Incidence, risk factors, clinical impact, and management of bioprosthesis structural valve degeneration

Durability of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is now utilised as a less invasive alternative to surgical aortic valve replacement (SAVR) across the whole spectrum of surgical risk. Long-term durability of the bioprosthetic valves has become a key goal of TAVI as this procedure is now considered for younger and lower-risk populations. The purpose of this article is to present a state-of-the-art overview on the definition, aetiology, risk factors, mechanisms, diagnosis, clinical impact, and management of bioprosthetic valve dysfunction (BVD) and failure (BVF) following TAVI with a comparative perspective versus SAVR. Structural valve deterioration (SVD) is the main factor limiting the durability of the bioprosthetic valves used for TAVI or SAVR, but non-structural BVD, such as prosthesis-patient mismatch and paravalvular regurgitation, as well as valve thrombosis or endocarditis may also lead to BVF. The incidence of BVF related to SVD or other causes is low (<5%) at midterm (5- to 8-year) follow-up and compares favourably with that of SAVR. The long-term follow-up data of randomised trials conducted with the first generations of transcatheter heart valves also suggest similar valve durability in TAVI versus SAVR at 10 years, but these trials suffer from major survivorship bias, and the long-term durability of TAVI will need to be confirmed by the analysis of the low-risk TAVI versus SAVR trials at 10 years.

Expanding treatment horizons: transcatheter mitral valve-in-valve replacement in bridging to heart transplant

Transcatheter mitral valve (MV) replacement is an option in complex MV disease with potentially more predictable treatment outcomes and less invasiveness that increases the treatment spectrum to high-risk or non-surgical patients. We present an interesting case of failed MV bioprosthesis who presented with progressively worsening heart failure for heart transplant evaluation, but was successfully managed with transcatheter mitral valve-in-valve replacement (TMViVR). This case illustrates the pivotal role of TMViVR utilization in addressing complex cardiac scenarios, particularly when re-operative surgical MV replacement poses a high risk and also bridging the gap between the present and future heart transplantation preparations by paving the way for a well-prepared patient in the subsequent phase. The lifetime disease management and patient-centric approach with meticulous risk assessment reinforces the importance of shared decision-making in complex cases.

Long-Term Outcomes of Bioprosthetic Valves in the Mitral Position: A Pooled Meta-Analysis of Reconstructed Time-to-Event Individual Patient Data

Bioprosthetic mitral valve replacement (bMVR) use is increasing; however, data regarding long-term durability are lacking. We sought to perform a reconstructed individual patient data meta-analysis from published Kaplan-Meier curves to ascertain survival, freedom from valve degeneration, and reoperation in studies published since 2010. We explored the effects of age and valve type (bovine pericardial or porcine valve) on outcomes. We searched MEDLINE, OVID, Embase, and Cochrane CENTRAL for studies reporting at least 3 years of follow-up after bMVR and published since 2010. The Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool was used to assess methodologic quality. Kaplan-Meier curves were digitized to extract individual patient data and reconstructed estimates for overall survival, freedom from structural valve deterioration (SVD), and freedom from reoperation. A total of 20 studies (16,465 patients) were included. A total of 9 studies reported on porcine valves, 6 reported on bovine, and 7 did not specify the valve type. The overall survival after bMVR at 15 years was 40% (confidence interval 38% to 42%), freedom from reoperation at 15 years was 79% (confidence interval 76% to 82%), and freedom from SVD at 15 years was 64% (58% to 70%). Freedom from SVD was improved in the 70+ years age group (93% up to 25 years, hazard ratio 6.6 [2.5 to 17] for 18 to 59 vs >70 years, p <0.0001). There was no difference in valve durability or survival between bovine pericardial or porcine valves. In this meta-analysis of patients who underwent bMVR using newer generation valves, the inverse relation between age and SVD was reiterated in the 70+ years age group. The prosthesis type made no difference in the outcomes.

Recent Advances in the Modification and Improvement of Bioprosthetic Heart Valves

Valvular heart disease (VHD) has become a burden and a growing public health problem in humans, causing significant morbidity and mortality worldwide. An increasing number of patients with severe VHD need to undergo heart valve replacement surgery, and artificial heart valves are in high demand. However, allogeneic valves from donors are lacking and cannot meet clinical practice needs. A mechanical heart valve can activate the coagulation pathway after contact with blood after implantation in the cardiovascular system, leading to thrombosis. Therefore, bioprosthetic heart valves (BHVs) are still a promising way to solve this problem. However, there are still challenges in the use of BHVs. For example, their longevity is still unsatisfactory due to the defects, such as thrombosis, structural valve degeneration, calcification, insufficient re-endothelialization, and the inflammatory response. Therefore, strategies and methods are needed to effectively improve the biocompatibility and longevity of BHVs. This review describes the recent research advances in BHVs and strategies to improve their biocompatibility and longevity.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Dementia Development during Long-Term Follow-Up after Surgical Aortic Valve Replacement with a Biological Prosthesis in a Geriatric Population

Surgical aortic valve replacement (SAVR) with a biological heart valve prosthesis (BHV) is often used as a treatment in elderly patients with symptomatic aortic valve disease. This age group is also at risk for the development of dementia in the years following SAVR. The research question is "what are the predictors for the development of dementia?". In 1500 patients undergoing SAVR with or without an associated procedure, preoperative (demographic, cardiac and non-cardiac comorbid conditions), perioperative (associated procedures, cross-clamp and cardiopulmonary bypass time) and postoperative 30-day adverse events (bleeding, thromboembolism, heart failure, conduction defects, arrhythmias, delirium, renal and pulmonary complications) were investigated for their effect on the occurrence of dementia by univariate analyses. Significant factors were entered in a multivariate analysis. The sum of the individual follow-up of the patients was 10,182 patient-years, with a mean follow-up of 6.8 years. Data for the development of dementia could be obtained in 1233 of the 1406 patients who left the hospital alive. Dementia during long-term follow-up developed in 216/1233 (17.2%) of the patients at 70 ± 37 months. Development of dementia reduced the mean survival from 123 (119-128) to 109 (102-116) months (p < 0.001). Postoperative delirium was the dominant predictor (OR = 3.55 with a 95%CI of 2.41-4.93; p < 0.00), followed by age > 80 years (2.38; 1.78-3.18; p < 0.001); preoperative atrial fibrillation (1.47; 1.07-2.01; p = 0.018); cardiopulmonary bypass time > 120 min (1.34; 1.02-1.78; p = 0.039) and postoperative thromboembolism (1.94; 1.02-3.70; p = 0.044). Postoperative delirium, as a marker for poor condition, and an age of 80 or more were the dominant predictors.

Transcatheter mitral valve implantation versus conventional redo surgery for degenerated mitral valve prostheses and rings in a multicenter registry

OBJECTIVES

Degeneration of mitral prostheses/rings may be treated by redo surgery, and, recently, by transcatheter valve-in-valve/ring implantation. This multicenter registry presents results of transcatheter valve-in-valve and repeat surgery for prostheses/rings degeneration.

METHODS

Data provided by 10 German heart centers underwent propensity score-matched retrospective analysis. The primary endpoint was 30-day/midterm mortality. Perioperative outcome was assessed according to the Mitral Valve Academic Research Consortium criteria. Further, the influence of moderate or greater tricuspid regurgitation (TR) on 30-day/midterm mortality was analyzed.

RESULTS

Between 2014 and 2019, 273 patients (79 transcatheter mitral valve-in-valve [TM-ViV] and 194 redo mitral valve replacement [Re-MVR]) underwent repeat procedure for mitral prosthesis/ring degeneration. Propensity score matching distinguished 79 patient pairs. European System for Cardiac Operative Risk Evaluation (EuroSCORE) II-predicted risk was 15.7 ± 13.7% in the TM-ViV group and 15.0% ± 12.7% in the Re-MVR group (P = .5336). TM-ViV patients were older (74.73 vs 72.2 years; P = .0030) and had higher incidence of atrial fibrillation (54 vs 40 patients; P = .0233). Severe TR incidence was similar (17.95% in TM-ViV vs 14.10%; P = .1741). Sixty-eight TM-ViV patients previously underwent mitral valve replacement, whereas 41 Re-MVR patients underwent valve repair (P < .0001). Stenosis was the leading degeneration mechanism in 42 TM-ViV versus 22 Re-MVR patients (P < .0005). The 30-day/midterm mortality did not differ between groups. Moderate or greater TR was a predictor of total (odds ratio [OR], 4.36; P = .0011), 30-day (OR, 3.76; P = .0180), and midterm mortality (OR, 4.30; P = .0378), irrespective of group.

CONCLUSIONS

In both groups, observed mortality was less than predicted. Redo surgery enabled treatment of concomitant conditions, such as atrial fibrillation or TR. TR was shown to be a predictor of total, 30-day, and midterm mortality in both groups.

Bioprosthetic pulmonary valve dysfunction in a primary cardiac sarcoma survivor: Clinical considerations and treatment options

The case highlights the good survival after radical surgery and chemotherapy of a cardiac sarcoma, and the need for close follow-up due to possible early postsurgical complications.

Role of lipoprotein(a) concentrations in bioprosthetic aortic valve degeneration

OBJECTIVES

Lipoprotein(a) (Lp(a)) is associated with an increased incidence of native aortic stenosis, which shares similar pathological mechanisms with bioprosthetic aortic valve (bAV) degeneration. However, evidence regarding the role of Lp(a) concentrations in bAV degeneration is lacking. This study aims to evaluate the association between Lp(a) concentrations and bAV degeneration.

METHODS

In this retrospective multicentre study, patients who underwent a bAV replacement between 1 January 2010 and 31 December 2020 and had a Lp(a) measurement were included. Echocardiography follow-up was performed to determine the presence of bioprosthetic valve degeneration, which was defined as an increase >10 mm Hg in mean gradient from baseline with concomitant decrease in effective orifice area and Doppler Velocity Index, or new moderate/severe prosthetic regurgitation. Levels of Lp(a) were compared between patients with and without degeneration and Cox regression analysis was performed to investigate the association between Lp(a) levels and bioprosthetic valve degeneration.

RESULTS

In total, 210 cases were included (mean age 74.1±9.4 years, 72.4% males). Median time between baseline and follow-up echocardiography was 4.4 (IQR 3.7) years. Bioprostheses degeneration was observed in 33 (15.7%) patients at follow-up. Median serum levels of Lp(a) were significantly higher in patients affected by degeneration versus non-affected cases: 50.0 (IQR 72.0) vs 15.6 (IQR 48.6) mg/dL, p=0.002. In the regression analysis, high Lp(a) levels (≥30 mg/dL) were associated with degeneration both in a univariable analysis (HR 3.6, 95% CI 1.7 to 7.6, p=0.001) and multivariable analysis adjusted by other risk factors for bioprostheses degeneration (HR 4.4, 95% CI 1.9 to 10.4, p=0.001).

CONCLUSIONS

High serum Lp(a) is associated with bAV degeneration. Prospective studies are needed to confirm these findings and to investigate whether lowering Lp(a) levels could slow bioprostheses degradation.

Transcatheter aortic valve durability, predictors of bioprosthetic valve dysfunction, longer-term outcomes - a review

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is one of the most significant inventions in cardiology, as it provides a viable minimally invasive treatment option for patients with aortic stenosis, the most common valvular disease in the developed world and one with a poor prognosis when left untreated. Using data available to date, this review aims to discuss and identify possible predictors of TAVI valve durability - an essential requirement for the device's wide-spread use, especially in younger patients.

AREAS COVERED

This article explores the main causes of bioprosthetic valve dysfunction (BVD) based on pathophysiology and available data, and reviews possible predictors of BVD including prosthesis-related, procedure-related, and patient-related factors. An emphasis is made on affectable predictors, which could potentially be targeted with prevention management and improve valve durability. A literature search of online medical databases was conducted using relevant key words and dates; significant clinical trials were identified. A brief overview of important randomized controlled trials with mid to long-term follow-up is included in this article.

EXPERT OPINION

Identifying modifiable predictors of valve dysfunction presents an opportunity to enhance and predict valve durability - a necessity as patients with longer life-expectancies are being considered for the procedure.

Severe aortic insufficiency-induced cardiogenic shock treated with left atrial VA-ECMO and emergent valve-in-valve TAVR

Conventional venoarterial extracorporeal membrane oxygenation (VA-ECMO) places a functional afterload burden on the left ventricle. In the setting of acute severe aortic insufficiency-induced cardiogenic shock, the utility of VA-ECMO in combination with a failing valve may result in catastrophic haemodynamic consequences. This challenge is compounded when the culprit is a failing surgical bioprosthetic valve. We present a case of severe rapid-onset bioprosthetic aortic insufficiency-induced cardiogenic shock successfully resuscitated with left atrial VA-ECMO promptly followed by emergent percutaneous valve-in-valve transaortic valve replacement. We discuss the logistics, implications, and associated haemodynamic manifestations in utilizing this strategy for such disease processes.

Long-term outcomes of bioprosthetic valves in the mitral position a systematic review of studies published over the last 20 years

OBJECTIVES

Although the use of bioprostheses for mitral valve replacement (bMVR) is on the rise, their long-term durability is not well described. Defining bMVR durability will be instrumental in setting the standard against which the performance of transcatheter mitral replacement is to be judged against. The authors of this systematic review aimed to identify, assess the quality and review the outcomes in studies reporting on long-term outcomes after bMVR published over the last 20 years.

METHODS

Medline, Embase and Cochrane CENTRAL were searched for studies that have reported outcomes beyond a minimum of 5 years of follow-up after bMVR. Cohort characteristics, definitions of structural valve deterioration (SVD) and outcomes were summarized. The risk of bias in included studies was assessed using the Cochrane QUIPS tool.

RESULTS

Twenty-one studies, including 15 833 patients, were identified. Sixty-four percent of all implants were porcine and the remaining bovine pericardial. Freedom from SVD at 10 years ranged from 58.9% to 100% and at 15 years from 58.3% to 93%. Freedom from reoperation ranged from 65% to 98.7% at 10 years and 78.5% to 91% at 15 years. Information on native valve pathology or dominant haemodynamic lesion was missing in 25% and 66% of studies, respectively. Reports of postoperative echocardiography were lacking, despite the heavy reliance on echocardiography for SVD diagnosis.

CONCLUSIONS

There is considerable variability in reporting bMVR long-term outcomes. As such, it is difficult to generate an unbiased, generalizable understanding of long- term outcomes after bMVR across the spectrum of mitral disease phenotypes.

Perfect prosthetic heart valve: generative design with machine learning, modeling, and optimization

Majority of modern techniques for creating and optimizing the geometry of medical devices are based on a combination of computer-aided designs and the utility of the finite element method This approach, however, is limited by the number of geometries that can be investigated and by the time required for design optimization. To address this issue, we propose a generative design approach that combines machine learning (ML) methods and optimization algorithms. We evaluate eight different machine learning methods, including decision tree-based and boosting algorithms, neural networks, and ensembles. For optimal design, we investigate six state-of-the-art optimization algorithms, including Random Search, Tree-structured Parzen Estimator, CMA-ES-based algorithm, Nondominated Sorting Genetic Algorithm, Multiobjective Tree-structured Parzen Estimator, and Quasi-Monte Carlo Algorithm. In our study, we apply the proposed approach to study the generative design of a prosthetic heart valve (PHV). The design constraints of the prosthetic heart valve, including spatial requirements, materials, and manufacturing methods, are used as inputs, and the proposed approach produces a final design and a corresponding score to determine if the design is effective. Extensive testing leads to the conclusion that utilizing a combination of ensemble methods in conjunction with a Tree-structured Parzen Estimator or a Nondominated Sorting Genetic Algorithm is the most effective method in generating new designs with a relatively low error rate. Specifically, the Mean Absolute Percentage Error was found to be 11.8% and 10.2% for lumen and peak stress prediction respectively. Furthermore, it was observed that both optimization techniques result in design scores of approximately 95%. From both a scientific and applied perspective, this approach aims to select the most efficient geometry with given input parameters, which can then be prototyped and used for subsequent in vitro experiments. By proposing this approach, we believe it will replace or complement CAD-FEM-based modeling, thereby accelerating the design process and finding better designs within given constraints. The repository, which contains the essential components of the study, including curated source code, dataset, and trained models, is publicly available at https://github.com/ViacheslavDanilov/generative_design.

Embedding and Backscattered Scanning Electron Microscopy (EM-BSEM) Is Preferential over Immunophenotyping in Relation to Bioprosthetic Heart Valves

Hitherto, calcified aortic valves (AVs) and failing bioprosthetic heart valves (BHVs) have been investigated by similar approaches, mostly limited to various immunostaining techniques. Having employed multiple immunostaining combinations, we demonstrated that AVs retain a well-defined cellular hierarchy even at severe stenosis, whilst BHVs were notable for the stochastic degradation of the extracellular matrix (ECM) and aggressive infiltration by ECM-digesting macrophages. Leukocytes (CD45+) comprised ≤10% cells in the AVs but were the predominant cell lineage in BHVs (≥80% cells). Albeit cells with uncertain immunophenotype were rarely encountered in the AVs (≤5% cells), they were commonly found in BHVs (≥80% cells). Whilst cell conversions in the AVs were limited to the endothelial-to-mesenchymal transition (represented by CD31+α-SMA+ cells) and the formation of endothelial-like (CD31+CD68+) cells at the AV surface, BHVs harboured numerous macrophages with a transitional phenotype, mostly CD45+CD31+, CD45+α-SMA+, and CD68+α-SMA+. In contrast to immunostaining, which was unable to predict cell function in the BHVs, our whole-specimen, nondestructive electron microscopy approach (EM-BSEM) was able to distinguish between quiescent and matrix-degrading macrophages, foam cells, and multinucleated giant cells to conduct the ultrastructural analysis of organelles and the ECM, and to preserve tissue integrity. Hence, we suggest EM-BSEM as a technique of choice for studying the cellular landscape of BHVs.

Bioinspired polymeric heart valves: A combined in vitro and in silico approach

Background

Polymeric heart valves (PHVs) may address the limitations of mechanical and tissue valves in the treatment of valvular heart disease. In this study, a bioinspired valve was designed, assessed in silico, and validated by an in vitro model to develop a valve with optimum function for pediatric applications.

Methods

A bioinspired heart valve was created computationally with leaflet curvature derived from native valve anatomies. A valve diameter of 18 mm was chosen to approach sizes suitable for younger patients. Valves of different thicknesses were fabricated via dip-coating with siloxane-based polyurethane and tested in a pulse duplicator for their hydrodynamic function. The same valves were tested computationally using an arbitrary Lagrangian-Eulerian plus immersed solid approach, in which the fluid-structure interaction between the valves and fluid passing through them was studied and compared with experimental data.

Results

Computational analysis showed that valves of 110 to 200 μm thickness had effective orifice areas (EOAs) of 1.20 to 1.30 cm2, with thinner valves exhibiting larger openings. In vitro tests demonstrated that PHVs of similar thickness had EOAs of 1.05 to 1.35 cm2 and regurgitant fractions (RFs) <7%. Valves with thinner leaflets exhibited optimal systolic performance, whereas thicker valves had lower RFs.

Conclusions

Bioinspired PHVs demonstrated good hydrodynamic performance that exceeded ISO 5840-2 standards. Both methods of analysis showed similar correlations between leaflet thickness and valve systolic function. Further development of this PHV may lead to enhanced durability and thus a more reliable heart valve replacement than contemporary options.

Hemodynamic Performance of Transcatheter Aortic Valves: A Comprehensive Review

Transcatheter aortic valve implantation (TAVI) is a widely adopted treatment option for patients with severe aortic stenosis. Its popularity has grown significantly in recent years due to advancements in technology and imaging. As TAVI use is increasingly expanded to younger patients, the need for long-term assessment and durability becomes paramount. This review aims to provide an overview of the diagnostic tools to evaluate the hemodynamic performance of aortic prosthesis, with a special focus on the comparison between transcatheter and surgical aortic valves and between self-expandable and balloon-expandable valves. Moreover, the discussion will encompass how cardiovascular imaging can effectively detect long-term structural valve deterioration.

Age-related enhanced degeneration of bioprosthetic valves due to leaflet calcification, tissue crosslinking, and structural changes

AIMS

Bioprosthetic heart valves (BHVs), made from glutaraldehyde-fixed heterograft materials, are subject to more rapid structural valve degeneration (SVD) in paediatric and young adult patients. Differences in blood biochemistries and propensity for disease accelerate SVD in these patients, which results in multiple re-operations with compounding risks. The goal of this study is to investigate the mechanisms of BHV biomaterial degeneration and present models for studying SVD in young patients and juvenile animal models.

METHODS AND RESULTS

We studied SVD in clinical BHV explants from paediatric and young adult patients, juvenile sheep implantation model, rat subcutaneous implants, and an ex vivo serum incubation model. BHV biomaterials were analysed for calcification, collagen microstructure (alignment and crimp), and crosslinking density. Serum markers of calcification and tissue crosslinking were compared between young and adult subjects. We demonstrated that immature subjects were more susceptible to calcification, microstructural changes, and advanced glycation end products formation. In vivo and ex vivo studies comparing immature and mature subjects mirrored SVD in clinical observations. The interaction between host serum and BHV biomaterials leads to significant structural and biochemical changes which impact their functions.

CONCLUSIONS

There is an increased risk for accelerated SVD in younger subjects, both experimental animals and patients. Increased calcification, altered collagen microstructure with loss of alignment and increased crimp periods, and increased crosslinking are three main characteristics in BHV explants from young subjects leading to SVD. Together, our studies establish a basis for assessing the increased susceptibility of BHV biomaterials to accelerated SVD in young patients.

Structural hemodynamic valve deterioration durability of RESILIA-tissue versus contemporary aortic bioprostheses

Aim: Durability of aortic valve replacement is becoming increasingly important. Aortic bioprostheses with RESILIA tissue have demonstrated outstanding outcomes thus far, but only in single-arm studies. Methods: We compared structural valve deterioration (SVD)-related hemodynamic valve deterioration (HVD) of grade ≥2 of RESILIA tissue valves from the COMMENCE trial (n = 689) to those from the PARTNER 2A contemporary AVR arm (n = 936) based upon annual core laboratory echocardiograms through 5 years of follow-up. Results: SVD-related HVD in the COMMENCE and PARTNER 2A cohorts were 1.8 versus 3.5%, respectively (one-sided 95% lower-bound hazard ratio of 0.92; p = 0.07). In propensity-matched cohorts (n = 239), these outcomes were 1.0 versus 4.8%, respectively (one-sided 95% lower-bound hazard ratio of 1.15; p = 0.03). Conclusion: RESILIA tissue-based AVR exhibited reduced SVD-related HVD compared with a contemporary AVR cohort devoid of RESILIA tissue.

Transcatheter mitral valve replacement versus redo surgery for mitral prosthesis failure: A systematic review and meta-analysis

Background

Transcatheter mitral valve replacement (TMVR) has emerged as an alternative to redo surgery. TMVR compared with redo surgical mitral valve replacement (SMVR) in patients with mitral prosthesis failure remains limited. In this study, we performed a meta-analysis to assess the outcomes of TMVR (including valve-in-valve and valve-in-ring) versus redo surgery for mitral prosthesis failure.

Methods

We comprehensively searched the PubMed, Embase, and Cochrane library databases according to predetermined inclusion and exclusion criteria, and then we extracted data. We compared the outcomes of TMVR and redo SMVR for mitral prosthesis failure in terms of the in-hospital mortality, stroke, renal dysfunction, vascular complication, pacemaker implantation, exploration for bleeding, paravalvular leak, mean mitral valve gradient, 30-day mortality, and 1-year mortality.

Results

Nine retrospective cohort studies and a total of 3,038 patients were included in this analysis. Compared with redo SMVR for mitral prosthesis failure, TMVR was associated with lower in-hospital mortality [odds ratios (OR): 0.44; 95% confidence interval (CI): 0.30-0.64; P < 0.001], stroke (OR: 0.44; 95% CI: 0.29-0.67; P = 0.0001), renal dysfunction (OR: 0.52; 95% CI: 0.37-0.75; P = 0.0003), vascular complication (OR: 0.58; 95% CI: 0.43-0.78; P = 0.004), pacemaker implantation (OR: 0.23; 95% CI: 0.15-0.36; P < 0.00001), and exploration for bleeding (OR: 0.24; 95% CI: 0.06-0.96; P = 0.04). Conversely, redo SMVR had lower paravalvular leak (OR: 22.12; 95% CI: 2.81-174.16; P = 0.003). There was no difference in mean mitral valve gradient (MD: 0.04; 95% CI: -0.47 to 0.55; P = 0.87), 30-day mortality (OR: 0.65; 95% CI: 0.36-1.17; P = 0.15), and 1-year mortality (OR: 0.96; 95% CI: 0.63-1.45; P = 0.84).

Conclusion

In patients with mitral prosthesis failure, TMVR is associated with lower in-hospital mortality and lower occurrence of postoperative complications, except for paravalvular leak. TMVR offers a viable alternative to the conventional redo surgery in selected patients.

Circulating Progenitor Cells Are Associated With Bioprosthetic Aortic Valve Deterioration: A Preliminary Study

Background Mechanisms underlying bioprosthetic valve deterioration are multifactorial and incompletely elucidated. Reparative circulating progenitor cells, and conversely calcification-associated osteocalcin expressing circulating progenitor cells, have been linked to native aortic valve deterioration. However, their role in bioprosthetic valve deterioration remains elusive. This study sought to evaluate the contribution of different subpopulations of circulating progenitor cells in bioprosthetic valve deterioration. Methods and Results This single-center prospective study enrolled 121 patients who had peripheral blood mononuclear cells isolated before bioprosthetic aortic valve replacement and had an echocardiographic follow-up ≥2 years after the procedure. Using flow cytometry, fresh peripheral blood mononuclear cells were analyzed for the surface markers CD34, CD133, and osteocalcin. Bioprosthetic valve deterioration was evaluated by hemodynamic valve deterioration (HVD) using echocardiography, which was defined as an elevated mean transprosthetic gradient ≥30 mm Hg or at least moderate intraprosthetic regurgitation. Sixteen patients (13.2%) developed HVD during follow-up for a median of 5.9 years. Patients with HVD showed significantly lower levels of reparative CD34⁺CD133⁺ cells and higher levels of osteocalcin-positive cells than those without HVD (CD34⁺CD133⁺ cells: 125 [80, 210] versus 270 [130, 420], P=0.002; osteocalcin-positive cells: 3060 [523, 5528] versus 670 [180, 1930], P=0.005 respectively). Decreased level of CD34⁺CD133⁺ cells was a significant predictor of HVD (hazard ratio, 0.995 [95% CI, 0.990%-0.999%]). Conclusions Circulating levels of CD34⁺CD133⁺ cells and osteocalcin-positive cells were significantly associated with the subsequent occurrence of HVD in patients undergoing bioprosthetic aortic valve replacement. Circulating progenitor cells might play a vital role in the mechanism, risk stratification, and a potential therapeutic target for patients with bioprosthetic valve deterioration.

A functionalized biological heart valve by double bond crosslinking with enhanced biocompatibility and antithrombogenicity

With the advancement of minimally invasive interventional therapy, biological heart valves (BHVs) have been extensively used in clinics. However, BHVs are generally prone to degeneration within 10-15 years after implantation due to defects including cytotoxicity, immune response, calcification and thrombosis, which are closely related to glutaraldehyde-crosslinking. In this work, we prepared a functionalized BHV through the in situ polymerization of methacrylated porcine pericardium and 2-hydroxyethyl methacrylate to avoid and overcome the defects of glutaraldehyde-crosslinked BHVs. The functionalized BHV was proven to be stable against enzymatic degradation and compatible towards HUVECs. After implantation in rats subcutaneously, a significantly mitigated immune response and reduced calcification were observed in the functionalized BHV. With the grafting of hydrophilic 2-hydroxyethyl methacrylate polymers, the antithrombogenicity of BHV was markedly enhanced by resisting the unfavorable adhesion of blood components. Moreover, the hydrodynamics of the functionalized BHV totally conformed to ISO 5840-3 under a wide range of simulated physiological conditions. These results indicate that the functionalized BHV with enhanced biocompatibility, anticalcification property and antithrombogenicity exhibited a low risk of degeneration and should be explored for further application.

Risk factors and outcomes with surgical bioprosthetic mitral valve dysfunction

BACKGROUND

There are insufficient data regarding the risk factors associated with valve dysfunction of bioprosthetic valves in the mitral position This study aimed to investigate the factors associated with bioprosthetic mitral valve (MV) dysfunction (MVD).

METHODS

A total of 245 patients (age 67.2±11.2 years, 74.9% women) who were followed up for more than 5 years after surgical bioprosthetic MV replacement were analysed in the setting of retrospective study design. MVD was defined as an increased mean gradient of >5 mm Hg with limited leaflet motion and/or newly developed MV regurgitation of at least moderate severity on follow-up echocardiography. The clinical outcome was defined as a composite of cardiovascular mortality, redo MV surgery or intervention and heart failure-related hospitalisations.

RESULTS

During a median of 96.0 months (IQR 67.0-125.0 months), bioprosthetic MVD occurred in 66 (27.6%) patients. Factors associated with bioprosthetic MVD detected by multivariate regression analysis were age at surgery (HR 0.98, 95% CI 0.96 to 0.99, p<0.001), chronic kidney disease (HR 3.27, 95% CI 1.74 to 6.12, p<0.001), elevated mean diastolic pressure gradient >5.5 mm Hg across the bioprosthetic MV early after operation (HR 2.02, 95% CI 1.08 to 3.78, p=0.028) and average haemoglobin level after surgery (HR 0.80, 95% CI 0.67 to 0.96, p=0.015). Patients with bioprosthetic MVD showed significantly poorer clinical outcomes than those without bioprosthetic MVD (log-rank p<0.001).

CONCLUSIONS

Young age at operation, chronic kidney disease, elevated pressure gradient across the bioprosthetic MV early after surgery and postsurgical anaemia are associated with bioprosthetic MVD. Bioprosthetic MVD is associated with poor clinical outcomes.

Preoperative hypomagnesemia as a possible predictive factor for postoperative increase of transvalvular pressure gradient in hemodialysis patients treated with transcatheter aortic valve implantation

BACKGROUND

Patients undergoing maintenance hemodialysis (HD) with severe aortic stenosis are at a high risk for bioprosthetic valve dysfunction after transcatheter aortic valve implantation (TAVI). Currently, preoperative factors that predict the occurrence of valve dysfunction after TAVI on HD patients remain to be elucidated. The aim of this study is to analyze the association between preoperative clinical factors and valve stenosis after TAVI on HD patients.

METHODS

Twenty-four of HD patients who underwent TAVI at our institution between April 2012 and January 2016 were analyzed. The mean aortic transvalvular pressure gradient (MPG) and effective orifice area index (EOAi) were assessed by serial echocardiography. Associations between preoperative clinical factors and time-series changes in MPG were examined using mixed-effects linear regression model for repeated measures.

RESULTS

Three patients developed severe structural valve deterioration with calcific valve stenosis requiring reoperation. A multivariate linear mixed-effects model showed that lower serum magnesium (sMg) levels were associated with the increase of MPG after TAVI (beta-coefficient = 0.019, p = 0.03). No correlation was observed with serum calcium, phosphorus, or intact parathyroid hormone. Time-series changes of MPG and EOAi had significant difference between lower and higher sMg group. All 3 of the patients who underwent reoperation showed lower preoperative sMgs.

CONCLUSION

Among bone-mineral metabolism markers, preoperative hypomagnesemia was associated with the increase of MPG after TAVI, suggesting that hypomagnesemia could predict post-TAVI valve dysfunction in HD patients. Further studies with larger sample sizes are warranted.

Acute Bioprosthetic Mitral Valve Failure Diagnosed Using Point-of-Care Ultrasound Leading to Prompt Treatment and Good Outcome

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Acute bioprosthetic mitral valve failure is a medical emergency.

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POCUS can confirm the diagnosis along with a good history and physical exam.

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Early diagnosis and prompt multidisciplinary treatment will deliver the best outcome.

Transcatheter Tricuspid Valve-in-Valve Replacement Using a J-Valve System for a Failed Tricuspid Bioprosthesis

Background

Redo operation for failed tricuspid bioprosthetic valves is associated with high morbidity and mortality. Transcatheter tricuspid valve-in-valve implantation has become an acceptable option for high-risk patients with a failed tricuspid bioprosthesis. We present a case of successful tricuspid valve-in-valve implantation using a J-valve in a failed tricuspid bioprosthesis position. Case Summary. A 48-year-old male, who had a failed tricuspid bioprosthesis, presented with right-side heart failure, right-to-left shunting at the atrial level, severe dyspnea, cyanosis, peripheral edema, hepatauxe, and ascites. After the interdisciplinary assessment, we successfully performed transcatheter tricuspid valve-in-valve implantation with the J-valve system. At 34-month postoperative follow-up, the patient had no symptoms of heart failure and the echocardiogram showed good valve position and well hemodynamic status.

Conclusions

This case demonstrated that the J-valve system may be a new option for high-risk patients with a failed tricuspid bioprosthetic valve.

The role of mechanical valves in the aortic position in the era of bioprostheses and TAVR: Evidence-based appraisal and focus on the On-X valve

Patients who need a prosthetic aortic heart valve may decide, working with their cardiologist and cardiac surgeon, among a variety of options: surgical or transcatheter approach, bioprosthetic or mechanical valve, or a Ross procedure if suitable to their age and anatomy. This review article examines the evidence for survival benefit with mechanical aortic valves, discusses bioprosthetic structural valve degeneration and its consequences, and considers the risks of redo aortic valve surgery or subsequent valve-in-valve (ViV) transcatheter intervention. It highlights the unique characteristics of the On-X aortic valve, including the US Food and Drug Administration approved and American College of Cardiology/American Heart Association guideline supported reduced anticoagulation target INR of 1.5 to 2.0, and discusses the PROACT Xa trial comparing apixaban vs warfarin anticoagulation. The choice of prosthetic valve should be individualized, carefully considering each patient's unique circumstances. In that context, the On-X aortic valve offers a potential lifetime solution without need for a repeat operation, while minimizing the risks of long-term anticoagulation. In an era of enthusiasm for bioprosthetic and transcatheter-based approaches, the option of a second-generation bileaflet mechanical valve with optimized hemodynamics-the On-X aortic valve-may well align with patient expectations.

Structural valve deterioration of the Labcor Dokimos aortic prosthesis: a single-centre experience

OBJECTIVES

The goal of this study was to assess the performance and incidence of the deterioration of the Labcor Dokimos bioprosthetic aortic valve.

METHODS

We performed a retrospective medical chart review of 116 patients who underwent surgical aortic valve replacement with the Labcor Dokimos aortic valve between 2010 and 2018. Abstracted data included patient demographic and echocardiographic data. Patients were divided into 2 groups: patients with structural valve deterioration (SVD) and patients without SVD.

RESULTS

Among the patients with complete follow-up (n = 95), 10 patients were excluded because they died within a year; 85 patients were included in the final analysis. Of the 85 patients, 32 (38%) developed SVD; 22 (26%) had severe SVD, 15 (18%) of whom underwent reintervention. The most common aetiology of SVD was severe central aortic regurgitation, which was detected in 91% of the patients who had severe SVD. The average time from operation to severe SVD was 4.7 years with a minimum of 1.5 years and a maximum of 7.9 years.

CONCLUSIONS

Bioprosthetic aortic valve deterioration due to severe aortic regurgitation is common and occurs early with the Labcor Dokimos valve. This occurrence needs to be furthered investigated in larger registries.

Simultaneous transcatheter tricuspid and mitral valve-in-valve replacement for the treatment of degenerated bioprosthetic valves

Transcatheter valve-in-valve replacement has become a viable option for patients with degenerated bioprosthetic valves at high risk for redo surgery. We report a case of a patient who had degenerated mitral and tricuspid bioprosthesis causing severe tricuspid and mitral regurgitation. We performed simultaneous mitral and tricuspid valve-in-valve replacement via a transfemoral approach. Although the data on performing both valve-in-valve procedures are limited, this case demonstrated that these procedures can be safely done as a single procedure.

The role of antibody responses against glycans in bioprosthetic heart valve calcification and deterioration

Bioprosthetic heart valves (BHVs) are commonly used to replace severely diseased heart valves but their susceptibility to structural valve degeneration (SVD) limits their use in young patients. We hypothesized that antibodies against immunogenic glycans present on BHVs, particularly antibodies against the xenoantigens galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc), could mediate their deterioration through calcification. We established a large longitudinal prospective international cohort of patients (n = 1668, 34 ± 43 months of follow-up (0.1–182); 4,998 blood samples) to investigate the hemodynamics and immune responses associated with BHVs up to 15 years after aortic valve replacement. Early signs of SVD appeared in <5% of BHV recipients within 2 years. The levels of both anti-αGal and anti-Neu5Gc IgGs significantly increased one month after BHV implantation. The levels of these IgGs declined thereafter but anti-αGal IgG levels declined significantly faster in control patients compared to BHV recipients. Neu5Gc, anti-Neu5Gc IgG and complement deposition were found in calcified BHVs at much higher levels than in calcified native aortic valves. Moreover, in mice, anti-Neu5Gc antibodies were unable to promote calcium deposition on subcutaneously implanted BHV tissue engineered to lack αGal and Neu5Gc antigens. These results indicate that BHVs manufactured using donor tissues deficient in αGal and Neu5Gc could be less prone to immune-mediated deterioration and have improved durability.

In a large cohort of patients who underwent aortic valve replacement, antibody responses to glycans present in bioprosthetic heart valves, notably galactose-α1,3-galactose and N-glycolylneuraminic acid, were implicated in valve calcification and deterioration.

The Role of Multimodality Imaging in Left-Sided Prosthetic Valve Dysfunction

Prosthetic valve (PV) dysfunction (PVD) is a complication of mechanical or biological PV. Etiologic mechanisms associated with PVD include fibrotic pannus ingrowth, thrombosis, structural valve degeneration, and endocarditis resulting in different grades of obstruction and/or regurgitation. PVD can be life threatening and often challenging to diagnose due to the similarities between the clinical presentations of different causes. Nevertheless, identifying the cause of PVD is critical to treatment administration (thrombolysis, surgery, or percutaneous procedure). In this report, we review the role of multimodality imaging in the diagnosis of PVD. Specifically, this review discusses the characteristics of advanced imaging modalities underlying the importance of an integrated approach including 2D/3D transthoracic and transesophageal echocardiography, fluoroscopy, and computed tomography. In this scenario, it is critical to understand the strengths and weaknesses of each modality according to the suspected cause of PVD. In conclusion, for patients with suspected or known PVD, this stepwise imaging approach may lead to a simplified, more rapid, accurate and specific workflow and management.

Surgical techniques for aortic valve xenotransplantation

Background

Heart valve replacement in neonates and infants is one of the remaining unsolved problems in cardiac surgery because conventional valve prostheses do not grow with the children. Similarly, heart valve replacement in children and young adults with contraindications to anticoagulation remains an unsolved problem because mechanical valves are thrombogenic and bioprosthetic valves are prone to early degeneration. Therefore, there is an urgent clinical need for growing heart valve replacements that are durable without the need for anticoagulation.

Methods

A human cadaver model was used to develop surgical techniques for aortic valve xenotransplantation.

Results

Aortic valve xenotransplantation is technically feasible. Subcoronary implantation of the valve avoids the need for a root replacement.

Conclusion

Aortic valve xenotransplantation is promising because the development of GTKO.hCD46.hTBM transgenic pigs has brought xenotransplantation within clinical reach.

Surgical pericardial heart valves: 50 Years of evolution

Valve disease carries a huge burden globally and the number of heart valve procedures are projected to increase from the current 300 000 to 800 000 annually by 2050. Since its genesis 50 years ago, pericardial heart valve has moved leaps and bounds to ever more ingenious designs and manufacturing methods with parallel developments in cardiology and cardiovascular surgical treatments. This feat has only been possible through close collaboration of many scientific disciplines in the fields of engineering, material sciences, basic tissue biology, medicine and surgery. As the pace of change continues to accelerate, we ask the readers to go back with us in time to understand developments in design and function of pericardial heart valves. This descriptive review seeks to focus on the qualities of pericardial heart valves, the advantages, successes and failures encapsulating the evolution of surgically implanted pericardial heart valves over the past five decades. We present the data on comparison of the pericardial heart valves to porcine valves, discuss structural valve deterioration and the future of heart valve treatments.

Long-Term Stability and Biocompatibility of Pericardial Bioprosthetic Heart Valves

The use of bioprostheses for heart valve therapy has gradually evolved over several decades and both surgical and transcatheter devices are now highly successful. The rapid expansion of the transcatheter concept has clearly placed a significant onus on the need for improved production methods, particularly the pre-treatment of bovine pericardium. Two of the difficulties associated with the biocompatibility of bioprosthetic valves are the possibilities of immune responses and calcification, which have led to either catastrophic failure or slow dystrophic changes. These have been addressed by evolutionary trends in cross-linking and decellularization techniques and, over the last two decades, the improvements have resulted in somewhat greater durability. However, as the need to consider the use of bioprosthetic valves in younger patients has become an important clinical and sociological issue, the requirement for even greater longevity and safety is now paramount. This is especially true with respect to potential therapies for young people who are afflicted by rheumatic heart disease, mostly in low- to middle-income countries, for whom no clinically acceptable and cost-effective treatments currently exist. To extend longevity to this new level, it has been necessary to evaluate the mechanisms of pericardium biocompatibility, with special emphasis on the interplay between cross-linking, decellularization and anti-immunogenicity processes. These mechanisms are reviewed in this paper. On the basis of a better understanding of these mechanisms, a few alternative treatment protocols have been developed in the last few years. The most promising protocol here is based on a carefully designed combination of phases of tissue-protective decellularization with a finely-titrated cross-linking sequence. Such refined protocols offer considerable potential in the progress toward superior longevity of pericardial heart valves and introduce a scientific dimension beyond the largely disappointing 'anti-calcification' treatments of past decades.

Valve Sparing Root Replacement versus Bio-Bentall: Inverse Propensity Weighting of 796 Patients

BACKGROUND

This large cohort, single center study aims to compare the 10-year survival and freedom from aortic valve reintervention between valve sparing root replacement (VSRR) and bioprosthetic Bentall (bio-Bentall).

METHODS

All patients undergoing elective VSRR or bio-Bentall for aortic root aneurysm between March 2005 through October 2019 were retrospectively reviewed (n=796 [VSRR = 360]). Inverse probability of treatment weighting (IPTW) balanced clinical variables between groups. Mean follow-up was 58.0 +/- 45.4 (range 0-167) months.

RESULTS

After IPTW adjustment, 10-year survival did not differ between groups (VSRR: 87.0% vs bio-Bentall: 92.7%, p=0.780). Cumulative incidence of aortic valve reintervention was 5.9% for VSRR (95% CI, 2.9%-10.4%) and 10.6% for bio-Bentall (95% CI, 6.2%-16.4%, p=0.798). Fine and Gray computing risk regression model identified age at surgery (sHR 0.97, 95% CI, 0.95-0.99, p=0.015), body surface area (sHR 6.21, 95% CI, 1.97-19.59, p=0.002) and bicuspid aortic valve (sHR 2.15, 95% CI, 1.04-4.44, p =0.038) as independently associated with aortic valve reintervention. For patients ≤50-year-old, cumulative incidence of aortic valve reintervention was 16.2% for VSRR (95% CI, 7.0%-28.8%) and 17.8% for bio-Bentall (95% CI, 6.9%-32.8%)(p=0.363).

CONCLUSIONS

VSRR and bio-Bentall show similar excellent survival and freedom from aortic reintervention rates up to 10 years; however, a durable valve solution for young patients with bicuspid aortic valve remains a challenge.

Bicuspid-Associated Aortic Root Aneurysm: Mid to Long-Term Outcomes of David V Versus the Bio-Bentall Procedure

David V valve-sparing root replacement (VSRR) and bio-Bentall (BB) are increasingly performed for aortic root aneurysms associated with a bicuspid aortic valve (BAV). However, durability remains a concern in both procedures. We compared the 10-year outcomes of VSRR vs BB for BAV-associated root aneurysms. A retrospective review identified 134 patients with a BAV-associated root aneurysm who underwent VSRR (n = 65) or BB (n = 69) from 2005 to 2019. Patients with aortic stenosis, endocarditis, previous aortic valve replacement, and emergent cases were excluded. Propensity-score matching was performed, resulting in 2 risk-adjusted groups (n = 40 per group). Median follow-up was 6.21 (1.43-8.28) years. The VSRR cohort was younger (46.0 years vs 56.0 years, P < 0.001) and had a lower incidence of at least moderate aortic insufficiency (AI) (78.5% vs 92.8%, P = 0.02). The incidence of Marfan syndrome, aortic root diameter, and ascending aortic diameter were similar. In-hospital mortality was 1.5% (n = 1) and 1.4% (n = 1) for VSRR and BB, respectively. There was no difference between VSRR and BB in 10-year survival (98.3% [95% confidence interval (CI): 88.6-99.8%] vs 96.2% [95% CI: 85.5-99.0%], P = 0.567) and aortic valve reintervention at 10 years (16.1% [95% CI: 6.3-29.8%] vs 12.9% [95% CI: 3.7-28.0%], P = 0.309). The most common reason for valve reintervention in both groups was AI. Survival and valve reintervention at 10 years were similar in the matched cohort. David V VSRR yields similar mid to long-term outcomes to BB for select patients with a BAV-associated aortic root aneurysm in regards to survival and reintervention rates. Further studies comparing longer term outcomes between root replacement techniques and native valve durability are needed.

Association of Bioprosthetic Aortic Valve Leaflet Calcification on Hemodynamic and Clinical Outcomes

BACKGROUND

The prognostic value of aortic valve calcification (AVC) measured by using multidetector computed tomography imaging has been well validated in native aortic stenosis, and sex-specific thresholds have been proposed. However, few data are available regarding the impact of leaflet calcification on outcomes after biological aortic valve replacement (AVR).

OBJECTIVES

The goal of this study was to analyze the association of quantitative bioprosthetic leaflet AVC with hemodynamic and clinical outcomes, as well as its possible interaction with sex.

METHODS

From 2008 to 2010, a total of 204 patients were prospectively enrolled with a median of 7.0 years (interquartile range: 5.1 to 9.2 years) after biological surgical AVR. AVC measured by using the Agatston method was indexed to the cross-sectional area of aortic annulus measured by echocardiography to calculate the AVC density (AVCd). Presence of hemodynamic valve deterioration (HVD; increase in mean gradient [MG] ≥10 mm Hg and/or increase in transprosthetic regurgitation ≥1) was assessed by echocardiography in 137 patients at the 3-year follow-up. The primary clinical endpoint was mortality or aortic valve re-intervention.

RESULTS

There was no significant sex-related difference in the relationship between bioprosthetic AVCd and the progression of MG. Baseline AVCd showed an independent association with HVD at 3 years. During follow-up, there were 134 (65.7%) deaths (n = 100) or valve re-interventions (n = 47). AVCd ≥58 AU/cm² was independently associated with an increased risk of mortality or aortic valve re-intervention (adjusted hazard ratio: 2.23; 95% confidence interval: 1.44 to 3.35; p < 0.001). The AVCd threshold combined with an MG progression threshold of 10 mm Hg amplified the stratification of patients at risk (log-rank, p < 0.001). The addition of AVCd threshold into the prediction model including traditional risk factors improved outcome prediction (net classification improvement: 0.25, p = 0.04; likelihood ratio test, p < 0.001).

CONCLUSIONS

Aortic bioprosthetic leaflet calcification is strongly and independently associated with HVD and the risk of death or aortic valve re-intervention. As opposed to native aortic stenosis, there is no sex-related differences in the relationship between AVCd and hemodynamic or clinical outcomes.

Noncalcific Mechanisms of Bioprosthetic Structural Valve Degeneration

Bioprosthetic heart valves (BHVs) largely circumvent the need for long‐term anticoagulation compared with mechanical valves but are increasingly susceptible to deterioration and reduced durability with reoperation rates of ≈10% and 30% at 10 and 15 years, respectively. Structural valve degeneration is a common, unpreventable, and untreatable consequence of BHV implantation and is frequently characterized by leaflet calcification. However, 25% of BHV reoperations attributed to structural valve degeneration occur with minimal leaflet mineralization. This review discusses the noncalcific mechanisms of BHV structural valve degeneration, highlighting the putative roles and pathophysiological relationships between protein infiltration, glycation, oxidative and mechanical stress, and inflammation and the structural consequences for surgical and transcatheter BHVs.

Premature Structural Failure of Trifecta Bioprosthesis in Midterm Follow-up: A Single-Center Study

BACKGROUND

A cluster of aortic bioprosthetic valve failures, most of which were Trifecta bioprostheses, was observed in Southampton General Hospital, Southampton, United Kingdom. This study was performed to assess whether the cluster represents a significant failure of this valve model or whether there is a selection bias that can explain the failure of these valves.

METHODS

This retrospective study evaluated all bioprosthetic aortic valve replacement operations performed between 2011 and 2016 inclusive in our center. The study compared the performance of the Trifecta valve (Abbott, Abbott Park, IL) with that of Perimount (Edwards Lifesciences, Irvine, CA), Perimount Magna Ease, and Mitroflow (LivaNova, London, United Kingdom) bioprostheses. In addition, the study analyzed patient-related and valve-related risk factors for early failure in the failed valves.

RESULTS

A total of 2807 bioprosthetic aortic valve replacements were performed. Of these, 836 were Trifecta valves, 1031 were Perimount, 449 were Perimount Magna Ease, and 351 were Mitroflow valves. A total of 24 Trifecta valves had premature structural failure, a number significantly higher than seen with Perimount or Perimount Magna Ease (no failure, P < .001 and P < .005, respectively) valves and the Mitroflow valve (1 failure, P < .05). There was no difference in the incidence of endocarditis or death. At the time of valve failure, 17 (71%) of the failed Trifecta valves had moderate or severe regurgitation, and the average peak gradient was 61 ± 29 mm Hg. The median failed prosthetic size was 23 mm. One failed valve had severe patient-prosthesis mismatch. The mean time to failure was 4.5 ± 1.7 years.

CONCLUSIONS

The Trifecta bioprosthesis has an increased incidence of early structural valve failure, which is significantly higher than that of Perimount, Perimount Magna Ease, or Mitroflow. No patient-related or valve-related cause for the failure could be identified.

Glutaraldehyde and 2,3-butanediol treatment of bovine pericardium for aortic valve bioprosthesis in sheep: a preliminary study

Background

Bovine pericardium can be used for cardiovascular repair surgeries, but challenges involving biocompatibility and durability remain. This study aimed to carry out pre-clinical testing of aortic valve replacement using an aortic valve prosthesis made of bovine pericardium modified with glutaraldehyde (GA) and 2,3-butanediol (BD).

Methods

The mechanical, plasma protein adsorption, platelet adhesion, collagenase digestion, and ninhydrin properties of the material (control vs. GA vs. GA + BD) were tested. All 3 tissues were implanted in rats and observed after 8 weeks under microscopy with alizarin red staining for calcification. Aortic valves made from the fully-treated material were implanted in sheep. A commercial bioprosthesis was used as control. Effectiveness and safety indicators were observed at 180 days after implantation.

Results

Compared with the control group, the GA + BD material showed higher elongation at breaking and tensile load (both P<0.05), lower plasma protein adsorption, lower platelet adhesion, lower collagenase digestion, lower ninhydrin value, and higher cross-linking (all P<0.05). After implantation in rat models, the GA + BD material showed little or no dissolution; there was no obvious calcification; and it was surrounded by a small amount of fibrosis, with peripheral capillary proliferation. After implantation in sheep models, the aortic valve leaflets of the experimental animals freely opened and closed, their surface was smooth, and no abnormal echo was observed. The echocardiographic results and hemodynamic were comparable between the two groups. All safety parameters were normal.

Conclusions

Modification of bovine pericardium with GA and BD results in a biomaterial with favorable properties for use as an aortic valve prosthesis.

Ultrastructural Pathology of Atherosclerosis, Calcific Aortic Valve Disease, and Bioprosthetic Heart Valve Degeneration: Commonalities and Differences

Atherosclerosis, calcific aortic valve disease (CAVD), and bioprosthetic heart valve degeneration (alternatively termed structural valve deterioration, SVD) represent three diseases affecting distinct components of the circulatory system and their substitutes, yet sharing multiple risk factors and commonly leading to the extraskeletal calcification. Whereas the histopathology of the mentioned disorders is well-described, their ultrastructural pathology is largely obscure due to the lack of appropriate investigation techniques. Employing an original method for sample preparation and the electron microscopy visualisation of calcified cardiovascular tissues, here we revisited the ultrastructural features of lipid retention, macrophage infiltration, intraplaque/intraleaflet haemorrhage, and calcification which are common or unique for the indicated types of cardiovascular disease. Atherosclerotic plaques were notable for the massive accumulation of lipids in the extracellular matrix (ECM), abundant macrophage content, and pronounced neovascularisation associated with blood leakage and calcium deposition. In contrast, CAVD and SVD generally did not require vasculo- or angiogenesis to occur, instead relying on fatigue-induced ECM degradation and the concurrent migration of immune cells. Unlike native tissues, bioprosthetic heart valves contained numerous specialised macrophages and were not capable of the regeneration that underscores ECM integrity as a pivotal factor for SVD prevention. While atherosclerosis, CAVD, and SVD show similar pathogenesis patterns, these disorders demonstrate considerable ultrastructural differences.

Valve-in-valve-prosthesis embolization and aortic dissection: single procedure, double complication

Transcatheter aortic valve implantation (TAVI) is a recognized treatment method for high-risk patients with aortic stenosis. TAVI is also recommended for structural valve degeneration of a biological valve prosthesis. TAVI-specific complications, such as prosthesis embolization and aortic dissection, are uncommon but potential concerns. A 73-year-old woman presented with structural valve degeneration 14 years after aortic root replacement with a bioprosthetic valved conduit. The patient underwent TAVI valve-in-valve under monitored anaesthesia care. Intraoperatively, the self-expandable prosthesis was difficult to deploy within the valved conduit and ultimately migrated distally. During the technically difficult passage of the prosthesis delivery system through the tortuous aorta, the patient started reporting symptoms suggestive of aortic dissection. An emergency computed tomography scan confirmed type B dissection. Thoracic endovascular aortic repair followed by deployment of a balloon-expandable prosthesis below the self-expandable implant was performed. Careful prosthesis selection in valve-in-valve patients after aortic root replacement is crucial for procedural success.

A systematic evaluation on reporting quality of modern studies on pulmonary heart valve implantation in large animals

OBJECTIVES

Before new heart valves can be implanted safely in humans, animal experiments have to be performed. These animal experiments have to be clearly designed, analysed and reported to assess the accuracy and importance of the findings. We aimed to provide an overview of the reporting and methodological quality of preclinical heart valve research.

METHODS

We conducted a systematic literature search on biological and mechanical pulmonary valve implantations in large animals. We used the Animals in Research: Reporting In Vivo Experiments (ARRIVE) guidelines to score the quality of reporting in each article. We compared the scores before and after the introduction of the ARRIVE guidelines (2010).

RESULTS

We screened 348 articles, of which 31 articles were included. The included articles reported a mean of 54.7% adequately scored ARRIVE items (95% confidence interval 52.2-57.3%). We did not identify a difference in reporting quality (54.7% vs 54.8%) between articles published before and after 2010. We found an unclear (lack of description) risk of selection bias, performance bias and detection bias.

CONCLUSIONS

The reporting quality of studies that implanted bioprosthetic or mechanical valves in the pulmonary position in the large animal model is not on the desired level. The introduction of the ARRIVE guidelines in 2010 did not improve the reporting quality in this field of research. Hereby, we want to emphasize the importance of clearly describing the methods and transparently reporting the results in animal experiments. This is of great importance for the safe translation of new heart valves to the clinic.

CLINICAL TRIAL REGISTRATION NUMBER

PROSPERO (CRD42019147895).

Subclinical Structural Valve Degeneration in Young Patients With Bioprosthetic Aortic Valves

BACKGROUND

Bioprosthetic structural valve degeneration (SVD) has previously been a clinical diagnosis, but subclinical changes have been increasingly recognized in transcatheter valves. The significance of subclinical SVD after surgical aortic valve replacement (SAVR), however, is not well understood. The purpose of this study was to characterize the incidence and outcomes of subclinical SVD in young patients after SAVR.

METHODS

Patients aged ≤65 years who underwent bioprosthetic SAVR between January 2002 and June 2018 at a single institution were included. Endocarditis cases and those with in-hospital mortality were excluded. All available longitudinal postoperative echocardiograms were reviewed. Subclinical SVD was defined as an increase in mean transvalvular gradient of at least 10 mm Hg and/or new onset of mild intraprosthetic regurgitation or increase by at least 1 grade, compared with baseline postoperative echocardiogram.

RESULTS

Overall, 822 unique SAVR cases were included. Over the study period, 356 (43.3%) patients developed subclinical SVD. Only 21.5% of those with subclinical SVD progressed to clinical SVD or to repeat aortic valve procedures. In those with progression, the first signs of SVD occurred significantly earlier than in those whose changes remained stable (11 months vs 23 months; P = .036). Anticoagulation did not impact the development or progression of subclinical SVD. There was no difference in long-term survival for those who did or did not develop subclinical SVD.

CONCLUSIONS

Subclinical SVD occurred in a large proportion of young patients undergoing bioprosthetic SAVR. Despite its high prevalence, subclinical SVD was not associated with decreased survival or repeat procedures.

Degeneration of Bioprosthetic Heart Valves: Update 2020

The implantation of bioprosthetic heart valves (BHVs) is increasingly becoming the treatment of choice in patients requiring heart valve replacement surgery. Unlike mechanical heart valves, BHVs are less thrombogenic and exhibit superior hemodynamic properties. However, BHVs are prone to structural valve degeneration (SVD), an unavoidable condition limiting graft durability. Mechanisms underlying SVD are incompletely understood, and early concepts suggesting the purely degenerative nature of this process are now considered oversimplified. Recent studies implicate the host immune response as a major modality of SVD pathogenesis, manifested by a combination of processes phenocopying the long‐term transplant rejection, atherosclerosis, and calcification of native aortic valves. In this review, we summarize and critically analyze relevant studies on (1) SVD triggers and pathogenesis, (2) current approaches to protect BHVs from calcification, (3) obtaining low immunogenic BHV tissue from genetically modified animals, and (4) potential strategies for SVD prevention in the clinical setting.