means of a phonocardiographic apparatus, then analysed and classified. The ability to detect and classify thrombotic formations on mechanical valve leaflet would allow ranking patients by assigning them to one of the six risk classes, helping clinicians in establish adequate therapeutic approaches.
Erdbrügger, Wilhelm; Konertz, Wolfgang; Dohmen, Pascal M; Posner, Steffen; Ellerbrok, Heinz; Brodde, Otto-Erich; Robenek, Horst; Modersohn, Diethelm; Pruss, Axel; Holinski, Sebastian; Stein-Konertz, Marita; Pauli, Georg
We have developed an advanced tissue processing technique on porcine pulmonary heart valves for pulmonary valve replacement and its initial clinical application during the autograft operation according to Ross. The novel concept consists of a cell-free matrix achieved by deoxycholic acid treatment that is repopulated by host cells in vivo. Molecular biology, radioligand binding, and electron microscopy consistently showed that these valves are almost free of cellular components. Animal experiments and clinical investigations revealed excellent hemodynamic properties of the valves, no need for antithrombotic therapy, and repopulation by host cells without any signs of calcification. In juvenile sheep the internal diameter of the implanted valves significantly increased in growing animals by approximately 10 mm. The repopulation of the decellularized heart valves was found not only in sheep but also in humans, which indicates that the underlying mechanisms, presumably repair mechanisms, might be common in mammals. If these findings can be confirmed by others, they will lead to new concepts in the field of cardiovascular tissue engineering that will eliminate the need for in vitro construction of autologous heart valves.
Treede, Hendrik; Schirmer, Johannes; Rudolph, Volker
Surgical mitral valve repair carries an elevated perioperative risk in the presence of severely reduced ventricular function and relevant comorbidities. We sought to assess the feasibility of catheter-based mitral valve repair using a clip-based percutaneous edge-to-edge repair system in selected...
Wu, Yonggan; Willoughby, David A.; Lincoln, Joy
Heart valve disease affects up to 30% of the population and has been shown to have origins during embryonic development. Valvulogenesis begins with formation of endocardial cushions in the atrioventricular canal and outflow tract regions. Subsequently, endocardial cushions remodel, elongate and progressively form mature valve structures composed of a highly organized connective tissue that provides the necessary biomechanical function throughout life. While endocardial cushion formation has been well studied, the processes required for valve remodeling are less well understood. The transcription factor Scleraxis (Scx) is detected in mouse valves from E15.5 during initial stages of remodeling, and expression remains high until birth when formation of the highly organized mature structure is complete. Heart valves from Scx-/- mice are abnormally thick and develop fibrotic phenotypes similar to human disease by juvenile stages. These phenotypes begin around E15.5 and are associated with defects in connective tissue organization and valve interstitial cell differentiation. In order to understand the etiology of this phenotype, we analyzed the transcriptome of remodeling valves isolated from E15.5 Scx-/- embryos using RNA-seq. From this, we have identified a profile of protein and non-protein mRNAs that are dependent on Scx function and using bioinformatics we can predict the molecular functions and biological processes affected by these genes. These include processes and functions associated with gene regulation (methyltransferase activity, DNA binding, Notch signaling), vitamin A metabolism (retinoic acid biosynthesis) and cellular development (cell morphology, cell assembly and organization). In addition, several mRNAs are affected by alternative splicing events in the absence of Scx, suggesting additional roles in post-transcriptional modification. In summary, our findings have identified transcriptome profiles from abnormal heart valves isolated from E15.5 Scx
Damien N Barnette
Full Text Available Heart valve disease affects up to 30% of the population and has been shown to have origins during embryonic development. Valvulogenesis begins with formation of endocardial cushions in the atrioventricular canal and outflow tract regions. Subsequently, endocardial cushions remodel, elongate and progressively form mature valve structures composed of a highly organized connective tissue that provides the necessary biomechanical function throughout life. While endocardial cushion formation has been well studied, the processes required for valve remodeling are less well understood. The transcription factor Scleraxis (Scx is detected in mouse valves from E15.5 during initial stages of remodeling, and expression remains high until birth when formation of the highly organized mature structure is complete. Heart valves from Scx-/- mice are abnormally thick and develop fibrotic phenotypes similar to human disease by juvenile stages. These phenotypes begin around E15.5 and are associated with defects in connective tissue organization and valve interstitial cell differentiation. In order to understand the etiology of this phenotype, we analyzed the transcriptome of remodeling valves isolated from E15.5 Scx-/- embryos using RNA-seq. From this, we have identified a profile of protein and non-protein mRNAs that are dependent on Scx function and using bioinformatics we can predict the molecular functions and biological processes affected by these genes. These include processes and functions associated with gene regulation (methyltransferase activity, DNA binding, Notch signaling, vitamin A metabolism (retinoic acid biosynthesis and cellular development (cell morphology, cell assembly and organization. In addition, several mRNAs are affected by alternative splicing events in the absence of Scx, suggesting additional roles in post-transcriptional modification. In summary, our findings have identified transcriptome profiles from abnormal heart valves isolated
Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth
Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease Rasmussen, C.E. 1, Falk, T. 1, Zois, N.E. 1, Moesgaard, S.G. 1, Häggström, J. 2, Pedersen, H.D. 3 and Olsen, L.H1. 1Department of Basic Animal and Veterinary Sciences, Faculty of Life...... Sciences, University of Copenhagen, Frederiksberg, Denmark, 2Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; and 3Novo Nordic A/S, Maaloev, Denmark. Introduction: Modulation of heart rate by the autonomic nervous system can indirectly be measured by heart rate...... variability (HRV). Reduced HRV is seen in dogs with heart failure secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease progression in dogs with early stages of MMVD. Comparable results are found in people with primary mitral valve prolapse, a disease...
Famaey, Nele; Defever, Korijn; Bielen, Paul; Flameng, Willem; Vander Sloten, Jos; Sas, Paul; Meuris, Bart
Mechanical heart valves carry the disadvantage of lifelong antithrombotic therapy, due to the high risk of thrombus formation on the valve surface. Current diagnostic methods are incapable of detecting thrombus formation in an early stage. This article investigates a new diagnostic method, based on the analysis of the acoustic signal produced by the valve. This method should be capable of early detection of malfunction, thus permitting targeted medication and reducing valve-related complications and mortality. A measurement setup assuring optimal signal quality was developed, and a signal analysis program was implemented and validated on an in vitro mock circulatory loop. Next, four sheep were implanted with a bileaflet mechanical valve. The signals of their valves developing thrombosis were assessed on a weekly basis before explantation. Three sheep were sacrificed shortly after detection of malfunction according to the newly developed method. In each case, thrombus or membrane formation was detected on the leaflets upon explantation. In one sheep, no malfunction was found in the analysis, which was also confirmed by the condition of the valve upon explantation. These preliminary results indicate that acoustical analysis of mechanical heart valves permits early detection of valvular malfunction. Further research with more in vitro and animal testing is required to statistically validate these findings. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.
Full Text Available Endocardiosis is a disease commonly found in Pomeranian dog characterized by progressive myxomatousdegeneration of the atrio-ventricular valves especially in the mitral valve. The purpose of this study was todefine the diagnose and severeity of this disease on the Pomeranian by using brightness mode, motion mode,dan color flow Doppler echocardiography technique. Echocardiography was performed on 8 Pomeranianconsisting of 6 males and 2 females with age range of 2-14 years. Brightness mode echocardiography wasused to see the echotexture of endocardium, mitral valve, and the valve movement. The results showedendocardium thickening, along with chronic fibrosis and nodular thickening of the anterior and posteriormitral valve leaflet. Three out of seven cases showed prolapsed of the mitral valve. Motion modeechocardiography was performed in order to measure left ventricle internal dimension, myocardium thickness,fractional shortening, left atrial and aortic dimension. The results showed myocardium thickening, alongwith left atrial enlargement. Color flow Doppler echocardiography was used to confirm the mitral valveregurgitation. Three of seven cases showed the presence of regurgitation signed by turbulence color of theprolapsed mitral valve. Based on the degree of severity, scoring system used in this study, endocardiosis canbe divided into three types that are mild, moderate and severe.
Romano, Simone; Mansour, Ibrahim N; Kansal, Mayank; Gheith, Hana; Dowdy, Zachary; Dickens, Carolyn A; Buto-Colletti, Cassandra; Chae, June M; Saleh, Hussam H; Stamos, Thomas D
The goal of this study was to determine if left ventricular (LV) global longitudinal strain (GLS) predicts heart failure (HF) readmission in patients with acute decompensated heart failure. Two hundred ninety one patients were enrolled at the time of admission for acute decompensated heart failure between January 2011 and September 2013. Left ventricle global longitudinal strain (LV GLS) by velocity vector imaging averaged from 2, 3 and 4-chamber views could be assessed in 204 out of 291 (70%) patients. Mean age was 63.8 ± 15.2 years, 42% of the patients were males and 78% were African American or Hispanic. Patients were followed until the first HF hospital readmission up to 44 months. Patients were grouped into quartiles on the basis of LV GLS. Kaplan-Meier curves showed significantly higher readmission rates in patients with worse LV GLS (log-rank p heart disease, dementia, New York Heart Association class, LV ejection fraction, use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers, systolic and diastolic blood pressure on admission and sodium level on admission, worse LV GLS was the strongest predictor of recurrent HF readmission (p heart failure with a higher risk of readmission in case of progressive worsening of LV GLS, independent of the ejection fraction.
Full Text Available For the treatment of severe symptomatic aortic valve stenosis, minimally invasive heart valve prostheses are increasingly used, especially for elderly patients. The current generation of devices is based on xenogenic leaflet material, involving limitations with regard to calcification and durability. Artificial polymeric leaflet-structures re-present a promising approach for improvement of valve performance. Within the current work, finite-element ana-lysis (FEA design studies of polymeric leaflet structures were conducted. Design of an unpressurized and axially-symmetric trileaflet heart valve was developed based on nine parameters. Physiological pressurization in FEA was specified, based on in vitro hydrodynamic testing of a commercially available heart valve prosthesis. Hyper-elastic constitutive law for polymeric leaflet material was implemented based on experimental stress strain curves resulting from uniaxial tensile and planar shear testing. As a result of FEA, time dependent leaflet deformation of the leaflet structure was calculated. Obtained leaflet dynamics were comparable to in vitro performance of the analyzed prosthesis. As a major design parameter, the lunula angle has demonstrated crucial influence on the performance of the polymeric leaflet structures. FEA represented a useful tool for design of improved polymeric leaflet structures for minimally invasive implantable heart valve prostheses.
Balguid, Angelique; Mol, Anita; van Vlimmeren, Marijke A A; Baaijens, Frank P T; Bouten, Carlijn V C
Previous attempts in heart valve tissue engineering (TE) failed to produce autologous valve replacements with native-like mechanical behavior to allow for systemic pressure applications. Because hypoxia and insulin are known to promote protein synthesis by adaptive cellular responses, a physiologically relevant oxygen tension and insulin supplements were applied to the growing heart valve tissues to enhance their mechanical properties. Scaffolds of rapid-degrading polyglycolic acid meshes coated with poly-4-hydroxybutyrate were seeded with human saphenous vein myofibroblasts. The tissue-engineered constructs were cultured under normal oxygen tension (normoxia) or hypoxia (7% O(2)) and incubated with or without insulin. Glycosaminoglycan production in the constructs approached that of native values under the influence of hypoxia and under the influence of insulin. Both insulin and hypoxia were associated with enhanced matrix production and improved mechanical properties; however, a synergistic effect was not observed. Although the amount of collagen and cross-links in the engineered tissues was still lower than that in native adult human aortic valves, constructs cultured under hypoxic conditions reached native human aortic valve levels of tissue strength and stiffness after 4 weeks of culturing. These results indicate that oxygen tension may be a key parameter for the achievement of sufficient tissue quality and mechanical integrity in tissue-engineered heart valves. Engineered tissues of such strength, based on rapid-degrading polymers, have not been achieved to date. These findings bring the potential use of tissue-engineered heart valves for systemic applications a step closer and represent an important improvement in heart valve tissue engineering.
Vladimir A. Voskoboinick
Full Text Available Background. Numerical simulation and experimental research have been used as powerful tools to understand and predict the behavior and mechanics of the operation of natural heart valves and their prostheses in natural and pathological conditions. Such studies help to evaluate the effectiveness of the valves, their design and the results of surgical procedures, to diagnose healthy and impaired function of the heart valves. There is an actual problem in creating more reliable methods and tools for the operation diagnostics of mechanical heart valves. Objective. The aim of the research is to investigate the effect of fluid viscosity on the hydroacoustic characteristics of jets that flow from a semi-closed and open mechanical bileaflet heart valve. To study the possibility of using hydroacoustic measuring instruments as diagnostic equipment for determining the working conditions of the bileaflet prosthetic heart valve. Methods. The experimental research was carried out by means of hydroacoustic measurements of the hydrodynamic noise in the near wake of the side and central jets of the glycerin solution and the pure water flow downstream of the prosthetic bileaflet heart valve. Results. The effect of fluid viscosity on the hydroacoustic characteristics of the jets that flow from a semi-closed and open mechanical bileaflet heart valve has been experimentally determined. Integral and spectral characteristics of the hydrodynamic noise of jets of the glycerin solution and the pure water flow downstream of the bileaflet mitral heart valve for different fluid rate were detected. Conclusions. In the stream conditions of pure water, the integral characteristics of the pressure field are lower than in stream conditions of the aqueous glycerin solution. As the glycerin concentration in the solution increases, increase average pressures and especially RMS pressure fluctuations. The spectral levels of the hydrodynamic noise in the near wake of the side
Fang, Ning-Tao; Xie, Shang-Zhe; Wang, Song-Mei; Gao, Hong-Yang; Wu, Chun-Gen; Pan, Luan-Feng
Tissue-engineered heart valves have the potential to overcome the limitations of present heart valve replacements. This study was designed to develop a tissue engineering heart valve by using human umbilical cord blood-derived endothelial progenitor cells (EPCs) and decellularized valve scaffolds. Decellularized valve scaffolds were prepared from fresh porcine heart valves. EPCs were isolated from fresh human umbilical cord blood by density gradient centrifugation, cultured for 3 weeks in EGM-2-MV medium, by which time the resultant cell population became endothelial in nature, as assessed by immunofluorescent staining. EPC-derived endothelial cells were seeded onto the decellularized scaffold at 3 x 10(6) cells/cm(2) and cultured under static conditions for 7 days. Proliferation of the seeded cells on the scaffolds was detected using the MTT assay. Tissue-engineered heart valves were analyzed by HE staining, immunofluorescent staining and scanning electron microscopy. The anti-thrombogenic function of the endothelium on the engineered heart valves was evaluated by platelet adhesion experiments and reverse transcription-polymerase chain reaction (RT-PCR) analysis for the expression of endothelial nitric oxide synthase (eNOS) and tissue-type plasminogen activator (t-PA). EPC-derived endothelial cells showed a histolytic cobblestone morphology, expressed specific markers of the endothelial cell lineage including von Willebrand factor (vWF) and CD31, bound a human endothelial cell-specific lectin, Ulex Europaeus agglutinin-1 (UEA-1), and took up Dil-labeled low density lipoprotein (Dil-Ac-LDL). After seeding on the decellularized scaffold, the cells showed excellent metabolic activity and proliferation. The cells formed confluent endothelial monolayers atop the decellularized matrix, as assessed by HE staining and immunostaining for vWF and CD31. Scanning electron microscopy demonstrated the occurrence of tight junctions between cells forming the confluent monolayer
Hennessy, Ryan S.; Jana, Soumen; Tefft, Brandon J.; Helder, Meghana R.; Young, Melissa D.; Hennessy, Rebecca R.; Stoyles, Nicholas J.; Lerman, Amir
Objective The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Background Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Methods Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Results Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Conclusions Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Summary Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated
Yosefy, Chaim; Malushitsky, Ariela; Jamal, Jafary; Sahar, Gideon; Katz, Amos
Mitral annular calcification (MAC) and aortic valve calcification (AVC) are predictive of coronary artery disease (CAD). However, no data exist concerning the association between preferential CAD side localization to the left or right coronary arteries and MAC or AVC. A cohort analysis was performed of 1,000 consecutive coronary angiographies recorded in patients with CAD. The angiographies were divided according to the distribution of CAD to the isolated right coronary tree disease, left coronary tree disease, or both. The echocardiograms were reviewed for MAC, AVC or combined valvular calcification (CVC). Significant CAD (lumenal stenosis > 70%) was observed in 688 patients, among whom 167 had isolated (right or left) CAD and 521 double-sided coronary tree disease. Valvular calcification (VC) was observed in 70 (42%) of the isolated CAD patients; of these, 41 had isolated left CAD and 29 isolated right CAD. Among the isolated left CAD patients with VC, 13 (32%) had AVC, 22 (53%) had CVC, and only six (15%) had MAC (p AVC (p AVC, and 11 (4%) had MAC (p AVC or CVC more frequently than with MAC. In contrast, isolated right CAD is associated with MAC or CVC, but rarely with AVC.
Eli J Weinberg
Full Text Available The aortic heart valve undergoes geometric and mechanical changes over time. The cusps of a normal, healthy valve thicken and become less extensible over time. In the disease calcific aortic stenosis (CAS, calcified nodules progressively stiffen the cusps. The local mechanical changes in the cusps, due to either normal aging or pathological processes, affect overall function of the valve. In this paper, we propose a computational model for the aging aortic valve that connects local changes to overall valve function. We extend a previous model for the healthy valve to describe aging. To model normal/uncomplicated aging, leaflet thickness and extensibility are varied versus age according to experimental data. To model calcification, initial sites are defined and a simple growth law is assumed. The nodules then grow over time, so that the area of calcification increases from one model to the next model representing greater age. Overall valve function is recorded for each individual model to yield a single simulation of valve function over time. This simulation is the first theoretical tool to describe the temporal behavior of aortic valve calcification. The ability to better understand and predict disease progression will aid in design and timing of patient treatments for CAS.
Schiros, Chun G; Ahmed, Mustafa I; McGiffin, David C; Zhang, Xiaoxia; Lloyd, Steven G; Aban, Inmaculada; Denney, Thomas S; Dell'Italia, Louis J; Gupta, Himanshu
The relationship of mitral annular (MA) kinetics to left ventricular (LV) and left atrial (LA) function before and after mitral valve (MV) repair has not been well studied. Here we sought to provide comprehensive analysis that relates to MA motions, and LA and LV diastolic function post MV repair. Three-dimensional analyses of mitral annular motion, LA function, and LV volumetric and diastolic strain rates were performed on 35 degenerative mitral regurgitation (MR) patients at baseline and 1-year post MV repair, and 51 normal controls, utilizing cardiac magnetic resonance imaging with tissue tagging. All had normal LV ejection fraction (EF) at baseline. LV and LA EFs decreased 1-year post-surgery vs. controls. LV early diastolic myocardial strain rates decreased post-surgery along with decreases in normalized early diastolic filling rate, E/A ratio, and early diastolic MA relaxation rates. Post-surgical LA late active kick remained higher in MR patients vs. control. LV and LA EFs were significantly associated with peak MA centroid to apex shortening. Furthermore, during LV systolic phase, peak LV ejection and LA filling rates were significantly correlated with peak MA centroid to apex shortening rate, respectively. While during LV diastolic phase, both peak early diastolic MA centroid to apex relaxation rate and LA ejection rate were positively significantly associated with LV peak early diastolic filling rate. MA motion is significantly associated with LA and LV function. Mitral annular motion, left atrial function, and LV diastolic strain rates are still impaired 1 year post MV repair. Long-term effects of these impairments should be prospectively evaluated.
Scandura, Salvatore; Ussia, Gian Paolo; Capranzano, Piera; Caggegi, Anna; Sarkar, Kunal; Cammalleri, Valeria; Mangiafico, Sarah; Chiarandà, Marta; Immè, Sebastiano; Di Pasqua, Fabio; Pistritto, Anna Maria; Millan, Giovanni; Tamburino, Corrado
Successful mitral valve surgical repair, decreasing volume overload, has been shown to provide reverse left ventricular (LV) and/or left atrial remodeling in most patients. Percutaneous mitral valve repair with the MitraClip system (Abbott, Abbott Park, IL) has been associated with favorable clinical outcomes in patients with mitral regurgitation at high risk of surgery. However, specific data on left cardiac chambers reverse remodeling after such procedures are limited. This was a prospective observational study of consecutive patients at high risk of surgery, with moderate-to-severe or severe mitral regurgitation undergoing MitraClip system implantation. Follow-up echocardiography was performed at 6 months. The evaluated parameters were the LV end-diastolic and end-systolic volume indexes, LV sphericity index, LV ejection fraction, and left atrial volume index. Reverse LV remodeling was defined as a decrease of 10% in the LV end-diastolic volume index. The study population included 44 patients: 14 with degenerative and 30 with functional mitral regurgitation. At 6 months of follow-up, significant reductions in the median and interquartile range of the sphericity index (from 0.57 [interquartile range 0.54-0.62] to 0.54 [interquartile range 0.50-0.58]; P interquartile range 63.0-102.2] to 60.7 mL/m(2) [50.8-84.4]; P interquartile range 28.2-70.5] to 28.9 mL/m(2) [interquartile range 22.2-55.8]; P interquartile range 30.0-55.0%] to 46.0% [interquartile range 35.0-58.0%]; P < .001) from baseline to 6 months. Minor differences in the left atrial volume index were observed. Reverse remodeling, according to the specified definition, was observed in 77.3% of the patients. The present study reports positive LV reshape effects after mitral valve repair with the MitraClip system, showing significant improvements in LV size and function. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.
Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi
To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves. © IMechE 2016.
Full Text Available Abstract Heart failure (HF is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood. Echocardiography represents the "gold standard" in the assessment of LV systolic dysfunction and in the recognition of systolic heart failure, since dilatation of the LV results in alteration of intracardiac geometry and hemodynamics leading to increased morbidity and mortality. The functional mitral regurgitation is a consequence of adverse LV remodelling that occurs with a structurally normal valve and it is a marker of adverse prognosis. Diastolic dysfunction plays a major role in signs and symptoms of HF and in the risk stratification, and provides prognostic information independently in HF patients and impaired systolic function. Ultrasound lung comets are a simple echographic sign of extravascular lung water, more frequently associated with left ventricular diastolic and/or systolic dysfunction, which can integrate the clinical and pathophysiological information provided by conventional echocardiography and provide a useful information for prognostic stratification of HF patients. Contractile reserve is defined as the difference between values of an index of left ventricular contractility during peak stress and its baseline values and the presence of myocardial viability predicts a favorable outcome. A non-invasive echocardiographic method for the evaluation of force-frequency relationship has been proposed to assess the changes in contractility during stress echo. In conclusion, in HF patients, the evaluation of systolic, diastolic function and myocardial contractile reserve plays a fundamental role in the risk stratification. The highest risk is present in HF patients with a heart that is weak, big, noisy, stiff and wet.
Lindman, Brian R; Stewart, William J; Pibarot, Philippe; Hahn, Rebecca T; Otto, Catherine M; Xu, Ke; Devereux, Richard B; Weissman, Neil J; Enriquez-Sarano, Maurice; Szeto, Wilson Y; Makkar, Raj; Miller, D Craig; Lerakis, Stamatios; Kapadia, Samir; Bowers, Bruce; Greason, Kevin L; McAndrew, Thomas C; Lei, Yang; Leon, Martin B; Douglas, Pamela S
This study sought to examine the relationship between left ventricular mass (LVM) regression and clinical outcomes after transcatheter aortic valve replacement (TAVR). LVM regression after valve replacement for aortic stenosis is assumed to be a favorable effect of LV unloading, but its relationship to improved clinical outcomes is unclear. Of 2,115 patients with symptomatic aortic stenosis at high surgical risk receiving TAVR in the PARTNER (Placement of Aortic Transcatheter Valves) randomized trial or continued access registry, 690 had both severe LV hypertrophy (left ventricular mass index [LVMi] ≥ 149 g/m(2) men, ≥ 122 g/m(2) women) at baseline and an LVMi measurement at 30-day post-TAVR follow-up. Clinical outcomes were compared for patients with greater than versus lesser than median percentage change in LVMi between baseline and 30 days using Cox proportional hazard models to evaluate event rates from 30 to 365 days. Compared with patients with lesser regression, patients with greater LVMi regression had a similar rate of all-cause mortality (14.1% vs. 14.3%, p = 0.99), but a lower rate of rehospitalization (9.5% vs. 18.5%, hazard ratio [HR]: 0.50, 95% confidence interval [CI]: 0.32 to 0.78; p = 0.002) and a lower rate of rehospitalization specifically for heart failure (7.3% vs. 13.6%, p = 0.01). The association with a lower rate of rehospitalization was consistent across subgroups and remained significant after multivariable adjustment (HR: 0.53, 95% CI: 0.34 to 0.84; p = 0.007). Patients with greater LVMi regression had lower B-type natriuretic peptide (p = 0.002) and a trend toward better quality of life (p = 0.06) at 1-year follow-up than did those with lesser regression. In high-risk patients with severe aortic stenosis and severe LV hypertrophy undergoing TAVR, those with greater early LVM regression had one-half the rate of rehospitalization over the subsequent year compared to those with lesser regression. Copyright © 2014 American College of
Govindarajan, V; Udaykumar, H S; Herbertson, L H; Deutsch, S; Manning, K B; Chandran, K B
The fluid dynamics during valve closure resulting in high shear flows and large residence times of particles has been implicated in platelet activation and thrombus formation in mechanical heart valves. Our previous studies with bi-leaflet valves have shown that large shear stresses induced in the gap between the leaflet edge and the valve housing results in relatively high platelet activation levels whereas flow between the leaflets results in shed vortices not conducive to platelet damage. In this study we compare the result of closing dynamics of a tilting disc valve with that of a bi-leaflet valve. The two-dimensional fluid-structure interaction analysis of a tilting disc valve closure mechanics is performed with a fixed grid Cartesian mesh flow solver with local mesh refinement, and a Lagrangian particle dynamic analysis for computation of potential for platelet activation. Throughout the simulation the flow remains in the laminar regime and the flow through the gap width is marked by the development of a shear layer which separates from the leaflet downstream of the valve. Zones of re-circulation are observed in the gap between the leaflet edge and the valve housing on the major orifice region of the tilting disc valve and are seen to be migrating towards the minor orifice region. Jet flow is observed at the minor orifice region and a vortex is formed which sheds in the direction of fluid motion as observed in experiments using PIV measurements. The activation parameter computed for the tilting disc valve, at the time of closure was found to be 2.7 times greater than that of the bi-leaflet mechanical valve and was found to be in the vicinity of the minor orifice region mainly due to the migration of vortical structures from the major to the minor orifice region during the leaflet rebound of the closing phase.
Full Text Available Background: About half of all patients who undergo mitral valve surgery suffer from atrial fibrillation (AF. Cox described the surgical cut-and-sew Maze procedure, which is an effective surgical method but has some complications. This study was designed to evaluate the efficacy of a substitution method of radiofrequency ablation (RFA for patients undergoing mitral valve surgery with AF.Methods: We evaluated 50 patients, comprising 40 men and 10 women at a mean age of 61.8 ± 7.5 years, who underwent mitral valve surgery with RFA between March 2010 and August 2013. All the patients had permanent AF with an enlarged left atrium (LA. The first indication for surgery was underlying organic lesions. Mitral valve replacement or repair was performed in the patients as a single procedure or in combination with aortic valve replacement or coronary artery bypass grafting. Radiofrequency energy was used to create continuous endocardial lesions mimicking most incisions and sutures. We evaluated the pre- and postoperative LA size, duration of aortic cross-clamping, cardiopulmonary bypass time, intensive care unit stay, and total hospital stay.Results: The mean preoperative and postoperative LA sizes were 7.5 ± 1.4 cm and 4.3 ± 0.7 cm (p value = 0.0001, respectively. The mean cardiopulmonary bypass time and the aortic cross-clamping time were 134.3 ± 33.7 minand 109.0 ± 28.4 min, respectively. The average stay at the intensive care unit was 2.1 ± 1.2 days, and the total hospital stay was 8.3 ± 2.4 days. Rebleeding was the only complication, found in one patient. There was no early or late mortality. Eighty-two percent of the patients were discharged in normal sinus rhythm. Five other patients had normal sinus rhythm at 6months' follow-up, and the remaining 4 patients did not have a normal sinus rhythm after 6 months.Conclusion: Radiofrequency ablation, combined with LA reduction, is an effective option for the treatment of permanent AF concomitant with
Full Text Available Heart failure potentially developing in most of heart diseases is a progressive process associated with high morbidity and mortality. Almost 3/4 of patients die within five years after first hospitalization because of heart failure. The main treatment for patients with terminal heart failure is heart transplantation. Left ventricular assist device is a main alternative to heart transplantation. We present case of long-term mechanical support applied in patients with heart failure class IV NYHA, refractory to medical therapy. Long-term implantation of mechanical heart support system may serve as an effective bridge to heart transplantation in patients with advanced congestive heart failure.
Bouayed Abdelmoula, Nouha; Abdelmoula, Balkiss; Smaoui, Walid; Trabelsi, Imen; Louati, Rim; Aloulou, Samir; Aloulou, Wafa; Abid, Fatma; Kammoun, Senda; Trigui, Khaled; Bedoui, Olfa; Denguir, Hichem; Mallek, Souad; Ben Aziza, Mustapha; Dammak, Jamila; Kaabi, Oldez; Abdellaoui, Nawel; Turki, Fatma; Kaabi, Asma; Kamoun, Wafa; Jabeur, Jihen; Ltaif, Wided; Chaker, Kays; Fourati, Haytham; M'rabet, Samir; Ben Ameur, Hedi; Gouia, Naourez; Mhiri, Mohamed Nabil; Rebai, Tarek
In the era of the diseasomes and interactome networks, linking genetics with phenotypic traits in Turner syndrome should be studied thoroughly. As a part of this stratagem, mosaicism of both X and Y chromosome which is a common finding in TS and an evaluation of congenital heart diseases in the different situations of mosaic TS types, can be helpful in the identification of disturbed sex chromosomes, genes and signaling pathway actors. Here we report the case of a mosaic TS associated to four left-sided CHD, including BAV, COA, aortic aneurysms and dissections at an early age. The mosaicism included two cell lines, well-defined at the cytogenetic and molecular levels: a cell line which is monosomic for Xp and Xq genes (45,X) and another which is trisomic for pseudoautosomal genes that are present on the X and Y chromosomes and escape X inactivation: 45,X/46,X,idic(Y)(pter→q11.2::q11.2→pter). This case generates two hypotheses about the contribution of genes linked to the sex chromosomes and the signaling pathways involving these genes, in left-sided heart diseases. The first hypothesis suggests the interaction between X chromosome and autosomal genes or loci of aortic development, possibly dose-dependent, and which could be in the framework of TGF-β-SMAD signaling pathways. The second implies that left-sided congenital heart lesions involve sex chromosomes loci. The reduced dosage of X chromosome gene(s), escaping X inactivation during development, contributes to this type of CHD. Regarding our case, these X chromosome genes may have homologues at the Y chromosome, but the process of inactivation of the centromeres of the isodicentric Y spreads to the concerned Y chromosome genes. Therefore, this case emerges as an invitation to consider the mosaics of Turner syndrome and to study their phenotypes in correlation with their genotypes to discover the underlying developmental and genetic mechanisms, especially the ones related to sex chromosomes.
Symersky, Petr; Budde, Ricardo P. J.; Westers, Paul; de Mol, Bas A. J. M.; Prokop, Mathias
Objectives Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. Methods
Symersky, Petr; Budde, Ricardo P. J.; Westers, Paul; de Mol, Bas A. J. M.; Prokop, Mathias
Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. A Medtronic Hall
Brennan, J Matthew; Zhao, Yue; Williams, Judson; O'Brien, Sean; Dokholyan, Rachel; Gammie, James; Edwards, Fred; Loyo-Berrios, Nilsa; Canos, Daniel; Gross, Thomas; Marinac-Dabic, Danica; Peterson, Eric
Since the voluntary recall of St. Jude Medical (SJM) Silzone impregnated heart valves, no large-scale study has examined their long-term outcomes. Using Medicare-linked records from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (1993-2004), the clinical outcomes were evaluated through eight years among those patients who received SJM mechanical heart valves during the Silzone era (March 1998 to December 1999; n = 3,775), relative to those in both the pre-Silzone era (January 1993 to February 1998; n = 13,570) and the post-Silzone era (January 2000 to December 2004; n = 6,882). An inverse probability weighting was used to balance the observed differences in case mix. During the Silzone era, 79% of all implanted mechanical heart valves were manufactured by SJM. By eight years post-implantation, the most common adverse events in this Medicare-linked cohort (median age 71 years) were death (43.5%) and thromboembolism (14.7%), while valve reoperation (1.7%) and endocarditis (1.4%) were less common. Patients treated during the Silzone era experienced a lower associated risk of mortality to eight years than those in both the pre-Silzone era (adjusted hazards ratio (HR) 0.93, 95% confidence interval (CI) 0.88-0.98) and post-Silzone era (adjusted HR 0.92, CI 0.67-0.98), while the adjusted eight-year risks of reoperation, thromboembolism and endocarditis were similar across the three eras for the overall cohort and among both aortic valve and mitral valve patients. Medicare patients who received SJM mechanical heart valves during the Silzone era experienced similar clinical outcomes as those treated before or after the Silzone era. These data do not substantiate continued public health concerns associated with Silzone era valve prostheses among older individuals.
Freud, Lindsay R.; McElhinney, Doff B.; Marshall, Audrey C.; Marx, Gerald R.; Friedman, Kevin G.; del Nido, Pedro J.; Emani, Sitaram M.; Lafranchi, Terra; Silva, Virginia; Wilkins-Haug, Louise E.; Benson, Carol B.; Lock, James E.; Tworetzky, Wayne
Background Fetal aortic valvuloplasty (FAV) can be performed for severe mid-gestation aortic stenosis (AS) in an attempt to prevent progression to hypoplastic left heart syndrome (HLHS). A subset of patients has achieved a biventricular (BV) circulation after FAV. The postnatal outcomes and survival of the BV patients, compared to those managed as HLHS, have not been reported. Methods and Results We included 100 patients who underwent FAV for severe mid-gestation AS with evolving HLHS from March 2000 to January 2013. Patients were categorized based on postnatal management as BV or HLHS. Clinical records were reviewed. Eighty-eight fetuses were live-born, and 38 had a BV circulation (31 from birth, 7 converted after initial univentricular palliation). Left-sided structures, namely aortic and mitral valve sizes and LV volume, were significantly larger in the BV group at the time of birth (p-values <0.01). After a median follow-up of 5.4 years, freedom from cardiac death among all BV patients was 96±4% at 5 years and 84±12% at 10 years, which was better than HLHS patients (log-rank p=0.04). There was no cardiac mortality in patients with a BV circulation from birth. All but 1 of the BV patients required postnatal intervention; 42% underwent aortic and/or mitral valve replacement. On most recent echocardiogram, the median LV end-diastolic volume z-score was +1.7 (range: -1.3, +8.2), and 80% had normal ejection fraction. Conclusions Short- and intermediate-term survival among patients who underwent FAV and achieved a BV circulation postnatally is encouraging. However, morbidity still exists, and on-going assessment is warranted. PMID:25052401
Tudorache, Igor; Calistru, Alex; Baraki, Hassina; Meyer, Tanja; Höffler, Klaus; Sarikouch, Samir; Bara, Christopher; Görler, Adelheid; Hartung, Dagmar; Hilfiker, Andres; Haverich, Axel; Cebotari, Serghei
Heart valve tissue engineering aims to create a graft with improved durability compared to routinely used valve substitutes. This study presents the function and morphological changes of a tissue-engineered aortic valve (TEV) compared to the cryopreserved valve (CPV), aortic valve (AV) allografts in an orthotopic position in sheep. Ovine AV conduits (n=5) were decellularized with detergents. Autologous endothelial cells (ECs) were seeded onto the valve surface and cultured under physiological conditions using a high pulsatile flow. Grafts were implanted as a root with reimplantation of coronary ostia in sheep. Crystalloid cardioplegia and isogenic blood transfusions from previous sacrificed sheep were used. Only antiplatelet aggregation therapy was used postoperatively. CPVs (n=4) served as controls. The grafts were investigated for function (echocardiography, magnetic resonance investigation), morpho/histological appearance, graft rejection, and calcification at 3 months. Decellularization led to cell-free scaffolds with preserved extracellular matrices, including the basement membrane. TEVs were covered with ECs expressing typical endothelial markers. Neither dilatation, stenosis, reductions of cusp mobility nor a significant transvalvular gradient, were observed in the TEV group. Explanted valves exhibited normal morphology without signs of inflammation. An endothelial monolayer covered cusps and the valve sinus. In the CPV group, sporadic, macroscopic, calcified degeneration with mild AV insufficiency was noted. Histology revealed signs of rejection and incipient calcification of the tissue. Tissue-engineered AV based on decellularized valve allografts satisfy short-term requirements of the systemic circulation in sheep. Although results of long-term experiments are pending, the lack of degenerative traits thus far, makes these grafts a promising alternative for future aortic heart valve surgery.
Moreira, Ricardo; Velz, Thaddaeus; Alves, Nuno; Gesche, Valentine N; Malischewski, Axel; Schmitz-Rode, Thomas; Frese, Julia; Jockenhoevel, Stefan; Mela, Petra
Transcatheter aortic valve implantation of (nonviable) bioprosthetic valves has been proven a valid alternative to conventional surgical implantation in patients at high or prohibitive mortality risk. In this study we present the in vitro proof-of-principle of a newly developed tissue-engineered heart valve for minimally invasive implantation, with the ultimate aim of adding the unique advantages of a living tissue with regeneration capabilities to the continuously developing transcatheter technologies. The tube-in-stent is a fibrin-based tissue-engineered valve with a tubular leaflet design. It consists of a tubular construct sewn into a self-expandable nitinol stent at three commissural attachment points and along a circumferential line so that it forms three coaptating leaflets by collapsing under diastolic back pressure. The tubular constructs were molded with fibrin and human umbilical vein cells. After 3 weeks of conditioning in a bioreactor, the valves were fully functional with unobstructed opening (systolic phase) and complete closure (diastolic phase). Tissue analysis showed a homogeneous cell distribution throughout the valve's thickness and deposition of collagen types I and III oriented along the longitudinal direction. Immunohistochemical staining against CD31 and scanning electron microscopy revealed a confluent endothelial cell layer on the surface of the valves. After harvesting, the valves underwent crimping for 20 min to simulate the catheter-based delivery. This procedure did not affect the valvular functionality in terms of orifice area during systole and complete closure during diastole. No influence on the extracellular matrix organization, as assessed by immunohistochemistry, nor on the mechanical properties was observed. These results show the potential of combining tissue engineering and minimally invasive implantation technology to obtain a living heart valve with a simple and robust tubular design for transcatheter delivery. The effect
Ledesma, R.; Zenit, R.; Pulos, G.; Sanchez, E.; Juarez, A.
Blood damage commonly appears in medical valve prothesis. It is a mayor concern for the designers and surgeons. It is well known that this damage and other complications result from the modified fluid dynamics through the replacement valve. To evaluate the performance of prosthetic heart valves, it is necessary to study the flow through them. To conduct this study , we have built a flow channel that emulates cardiac conditions and allows optical access such that a 3D-PIV velocimetry system could be used. The experiments are aimed to reconstruct the downstream structure of the flow through a mechanical and a bio-material tricuspid heart valve prothesis. Preliminary results show that the observed coherent structures can be related with haemolysis and trombosis, illnesses commonly found in valve prothesis recipients. The mean flow, the levels of strain rate and the turbulence intensity generated by the valves can also be directly related to blood damage. In general, bio-material made valves tend to reduce these complications.
Amin, Anubhav G; Ng, Julie; Hsu, Wesley; Pradilla, Gustavo; Raza, Shaan; Quinones-Hinojosa, Alfredo; Lim, Michael
Thromboembolic events and anticoagulation-associated bleeding events represent frequent complications following cardiac mechanical valve replacement. Management guidelines regarding the timing for resuming anticoagulation therapy following a surgically treated subdural hematoma (SDH) in patients with mechanical valves remains to be determined. To determine optimal anticoagulation management in patients with mechanical heart valves following treatment of SDH. Outcomes were retrospectively reviewed for 12 patients on anticoagulation therapy for thromboembolic prophylaxis for mechanical cardiac valves who underwent surgical intervention for a SDH at the Johns Hopkins Hospital between 1995 and 2010. The mean age at admission was 71 years. All patients had St. Jude's mechanical heart valves and were receiving anticoagulation therapy. All patients had their anticoagulation reversed with vitamin K and fresh frozen plasma and underwent surgical evacuation. Anticoagulation was withheld for a mean of 14 days upon admission and a mean of 9 days postoperatively. The average length of stay was 19 days. No deaths or thromboembolic events occurred during the hospitalization. Average follow-up time was 50 months, during which two patients had a recurrent SDH. No other associated morbidities occurred during follow-up. Interruptions in anticoagulation therapy for up to 3 weeks pose minimal thromboembolic risk in patients with mechanical heart valves. Close follow-up after discharge is highly recommended, as recurrent hemorrhages can occur several weeks after the resumption of anticoagulation.
Carneiro, Flavia; Kruithof, Boudewijn Pt; Balani, Kanthesh; Agarwal, Arvind; Gaussin, Vinciane; Kos, Lidia
Heart valves are complex structures composed of organized layers of extracellular matrix, and interstitial and overlying endothelial cells. In this article, we present the specific localization of a population of melanocytes within the murine heart valves at ages important for their post-natal development. In all stages analyzed in our study, melanocytes were found in high numbers populating the atrial aspect of the tricuspid and mitral leaflets. The pulmonary valve did not present melanocytes. To characterize a putative role for the valve melanocytes, the dynamic nanomechanical properties of tricuspid leaftets containing large numbers or no melanocytes were measured. The stiffness coefficient of hyperpigmented leaflets was higher (11.5 GPa) than the ones from wild-type (7.5 GPa) and hypopigmented (5.5 GPa) leaflets. These results suggest that melanocytes may contribute to the mechanical properties of the heart valves. The arrangement of extracellular matrix molecules such as Collagen I and Versican B is responsible for the mechanical characteristics of the leaflets. Melanocytes were found to reside primarily in areas of Versican B expression. The patterns of expression of Collagen I and Versican B were not, however, disrupted in hyper or hypopigmented leaflets. Melanocytes may affect other extracellular matrix molecules to alter the valves' microenvironment.
Germing, A; Lindstaedt, M; Holt, S; Reber, D; Mügge, A; Laczkovics, A; Fritz, M
Aortic valve replacement is a standard procedure for the treatment of severe aortic valve stenosis. Due to lower flow velocities stentless valves are associated with a more effective regression of left ventricular hypertrophy in comparison to stented valves. However, mismatch between body surface area and valve size supports unfavourable hemodynamic results. The aim of the study was to analyze hemodynamic parameters by echocardiography after implantation of the Shelhigh SuperStentless bioprosthesis and to analyze the occurrence of patient-prosthesis mismatch and left ventricular remodelling in this specific valve type. A total of 20 patients with severe aortic stenosis underwent implantation of a Shelhigh Super Stentless prosthesis. Clinical and echocardiographic assessment was done prior to, immediate after and six months after surgery. All surgical procedures were successful, no surgery-related complication was documented perioperatively. One patient died after development of multiorgan failure. Echocardiography during the first eight days after surgery showed mean gradients of 16 mmHg, mean valve orifice areas of 1.8 cm(2) and indexed effective orifice areas at 0.95 cm(2)/m(2). Six-months follow-up data were obtained in 19/20 patients. There were no relevant changes in echocardiographic hemodynamic findings at the time of follow-up measurements. Significant regression of left ventricular hypertrophy was shown (P=0.0088). A patient-prosthesis mismatch occurred in one patient (0.54 cm(2)/m(2)). No recurrent symptoms were documented. Patient-prosthesis mismatch after implantation of SuperStentless Shelhigh prosthesis is rare. A significant regression of left ventricular hypertrophy could be shown after six months. Hemodynamic valve function assessed by echocardiography may be predicted early after surgery.
Sibilitz, Kirstine Lærum; Berg, Selina Kikkenborg; Tang, Lars Hermann
BACKGROUND: Exercise-based cardiac rehabilitation may benefit heart valve surgery patients. We conducted a systematic review to assess the evidence for the use of exercise-based intervention programmes following heart valve surgery. OBJECTIVES: To assess the benefits and harms of exercise......-based cardiac rehabilitation compared with no exercise training intervention, or treatment as usual, in adults following heart valve surgery. We considered programmes including exercise training with or without another intervention (such as a psycho-educational component). SEARCH METHODS: We searched...... handsearched Web of Science, bibliographies of systematic reviews and trial registers (ClinicalTrials.gov, Controlled-trials.com, and The World Health Organization International Clinical Trials Registry Platform). SELECTION CRITERIA: We included randomised clinical trials that investigated exercise...
Schapkaitz, Elise; Jacobson, Barry Frank; Manga, Pravin; Chitsike, Rufaro Saeed; Benade, Estee; Jackson, S; Haas, Sylvia; Buller, Harry R
The management of pregnant patients with mechanical heart valves remains challenging because there are no large randomised studies to provide guidelines for effective anticoagulant therapy. Both vitamin K antagonists and heparins may be associated with maternal and foetal adverse events. The Southern African Society of Thrombosis and Haemostasis reviewed available literature and comprehensive evidence-based guidelines for the anticoagulation of pregnant patients with mechanical heart valves. A draft document was produced and revised by consensus agreement. The guidelines were adjudicated by independent international experts to avoid local bias. We present concise, practical guidelines for the clinical management of pregnant patients with mechanical heart valves. Recommendations reflect current best practice which will hopefully lead to improved anticoagulation practice in this select group of high risk patients.
Oomen, Pim J A; Holland, Maria A; Bouten, Carlijn V C; Kuhl, Ellen; Loerakker, Sandra
Tissue growth and remodeling are known to govern mechanical homeostasis in biological tissue, but their relative contributions to homeostasis remain unclear. Here, we use mechanical models, fueled by experimental findings, to demonstrate that growth and remodeling have different effects on heart valve stretch homeostasis during physiological postnatal development. Two developmental stages were considered: early-stage (from infant to adolescent) and late-stage (from adolescent to adult) development. Our models indicated that growth and remodeling play opposing roles in preserving tissue stretch and with time. During early-stage development, excessive tissue stretch was decreased by tissue growth and increased by remodeling. In contrast, during late-stage development tissue stretch was decreased by remodeling and increased by growth. Our findings contribute to an improved understanding of native heart valve adaptation throughout life, and are highly relevant for the development of tissue-engineered heart valves.
Moszura, Tomasz; Góreczny, Sebastian; Dryżek, Paweł
Due to the complex anatomical and haemodynamic consequences of hypoplastic left heart syndrome (HLHS), patients with the condition require multistage surgical and supportive interventional treatment. Percutaneous interventions may be required between each stage of surgical palliation, sometimes simultaneously with surgery as hybrid interventions, or after completion of multistage treatment. Recent advances in the field of interventional cardiology, including new devices and techniques, have significantly contributed to improving results of multistage HLHS palliation. Knowledge of the potential interventional options as well as the limitation of percutaneous interventions will enable the creation of safe and effective treatment protocols in this highly challenging group of patients. In this comprehensive review we discuss the types, goals, and potential complications of transcatheter interventions in patients with HLHS.
Loger, K; Engel, A; Haupt, J; Lima de Miranda, R; Lutter, G; Quandt, E
Heart valves are constantly exposed to high dynamic loading and are prone to degeneration. Therefore, it is a challenge to develop a durable heart valve substitute. A promising approach in heart valve engineering is the development of hybrid scaffolds which are composed of a mechanically strong inorganic mesh enclosed by valvular tissue. In order to engineer an efficient, durable and very thin heart valve for transcatheter implantations, we developed a fabrication process for microstructured heart valve leaflets made from a nickel-titanium (NiTi) thin film shape memory alloy. To examine the capability of microstructured NiTi thin film as a matrix scaffold for tissue engineered hybrid heart valves, leaflets were successfully seeded with smooth muscle cells (SMCs). In vitro pulsatile hydrodynamic testing of the NiTi thin film valve leaflets demonstrated that the SMC layer significantly improved the diastolic sufficiency of the microstructured leaflets, without affecting the systolic efficiency. Compared to an established porcine reference valve model, magnetron sputtered NiTi thin film material demonstrated its suitability for hybrid tissue engineered heart valves.
Moutaouekkil, El Mehdi; Najib, Abdelmalek; Ajaja, Rida; Arji, Moha; Slaoui, Anas
Background: Patients with the homozygous sickle cell disease have increased perioperative mortality. Some indications like heart valve surgery, may justify an exchange blood transfusion to reduce the proportion of hemoglobin S (HbS) and complications. Subjects and Methods: We report two female cases aged 20 and 27, of African origin with homozygous sickle cell anemia who underwent heart valve surgery to treat mitral valve regurgitation. This presentation describes the perioperative considerations including anesthesia and postoperative care. Results: A partial exchange blood transfusion decreased HbS levels from respectively, 90% and 84%, 9% to 27% and 34%, and simultaneously treated the anemia. Neither sickling crisis nor acidosis occurred in any patient, and no special postoperative complication occurred. Average hospital stay was 10 days. Currently, the two patients remain alive and free of cardiac symptoms. Discussion: Although the presence of sickle cell disorders is associated with increased risk of sickling and thus vaso-occlusive complications, they should not be taken as a contraindication for heart valve surgery. Nevertheless, monitoring of certain parameters such as venous, arterial oxygen content, pH, and body temperature is mandatory for a better outcome. Furthermore, preoperative exchange transfusion has a positive influence on the outcome of surgery and on the survival of patients undergoing heart valves surgery. Avoiding intraoperative hypoxia, hypothermia, and vaso-constrictive agents, minimizing HbS levels with preoperative exchange transfusion, and ensuring a stress-free environment with the judicious use of sedatives made surgery relatively safe in these cases. PMID:26139741
El Mehdi Moutaouekkil
Full Text Available Background: Patients with the homozygous sickle cell disease have increased perioperative mortality. Some indications like heart valve surgery, may justify an exchange blood transfusion to reduce the proportion of hemoglobin S (HbS and complications. Subjects and Methods: We report two female cases aged 20 and 27, of African origin with homozygous sickle cell anemia who underwent heart valve surgery to treat mitral valve regurgitation. This presentation describes the perioperative considerations including anesthesia and postoperative care. Results: A partial exchange blood transfusion decreased HbS levels from respectively, 90% and 84%, 9% to 27% and 34%, and simultaneously treated the anemia. Neither sickling crisis nor acidosis occurred in any patient, and no special postoperative complication occurred. Average hospital stay was 10 days. Currently, the two patients remain alive and free of cardiac symptoms. Discussion: Although the presence of sickle cell disorders is associated with increased risk of sickling and thus vaso-occlusive complications, they should not be taken as a contraindication for heart valve surgery. Nevertheless, monitoring of certain parameters such as venous, arterial oxygen content, pH, and body temperature is mandatory for a better outcome. Furthermore, preoperative exchange transfusion has a positive influence on the outcome of surgery and on the survival of patients undergoing heart valves surgery. Avoiding intraoperative hypoxia, hypothermia, and vaso-constrictive agents, minimizing HbS levels with preoperative exchange transfusion, and ensuring a stress-free environment with the judicious use of sedatives made surgery relatively safe in these cases.
Claiborne, Thomas E.; Xenos, Michalis; Sheriff, Jawaad; Chiu, Wei-Che; Soares, Joao; Alemu, Yared; Gupta, Shikha; Judex, Stefan; Slepian, Marvin J.; Bluestein, Danny
Aortic stenosis the is most prevalent and life threatening form of valvular heart disease. It is primarily treated via open-heart surgical valve replacement with either a tissue or mechanical prosthetic heart valve (PHV), each prone to degradation and thrombosis, respectively. Polymeric PHVs may be optimized to eliminate these complications, and they may be more suitable for the new transcatheter aortic valve replacement (TAVR) procedure and in devices like the Total Artificial Heart. However, the development of polymer PHVs has been hampered by persistent in vivo calcification, degradation, and thrombosis. To address these issues, we have developed a novel surgically implantable polymer PHV comprised of a new thermoset polyolefin called xSIBS, in which key parameters were optimized for superior functionality via our Device Thrombogenicity Emulation (DTE) methodology. In this parametric study, we compared our homogeneous optimized polymer PHV to a prior composite polymer PHV and to a benchmark tissue valve. Our results show significantly improved hemodynamics and reduced thrombogenicity in the optimized polymer PHV compared to the other valves. These results indicate that our new design may not require anticoagulants and may be more durable than its predecessor, and validates the improvement, towards optimization, of this novel polymeric PHV design. PMID:23644615
Ziegelmueller, Johannes A; Zaenkert, Eva K; Schams, Rahmin; Lackermair, Stephan; Schmitz, Christoph; Reichart, Bruno; Sodian, Ralf
Currently, one approach to tissue engineering has been to develop in vitro conditions to fabricate functional cardiovascular structures such as heart valves before final implantation. In vivo conditions are simulated using a bioreactor system that supplies cells with oxygen and culture media while providing mechanical stimulation to promote tissue maturation. In our experiment, we developed a novel combined optical monitoring and conditioning device. The entire system is made of acrylic glass and is completely transparent. The bioreactor is connected to an air-driven respirator pump, and the cell culture medium continuously circulates through a closed-loop system. By adjusting stroke volume, stroke rate, and inspiration/expiration time of the ventilator, the system allows various pulsatile flows and different levels of pressure. Our optical monitoring and conditioning device provides a sterile environment, mechanical stimulation, and optical monitoring for the in vitro maturation of a tissue-engineered heart valve. With the camera module attached, tissue-engineered valves can be observed during the entire in vitro phase. This setting helps to find the optimal dynamic conditions for tissue-engineered heart valves to mature by adjusting flow and pressure conditions to provide physiological opening and closing behavior of the heart valve construct.
Chakraborty, Santanu; Wirrig, Elaine E.; Hinton, Robert B.; Merrill, Walter H.; Spicer, Douglas B.; Yutzey, Katherine E.
During embryogenesis the heart valves develop from undifferentiated mesenchymal endocardial cushions (EC), and activated interstitial cells of adult diseased valves share characteristics of embryonic valve progenitors. Twist1, a class II basic-helix-loop-helix (bHLH) transcription factor, is expressed during early EC development and is downregulated later during valve remodeling. The requirements for Twist1 down-regulation in the remodeling valves and the consequences of prolonged Twist1 activity were examined in transgenic mice with persistent expression of Twist1 in developing and mature valves. Persistent Twist1 expression in the remodeling valves leads to increased valve cell proliferation, increased expression of Tbx20, and increased extracellular matrix (ECM) gene expression, characteristic of early valve progenitors. Among the ECM genes predominant in the EC, Col2a1 was identified as a direct transcriptional target of Twist1. Increased Twist1 expression also leads to dysregulation of fibrillar collagen and periostin expression, as well as enlarged hypercellular valve leaflets prior to birth. In human diseased aortic valves, increased Twist1 expression and cell proliferation are observed adjacent to nodules of calcification. Overall, these data implicate Twist1 as a critical regulator of valve development and suggest that Twist1 influences ECM production and cell proliferation during disease. PMID:20804746
Tsugu, Toshimitsu; Iwanaga, Shiro; Murata, Mitsushige; Fukuda, Keiichi
Carcinoid heart disease (CHD) commonly occurs in association with primary gastrointestinal tract carcinoid tumors with hepatic metastases. Unlike primary gastrointestinal tract carcinoid tumors, primary ovarian carcinoid tumors may cause CHD without hepatic metastases, accounting for only 0.3 % of all carcinoid tumors. Only 37 cases of CHD from primary ovarian carcinoid tumors have been reported. We present a case of CHD in which tricuspid valve thickening and shortening led to reduced valve mobility with the resulting severe tricuspid regurgitation. Considering these characteristics of an abnormal tricuspid valve, we suspected CHD, but prosthetic valve replacement was performed without sufficient systemic examination before surgery. Two years after valve replacement, the patient underwent excision of a mass in the lower abdomen, which was diagnosed as an ovarian carcinoid tumor by histopathological examination. The patient has been observed for more than 3 years after tricuspid valve replacement. She has not experienced bioprosthetic valve leaflet degeneration or dysfunction, although it has been reported that bioprosthetic valves may degenerate in patients with carcinoid tumors. Sufficient systemic examinations should be performed to explore the cause of disease.
Full Text Available Sirenomelia, also known as “mermaid malformation/syndrome,” is a rare, serious congenital anomaly characterized by variable degrees of fusion of the lower limbs and associated with severe malformations of vertebral, genitourinary, cardiovascular system and single umbilical artery. The first pregnancy of a 25-year-old woman resulted in one twin born by Cesarian section at 32 weeks’ gestation, who was referred to our hospital with cyanosis, a congenital anomaly and respiratory distress. On physical examination, there was no urogenital region and anal fissure and gender was indeterminate. The arms were in adduction and wrist in flexion position with four fingers on the right hand and two fingers on the left hand. There was a single lower extremity with a webbed single foot and two toes consistent with sirenomelia type IV radiologically. Abdominal ultrasonography showed urogenital system agenesis and echocardiography detected hypoplastic left heart. However, the patient died 4 hours after birth. The other twin was followed for 1 week for nutrition and respiratory support and was then discharged without any problems.
Vaesken, Antoine; Heim, Frederic; Chakfe, Nabil
Transcatheter aortic valve replacement (TAVR) has become today a largely considered alternative technique to surgical valve replacement in patients who are not operable or patients with high risk for open chest surgery. However, the biological valve tissue used in the devices implanted clinically appears to be fragile material when folded for low diameter catheter insertion purpose and released in calcified environment with irregular geometry. Textile polyester material is characterized by outstanding folding and strength properties combined with proven biocompatibility. It could thereof be considered to replace biological valve leaflets in the TAVR procedure. The textile construction parameters must however be tuned to obtain a material compatible with the valve requested durability. In that context, one issue to be addressed is the friction effect that occurs between filaments and between yarns within a fabric under flexure loading. This phenomenon could be critical for the resistance of the material on the long term. The purpose of the present work is to assess the fatigue performances of textile valve prototypes made from different fabric constructions (monofilament, multifilament, calendered mutifilament) under accelerated cyclic loading. The goal is to identify, which construction is the best suited to long term fatigue stress. Results show that calendered multifilament and monofilament fabric constructions undergo strong ruptures already from 40 Mio cycles, while non calendered multifilament appears more durable. The rupture patterns observed point out that durability is directly related to the flexure stiffness level of the fibrous elements in the construction. Copyright © 2014 Elsevier Ltd. All rights reserved.
The mitral valve is one of four valves in the human heart. The valve opens to allow oxygenated blood from the lungs to fill the left ventricle, and closes when the ventricle contracts to prevent backflow. The valve is composed of two fibrous leaflets which hang from a ring. These leaflets are supported like a parachute by a system of strings called chordae tendineae. In this talk, I will describe a new computational model of the mitral valve. To generate geometry, general information comes from classical anatomy texts and the author's dissection of porcine hearts. An MRI image of a human heart is used to locate the tips of the papillary muscles, which anchor the chordae tendineae, in relation to the mitral ring. The initial configurations of the valve leaflets and chordae tendineae are found by solving solving an equilibrium elasticity problem. The valve is then simulated in fluid (blood) using the immersed boundary method over multiple heart cycles in a model valve tester. We aim to identify features and mechanisms that influence or control valve function. Support from National Science Foundation, Graduate Research Fellowship Program, Grant DGE 1342536.
Yang, Min; Chen, Chang-Zhi; Wang, Xue-Ning; Zhu, Ya-Bin; Gu, Y. John
Bovine pericardium has been extensively applied as the biomaterial for artificial heart valves and may potentially be used as a scaffold for tissue-engineered heart valves after decellularization. Although various methods of decellularization are currently available, it is unknown which method is
Tremblay, Catherine; Ruel, Jean; Bourget, Jean-Michel; Laterreur, Véronique; Vallières, Karine; Tondreau, Maxime Y; Lacroix, Dan; Germain, Lucie; Auger, François A
Tissue engineering appears as a promising option to create new heart valve substitutes able to overcome the serious drawbacks encountered with mechanical substitutes or tissue valves. The objective of this article is to present the construction method of a new entirely biological stentless aortic valve using the self-assembly method and also a first assessment of its behavior in a bioreactor when exposed to a pulsatile flow. A thick tissue was created by stacking several fibroblast sheets produced with the self-assembly technique. Different sets of custom-made templates were designed to confer to the thick tissue a three-dimensional (3D) shape similar to that of a native aortic valve. The construction of the valve was divided in two sequential steps. The first step was the installation of the thick tissue in a flat preshaping template followed by a 4-week maturation period. The second step was the actual cylindrical 3D forming of the valve. The microscopic tissue structure was assessed using histological cross sections stained with Masson's Trichrome and Picrosirius Red. The thick tissue remained uniformly populated with cells throughout the construction steps and the dense extracellular matrix presented corrugated fibers of collagen. This first prototype of tissue-engineered heart valve was installed in a bioreactor to assess its capacity to sustain a light pulsatile flow at a frequency of 0.5 Hz. Under the light pulsed flow, it was observed that the leaflets opened and closed according to the flow variations. This study demonstrates that the self-assembly method is a viable option for the construction of complex 3D shapes, such as heart valves, with an entirely biological material.
Munnelly, Amy; Cochrane, Leonard; Leong, Joshua; Vyavahare, Naren
Percutaneous heart valves are revolutionizing valve replacement surgery by offering a less invasive treatment option for high-risk patient populations who have previously been denied the traditional open chest procedure. Percutaneous valves need to be crimped to accommodate a small-diameter catheter during deployment, and they must then open to the size of heart valve. Thus the material used must be strong and possess elastic recoil for this application. Most percutaneous valves utilize bovine pericardium as a material of choice. One possible method to reduce the device delivery diameter is to utilize a thin, highly elastic tissue. Here we investigated porcine vena cava as an alternative to bovine pericardium for percutaneous valve application. We compared the structural, mechanical, and in vivo properties of porcine vena cava to those of bovine pericardium. While the extracellular matrix fibers of pericardium are randomly oriented, the vena cava contains highly aligned collagen and elastin fibers that impart strength to the vessel in the circumferential direction and elasticity in the longitudinal direction. Moreover, the vena cava contains a greater proportion of elastin, whereas the pericardium matrix is mainly composed of collagen. Due to its high elastin content, the vena cava is significantly less stiff than the pericardium, even after crosslinking with glutaraldehyde. Furthermore, the vena cava’s mechanical compliance is preserved after compression under forces similar to those exerted by a stent, whereas pericardium is significantly stiffened by this process. Bovine pericardium also showed surface cracks observed by scanning electron microscopy after crimping that were not seen in vena cava tissue. Additionally, the vena cava exhibited reduced calcification (46.64 ± 8.15 μg Ca/mg tissue) as compared to the pericardium (86.79 ± 10.34 μg/mg). These results suggest that the vena cava may enhance leaflet flexibility, tissue resilience, and tissue
Haimerl, J; Freitag-Krikovic, A; Rauch, A; Sauer, E
MRI allows visualization and planimetry of the aortic valve orifice and accurate determination of left ventricular muscle mass, which are important parameters in aortic stenosis. In contrast to invasive methods, MRI planimetry of the aortic valve area (AVA) is flow independent. AVA is usually indexed to body surface area. Left ventricular muscle mass is dependent on weight and height in healthy individuals. We studied AVA, left ventricular muscle mass (LMM) and ejection fraction (EF) in 100 healthy individuals and in patients with symptomatic aortic valve stenosis (AS). All were examined by MRI (1.5 Tesla Siemens Sonate) and the AVA was visualized in segmented 2D flash sequences and planimetry of the performed AVA was manually. The aortic valve area in healthy individuals was 3.9+/-0.7 cm(2), and the LMM was 99+/-27 g. In a correlation analysis, the strongest correlation of AVA was to height (r=0.75, pvalve stenosis, AVA was 1.0+/-0.35 cm(2), in correlation to cath lab r=0.72, and LMM was 172+/-56 g. We compared the AS patients results with the data of the healthy subjects, where the reduction of the AVA was 28+/-10% of the expected normal value, while LMM was 42% higher in patients with AS. There was no correlation to height, weight or BSA in patients with AS. With cardiac MRI, planimetry of AVA for normal subjects and patients with AS offered a simple, fast and non-invasive method to quantify AVA. In addition LMM and EF could be determined. The strong correlation between height and AVA documented in normal subjects offered the opportunity to integrate this relation between expected valve area and definitive orifice in determining the disease of the aortic valve for the individual patient. With diagnostic MRI in patients with AS, invasive measurements of the systolic transvalvular gradient does not seem to be necessary.
Stock, U A; Degenkolbe, I; Attmann, T; Schenke-Layland, K; Freitag, S; Lutter, G
Endovascular application of pulmonary heart valves has been recently introduced clinically. A tissue-engineering approach was pursued to overcome the current limitations of bovine jugular vein valves (degeneration and limited longevity). However, deployment of the delicate tissue-engineered valves resulted in severe tissue damage. Therefore the objective of this study was to prevent tissue damage during the folding and deployment maneuver. Porcine pulmonary heart valves, small intestinal submucosa, and ovine carotid arteries were obtained from a slaughterhouse. After dissection and antimicrobial incubation, the valves were trimmed (removal of sinus and most of the muscular ring) to fit into the deployment catheter. The inside (in-stent group, n = 6) or outside (out-stent group, n = 6) of a nitinol stent was covered by an acellular small intestinal submucosa, and the valves were sutured into the stent. The valves were folded, tested for placement in the deployment catheter, and decellularized enzymatically. Myofibroblasts were obtained from carotid artery segments and seeded onto the scaffolds. The seeded constructs were placed in a dynamic bioreactor system and cultured for 16 consecutive days. After endothelial cell seeding, the constructs were folded, deployed, and processed for histology and surface electron microscopy. The valves opened and closed competently throughout the entire dynamic culture. Surface electron microscopy revealed an almost completely preserved tissue in the in-stent group. Stents covered with small intestinal submucosa on the outside, however, showed severe damage. This study demonstrates that small intestinal submucosa covering of the inside of a pulmonary valved stent can prevent stent strut-related tissue damage.
Mathieu, Cédric; Mikaïl, Nidaa; Benali, Khadija; Iung, Bernard; Duval, Xavier; Nataf, Patrick; Jondeau, Guillaume; Hyafil, Fabien; Le Guludec, Dominique; Rouzet, François
18 F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has been recently acknowledged as a diagnostic tool for prosthetic valve endocarditis, but its specificity is limited by uptake on noninfected valves. The objective of this study was to outline the main features of FDG uptake on PET/CT in patients with noninfected prosthetic heart valve (PHV). Our institution's PET/CT database was reviewed to identify patients with PHV, excluding those suspected of infection or who had received antibiotic treatment. PET indication, valve location, and type (biological/mechanical) and time from implantation were collected for each patient. Images with and without attenuation correction were considered for interpretation. The pattern of FDG uptake (absent, homogeneous, or heterogeneous) was recorded. Fifty-four PHVs (51 patients) were identified, including 32 biological valves. Indications for PET were oncology (n=26), suspicion of prosthetic valve endocarditis subsequently excluded (n=17), and history of vasculitis (n=11). A periprosthetic FDG uptake was present in 47 (87%) and 30 (56%) PHVs with and without attenuation correction, respectively, and the pattern was homogeneous in all but 4 (7%) and 3 (6%) PHVs, respectively. On quantitative analysis, maximum standardized uptake values was greater in mechanical than in biological valves (4.0 [2.4-8.0] versus 3.3 [2.1-6.1]; P =0.01) and in patients with vasculitis than in those referred for other indications. The uptake intensity did not differ before and 3 months after valve replacement. Noninfected PHVs frequently display homogeneous FDG uptake, which remains steady over time. Caution is, therefore, needed when interpreting FDG PET/CT in suspected prosthetic valve endocarditis, with specific attention to uptake pattern. © 2017 American Heart Association, Inc.
Yamabe, Sayuri; Dohi, Yoshihiro; Higashi, Akifumi; Kinoshita, Hiroki; Sada, Yoshiharu; Hidaka, Takayuki; Kurisu, Satoshi; Shiode, Nobuo; Kihara, Yasuki
Electrocardiographic left ventricular hypertrophy (ECG-LVH) gradually regressed after aortic valve replacement (AVR) in patients with severe aortic stenosis. Sokolow-Lyon voltage (SV1 + RV5/6) is possibly the most widely used criterion for ECG-LVH. The aim of this study was to determine whether decrease in Sokolow-Lyon voltage reflects left ventricular reverse remodeling detected by echocardiography after AVR. Of 129 consecutive patients who underwent AVR for severe aortic stenosis, 38 patients with preoperative ECG-LVH, defined by SV1 + RV5/6 of ≥3.5 mV, were enrolled in this study. Electrocardiography and echocardiography were performed preoperatively and 1 year postoperatively. The patients were divided into ECG-LVH regression group (n = 19) and non-regression group (n = 19) according to the median value of the absolute regression in SV1 + RV5/6. Multivariate logistic regression analysis was performed to assess determinants of ECG-LVH regression among echocardiographic indices. ECG-LVH regression group showed significantly greater decrease in left ventricular mass index and left ventricular dimensions than Non-regression group. ECG-LVH regression was independently determined by decrease in the left ventricular mass index [odds ratio (OR) 1.28, 95 % confidence interval (CI) 1.03-1.69, p = 0.048], left ventricular end-diastolic dimension (OR 1.18, 95 % CI 1.03-1.41, p = 0.014), and left ventricular end-systolic dimension (OR 1.24, 95 % CI 1.06-1.52, p = 0.0047). ECG-LVH regression could be a marker of the effect of AVR on both reducing the left ventricular mass index and left ventricular dimensions. The effect of AVR on reverse remodeling can be estimated, at least in part, by regression of ECG-LVH.
Beall, A C
Phenomenal advances in the development of cardiac valve prostheses have taken place in less than two decades. However, the currently prevailing atmosphere of consumer protectionism in existence 20 years ago probably would have made such developments impossible. Recent passage of the Medical Device Amendments of 1976 (P.L. 94-295) will not only make future development extremely difficult, but also may force the field of cardiac valve replacement back into the era of the 1950s. Regulations implementing this legislation may be even more disastrous. It is time for someone to protect patients from their so-called protectors.
McLintock, C; McCowan, L M E; North, R A
To determine maternal and fetal outcomes in women with mechanical heart valves managed with therapeutic dose enoxaparin during pregnancy. Retrospective audit. Hospital-based high-risk antenatal clinics. Pregnant women with mechanical heart valves attending high-risk antenatal clinics, treated with enoxaparin (1 mg/kg twice daily) during pregnancy. Women with mechanical heart valves treated with enoxaparin at any stage during pregnancy (1997-2008) identified using a database of women with mechanical heart valves attending the high-risk clinics and a prospective database of women prescribed enoxaparin for any indication during pregnancy. Maternal outcomes included thromboembolic and haemorrhagic complications. Pregnancy and fetal outcomes included miscarriage, stillbirth, baby death and live birth, small-for-gestational-age infants, warfarin embryopathy and warfarin-related fetal loss. Thirty-one women underwent 47 pregnancies. In 34 pregnancies (72.3%), anticoagulation was with predominantly enoxaparin and 13 (27.7%) pregnancies women received mainly warfarin, with enoxaparin given in the first trimester and/or peri-delivery. Seven (14.9%) thrombotic complications occurred, of which five (10.6%) were associated with enoxaparin treatment. Non-compliance or sub-therapeutic anti-Xa levels contributed in each case. Antenatal and postpartum haemorrhagic complications occurred in eight (17%) and 15 (32%) pregnancies respectively. Of 35 pregnancies continuing after 20 weeks' gestation, 96% (22/23) of women taking predominantly enoxaparin had a surviving infant compared with 75% (9/12) in women taking primarily warfarin. Four perinatal deaths occurred, three attributable to warfarin. Compliance with therapeutic dose enoxaparin and aspirin during pregnancy in women with mechanical heart valves is associated with a low risk of valve thrombosis and good fetal outcomes, but close monitoring is essential.
Xue, Yingfei; Sant, Vinayak; Phillippi, Julie; Sant, Shilpa
Valvular heart diseases are the third leading cause of cardiovascular disease, resulting in more than 25,000 deaths annually in the United States. Heart valve tissue engineering (HVTE) has emerged as a putative treatment strategy such that the designed construct would ideally withstand native dynamic mechanical environment, guide regeneration of the diseased tissue and more importantly, have the ability to grow with the patient. These desired functions could be achieved by biomimetic design of tissue-engineered constructs that recapitulate in vivo heart valve microenvironment with biomimetic architecture, optimal mechanical properties and possess suitable biodegradability and biocompatibility. Synthetic biodegradable elastomers have gained interest in HVTE due to their excellent mechanical compliance, controllable chemical structure and tunable degradability. This review focuses on the state-of-art strategies to engineer biomimetic elastomeric scaffolds for HVTE. We first discuss the various types of biodegradable synthetic elastomers and their key properties. We then highlight tissue engineering approaches to recreate some of the features in the heart valve microenvironment such as anisotropic and hierarchical tri-layered architecture, mechanical anisotropy and biocompatibility. Heart valve tissue engineering (HVTE) is of special significance to overcome the drawbacks of current valve replacements. Although biodegradable synthetic elastomers have emerged as promising materials for HVTE, a mature HVTE construct made from synthetic elastomers for clinical use remains to be developed. Hence, this review summarized various types of biodegradable synthetic elastomers and their key properties. The major focus that distinguishes this review from the current literature is the thorough discussion on the key features of native valve microenvironments and various up-and-coming approaches to engineer synthetic elastomers to recreate these features such as anisotropic tri
Rodrigo P. Franco
Full Text Available Abstract: The left atrial volume (LAV can be obtained using the biplane Simpson's method via echocardiography. Although in medicine this parameter has been considered to be a prognostic marker of left atrial enlargement in several cardiac diseases, in dogs with myxomatous mitral valve degeneration (MMVD, a valvulopathy characterized by left atrial (LA volume overload, atrial enlargement is usually assessed by the LA-to-Aorta ratio (LA:Ao. Therefore, the body surface area (BSA-indexed LAV was measured in healthy dogs and in dogs with MMVD using the biplane Simpson's method. For this purpose, a total of 107 healthy dogs (control and 81 dogs with MMVD in ACVIM stages B1, B2 and C were assessed, with LAV being calculated during atrial diastole (d and systole (s through the biplane Simpson's method. Two-dimensional apical four-chamber (4C and two-chamber (2C images were obtained in every dog through the left parasternal window. The values obtained from healthy dogs were correlated with body weight using Pearson's test. An analysis of variance (ANOVA and Tukey's test were used to compare healthy and MMVD dogs, as well as to investigate differences according with MMVD stages. A strong positive correlation was documented between either LAVd (r> 0.77 or LAVs (r> 0.73 and body weight in healthy dogs. The BSA-indexed LAV calculated for MMVD dogs was significantly different (p<0.01 from that obtained for the control group. Also, LAV was significantly different (P<0.05 when stages B2 and C, and B1 and C were compared. In conclusion, this study provided a reference for left atrial volume and the applicability of this technique to assess atrial overload in dogs with varying-stage MMVD.
Khalighi, Amir H; Drach, Andrew; Gorman, Robert C; Gorman, Joseph H; Sacks, Michael S
An essential element of cardiac function, the mitral valve (MV) ensures proper directional blood flow between the left heart chambers. Over the past two decades, computational simulations have made marked advancements toward providing powerful predictive tools to better understand valvular function and improve treatments for MV disease. However, challenges remain in the development of robust means for the quantification and representation of MV leaflet geometry. In this study, we present a novel modeling pipeline to quantitatively characterize and represent MV leaflet surface geometry. Our methodology utilized a two-part additive decomposition of the MV geometric features to decouple the macro-level general leaflet shape descriptors from the leaflet fine-scale features. First, the general shapes of five ovine MV leaflets were modeled using superquadric surfaces. Second, the finer-scale geometric details were captured, quantified, and reconstructed via a 2D Fourier analysis with an additional sparsity constraint. This spectral approach allowed us to easily control the level of geometric details in the reconstructed geometry. The results revealed that our methodology provided a robust and accurate approach to develop MV-specific models with an adjustable level of spatial resolution and geometric detail. Such fully customizable models provide the necessary means to perform computational simulations of the MV at a range of geometric accuracies in order to identify the level of complexity required to achieve predictive MV simulations.
... Replacement Menu Topics Topics FAQs Valve Repair or Replacement Heart valves play a key role in this ... leaflets with a tissue patch. What is valve replacement? Severe valve damage means the valve must be ...
Full Text Available INTRODUCTION: In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. OBJECTIVE: To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models exposed to a steady flow regime, on four distinct sections, three downstream and one upstream. METHODS: To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements. RESULTS: It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found. CONCLUSIONS: Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM is superior to the 21 AJ - 501 model (Master Series. Based on the results, future studies can choose to focus on specific regions of the these valves.
Bazan, Ovandir; Ortiz, Jayme Pinto; Vieira Junior, Francisco Ubaldo; Vieira, Reinaldo Wilson; Antunes, Nilson; Tabacow, Fabio Bittencourt Dutra; Costa, Eduardo Tavares; Petrucci Junior, Orlando
Introduction In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. Objective To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream. Methods To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements. Results It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found. Conclusions Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves. PMID:24598950
Moreira, Ricardo; Neusser, Christine; Kruse, Magnus; Mulderrig, Shane; Wolf, Frederic; Spillner, Jan; Schmitz-Rode, Thomas; Jockenhoevel, Stefan; Mela, Petra
The mechanical properties of tissue-engineered heart valves still need to be improved to enable their implantation in the systemic circulation. The aim of this study is to develop a tissue-engineered valve for the aortic position - the BioTexValve - by exploiting a bio-inspired composite textile scaffold to confer native-like mechanical strength and anisotropy to the leaflets. This is achieved by multifilament fibers arranged similarly to the collagen bundles in the native aortic leaflet, fixed by a thin electrospun layer directly deposited on the pattern. The textile-based leaflets are positioned into a 3D mould where the components to form a fibrin gel containing human vascular smooth muscle cells are introduced. Upon fibrin polymerization, a complete valve is obtained. After 21 d of maturation by static and dynamic stimulation in a custom-made bioreactor, the valve shows excellent functionality under aortic pressure and flow conditions, as demonstrated by hydrodynamic tests performed according to ISO standards in a mock circulation system. The leaflets possess remarkable burst strength (1086 mmHg) while remaining pliable; pronounced extracellular matrix production is revealed by immunohistochemistry and biochemical assay. This study demonstrates the potential of bio-inspired textile-reinforcement for the fabrication of functional tissue-engineered heart valves for the aortic position. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Weber, Miriam; Heta, Eriona; Moreira, Ricardo; Gesche, Valentine N; Schermer, Thomas; Frese, Julia; Jockenhoevel, Stefan; Mela, Petra
The general approach in heart valve tissue engineering is to mimic the shape of the native valve in the attempt to recreate the natural haemodynamics. In this article, we report the fabrication of the first tissue-engineered heart valve (TEHV) based on a tubular leaflet design, where the function of the leaflets of semilunar heart valves is performed by a simple tubular construct sutured along a circumferential line at the root and at three single points at the sinotubular junction. The tubular design is a recent development in pericardial (nonviable) bioprostheses, which has attracted interest because of the simplicity of the construction and the reliability of the implantation technique. Here we push the potential of the concept further from the fabrication and material point of view to realize the tube-in-tube valve: an autologous, living HV with remodelling and growing capability, physiological haemocompatibility, simple to construct and fast to implant. We developed two different fabrication/conditioning procedures and produced fibrin-based constructs embedding cells from the ovine umbilical cord artery according to the two different approaches. Tissue formation was confirmed by histology and immunohistology. The design of the tube-in-tube foresees the possibility of using a textile coscaffold (here demonstrated with a warp-knitted mesh) to achieve enhanced mechanical properties in vision of implantation in the aortic position. The tube-in-tube represents an attractive alternative to the conventional design of TEHVs aiming at reproducing the valvular geometry.
Renal haemosiderosis is the anatomical indicator of intravascular haemolysis. The incidence of renal haemosiderosis was studied in 66 patients with valve prostheses, 32 patients with advanced rheumatic-type valvular deformities and in 21 consecutive routine adult autopsy cases. Significant renal haemosiderosis was ...
Apr 13, 1974 ... showing renal siderosis was a 57-year-old White male who had mitral stenosis, trivial aortic stenosis and functional tricuspid incompetence. Cardiac symptoms had been pre- sent for 10 years. This same patient had large amounts of. Valve lesion. Mitral stenosis/incompetence. Aortic stenosis/incompetence.
Apr 13, 1974 ... Renal haemosiderosis is the anatomical indicator of intra- vascular haemolysis. The incidence of renal haemosiderosis was studied in 66 patients with valve prostheses, 32 patients with advanced rheumatic-type valvular deformities and in 21 consecutive routine adult autopsy cases. Significant renal ...
Fukunaga, Naoto; Yuzaki, Mitsuru; Hamakawa, Hiroshi; Nasu, Michihiro; Takahashi, Yutaka; Okada, Yukikatsu
Cardiovascular surgery in the setting of chest wall deformities is a clinical challenge. Pectus excavatum, for example, can cause heart displacement to the left thoracic cavity, following the poor operative field. This report highlights a case in which a successful aortic valve-sparing operation via conventional median sternotomy after correction of the heart displacement due to pectus excavatum using Nuss procedure in Marfan syndrome. This technique can be one surgical option in Marfan syndrome patients with pectus excavatum and thoracic aortic aneurysm under close follow up.
Aung, S M; Güler, A; Güler, Y; Huraibat, A; Karabay, C Y; Akdemir, I
Heart failure with preserved ejection fraction (HFpEF) is a syndrome in which patients have symptoms and signs of heart failure but preserved ejection fraction. Left atrial (LA) volume and function are known to be impaired in these patients. Two-dimensional speckle-tracking echocardiography (2D-STE) has recently enabled the quantification of LA deformation dynamics. In this study, we evaluated the use of 2D-STE for the diagnosis of HFpEF. The study included 83 patients with suspected HFpEF. Patients were divided into two groups after HFpEF had been diagnosed according to current guidelines. Parameters of diastolic dysfunction were evaluated, including left ventricular mass index (LVMI), LA volume index (LAVI), E/A ratio, deceleration time (DT), E/E', and STE parameters such as global longitudinal LA strain during ventricular systole (GLAs-res) and strain during late diastole (GLAs-pump). The values of BNP, LVMI, DT, LAVI, and GLAs-res were significantly different between the two groups. In univariate analysis, a strong negative correlation was seen between GLAs-res and BNP (r = -0.567, p < 0.001) as well as between GLAs-res and DT (r = -0.665, p < 0.001), while a moderate negative correlation was found between GLAs-res and LVMI (r = -0.458, p < 0.001) and GLAs-res and LAVI (r = -0.316, p = 0.004). In logistic regression analysis, GLAs-res (p = 0.049, OR = 0.71, 95 % CI = 0.451-0.99), BNP (p = 0.025, OR = 1.08, 95 % CI = 1.01-1.14), and LAVI (p = 0.042, OR = 1.59, 95 % CI = 1.02-2.48) were found to be independent predictors of HFpEF. LA function as assessed by 2D-STE is impaired in patients with HFpEF. A GLAs-res value of < 17.5 % can be useful for the diagnosis of HFpEF.
Parvin Nejad, Shouka; Blaser, Mark C; Santerre, J Paul; Caldarone, Christopher A; Simmons, Craig A
Surgical replacement of dysfunctional valves is the primary option for the treatment of valvular disease and congenital defects. Existing mechanical and bioprosthetic replacement valves are far from ideal, requiring concomitant anticoagulation therapy or having limited durability, thus necessitating further surgical intervention. Heart valve tissue engineering (HVTE) is a promising alternative to existing replacement options, with the potential to synthesize mechanically robust tissue capable of growth, repair, and remodeling. The clinical realization of a bioengineered valve relies on the appropriate combination of cells, biomaterials, and/or bioreactor conditioning. Biomechanical conditioning of valves in vitro promotes differentiation of progenitor cells to tissue-synthesizing myofibroblasts and prepares the construct to withstand the complex hemodynamic environment of the native valve. While this is a crucial step in most HVTE strategies, it also may contribute to fibrosis, the primary limitation of engineered valves, through sustained myofibrogenesis. In this review, we examine the progress of HVTE and the role of mechanical conditioning in the synthesis of mechanically robust tissue, and suggest approaches to achieve myofibroblast quiescence and prevent fibrosis. Copyright © 2015 Elsevier B.V. All rights reserved.
Cebotari, Serghei; Lichtenberg, Artur; Tudorache, Igor; Hilfiker, Andres; Mertsching, Heike; Leyh, Rainer; Breymann, Thomas; Kallenbach, Klaus; Maniuc, Liviu; Batrinac, Aurel; Repin, Oleg; Maliga, Oxana; Ciubotaru, Anatol; Haverich, Axel
Tissue engineering (TE) of heart valves reseeded with autologous cells has been successfully performed in vitro. Here, we report our first clinical implantation of pulmonary heart valves (PV) engineered with autologous endothelial progenitor cells (EPCs) and the results of 3.5 years of follow-up. Human PV allografts were decellularized (Trypsin/EDTA) and resulting scaffolds reseeded with peripheral mononuclear cells isolated from human blood. Positive stain for von Willebrand factor, CD31, and Flk-1 was observed in monolayers of cells cultivated and differentiated on the luminal surface of the scaffolds in a dynamic bioreactor system for up to 21 days, indicating endothelial nature. PV reseeded with autologous cells were implanted into 2 pediatric patients (age 13 and 11) with congenital PV failure. Postoperatively, a mild pulmonary regurgitation was documented in both children. Based on regular echocardiographic investigations, hemodynamic parameters and cardiac morphology changed in 3.5 years as follows: increase of the PV annulus diameter (18 to 22.5 mm and 22 to 26 mm, respectively), decrease of valve regurgitation (trivial/mild and trivial, respectively), decrease (16 to 9 mm Hg) or a increase (8 to 9.5 mm Hg) of mean transvalvular gradient, remained 26 mm or decreased (32 to 28 mm) right-ventricular end-diastolic diameter. The body surface area increased (1.07 to 1.42 m2 and 1.07 to 1.46 m2, respectively). No signs of valve degeneration were observed in both patients. TE of human heart valves using autologous EPC is a feasible and safe method for pulmonary valve replacement. TE valves have the potential to remodel and grow accordingly to the somatic growth of the child.
Kasimir, Marie-Theres; Rieder, Erwin; Seebacher, Gernot; Nigisch, Anneliese; Dekan, Barbara; Wolner, Ernst; Weigel, Guenter; Simon, Paul
In tissue engineering of heart valves using decellularized xenogenic valves, it has been suggested that cell elimination would result in a biologically inert matrix. The aim of this in-vitro investigation was to evaluate different decellularization methods in regard to the completeness of cell removal, inflammatory response, and thrombocyte activation. Decellularized porcine Synergraft valves were compared with porcine pulmonary conduits decellularized with Triton X-100, sodium deoxycholate, Igepal CA-630 and ribonuclease. Completeness of decellularization was evaluated with staining for nuclei and alpha-Gal epitope. Decellularized heart valves with and without seeding with endothelial cells (ECs) were incubated with human platelet-rich plasma and stained for CD41 and PAC-1 to evaluate thrombocyte activation. Samples were processed for laser scanning microscopy (LSM) and scanning electron microscopy (SEM). Migration of human monocytic cells towards extracted valve proteins was tested. In contrast to the Synergraft, complete cell removal and elimination of the alpha-gal epitope was achieved with the new decellularization method. Numerous adherent and activated platelets were found on the decellularized matrix. This was inhibited by seeding with ECs. Even in completely cell-free valve tissue extracellular matrix proteins attracted human monocytic cells as in early inflammation, depending on whether porcine or human tissue was used. Important differences were found in the decellularization efficacy of treatment methods. However, even complete elimination of cells and their remnants did not result in a biologically inert matrix. The decellularized porcine heart valve matrix has the potential to attract inflammatory cells and to induce platelet activation. These findings suggest that it will be important to control the different inflammation-stimulating factors if porcine tissues are to be used successfully in tissue engineering.
Flanagan, Thomas C; Sachweh, Jörg S; Frese, Julia; Schnöring, Heike; Gronloh, Nina; Koch, Sabine; Tolba, Rene H; Schmitz-Rode, Thomas; Jockenhoevel, Stefan
Autologous fibrin-based tissue-engineered heart valves have demonstrated excellent potential as patient-derived valve replacements. The present pilot study aims to evaluate the structure and mechanical durability of fibrin-based heart valves after implantation in a large-animal model (sheep). Tissue-engineered heart valves were molded using a fibrin scaffold and autologous arterial-derived cells before 28 days of mechanical conditioning. Conditioned valves were subsequently implanted in the pulmonary trunk of the same animals from which the cells were harvested. After 3 months in vivo, explanted valve conduits (n = 4) had remained intact and exhibited native tissue consistency, although leaflets demonstrated insufficiency because of tissue contraction. Routine histology showed remarkable tissue development and cell distribution, along with functional blood vessel ingrowth. A confluent monolayer of endothelial cells was present on the valve surface, as evidenced by scanning electron microscopy and positive von Willebrand factor staining. Immunohistochemistry and extracellular matrix (ECM) assay demonstrated complete resorption of the fibrin scaffold and replacement with ECM proteins. Transmission electron microscopy revealed mature collagen formation and viable, active resident tissue cells. The preliminary findings of implanted fibrin-based tissue-engineered heart valves are encouraging, with excellent tissue remodeling and structural durability after 3 months in vivo. The results from this pilot study highlight the potential for construction of completely "autologous" customized tissue-engineered heart valves based on a patient-derived fibrin scaffold.
Böning, A; Boedeker, R H; Rosendahl, U P; Niemann, B; Haberer, S; Roth, P; Ennker, J A C
We wanted to answer the question whether biological heart valves are inferior compared to mechanical heart valves in end-stage renal disease (ESRD) patients. Between 01/1996 und 12/2006, 44 of 3293 patients undergoing aortic valve replacement (AVR) in a single institution suffered from dialysis-dependent ESRD and underwent a follow-up investigation after 1.9 years (median). Twelve (28.9 %) of these patients received a biological, 32 (71.1 %) of these patients a mechanical aortic valve prosthesis. To evaluate a possible influence of the valve type (biological/mechanical) on survival, uni- and multivariate logistic regression was used. ESRD patients after AVR had a relatively poor short-term (30-day mortality: 22.7 %) and long-term survival (median survival time: 24.7 months; 95 % CI: 0.2-47.7 months), irrespective of the type of heart valve prosthesis (hazard ratio for mortality depending on heart valve type in dialysis patients: 1.31, P = 0.400). Dialysis-dependent patients were not reoperated due to valve-related reasons. The long-term survival of dialysis-dependent patients after AVR is low (5-year survival: 29.5 %) irrespective of the type of heart valve prosthesis. Therefore, the use of biological AVR is not contraindicated in this group of patients. © Georg Thieme Verlag KG Stuttgart · New York.
... phen and Redux, which were removed from the market after being linked to heart valve disease. An ... have a prosthetic valve made of synthetic material. Beta-blockers control your heart rate and lower your ...
Christensen, Thomas D; Attermann, Jørn; Pilegaard, Hans K
of conventionally managed heart valve patients (control group) was used as reference. Results: The median observation time was 1175 days (range: 174–1428 days). The self-managed patients were within therapeutic INR target range for a mean of 78.0% (range: 36.1%–93.9%) of the time compared with 61.0% (range 37.......4%–2.9%) for the control group. Conclusion: Self-management of OAT is a feasible and safe concept for selected patients with mechanical heart valve prostheses also on a long-term basis. It provides at least as good and most likely better quality of anticoagulant therapy than conventional management assessed by time within...... of self-management of OAT in patients with mechanical heart valve prostheses on a 4-year perspective in a prospective, non-randomized study. Design: Twenty-four patients with mechanical heart valves and on self-managed OAT were followed for up to 4 years. A matched, retrospectively selected group...
Vink, Roel; van den Brink, Renée B. A.; Levi, Marcel
There is a wide array of recommendations for the management of anticoagulant therapy in patients with mechanical heart valves. Especially the optimal intensity of vitamin K antagonists (VKA) is a ongoing matter of debate. On the basis of several studies, recommendations for daily clinical practice
van Slooten, Ymkje J.; Freling, Hendrik G.; van Melle, Joost P.; Mulder, Barbara J. M.; Jongbloed, Monique R. M.; Ebels, Tjark; Voors, Adriaan A.; Pieper, Petronella G.
In patients with acquired valvar disease, morbidity and mortality rates after tricuspid valve replacement (TVR) are high. However, in adult patients with congenital heart disease, though data concerning outcome after TVR are scarce, even poorer results are suggested in patients with Ebstein anomaly.
van Slooten, Ymkje J.; Freling, Hendrik G.; van Melle, Joost P.; Mulder, Barbara J. M.; Jongbloed, Monique R. M.; Ebels, Tjark; Voors, Adriaan A.; Pieper, Petronella G.
OBJECTIVES: In patients with acquired valvar disease, morbidity and mortality rates after tricuspid valve replacement (TVR) are high. However, in adult patients with congenital heart disease, though data concerning outcome after TVR are scarce, even poorer results are suggested in patients with
Khamoushi, Amir Jamshid; Kashfi, Fahimeh; Hosseini, Saeid; Alizadeh Ghavidel, Ali Reza; Samiei, Niloufar; Haddadzadeh, Mehdi
Pregnancy is associated with a hypercoagulable state, therefore the optimal anticoagulants for potential use in pregnant women with prosthetic heart valves are controversial. The aim of this study is to investigate the effect of anticoagulants on pregnancy outcomes and their potential risks in pregnant women with mechanical heart valves. In this prospective cohort study, we followed 44 women with 49 pregnancies who had mechanical heart valves from September 2002 to September 2007. A total of 38 patients took warfarin throughout their pregnancies (group A). In 11 patients, warfarin was changed to heparin during the first trimester and then again to warfarin during 12thto 36thweeks of gestational age (group B). All women took warfarin from 36thweeks of gestational age until delivery. In group A, there were 22 live births (57.9%), 15 abortions (39.5%) and 1 maternal death (2.6%). In group B, there were seven live births (63.6%), three spontaneous abortions (27.3%) and one intra-uterine fetal death (9.1%). There was no significant difference in live birth rate between the two groups (p=0.24). Thirty-three pregnancies (86.8%) in group A and five pregnancies (45.4%) in group B had no maternal complications (p=0.004). The difference in pregnancy complications between both groups was significant (pmechanical heart valves remain on a warfarin regimen. The risk of embryopathy does not necessarily increase.
Schapkaitz, Elise; Jacobson, Barry Frank; Manga, Pravin; Chitsike, Rufaro Saeed; Benade, Estee; Haas, Sylvia; Buller, Harry R.
The management of pregnant patients with mechanical heart valves remains challenging because there are no large randomised studies to provide guidelines for effective anticoagulant therapy. Both vitamin K antagonists and heparins may be associated with maternal and foetal adverse events. The
... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2009-D-0559... Approval (PMA) Applications.'' It does not create or confer any rights for or on any person and does not... a copy of the draft guidance may do so by using the Internet. To receive ``Heart Valves...
Nagendra Boopathy Senguttuvan
Full Text Available We describe a young male who had undergone a Bentall's procedure seven years ago presenting with acute severe chest pain. He was diagnosed to have coronary embolism from prosthetic heart valve thrombosis. Multiple treatment strategies for the patient were available and we briefly discuss the merits of each of them. We also describe the encountered difficulties in the percutaneous revascularization procedure.
Craig, Brian T; Rellinger, Eric J; Mettler, Bret A; Watkins, Scott; Donahue, Brian S; Chung, Dai H
Patients with hypoplastic left heart syndrome (HLHS) experience a higher risk for complications from gastroesophageal reflux, prompting frequent need for fundoplication. Patients between stage I and II palliation ("interstage") are at particularly high operative risk because of the parallel nature of their pulmonary and systemic blood flow. Laparoscopic approach for fundoplication is common for pediatric patients. However, its safety in interstage HLHS is relatively unknown. We examined the perioperative physiologic burden of a laparoscopic fundoplication in HLHS patients. All patients who underwent open or laparoscopic fundoplication during the interstage period at our institution since 2006 were reviewed. Perioperative physiologic data, echocardiographic findings, survival, and complications were collected from the anesthetic record and patient chart. Nineteen patients with HLHS had laparoscopic fundoplication, 13 (68%) during the interstage period, compared to 64 performed by the open approach. Ten (77%) of 13 interstage patients had perioperative hemodynamic instability. Incidence of instability between open and laparoscopic groups was not different. One laparoscopic patient required ECMO support for shunt thrombosis. Despite a high incidence of hemodynamic instability, overall outcomes are consistent with those reported in the literature for this high-risk patient population. Laparoscopic approach for fundoplication during the interstage period appears to be a relatively safe option for these patients. Copyright © 2016 Elsevier Inc. All rights reserved.
Bradley, Elisa A.; Novak, Eric L.; Rasalingam, Ravi; Cedars, Ari M.; Ewald, Gregory A.; Silvestry, Scott C.; Joseph, Susan M.
Left ventricular assist device (LVAD)-supported patients are evaluated routinely with use of transthoracic echocardiography. Values of left ventricular unloading in this unique patient population are needed to evaluate LVAD function and assist in patient follow-up. We introduce a new M-mode measurement, the slope of the anterior mitral valve leaflet (SLAM), and compare its efficacy with that of other standard echocardiographically evaluated values for left ventricular loading, including E/e′ and pulmonary artery systolic pressures. Average SLAM values were determined retrospectively for cohorts of random, non-LVAD patients with moderately to severely impaired left ventricular ejection fraction (LVEF) (ventricular unloading in LVAD patients remains challenging. Our novel M-mode value correlates with echocardiographic values of left ventricular filling in patients with moderate-to-severe systolic function and dynamically improves with the ventricular unloading of an LVAD. PMID:24955040
van Slooten, Ymkje J; Freling, Hendrik G; van Melle, Joost P; Mulder, Barbara J M; Jongbloed, Monique R M; Ebels, Tjark; Voors, Adriaan A; Pieper, Petronella G
In patients with acquired valvar disease, morbidity and mortality rates after tricuspid valve replacement (TVR) are high. However, in adult patients with congenital heart disease, though data concerning outcome after TVR are scarce, even poorer results are suggested in patients with Ebstein anomaly. To investigate the applicability of these results to a broader array of congenital heart disease patients, we report the long-term follow-up of prosthesis-related complications, including re-replacement of patients with a tricuspid valve prosthesis and congenital heart disease. From the Dutch Congenital Corvitia (CONCOR) registry, we identified 20 patients with a biological or mechanical tricuspid valve prosthesis implanted between 1977 and 2012 (total of 31 prostheses). We analysed the tricuspid valve-related complications and mortality. Ten patients with a median age of 16.2 years at the time of surgery (interquartile range 13.2-28.2 years) received a bioprosthesis while 10 patients with a median age of 36.4 years (interquartile range 14.0-47.0) at the time of surgery received a mechanical prosthesis (P = 0.28). During a mean follow-up of 14 years, 50% needed a re-replacement because of valve-related complications (e.g. valve degeneration or valve thrombosis). The yearly percentage of patients with valve-related complications was 4.2% in patients with a bioprosthesis and 2.7% in those with a mechanical prosthesis. Within 20 years of implantation, the median duration of event-free survival was significantly shorter in 3 patients with a prosthesis-patient mismatch (PPM; 1.0 year; interquartile range 0.01-2.6), compared with 7 without mismatch (8.0 years; interquartile range 5.1-12.3; P = 0.02). Compared with previous literature on acquired valvar disease, we found a higher incidence of valve-related complications in patients with congenital heart disease that was unrelated to prosthesis material. Our data suggest that PPM may have a negative effect on the event
Butany, Jagdish; Leask, Richard L; Desai, Nimesh D; Jegatheeswaran, Anusha; Silversides, Candice; Scully, Hugh E; Feindel, Christopher
The St. Jude Medical Silzone (Silzone) mechanical heart valve was voluntarily recalled (January 2000) due to an unusually high incidence of paravalvular leaks. We present the first series of human morphological data on the failure of these valves. Nineteen Silzone valves were evaluated from the 176 Silzone valves implanted in 147 patients at our institution between 1997 and 1999. Explanted prostheses were fixed in 10% formalin, photographed, and X-rayed. Histological sections were collected from the sewing cuff, accompanying tissues, and thrombus. For comparison, six age-matched SJM-standard valves were similarly analyzed. Nineteen Silzone valves from 16 patients (10 male, six female, 52.0 +/- 15.2 years) were examined. Significantly more mitral (15/95) prostheses were removed than aortic (4/81) despite the nearly equal number implanted (p = 0.027). Fifteen of the Silzone valves (13/16 patients) were explanted in the early postoperative period (within six months of implantation), although collection continued for eight years after our institution stopped implanting them. The common indications for surgical explantation were paravalvular leak (8/12) and clinically suspected infective endocarditis (IE) (four patients, five valves). IE was not confirmed by histology or culture in any valve. The sewing cuffs of many Silzone valves showed large regions of pannus, granulation tissue, and purulent exudate. Polymorphonuclear leukocytes were more common in the sewing cuff of Silzone valves; however, the cellular infiltrate was superficial when compared to SJM-standard valves. This is the largest morphologically analyzed series of Silzone explants. It demonstrates a consistent pattern of atypical tissue incorporation into the silver-coated sewing ring particularly in the mitral position. Clinical and morphologic features of IE (sterile) are seen in the early postimplant period. Prosthesis-related problems were almost wholly seen at the mitral site, in our group. Our current
Alnasser, Sami; Cheema, Asim N; Horlick, Eric
: For each surgical type and label size, the two commonly used THV sizes, a given THV “standard” vs. a size larger “oversized” were compared among patients undergoing aortic ViV within VIVID Registry. The degree of THV perimeter oversizing was calculated as: (THV nominal size – surgical valve true ID...... group received a larger THV (25.5± 1.4 mm vs. 23.3 ± 1.0 mm, pdegree of THV oversizing (31% ± 10.6 vs. 20% ± 9.5, p=vs. 1.37± 0.5cm2, p....1±8.1mmHg vs. 17.4±8.5mmHg, p=0.002) in comparison to the standard cohort. The oversized group however, had a higher rate of moderate to severe AI (6.9% vs. 2.7%, p=0.001) and second THV requirement (5.5%vs. 2.2%, p=0.04). THV mal-positioning, coronary obstruction and postoperative pacemaker requirement...
Cazelli, José Guilherme; Camargo, Gabriel Cordeiro; Kruczan, Dany David; Weksler, Clara; Felipe, Alexandre Rouge; Gottlieb, Ilan
The prevalence of coronary artery disease (CAD) in valvular patients is similar to that of the general population, with the usual association with traditional risk factors. Nevertheless, the search for obstructive CAD is more aggressive in the preoperative period of patients with valvular heart disease, resulting in the indication of invasive coronary angiography (ICA) to almost all adult patients, because it is believed that coronary artery bypass surgery should be associated with valve replacement. To evaluate the prevalence of obstructive CAD and factors associated with it in adult candidates for primary heart valve surgery between 2001 and 2014 at the National Institute of Cardiology (INC) and, thus, derive and validate a predictive obstructive CAD score. Cross-sectional study evaluating 2898 patients with indication for heart surgery of any etiology. Of those, 712 patients, who had valvular heart disease and underwent ICA in the 12 months prior to surgery, were included. The P value arterial hypertension, diabetes mellitus, dyslipidemia, smoking, and male gender. The model showed excellent correlation and calibration (R² = 0.98), as well as excellent accuracy (ROC of 0.848; 95%CI: 0.817-0.879) and validation (ROC of 0.877; 95%CI: 0.830 - 0.923) in different valve populations. Obstructive CAD can be estimated from clinical data of adult candidates for valve repair surgery, using a simple, accurate and validated score, easy to apply in clinical practice, which may contribute to changes in the preoperative strategy of acquired heart valve surgery in patients with a lower probability of obstructive disease.
Full Text Available Valvular tumors and tumor-like lesions may have similar morphological and clinical characteristics, and may place the patients at a high risk of stroke in different ways. From January 2004 to June 2008, 11 patients underwent surgery for a suspected valvular tumor. Valvular tumor and tumor-like lesions accounted for 0.32% of adult cardiac operations. Five (45.5% valvular lesions were papillary fibroelastomas, one (9.1% was myxoma, 2 (18.2% were organized thrombi, and 3 (27.3% were calcification lesions. There was a total of 5 (45.5% atrioventricular valve lesions, 4 arising from the atrial side of the leaflets, and one from the ventricular side. All 5 (45.5% semilunar valvular lesions were from the aortic valve. One (9.1% lesion originated from the chorda tendinea of the mitral valve. All leaflet lesions were resected by a simple shave technique, and all the patients recovered favorably. Valvular tumor and tumor-like lesions are rare. Pre-operative differential diagnoses among these valvular lesions pose important clinical implications for appropriate treatment for the underlying diseases. Prompt therapeutic measures in view of the underlying diseases of the valvular lesions are essential to prevent potential embolic events.
Baron Toaldo, M; Poser, H; Menciotti, G; Battaia, S; Contiero, B; Cipone, M; Diana, A; Mazzotta, E; Guglielmini, C
In human medicine, right ventricular (RV) functional parameters represent a tool for risk stratification in patients with congestive heart failure caused by left heart disease. Little is known about RV alterations in dogs with left-sided cardiac disorders. To assess RV and left ventricular (LV) function in dogs with myxomatous mitral valve disease (MMVD) with or without pulmonary hypertension (PH). One-hundred and fourteen dogs: 28 healthy controls and 86 dogs with MMVD at different stages. Prospective observational study. Animals were classified as healthy or having MMVD at different stages of severity and according to presence or absence of PH. Twenty-eight morphological, echo-Doppler, and tissue Doppler imaging (TDI) variables were measured and comparison among groups and correlations between LV and RV parameters were studied. No differences were found among groups regarding RV echo-Doppler and TDI variables. Sixteen significant correlations were found between RV TDI and left heart echocardiographic variables. Dogs with PH had significantly higher transmitral E wave peak velocity and higher E/e' ratio of septal (sMV) and lateral (pMV) mitral annulus. These 2 variables were found to predict presence of PH with a sensitivity of 84 and 72%, and a specificity of 71 and 80% at cut-off values of 10 and 9.33 for sMV E/e' and pMV E/e', respectively. No association between variables of RV function and different MMVD stage and severity of PH could be detected. Some relationships were found between echocardiographic variables of right and left ventricular function. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
Gaia, Diego Felipe; Braz, Ademir Massarico; Simonato, Matheus; Dvir, Danny; Breda, João Roberto; Ribeiro, Gustavo Calado; Ferreira, Carolina Baeta; Souza, José Augusto Marcondes; Buffolo, Enio; Palma, José Honório
Reoperative procedure for the treatment of a failed mitral bioprosthesis is associated with considerable risk. In some cases, mortality is high and might contraindicate the benefit of the procedure. The minimally invasive valve-in-valve (ViV) transcatheter mitral valve implant offers an alternative less-invasive approach, reducing morbidity and mortality. The objective of this paper was to evaluate the mitral ViV approach using the Braile Inovare prosthesis. The transcatheter balloon-expandable Braile Inovare prosthesis was used in 12 cases. Procedures were performed in a hybrid operating room, under fluoroscopic and echocardiographic control. Through left minithoracotomy, the prostheses were implanted through the cardiac apex. Serial echocardiographic and clinical examinations were performed. Follow-up varied from 1 to 30 months. A total of 12 transapical mitral ViV procedures were performed. Patients had a mean age of 61.6 ± 9.9 years and 92% were women. Mean logistic EuroSCORE was 20.1%. Successful valve implantation was possible in all cases. In one case, a right lateral thoracotomy was performed for the removal of an embolized prosthesis. There was no operative mortality. Thirty-day mortality was 8.3%. Ejection fraction was preserved after the implant (66.7%; 64.8%; P = 0.3). The mitral gradient showed a significant reduction (11 mmHg; 6 mmHg; P < 0.001). Residual mitral regurgitation was not present. There was no left ventricular outflow tract obstruction. The mitral ViV implant in a failed bioprosthesis is an effective procedure. This possibility might alter prosthesis selection in the future initial surgical prosthesis selection, favouring bioprostheses. Further large trials should explore its safety. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Cheng, Lingbo; Sharifi, Mojtaba; Tavakoli, Mahdi
Beating-heart intracardiac surgery promises significant benefits for patients compared with cardiopulmonary bypass based procedures. However, the fast motions of the heart introduce serious challenges for surgeons. In this work, a new impedance-controlled master-slave telerobotic system is developed to help perform anchor deployment for mitral valve annuloplasty under the guidance of live ultrasound images of the heart. The proposed bilateral teleoperation system can both reflect the non-oscillatory portion of slave-heart tissue interaction force on the surgeon's hand as haptic feedback and implement rapid compensation for the beating heart's motion. The surgical task involves performing anchor deployment on a simulated moving heart tissue to evaluate the effectiveness of the proposed strategy for safely interacting with a moving organ. The results obtained show that the telerobotic system increases the success rate of anchor deployment by 100% and reduces the excess force application rate by 70% compared with manual attempts. Copyright © 2018 John Wiley & Sons, Ltd.
Höllmer, M.; Willesen, J. L.; Tolver, A.
stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume heart failure in dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100......%. An active LA emptying fraction heart failure in dogs with chronic MMVD with a sensitivity of 77% and a specificity of 89% and a sensitivity of 82% and a specificity of 82%, respectively. CONCLUSION: Dogs with MMVD appear to have larger LA...... of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. ANIMALS: This prospective study included 205 client-owned dogs of different breeds, 114...
Kagramanov, I I; Kokshenev, I V; Dobrova, N B; Kastava, V T; Serov, R A; Zaets, S B
The optimal material for heart valve bioprostheses remains disputable. This investigation was initiated to compare the properties of hepatic Glisson's capsule, clinical experience of which in cardiovascular surgery is minimal, with those of bovine pericardium. Hepatic Glisson's capsule was harvested from bull calves and used to create composite pulmonary arterial monocusp grafts and bioprostheses. Comparison of the strength and elastic properties of Glisson's capsule and bovine pericardium, as well as the hydrodynamic characteristics of valves made from these materials, was performed. Late results of operations using these materials were estimated echocardiographically. Although Glisson's capsule tissue is thinner than the bovine pericardium, its elasticity modulus is greater. However, the hydrodynamic characteristics of heart valves made from either tissue are similar. Moreover, valves made from Glisson's capsule have a lower systolic pressure gradient on the prosthesis and a higher effective orifice area. Composite pulmonary arterial xenopericardial grafts with a monocusp of Glisson's capsule were used in 30 patients during tetralogy of Fallot repair. Glisson's capsule was also used for tricuspid valve reconstruction and as a bioprosthesis in six patients with Ebstein's anomaly. At 1-2 years after surgery, the Glisson's capsule tissue remained thin and flexible, with no calcification. Although the hydrodynamic properties of hepatic Glisson's capsule and the bovine pericardium are similar, the capsule tissue is thinner and has a greater elasticity modulos. Thus, Glisson's capsule may be used for bioprosthesis construction both independently and in combination with bovine pericardium.
Bark, David L.; Vahabi, Hamed; Bui, Hieu; Movafaghi, Sanli; Moore, Brandon; Kota, Arun K.; Popat, Ketul; Dasi, Lakshmi P.
In this study, we explore how blood-material interactions and hemodynamics are impacted by rendering a clinical quality 25 mm St. Jude Medical Bileaflet mechanical heart valve (BMHV) superhydrophobic (SH) with the aim of reducing thrombo-embolic complications associated with BMHVs. Basic cell adhesion is evaluated to assess blood-material interactions, while hemodynamic performance is analyzed with and without the SH coating. Results show that a SH coating with a receding contact angle (CA) of 160º strikingly eliminates platelet and leukocyte adhesion to the surface. Alternatively, many platelets attach to and activate on pyrolytic carbon (receding CA=47), the base material for BMHVs. We further show that the performance index increases by 2.5% for coated valve relative to an uncoated valve, with a maximum possible improved performance of 5%. Both valves exhibit instantaneous shear stress below 10 N/m2 and Reynolds Shear Stress below 100 N/m2. Therefore, a SH BMHV has the potential to relax the requirement for antiplatelet and anticoagulant drug regimens typically required for patients receiving MHVs by minimizing blood-material interactions, while having a minimal impact on hemodynamics. We show for the first time that SH-coated surfaces may be a promising direction to minimize thrombotic complications in complex devices such as heart valves. PMID:27098219
Full Text Available A 23-year-old African American woman with a past medical history of systemic lupus erythematous (SLE, secondary hypertension, and end stage renal disease (ESRD on hemodialysis for eight years was stable until she developed symptomatic severe mitral regurgitation with preserved ejection fraction. She underwent a bioprosthetic mitral valve replacement (MVR at outside hospital. However, within a year of her surgery, she presented to our hospital with NYHA class IV symptoms. She was treated for heart failure but in view of her persistent symptoms and low EF was considered for heart and kidney transplant. This was a challenge in view of her history of lupus. We presumed that her stenosis of bioprosthetic valve was secondary to lupus and renal disease. We hypothesized that her low ejection fraction was secondary to mitral stenosis and potentially reversible. We performed a dobutamine stress echocardiogram, which revealed an improved ejection fraction to more than 50% and confirmed preserved inotropic contractile reserve of her myocardium. Based on this finding, she underwent a metallic mitral valve and tricuspid valve replacement. Following surgery, her symptoms completely resolved. This case highlights the pathophysiology of lupus causing stenosis of prosthetic valves and low ejection cardiomyopathy.
An improved understanding of the roles of hemodynamic forces play in cardiac development and the pathogenesis of cardiac disease will have significant scientific and clinical impact. I will focus on the role of fluid dynamics in congenital heart disease and aortic valve calcification. Congenital heart defects are the most common form of birth defect. Aortic valve calcification/stenosis is the third leading cause of adult heart disease and the most common form of acquired valvular disease in developed countries. Given the high incidence of these diseases and their associated morbidity and mortality, the potential translational impact of an improved understanding of cardiac hemodynamic forces is very large. Division of Pediatric Cardiology, Rady Children's Hospital, San Diego
Sibilitz, Kirstine Lærum; Berg, Selina Klikkenborg; Rasmussen, Trine Bernholdt
-educational consultations (intervention) versus usual care without structured physical exercise or psycho-educational consultations (control). Primary outcome was physical capacity measured by VO2 peak and secondary outcome was self-reported mental health measured by Short Form-36. Results: 76% were men, mean age 62 years.......40) or the exploratory physical and mental outcomes. Cardiac rehabilitation increased the occurrence of self-reported non-serious adverse events (11/72 vs 3/75, p=0.02). Conclusions: Cardiac rehabilitation after heart valve surgery significantly improves VO2 peak at 4 months but has no effect on mental health and other......Objective: The evidence for cardiac rehabilitation after valve surgery remains sparse. Current recommendations are therefore based on patients with ischaemic heart disease. The aim of this randomised clinical trial was to assess the effects of cardiac rehabilitation versus usual care after heart...
Hansen, Tina Birgitte; Zwisler, Ann Dorthe Olsen; Kikkenborg Berg, Selina
AIMS: To explore the structure and content of narratives about the recovery process among patients undergoing heart valve surgery participating in cardiac rehabilitation. BACKGROUND: Several studies with short-term follow-up have shown that recovering from cardiac surgery can be challenging......, but evidence on the long-term recovery process is very limited, especially following heart valve surgery. Furthermore, few studies have explored the recovery process among cardiac rehabilitation participants. DESIGN: A qualitative study with serial interviews analysed using narrative methods. METHODS: We......, the participants expected to return to normality. The analysis identified four courses of recovery, with three non-linear complex pathways deviating from the classic restitution narrative: the frustrated struggle to resume normality, the challenged expectation of normality - being in a limbo and becoming a heart...
Sierad, Leslie Neil; Simionescu, Agneta; Albers, Christopher; Chen, Joseph; Maivelett, Jordan; Tedder, Mary Elizabeth; Liao, Jun; Simionescu, Dan T
Heart valve tissue engineering requires biocompatible and hemocompatible scaffolds that undergo remodeling and repopulation, but that also withstand harsh mechanical forces immediately following implantation. We hypothesized that reversibly stabilized acellular porcine valves, seeded with endothelial cells and conditioned in pulsatile bioreactors would pave the way for next generations of tissue engineered heart valves (TEHVs). A novel valve conditioning system was first designed, manufactured and tested to adequately assess TEHVs. The bioreactor created proper closing and opening of valves and allowed for multiple mounting methods in sterile conditions. Porcine aortic heart valve roots were decellularized by chemical extractions and treated with penta-galloyl glucose (PGG) for stabilization. Properties of the novel scaffolds were evaluated by testing resistance to collagenase and elastase, biaxial mechanical analysis, and thermal denaturation profiles. Porcine aortic endothelial cells were seeded onto the leaflets and whole aortic roots were mounted within the dynamic pulsatile heart valve bioreactor system under physiologic pulmonary valve pressures and analyzed after 17 days for cell viability, morphology, and metabolic activity. Our tissue preparation methods effectively removed cells, including the potent α-Gal antigen, while leaving a well preserved extra-cellular matrix scaffold with adequate mechanical properties. PGG enhanced stabilization of extracellular matrix components but also showed the ability to be reversible. Engineered valve scaffolds encouraged attachment and survival of endothelial cells for extended periods and showed signs of widespread cell coverage after conditioning. Our novel approach shows promise toward development of sturdy and durable TEHVs capable of remodeling and cellular repopulation.
Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki
Our group is currently developing a pneumatic ventricular assist device (PVAD). In general, the major causes of hemolysis in a pulsatile VAD are cavitation, and Reynolds shear stress (RSS) in the mechanical heart valve (MHV). In a previous study, we investigated MHV cavitation. To select the optimal bileaflet valve for our PVAD, in the current study, we investigated RSS and viscous shear stress (VSS) downstream of three different types of commercial bileaflet valves by means of 2D particle image velocimetry (PIV). To carry out flow visualization inside the blood pump and near the valve, we designed a model pump with the same configuration as that of our PVAD. Three types of bileaflet valves (i.e., the ATS valve, the St. Jude valve, and the Sorin Bicarbon valve) were mounted at the aortic position of the model pump, and flow was visualized according to the PIV method. The maximum flow velocity and RSS of the Sorin Bicarbon valve were lower than those of the other two bileaflet valves. The maximum VSS was only 1% of the maximum RSS. Thus, the effect of VSS on blood cell trauma was neglected. The Sorin Bicarbon valve exhibited relatively low levels of RSS, and was therefore considered to be the best valve for our PVAD among the three valves tested.
Weber, Miriam; Gonzalez de Torre, Israel; Moreira, Ricardo; Frese, Julia; Oedekoven, Caroline; Alonso, Matilde; Rodriguez Cabello, Carlos J; Jockenhoevel, Stefan; Mela, Petra
Heart valves are elaborate and highly heterogeneous structures of the circulatory system. Despite the well accepted relationship between the structural and mechanical anisotropy and the optimal function of the valves, most approaches to create tissue-engineered heart valves (TEHVs) do not try to mimic this complexity and rely on one homogenous combination of cells and materials for the whole construct. The aim of this study was to establish an easy and versatile method to introduce spatial diversity into a heart valve fibrin scaffold. We developed a multiple-step injection molding process that enables the fabrication of TEHVs with heterogeneous composition (cell/scaffold material) of wall and leaflets without the need of gluing or suturing components together, with the leaflets firmly connected to the wall. The integrity of the valves and their functionality was proved by either opening/closing cycles in a bioreactor (proof of principle without cells) or with continuous stimulation over 2 weeks. We demonstrated the potential of the method by the two-step molding of the wall and the leaflets containing different cell lines. Immunohistology after stimulation confirmed tissue formation and demonstrated the localization of the different cell types. Furthermore, we showed the proof of principle fabrication of valves using different materials for wall (fibrin) and leaflets (hybrid gel of fibrin/elastin-like r