Patient Risk Factors for Bioprosthetic Aortic Valve Degeneration: A Systematic Review and Meta-Analysis

The association of bisphosphonates, calcium levels and PTH levels with bioprosthetic aortic valve degeneration

BACKGROUND

Bioprosthetic aortic valve (bAV) degeneration represents a major concern following aortic valve replacement (AVR). The association of bisphosphonates, serum calcium and serum parathyroid hormone (PTH) with native AV degeneration have been studied extensively. However, their association with structural valve degeneration (SVD) is yet to be elucidated.

METHODS

Patients who underwent AVR and had a baseline transthoracic echocardiogram (TTE) and at least one follow-up TTE spaced three months apart were included. SVD diagnosis was made according to American Society of Echocardiography guidelines. Patients' exposure to bisphosphonates and serum calcium and PTH levels were collected. A cutoff of 10.2 mg/dL for calcium and 65 pg/mL for PTH were used, respectively, to define pathological thresholds. Multivariable Cox proportional hazards regression models were built to evaluate the association between predictors and SVD.

RESULTS

Overall, 2002 patients were included, of whom 214 (10.7 %) had SVD, with median degeneration time of 4 (IQR: 1.9, 6.1) years. Among them, reintervention occurred in 82 (4.1 %) without significant differences according to bisphosphonate use (Log Rank p = 0.300), elevated PTH or calcium levels (Log Rank p = 0.702 and p = 0.703, respectively). In the multivariate analysis, neither bisphosphonates use (HR: 0.95, 95 % CI: 0.56-1.60; p = 0.862), elevated calcium levels >10.2 mg/dL (HR: 0.74, 95 % CI: 0.31-1.72; p = 0.489), nor elevated PTH levels >65 pg/mL (HR: 1.91, 95 % CI: 0.99-3.68; p = 0.052) was associated with SVD.

CONCLUSIONS

The use of bisphosphonates, elevated serum calcium levels and elevated serum PTH levels were not associated with SVD nor with reintervention on the bAV.

[Structural valve deterioration after transcatheter aortic valve replacement: a research update]

Structural valve deterioration (SVD) refers to intrinsic and irreversible pathological changes in the components of prosthetic heart valves, manifesting as fibrosis, calcification, wear and tear, loosening, as well as strut fracture or deformation of the valve framework. These changes ultimately lead to valve stenosis and/or regurgitation.The mechanisms may be related to mechanical stress, immune response and abnormal calcium-phosphorus metabolism. Studies have shown that risk factors for SVD include patient factors (such as age, underlying cardiovascular disease and comorbidities), valve factors (such as material properties, processing techniques, and valve type), and surgical factors (such as valve injury, suboptimal stent expansion, and irregular stent release morphology). Clinical imaging assessment of SVD demonstrates complementary advantages among echocardiography, multi-detector spiral CT and cardiac magnetic resonance imaging, with distinct diagnostic objectives. The primary management strategies for SVD after trans-catheter aortic valve replacement (TAVR) include drug therapy, redo-TAVR, surgical aortic valve replacement (SAVR) and the novel SURPLUS technique. Among them, redo-TAVR has become a common method because of its minimally invasive nature, but it is still necessary to further clarify the patient indications and optimize the surgical strategy. SAVR is reserved for young, low-risk patients; SURPLUS combines the advantages of SAVR and TAVR, making it suitable for cases where redo-TAVR is unfeasible or contraindicated, while the risk of SAVR is excessively high. This article reviews the latest progress of SVD following TAVR treatment to provide reference for research into the durability of bioprosthetic valve and clinical intervention of SVD.

Bioprosthetic Aortic Valve Degeneration After TAVR and SAVR: Incidence, Diagnosis, Predictors, and Management

Bioprosthetic aortic valve degeneration (BAVD) is a significant clinical concern following both transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR). The increasing use of bioprosthetic valves in aortic valve replacement in younger patients and the subsequent rise in cases of BAVD are acknowledged in this review which aims to provide a comprehensive overview of the incidence, diagnosis, predictors, and management of BAVD. Based on a thorough review of the existing literature, this article provides an updated overview of the biological mechanisms underlying valve degeneration, including calcification, structural deterioration, and inflammatory processes and addresses the various risk factors contributing to BAVD, such as patient demographics, comorbidities, and procedural variables. The difficulties in early detection and accurate diagnosis of BAVD are discussed with an emphasis on the need for improved imaging techniques. The incidence and progression of BAVD in patients undergoing TAVR versus SAVR are compared, providing insights into the differences and similarities between the two procedures and procedural impacts on valve longevity. The current strategies for managing BAVD, including re-intervention options of redo surgery and valve-in-valve TAVR, along with emerging treatments are discussed. The controversies in the existing literature are highlighted to offer directions for future investigations to enhance the understanding and management of BAVD.

Ectopic Calcification in Congenital Heart Surgery: A Material-Centric Review

The modern congenital heart surgeon has an array of materials available for cardiovascular repair. With advancements in the surgical outcomes for pediatric cardiac defects, choice of material has become increasingly dependent on late-term complications associated with each material. Calcification is a leading long-term complication and is increasing in prevalence with materials lasting longer in patients. Material calcification can impair functionality, lead to subsequent complications, and require additional interventions. A comprehensive literature review was conducted to investigate ectopic calcification of commonly used materials for congenital heart defect repair. Mechanisms of ectopic calcification among commonly used materials were investigated. Ectopic calcification is initiated by material-specific immunological reactions. Recent efforts have focused on developing new materials that are not prone to calcification. ePTFE was widely used in cardiovascular applications but still has reported instances of calcification in various situations, such as long-term use. Tissue engineering techniques have shown reduced calcification in reports. Calcification can occur in all conventional materials we reviewed and, in some cases, has led to life-threatening complications. Favorable outcomes have been reported with tissue-engineered materials, with the expectation of continued positive results in future reports. With an array of synthetic and biological materials now displaying acceptable surgical and short-term outcomes, there is a pressing need to review the long-term viability of these materials, especially considering improved patient survival to adulthood. Furthermore, developing new materials to mitigate calcification remains a promising avenue of research in this field.

Outcomes of Valve-in-Valve (VIV) Transcatheter Aortic Valve Replacement (TAVR) after Surgical Aortic Valve Replacement with Sutureless Surgical Aortic Valve Prostheses Perceval™: A Systematic Review of Published Cases

Background: Valve-in-Valve (VIV) transcatheter aortic valve replacement (TAVR) is a potential solution for malfunctioning surgical aortic valve prostheses, though limited data exist for its use in Perceval valves. Methods: searches were performed on PubMed and Scopus up to 31 July 2023, focusing on case reports and series addressing VIV replacement for degenerated Perceval bioprostheses. Results: Our analysis included 57 patients from 27 case reports and 6 case series. Most patients (68.4%) were women, with a mean age of 76 ± 4.4 years and a mean STS score of 6.1 ± 4.3%. Follow-up averaged 9.8 ± 8.9 months, the mean gradient reduction was 15 ± 5.9 mmHg at discharge and 13 ± 4.2 mmHg at follow-up. Complications occurred in 15.7% of patients, including atrioventricular block III in four patients (7%), major bleeding or vascular complications in two patients (3.5%), an annular rupture in two patients (3.5%), and mortality in two patients (3.5%). No coronary obstruction was reported. Balloon-expanding valves were used in 61.4% of patients, predominantly the Sapien model. In the self-expanding group (38.6%), no valve migration occurred, with a permanent pacemaker implantation rate of 9%, compared to 5.7% for balloon-expanding valves. Conclusions: VIV-TAVR using both balloon-expanding and self-expanding technologies is feasible after the implantation of Perceval valves; however, it should be performed by experienced operators with experience both in TAVR and VIV procedures.

Transcatheter or surgical aortic valve implantation: 10-year outcomes of the NOTION trial

BACKGROUND AND AIMS

Transcatheter aortic valve implantation (TAVI) has become a viable treatment option for patients with severe aortic valve stenosis across a broad range of surgical risk. The Nordic Aortic Valve Intervention (NOTION) trial was the first to randomize patients at lower surgical risk to TAVI or surgical aortic valve replacement (SAVR). The aim of the present study was to report clinical and bioprosthesis outcomes after 10 years.

METHODS

The NOTION trial randomized 280 patients to TAVI with the self-expanding CoreValve (Medtronic Inc.) bioprosthesis (n = 145) or SAVR with a bioprosthesis (n = 135). The primary composite outcome was the risk of all-cause mortality, stroke, or myocardial infarction. Bioprosthetic valve dysfunction (BVD) was classified as structural valve deterioration (SVD), non-structural valve dysfunction (NSVD), clinical valve thrombosis, or endocarditis according to Valve Academic Research Consortium-3 criteria. Severe SVD was defined as (i) a transprosthetic gradient of 30 mmHg or more and an increase in transprosthetic gradient of 20 mmHg or more or (ii) severe new intraprosthetic regurgitation. Bioprosthetic valve failure (BVF) was defined as the composite rate of death from a valve-related cause or an unexplained death following the diagnosis of BVD, aortic valve re-intervention, or severe SVD.

RESULTS

Baseline characteristics were similar between TAVI and SAVR: age 79.2 ± 4.9 years and 79.0 ± 4.7 years (P = .7), male 52.6% and 53.8% (P = .8), and Society of Thoracic Surgeons score < 4% of 83.4% and 80.0% (P = .5), respectively. After 10 years, the risk of the composite outcome all-cause mortality, stroke, or myocardial infarction was 65.5% after TAVI and 65.5% after SAVR [hazard ratio (HR) 1.0; 95% confidence interval (CI) 0.7-1.3; P = .9], with no difference for each individual outcome. Severe SVD had occurred in 1.5% and 10.0% (HR 0.2; 95% CI 0.04-0.7; P = .02) after TAVI and SAVR, respectively. The cumulative incidence for severe NSVD was 20.5% and 43.0% (P < .001) and for endocarditis 7.2% and 7.4% (P = 1.0) after TAVI and SAVR, respectively. No patients had clinical valve thrombosis. Bioprosthetic valve failure occurred in 9.7% of TAVI and 13.8% of SAVR patients (HR 0.7; 95% CI 0.4-1.5; P = .4).

CONCLUSIONS

In patients with severe AS and lower surgical risk randomized to TAVI or SAVR, the risk of major clinical outcomes was not different 10 years after treatment. The risk of severe bioprosthesis SVD was lower after TAVR compared with SAVR, while the risk of BVF was similar.

Tissue engineered vascular grafts are resistant to the formation of dystrophic calcification

Advancements in congenital heart surgery have heightened the importance of durable biomaterials for adult survivors. Dystrophic calcification poses a significant risk to the long-term viability of prosthetic biomaterials in these procedures. Herein, we describe the natural history of calcification in the most frequently used vascular conduits, expanded polytetrafluoroethylene grafts. Through a retrospective clinical study and an ovine model, we compare the degree of calcification between tissue-engineered vascular grafts and polytetrafluoroethylene grafts. Results indicate superior durability in tissue-engineered vascular grafts, displaying reduced late-term calcification in both clinical studies (p < 0.001) and animal models (p < 0.0001). Further assessments of graft compliance reveal that tissue-engineered vascular grafts maintain greater compliance (p < 0.0001) and distensibility (p < 0.001) than polytetrafluoroethylene grafts. These properties improve graft hemodynamic performance, as validated through computational fluid dynamics simulations. We demonstrate the promise of tissue engineered vascular grafts, remaining compliant and distensible while resisting long-term calcification, to enhance the long-term success of congenital heart surgeries.

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.

Bioprosthetic Valves for Lifetime Management of Aortic Stenosis: Pearls and Pitfalls

This review explores the use of bioprosthetic valves for the lifetime management of patients with aortic stenosis, considering recent advancements in surgical (SAV) and transcatheter bioprostheses (TAV). We examine the strengths and challenges of each approach and their long-term implications. We highlight differences among surgical bioprostheses regarding durability and consider novel surgical valves such as the Inspiris Resilia, Intuity rapid deployment, and Perceval sutureless bioprostheses. The impact of hemodynamics on the performance and durability of these prostheses is discussed, as well as the benefits and considerations of aortic root enlargement during Surgical Aortic Valve Replacement (SAVR). Alternative surgical methods like the Ross procedure and the Ozaki technique are also considered. Addressing bioprosthesis failure, we compare TAV-in-SAV with redo SAVR. Challenges with TAVR, such as TAV explantation and considerations for coronary circulation, are outlined. Finally, we explore the potential challenges and limitations of several clinical strategies, including the TAVR-first approach, in the context of aortic stenosis lifetime management. This concise review provides a snapshot of the current landscape in aortic bioprostheses for physicians and surgeons.

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.

Differential Immune Response to Bioprosthetic Heart Valve Tissues in the α1,3Galactosyltransferase-Knockout Mouse Model

Structural valve deterioration (SVD) of bioprosthetic heart valves (BHVs) has great clinical and economic consequences. Notably, immunity against BHVs plays a major role in SVD, especially when implanted in young and middle-aged patients. However, the complex pathogenesis of SVD remains to be fully characterized, and analyses of commercial BHVs in standardized-preclinical settings are needed for further advancement. Here, we studied the immune response to commercial BHV tissue of bovine, porcine, and equine origin after subcutaneous implantation into adult α1,3-galactosyltransferase-knockout (Gal KO) mice. The levels of serum anti-galactose α1,3-galactose (Gal) and -non-Gal IgM and IgG antibodies were determined up to 2 months post-implantation. Based on histological analyses, all BHV tissues studied triggered distinct infiltrating cellular immune responses that related to tissue degeneration. Increased anti-Gal antibody levels were found in serum after ATS 3f and Freedom/Solo implantation but not for Crown or Hancock II grafts. Overall, there were no correlations between cellular-immunity scores and post-implantation antibodies, suggesting these are independent factors differentially affecting the outcome of distinct commercial BHVs. These findings provide further insights into the understanding of SVD immunopathogenesis and highlight the need to evaluate immune responses as a confounding factor.

What's New with TAVR? An Update on Device Technology

Over the last 20 years, transcatheter aortic valve replacement (TAVR) has revolutionized the management of aortic stenosis and has become the standard of care across the entire spectrum of surgical risk. Expansion of TAVR in treating younger, lower-risk patients with longer life expectancies, and treating earlier in the disease process, has seen a continuous evolution in device technology, with several next-generation transcatheter heart valves developed to minimize procedural complications and improve patient outcomes. This review provides an update on the latest advances in transcatheter delivery systems, devices, and leaflet technology.

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.

Clinical performance of a novel bioprosthetic surgical aortic valve in a German high-volume center

BACKGROUND AND AIM

Bioprosthetic surgical aortic valve replacement (SAVR) is increasingly adopted in younger patients. We aimed to analyze mid-term follow-up data after SAVR to assess the performance of the prosthesis.

METHODS

Data were collected from a single-center series of 154 patients, who underwent SAVR with a bioprosthetic heart valve with the RESILIA tissue at our Heart Centre in Siegburg. All procedural and midterm patient outcomes were documented.

RESULTS

Patients had a mean age of 56.8 ± 9.9 years, 35.7% were female, and the mean logistic European system for cardiac operative risk evaluation (EuroSCORE) was 3.4 ± 3.6%. Diabetes (12.3%), atrial fibrillation (10.4%), and chronic obstructive pulmonary disease (COPD) (5.8%) were common comorbidities. The mean surgery duration was 163.8 ± 73.4 min, with the 23 mm (34.4%) and 25 mm (33.8%) heart valves being most frequently implanted. At 3-year follow-up, mean pressure gradient was 13.9 ± 5.9 mmHg, peak gradient was 23.6 ± 7.7 mmHg, and effective orifice area (EOA) was 1.9 ± 0.4 cm². No patient died during the operation, 3 (2.1%) patients within 30 days, and 4 (2.7%) thereafter with an overall mortality of n = 7. Of the surviving patients, 97.8% were in New York Heart Association (NYHA) class I/II and none had structural valve deterioration (SVD).

CONCLUSION

Results of our single-center study indicate favorable procedural outcomes. The safety outcomes confirm preliminary earlier results of this novel bioprosthesis but include more patients and a longer midterm follow-up.

Review of bioprosthetic structural valve deterioration: Patient or valve?

BACKGROUND

With guidelines progressively recommending bioprosthetic aortic valves in younger patients, a greater emphasis is placed on structural valve deterioration (SVD) as an important clinical endpoint for both transcatheter and surgically implanted valves. However, SVD of bioprosthetic valves is a complex entity with varying definitions in the literature and a multifaceted pathogenesis.

AIM

This review first aims to establish the most updated definitions of SVD as per the literature. We then explore the patient- and valve-related factors that play the greatest roles in facilitating early SVD.

METHODS

A PubMed literature review was conducted to identify the relevant research in this field within the past two decades.

CONCLUSION

Increasing rates of obesity and metabolic syndrome pose a significant risk to the longevity of bioprosthetic valves. Additionally, externally mounted valves have proven to sacrifice durability for superior haemodynamics. Bioprosthetic SVD continues to be a multifactorial issue that will require various patient- and valve-related factors to be addressed.

Management of Failed Bioprosthetic Aortic Valves: Mitigating Complications and Optimizing Outcomes

The use of bioprosthetic prostheses during surgical aortic valve replacements has increased dramatically over the last two decades, accounting for over 85% of surgical implantations. Given limited long-term durability, there has been an increase in aortic valve reoperations and reinterventions. With the advent of new technologies, multiple treatment strategies are available to treat bioprosthetic valve failure, including valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR). However, ViV TAVR has an increased risk of higher gradients and patient prosthesis mismatch (PPM) secondary to placing the new valve within the rigid frame of the prior valve, especially in patients with a small surgical bioprosthesis in situ. Bioprosthetic valve fracture allows for placement of a larger transcatheter valve, as well as a fully expanded transcatheter valve, decreasing postoperative gradients and the risk of PPM.

Prosthesis-patient mismatch following transcatheter aortic valve replacement for degenerated transcatheter aortic valves: the TRANSIT-PPM international project

BACKGROUND

A severe prosthesis-patient mismatch (PPM) is associated with adverse outcomes following transcatheter aortic valve replacement (TAVR) for de novo aortic stenosis or a failed surgical bioprosthesis. The impact of severe PPM in patients undergoing TAV-in-TAVR is unknown.

AIM

We sought to investigate the incidence and 1-year outcomes of different grades of PPM in patients undergoing TAV-in-TAVR.

MATERIALS AND METHODS

The TRANSIT-PPM is an international registry, including cases of degenerated TAVR treated with a second TAVR. PPM severity, as well as in-hospital, 30-day, and 1-year outcomes were defined according to the Valve Academic Research Consortium-3 (VARC-3) criteria.

RESULTS

Among 28 centers, 155 patients were included. Severe PPM was found in 6.5% of patients, whereas moderate PPM was found in 14.2% of patients. The rate of severe PPM was higher in patients who underwent TAV-in-TAVR with a second supra-annular self-expanding (S-SE) TAVR (10%, p = 0.04). Specifically, the rate of severe PPM was significantly higher among cases of a SE TAVR implanted into a balloon-expandable (BE) device (19%, p = 0.003). At 1-year follow-up, the rate of all-cause mortality, and the rate of patients in the New York Heart Association (NYHA) class III/IV were significantly higher in the cohort of patients with severe PPM (p = 0.016 and p = 0.0001, respectively). Almost all the patients with a severe PPM after the first TAVR had a failed < 23 mm BE transcatheter heart valve (THV): the treatment with an S-SE resolved the severe PPM in the majority of the cases.

CONCLUSION

After TAV-in-TAVR, in a fifth of the cases, a moderate or severe PPM occurred. A severe PPM is associated with an increased 1-year all-cause mortality.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov], identifier [NCT04500964].

Mechanisms and Drug Therapies of Bioprosthetic Heart Valve Calcification

Valve replacement is the main therapy for valvular heart disease, in which a diseased valve is replaced by mechanical heart valve (MHV) or bioprosthetic heart valve (BHV). Since the 2000s, BHV surpassed MHV as the leading option of prosthetic valve substitute because of its excellent hemocompatible and hemodynamic properties. However, BHV is apt to structural valve degeneration (SVD), resulting in limited durability. Calcification is the most frequent presentation and the core pathophysiological process of SVD. Understanding the basic mechanisms of BHV calcification is an essential prerequisite to address the limited-durability issues. In this narrative review, we provide a comprehensive summary about the mechanisms of BHV calcification on 1) composition and site of calcifications; 2) material-associated mechanisms; 3) host-associated mechanisms, including immune response and foreign body reaction, oxidative stress, metabolic disorder, and thrombosis. Strategies that target these mechanisms may be explored for novel drug therapy to prevent or delay BHV calcification.

The role of echocardiography in the management of structural valve degeneration of transcatheter valves

Transcatheter valve implantation in patients with aortic stenosis has evolved as an acceptable alternative to surgical aortic valve replacement in a subset of patients at excessively high risk from surgery. The structural valve degeneration (SVD) is a known phenomenon in catheter-based valves too, which was hitherto seen with surgical bioprosthetic valves. Echocardiography plays a pivotal role not only in early detection but also in the management of SVD of Transcatheter valves. The goal of this report is to agglomerate our experience of an unusual case of SVD of a catheter-based valve implanted inside the bioprosthetic aortic and mitral valve apparatus and its management with aortic and mitral valve replacement with mechanical valve prosthesis.

Carpentier-Edwards Magna Ease bioprosthesis: a multicentre clinical experience and 12-year durability

OBJECTIVES

The goal of this multicentre retrospective study was to compare long-term clinical and haemodynamic outcomes of the Carpentier-Edwards Magna Ease (CEME) bioprosthesis by patient age.

METHODS

We included consecutive patients who underwent isolated and combined surgical aortic valve replacement (AVR) with CEME valve between January 2008 and March 2020 at 4 cardiac surgery centres in Italy. Survival distribution was evaluated at follow-up according to age and surgery type (combined or isolated AVR), together with freedom from structural valve deterioration (SVD), reoperation and combined events, i.e. SVD, reoperation, endocarditis and thromboembolic events.

RESULTS

A total of 1027 isolated and 1121 combined AVR were included; 776 patients were younger than 65 years whereas 1372 were 65 years or older. The 30-day Valve-Academic-Research-Consortium mortality was 2% (<65 years) and 6% (≥ 65 years) (P < 0.001), whereas it was 3% for isolated AVR and 7% for combined AVR (P < 0.001). The 12-year survival was 81% for those younger than 65 years vs 45% for those equal to or older than 65 years (P < 0.001), whereas they were 61% vs 49% for isolated and combined AVR (P = 0.10). The 12-year freedom from combined events, excluding death, was 79% for those younger than 65 years vs 87% for those equal to or older than (P = 0.51), whereas they were 83% for isolated and 86% for combined AVR (P = 0.10). The 12-year freedom from SVD was 93% and 93% in patients younger than 65 and those equal to or older than 65 years (P = 0.63), and the results were comparable even in cases with isolated and combined AVR (92% vs 94%, P = 0.21). A multivariable Cox analysis including gender, presence of patient-prosthesis mismatch, isolated AVR and age showed that only the age was an independent risk factor for the incidence of SVD (P = 0.029).

CONCLUSIONS

Outcomes from this large multicentre analysis demonstrated that a CEME bioprosthesis provides good clinical results and long-term durability even in patients younger than 65 years. Furthermore, the hazard for SVD has been shown to be lower for older age.

CLINICAL TRIAL REGISTRATION NUMBER

105n/AO/21.

Early Leaflet Thickening, Durability and Bioprosthetic Valve Failure in TAVR

All bioprosthetic valves, both surgical and transcatheter, have a finite lifespan before their leaflets inevitably degenerate, leading to stenosis or regurgitation. As younger, low-risk patients receive a transcatheter aortic valve, it is expected that they will most likely outlive their bioprosthetic valve. The heterogeneity of studies regarding surgical valve durability makes the interpretation of the data challenging. Leaflet thickening is seen in transcatheter heart valves but currently there is no evidence that it leads to premature valve deterioration or clinical events. Standardized definitions of structural valve deterioration should allow for comparisons between future clinical trials to assess the durability of different transcatheter heart valves.

Reintervention rates following bioprosthetic surgical aortic valve replacement-a Danish Nationwide Cohort Study

OBJECTIVES

Updated European guidelines recommend annual echocardiographic evaluation after bioprosthetic surgical aortic valve replacement (bio-SAVR). Given the increased demand on health care resources, only clinically relevant controls can be prioritized. We therefore aimed to explore reintervention rates following bio-SAVR.

METHODS

From the nationwide Danish Register of Surgical Procedures, we identified all patients ≥40 years with isolated bio-SAVR ± concomitant coronary artery bypass graft surgery (CABG) during 2000-2016. In 90-day reintervention-free survivors, we assessed aortic valve reintervention rates (primary outcome) and all-cause mortality rates (secondary outcome) at 1, 3 and 5 years with total follow-up until 31 December 2017 and further estimated annual theoretical echocardiographic control visits.

RESULTS

In 10 518 patients with bio-SAVR (+CABG 39.7%), we observed low reintervention rates at 1, 3 and 5 years, but with high rates of all-cause mortality; i.e. 5-year reintervention rate of 3.7/1000 person-years (≤1.5%) and 5-year mortality rate of 21.7/1000 person-years. Accounting for the competing risk of death, 5-year rates were inversely related to age group and remained relatively low across all age categories but increased gradually in the long term. A significant proportion of reinterventions were presumed due to infectious endocarditis (48% at 3 years, 37% at 5 years). With annual transthoracic echocardiography, the theoretical ratio of echocardiographies per reintervention in the first 5 years was 248, and 425 when endocarditis events were excluded.

CONCLUSION

Reintervention rates within the first 5 years following bio-SAVR were relatively rare, and with a substantial number due to endocarditis.

Elimination of macrophages reduces glutaraldehyde-fixed porcine heart valve degeneration in mice subdermal model

Glutaraldehyde-fixed porcine heart valve (GPHV) calcify and deteriorate over time. The aim of this study was to explore the roles macrophages play in mediating calcification and degeneration of the valve's connective tissue matrix. GPHV were implanted subcutaneously in the abdomens of C57BL/6 mice. The mice were equally divided into two study groups: (a) GPHV +phosphate buffered saline (PBS) liposomes, and (b) GPHV +clodronate liposomes. GPHV were collected for further analyses at 4 weeks post implant. Macrophages were almost depleted from the spleens of mice injected with clodronate liposomes as indicated by immunohistochemical staining. Furthermore, the expression of matrix metalloproteinase-2 (MMP-2), MMP-9, and proinflammatory cytokines like IL-1β, IL-6, MCP-1, MIP-1a, MIP-1b, were downregulated in the GPHV +Clodronate liposomal group compared with the GPHV+PBS liposomal group. Clodronate liposomal treatment led to significant decreases in the expression of RUNX2, ALP and OPN as well as less calcium deposits in GPHVs compared with PBS liposomal treatment. This finding indicated that infiltrating macrophages are critically involved in the development of calcification and deterioration in GPHVs. Macrophage depletion by clodronate liposomes decreased the extent of GPHV's calcification and deterioration.

Comparison of outcomes following isolated repair of tricuspid versus bicuspid aortic valves

Background

Aortic valve repair (AV-repair) is an alternative treatment option for patients with aortic regurgitation (AR), but durability is still reason for concern, especially for bicuspid aortic valves (BAV). We retrospectively evaluated mid-term results after AV-repair in patients with BAV or tricuspid aortic valves (TAV), including reoperation rates, recurrence of regurgitation, and survival.

Methods

Patients undergoing AV-repair between November 2004 and March 2016 without procedures involving the aortic root were included. Echocardiographic examinations were performed before and after the operation and at follow-up. Repair techniques were recorded and evaluated.

Results

Of 150 patients, 89 (59.3%) had TAV and 61 (40.7%) BAV. AR ≥ moderate was found in 66 patients with TAV (74.2%) and 49 with BAV (80.3%). At discharge, 74 TAV-patients had ≤ mild AR (84.4%), 11 (12.4%) moderate. 57 patients (93.4%) with BAV had ≤ mild AR, 1 (1.6%) moderate and 2 (3.3%) severe. Mean follow-up was 4.4±2.7 years with ≤ mild AR in 56 TAV patients (73.7%) and moderate in 18 (20.2%). In patients with BAV, 43 (76.8%) had ≤ mild AR and 4 (6.6%) moderate. Survival in patients with TAV was significantly decreased compared to BAV (P=0.033), but reoperation-rates did not differ significantly (P=0.651).

Conclusions

AV-repair is a safe and feasible option in patients with AR and can achieve similar results in patients with TAV and BAV. The complexity of the repair technique predicts repair failure.

Impact of Transcatheter Aortic Valve Durability on Life Expectancy in Low-Risk Patients With Severe Aortic Stenosis

Background:

Recent clinical trial results showed that transcatheter aortic valve replacement (TAVR) is noninferior and may be superior to surgical aortic valve replacement (SAVR) for mortality, stroke, and rehospitalization. However, the impact of transcatheter valve durability remains uncertain.

Methods:

Discrete event simulation was used to model hypothetical scenarios of TAVR versus SAVR durability in which TAVR failure times were varied to determine the impact of TAVR valve durability on life expectancy in a cohort of low-risk patients similar to those in recent trials. Discrete event simulation modeling was used to estimate the tradeoff between a less invasive procedure with unknown valve durability (TAVR) and that of a more invasive procedure with known durability (SAVR). Standardized differences were calculated, and a difference >0.10 was considered clinically significant. In the base-case analysis, patients with structural valve deterioration requiring reoperation were assumed to undergo a valve-in-valve TAVR procedure. A sensitivity analysis was conducted to determine the impact of TAVR valve durability on life expectancy in younger age groups (40, 50, and 60 years).

Results:

Our cohort consisted of patients with aortic stenosis at low surgical risk with a mean age of 73.4±5.9 years. In the base-case scenario, the standardized difference in life expectancy was <0.10 between TAVR and SAVR until transcatheter valve prosthesis failure time was 70% shorter than that of surgical prostheses. At a transcatheter valve failure time <30% compared with surgical valves, SAVR was the preferred option. In younger patients, life expectancy was reduced when TAVR durability was 30%, 40%, and 50% shorter than that of surgical valves in 40-, 50-, and 60-year-old patients, respectively.

Conclusions:

According to our simulation models, the durability of TAVR valves must be 70% shorter than that of surgical valves to result in reduced life expectancy in patients with demographics similar to those of recent trials. However, in younger patients, this threshold for TAVR valve durability was substantially higher. These findings suggest that durability concerns should not influence the initial treatment decision concerning TAVR versus SAVR in older low-risk patients on the basis of current evidence supporting TAVR valve durability. However, in younger low-risk patients, valve durability must be weighed against other patient factors such as life expectancy.