Standardized Definition of Structural Valve Degeneration for Surgical and Transcatheter Bioprosthetic Aortic Valves

Effects of leaflet curvature and thickness on the crimping stresses in transcatheter heart valve

With the current advances and expertise in biomedical device technologies, transcatheter heart valves (THVs) have been drawing significant attention. Various studies have been carried out on their durability and damage by dynamic loading in operational conditions. However, very few numerical investigations have been conducted to understand the effects of leaflet curvature and thickness on the crimping stresses which arise during the surgical preparation processes. In order to contribute to the current state of the art, a full heart valve model was presented, the leaflet curvature and thickness of which were then parameterized so as to understand the stress generation as a result of the crimping procedure during the surgical preparations. The results show that the existence of stresses is inevitable during the crimping procedure, which is a reduction factor for valve durability. Especially, stresses on the leaflets at the suture sites connected with the skirt were deduced to be critical and may result in leaflet ruptures after THV implantation.

In Vitro Proof of Concept of a First-Generation Growth-Accommodating Heart Valved Conduit for Pediatric Use

Currently available heart valve prostheses have no growth potential, requiring children with heart valve diseases to endure multiple valve replacement surgeries with compounding risks. This study demonstrates the in vitro proof of concept of a biostable polymeric trileaflet valved conduit designed for surgical implantation and subsequent expansion via transcatheter balloon dilation to accommodate the growth of pediatric patients and delay or avoid repeated open-heart surgeries. The valved conduit is formed via dip molding using a polydimethylsiloxane-based polyurethane, a biocompatible material shown here to be capable of permanent stretching under mechanical loading. The valve leaflets are designed with an increased coaptation area to preserve valve competence at expanded diameters. Four 22 mm diameter valved conduits are tested in vitro for hydrodynamics, balloon dilated to new permanent diameters of 23.26 ± 0.38 mm, and then tested again. Upon further dilation, two valved conduits sustain leaflet tears, while the two surviving devices reach final diameters of 24.38 ± 0.19 mm. After each successful dilation, the valved conduits show increased effective orifice areas and decreased transvalvular pressure differentials while maintaining low regurgitation. These results demonstrate concept feasibility and motivate further development of a polymeric balloon-expandable device to replace valves in children and avoid reoperations.

Valve-in-valve transcatheter mitral valve replacement procedure in prosthetic valve stenosis

A patient presented with acute respiratory failure and shock due to severe prosthetic mitral valve stenosis. A valve-in-valve transcatheter mitral valve replacement procedure was performed via the transeptal approach due to his high-risk presentation with good results.

Long-Term Outcomes of Bovine versus Porcine Mitral Valve Replacement: A Multicenter Analysis

Introduction

Recent national guidelines recommending mitral valve replacement (MVR) for severe secondary mitral regurgitation have resulted in an increased utilization of mitral bioprosthesis. There is a paucity of data on how longitudinal clinical outcomes vary by prosthesis type. We examined long-term survival and risk of reoperation between patients having bovine vs. porcine MVR. Study Design. A retrospective analysis of MVR or MVR + coronary artery bypass graft (CABG) from 2001 to 2017 among seven hospitals reporting to a prospectively maintained clinical registry was conducted. The analytic cohort included 1,284 patients undergoing MVR (801 bovine and 483 porcine). Baseline comorbidities were balanced using 1 : 1 propensity score matching with 432 patients in each group. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation.

Results

In the overall cohort, patients receiving porcine valves were more likely to have diabetes (19% bovine vs. 29% porcine; p < 0.001), COPD (20% bovine vs. 27% porcine; p=0.008), dialysis or creatinine >2 mg/dL (4% bovine vs. 7% porcine; p=0.03), and coronary artery disease (65% bovine vs. 77% porcine; p < 0.001). There was no difference in stroke, acute kidney injury, mediastinitis, pneumonia, length of stay, in-hospital morbidity, or 30-day mortality. In the overall cohort, there was a difference in long-term survival (porcine HR 1.17 (95% CI: 1.00-1.37; p=050)). However, there was no difference in reoperation (porcine HR 0.56 (95% CI: 0.23-1.32; p=0.185)). In the propensity-matched cohort, patients were matched on all baseline characteristics. There was no difference in postoperative complications or in-hospital morbidity and 30-day mortality. After 1 : 1 propensity score matching, there was no difference in long-term survival (porcine HR 0.97 (95% CI: 0.81-1.17; p=0.756)) or risk of reoperation (porcine HR 0.54 (95% CI: 0.20-1.47; p=0.225)).

Conclusions

In this multicenter analysis of patients undergoing bioprosthetic MVR, there was no difference in perioperative complications and risk of reoperation of long-term survival after matching.

Analysis of the Effect of Thickness on the Performance of Polymeric Heart Valves

Polymeric heart valves (PHVs) are a promising and more affordable alternative to mechanical heart valves (MHVs) and bioprosthetic heart valves (BHVs). Materials with good durability and biocompatibility used for PHVs have always been the research focus in the field of prosthetic heart valves for many years, and leaflet thickness is a major design parameter for PHVs. The study aims to discuss the relationship between material properties and valve thickness, provided that the basic functions of PHVs are qualified. The fluid-structure interaction (FSI) approach was employed to obtain a more reliable solution of the effective orifice area (EOA), regurgitant fraction (RF), and stress and strain distribution of the valves with different thicknesses under three materials: Carbothane PC-3585A, xSIBS and SIBS-CNTs. This study demonstrates that the smaller elastic modulus of Carbothane PC-3585A allowed for a thicker valve (>0.3 mm) to be produced, while for materials with an elastic modulus higher than that of xSIBS (2.8 MPa), a thickness less than 0.2 mm would be a good attempt to meet the RF standard. What is more, when the elastic modulus is higher than 23.9 MPa, the thickness of the PHV is recommended to be 0.l-0.15 mm. Reducing the RF is one of the directions of PHV optimization in the future. Reducing the thickness and improving other design parameters are reliable means to reduce the RF for materials with high and low elastic modulus, respectively.

Aortic Valve Replacement With Mechanical Valves vs Perimount Bioprostheses in 50- to 69-Year-Old Patients

Background

Evidence is mixed regarding the most appropriate type of valve prosthesis for surgical aortic valve replacement (AVR) in patients 50 to 69 years. American and European guidelines differ.

Objectives

The purpose of this study was to determine the long-term all-cause mortality and complication rates after AVR in patients aged 50 to 69 years according to implantation of a Perimount bioprosthetic valve or a mechanical valve.

Methods

In this nationwide observational cohort study, all patients aged 50 to 69 years who underwent primary surgical AVR in Sweden 2003 to 2018 using a Perimount bioprosthesis or mechanical valve were identified from the SWEDEHEART register. Primary outcome; all-cause mortality, secondary outcomes; major bleeding, aortic valve reintervention, heart failure hospitalization, and stroke. National health-data registers were used to ascertain outcomes. Regression standardization addressed confounding.

Results

A total of 6,907 patients aged 50 to 69 years were included (Perimount group, n = 3,831 and mechanical valve group, n = 3,076) and 74% were men. The use of bioprostheses increased during the study period. At 15 years of follow-up, the estimated cumulative incidence of all-cause mortality was 37% (95% CI: 35%-40%) vs 45% (95% CI: 42%-48%) in the mechanical and Perimount groups, respectively (survival difference -7.9% [95% CI: -11% to -4.6%]). Patients with mechanical valves had a lower risk of aortic valve reintervention but a higher risk for bleeding. Survival difference at 15 years in ages 50 to 59 years was -15% (95% CI: -8.4% to -21%).

Conclusions

In patients aged 50 to 69 years who underwent surgical AVR, survival was better in those who received mechanical compared to Perimount bioprosthetic valves. While valve choice should be guided by individual patient factors and patient preference rather than by chronological age, the substantial survival advantage observed in patients with mechanical valves in ages 50 to 59 years must be recognized.

Serum lipoprotein(a) and bioprosthetic aortic valve degeneration

AIMS

Bioprosthetic aortic valve degeneration demonstrates pathological similarities to aortic stenosis. Lipoprotein(a) [Lp(a)] is a well-recognized risk factor for incident aortic stenosis and disease progression. The aim of this study is to investigate whether serum Lp(a) concentrations are associated with bioprosthetic aortic valve degeneration.

METHODS AND RESULTS

In a post hoc analysis of a prospective multimodality imaging study (NCT02304276), serum Lp(a) concentrations, echocardiography, contrast-enhanced computed tomography (CT) angiography, and 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) were assessed in patients with bioprosthetic aortic valves. Patients were also followed up for 2 years with serial echocardiography. Serum Lp(a) concentrations [median 19.9 (8.4-76.4) mg/dL] were available in 97 participants (mean age 75 ± 7 years, 54% men). There were no baseline differences across the tertiles of serum Lp(a) concentrations for disease severity assessed by echocardiography [median peak aortic valve velocity: highest tertile 2.5 (2.3-2.9) m/s vs. lower tertiles 2.7 (2.4-3.0) m/s, P = 0.204], or valve degeneration on CT angiography (highest tertile n = 8 vs. lower tertiles n = 12, P = 0.552) and 18F-NaF PET (median tissue-to-background ratio: highest tertile 1.13 (1.05-1.41) vs. lower tertiles 1.17 (1.06-1.53), P = 0.889]. After 2 years of follow-up, there were no differences in annualized change in bioprosthetic hemodynamic progression [change in peak aortic valve velocity: highest tertile [0.0 (-0.1-0.2) m/s/year vs. lower tertiles 0.1 (0.0-0.2) m/s/year, P = 0.528] or the development of structural valve degeneration.

CONCLUSION

Serum lipoprotein(a) concentrations do not appear to be a major determinant or mediator of bioprosthetic aortic valve degeneration.

Imaging of Bioprosthetic Valve Dysfunction after Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has become the standard of care in elderly high-risk patients with symptomatic severe aortic stenosis. Recently, TAVI has been increasingly performed in younger-, intermediate- and lower-risk populations, which underlines the need to investigate the long-term durability of bioprosthetic aortic valves. However, diagnosing bioprosthetic valve dysfunction after TAVI is challenging and only limited evidence-based criteria exist to guide therapy. Bioprosthetic valve dysfunction encompasses structural valve deterioration (SVD) resulting from degenerative changes in the valve structure and function, non-SVD resulting from intrinsic paravalvular regurgitation or patient-prosthesis mismatch, valve thrombosis, and infective endocarditis. Overlapping phenotypes, confluent pathologies, and their shared end-stage bioprosthetic valve failure complicate the differentiation of these entities. In this review, we focus on the contemporary and future roles, advantages, and limitations of imaging modalities such as echocardiography, cardiac computed tomography angiography, cardiac magnetic resonance imaging, and positron emission tomography to monitor the integrity of transcatheter heart valves.

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.

Hemocompatibility tuning of an innovative glutaraldehyde-free preparation strategy using riboflavin/UV crosslinking and electron irradiation of bovine pericardium for cardiac substitutes

Hemocompatibility tuning was adopted to explore and refine an innovative, GA-free preparation strategy combining decellularization, riboflavin/UV crosslinking, and low-energy electron irradiation (SULEEI) procedure. A SULEEI-protocol was established to avoid GA-dependent deterioration that results in insufficient long-term aortic valve bioprosthesis durability. Final SULEEI-pericardium, intermediate steps and GA-fixed reference pericardium were exposed in vitro to fresh human whole blood to elucidate effects of preparation parameters on coagulation and inflammation activation and tissue histology. The riboflavin/UV crosslinking step showed to be less efficient in inactivating extracellular matrix (ECM) protein activity than the GA fixation, leading to tissue-factor mediated blood clotting. Intensifying the riboflavin/UV crosslinking with elevated riboflavin concentration and dextran caused an enhanced activation of the complement system. Yet activation processes induced by the previous protocol steps were quenched with the final electron beam treatment step. An optimized SULEEI protocol was developed using an intense and extended, trypsin-containing decellularization step to inactivate tissue factor and a dextran-free, low riboflavin, high UV crosslinking step. The innovative and improved GA-free SULEEI-preparation protocol results in low coagulant and low inflammatory bovine pericardium for surgical application.

Mid-Term Clinical Outcomes and Hemodynamic Performances of Trifecta and Perimount Bioprostheses following Aortic Valve Replacement

Aims of the Study: We evaluated the clinical outcome and the hemodynamic and freedom from structural valve degeneration of two standard aortic bioprostheses. Methods: Clinical results, echocardiographic findings and follow-up data of patients operated for isolated or combined aortic valve replacement with the Perimount or the Trifecta bioprosthesis were prospectively collected, retrospectively analysed and compared. We weighted all the analyses by the inverse of the propensity of choosing either valves. Results: Between April 2015 and December 2019, 168 consecutive patients (all comers) underwent aortic valve replacement with Trifecta (n = 86) or Perimount (n = 82) bioprostheses. Mean age was 70.8 ± 8.6 and 68.8 ± 8.6 years for the Trifecta and Perimount groups, respectively (p = 0.120). Perimount patients presented a greater body mass index (27.6 ± 4.5 vs. 26.0 ± 4.2; p = 0.022), and 23% of them suffered from angina functional class 2–3 (23.2% vs. 5.8%; p = 0.002). Mean ejection fraction was 53.7 ± 11.9% (Trifecta) and 54.5 ± 10.4% (Perimount) (p = 0.994), with mean gradients of 40.4 ± 15.9 mmHg (Trifecta) and 42.3 ± 20.6 mmHg (Perimount) (p = 0.710). Mean EuroSCORE-II was 7 ± 11% and 6 ± 9% for the Trifecta and Perimount group, respectively (p = 0.553). Trifecta patients more often underwent isolated aortic valve replacement (45.3% vs. 26.8%; p = 0.016) and annulus enlargement (10.5% vs. 2.4%; p = 0.058). All-cause mortality at 30 days was 3.5% (Trifecta) and 8.5% (Perimount), (p = 0.203) while new pacemaker implantation (1.2% vs. 2.5%; p = 0.609) and stroke rate (1.2% vs. 2.5%; p = 0.609) were similar. Acute MACCE were observed in 5% (Trifecta) and 9% (Perimount) of patients with an unweighted OR of 2.22 (95%CI 0.64–7.66; p = 0.196) and a weighted OR of 1.10 (95%CI: 0.44–2.76, p = 0.836). Cumulative survival at 24 months was 98% (95%CI: 0.91–0.99) and 96% (95%CI: 0.85–0.99) for Trifecta and Perimount groups, respectively (log-rank test; p = 0.555). The 2-year freedom from MACCE was 94% (95%CI: 0.65–0.99) for Trifecta and 96% (95%CI: 0.86–0.99) for Perimount (log-rank test; p = 0.759, HR 1.46 (95%CI: 0.13–16.48)) in the unweighted analysis (not estimable in the weighted analysis). During the follow-up (median time: 384 vs. 593 days; p = 0.0001) there were no re-operations for structural valve degeneration. Mean valve gradient at discharge was lower for Trifecta across all valve sizes (7.9 ± 3.2 vs. 12.1 ± 4.7 mmHg; p < 0.001), but the difference did not persist during follow-up (8.2 ± 3.7 mmHg for Trifecta, 8.9 ± 3.6 mmHg for Perimount; p = 0.224); Conclusions: Postoperative outcome and mid-term follow-up were similar. An early better hemodynamic performance was detected for the Trifecta valve but did not persist over time. No difference in the reoperation rate for structural valve degeneration was found.

Three-Year Outcomes of Balloon-Expandable Transcatheter Aortic Valve Implantation According to Annular Size

Data on the association between annular size and transcatheter aortic valve implantation (TAVI) outcomes beyond 1 year are limited. The present study assessed the association between the aortic annulus size and TAVI clinical and hemodynamic outcomes at 3 years of follow-up. Patients were classified according to the aortic annulus size as having small, intermediate, and large annuli (size <400, 400 to 574, and ≥575 mm², respectively). The co-primary endpoints were all-cause mortality and heart failure hospitalization. Further, the changes in hemodynamic outcomes over the follow-up period (median 37, interquartile range: 26 to 45 months) were assessed. The present analysis included 850 patients, with 182 patients (21.4%), 538 patients (63.3%), and 130 patients (15.3%) in the small, intermediate, and large-sized aortic annulus groups, respectively. The groups had comparable age and pre-TAVI pressure gradients; however, patients with small annuli had higher Society of Thoracic Surgeons risk scores. Adjusted Cox regression analysis showed that compared to patients with intermediate-sized annuli, patients with small and large annuli had similar all-cause mortality (hazard ratio [HR] = 1.11, 95% confidence interval [CI] 0.72 to 1.69 and HR = 0.74, 95% CI 0.48 to 1.16, respectively) and heart failure hospitalization rates (HR = 0.96, 95% CI 0.55 to 1.69 and HR = 1.26, 95% CI 0.73 to 2.17, respectively). However, patients with small annuli had consistently higher mean and peak pressure gradients and a higher risk of patient-prosthesis mismatch. The risks of moderate-to-severe regurgitation and structural valve deterioration were similar between the three groups. In conclusion, although patients with small annuli had higher transvalvular gradients, there was no significant association between the aortic annulus size and TAVI clinical outcomes at 3 years of follow-up. Future studies should compare the performance of transcatheter valve types in patients with different aortic annulus sizes.

Examination of Non-Infected Operatively-Excised Bioprostheses in the Aortic Valve Position to Determine the Reason for their Dysfunction

Described herein are findings in 55 non-infected bioprostheses that had been in the aortic valve position from 2 to 276 months (mean 107). The major purpose of this study was to illustrate the variable causes prompting excision of the bioprostheses. Fifty-three (96%) patients survived ≥ 30 days following the bioprosthetic excision and 50 (91%) patients lived ≥1 year postoperatively. The techniques used to explant the bioprostheses appear to vary considerably among the operating surgeons.

Long-Term Valve Durability in Patients Undergoing Transcatheter Aortic Valve Implantation

AIMS

To evaluate the long-term incidence of structural valve deterioration (SVD) in patients who underwent transcatheter aortic valve implantation (TAVI).

METHOD AND RESULTS

Between 2008 and 2018, 693 underwent TAVI at two centres. Four hundred and twenty-one (421) patients (mean age 83.6±6.0 yrs) survived for ≥2 years post TAVI and had at least two consecutive transthoracic echocardiographies (TTEs) with the latest TTE no less than 2 years after TAVI, and were therefore included in the analysis for SVD. Median follow-up was 4.7 (3.6-6.0) years and median echocardiography follow-up 3 (3.0-4.0) years. All-cause mortality was 30.9% (130) with a median time to death of 4.1 (3.0-5.6) years. The cumulative incidence of SVD increased from 1.7% (95% CI, 0.4-2.9) at 3 years to 3.5% (95% CI, 1.5-5.8) at 5 years and 4.7% (95% CI, 1.6-7.9) at 10 years. The overall median time to SVD was 3 (2-4) years. Twelve (12) patients demonstrated SVD stage 2, and 1 patient stage 3. No SVD required re-intervention. All other patients showed no significant changes in valve parameters over time.

CONCLUSIONS

Structural valve deterioration is an uncommon event, occurring in 5% over a total follow-up of 10 years. Most patients show stable valve parameters. However, the analysis is limited by the loss of follow-up (owing to patient mortality), which renders extrapolation of the data to a younger patient population difficult.

BAlloon expandable vs. SElf expanding transcatheter vaLve for degenerated bioprosthesIs: design and rationale of the BASELINE trial

BACKGROUND

Surgical aortic valve bioprostheses may degenerate over time and require redo intervention. Transcatheter aortic valve replacement (TAVR) is a less invasive alternative to redo surgery. The BAlloon Expandable vs. SElf Expanding Transcatheter VaLve for Degenerated BioprosthesIs (BASELINE) trial was designed to compare the performance of the balloon-expandable SAPIEN-3 Ultra and the self-expanding EVOLUT PRO+ valve systems in symptomatic patients with a failing surgical bioprosthesis.

METHODS

The BASELINE trial is an investigator-initiated, non-funded, prospective, randomized, open-label, superiority trial enrolling a total of 440 patients in up to 50 sites in 12 countries in Europe and North-America. The primary endpoint is device success at 30-days defined by the Valve Academic Research Consortium-3 Criteria as the composite of technical success, freedom from mortality, freedom for surgery or intervention related to the device or to a major vascular or access-related or cardiac structural complication with an intended performance of the valve (mean gradient <20 mmHg and less than moderate aortic regurgitation). The co-primary endpoint at 1 year is defined as the composite of all-cause death, disabling stroke, rehospitalization for heart failure or valve related problems. Independent Core Laboratories will conduct uniform analyses of echocardiography (pre-, post-, 1-year post-procedure), multi-sliced computed tomography (pre-, and if available post-procedure) and cine-fluoroscopy studies.

CONCLUSIONS

The BASELINE trial is a head-to-head comparative trial investigating the 2 most used contemporary transcatheter heart valves for the treatment of a failing surgical aortic bioprosthesis. (ClinicalTrials.gov number NCT04843072).

Structural Valve Deterioration After Self-Expanding Transcatheter or Surgical Aortic Valve Implantation in Patients at Intermediate or High Risk

Importance

The frequency and clinical importance of structural valve deterioration (SVD) in patients undergoing self-expanding transcatheter aortic valve implantation (TAVI) or surgery is poorly understood.

Objective

To evaluate the 5-year incidence, clinical outcomes, and predictors of hemodynamic SVD in patients undergoing self-expanding TAVI or surgery.

Design, Setting, and Participants

This post hoc analysis pooled data from the CoreValve US High Risk Pivotal (n = 615) and SURTAVI (n = 1484) randomized clinical trials (RCTs); it was supplemented by the CoreValve Extreme Risk Pivotal trial (n = 485) and CoreValve Continued Access Study (n = 2178). Patients with severe aortic valve stenosis deemed to be at intermediate or increased risk of 30-day surgical mortality were included. Data were collected from December 2010 to June 2016, and data were analyzed from December 2021 to October 2022.

Interventions

Patients were randomized to self-expanding TAVI or surgery in the RCTs or underwent self-expanding TAVI for clinical indications in the nonrandomized studies.

Main Outcomes and Measures

The primary end point was the incidence of SVD through 5 years (from the RCTs). Factors associated with SVD and its association with clinical outcomes were evaluated for the pooled RCT and non-RCT population. SVD was defined as (1) an increase in mean gradient of 10 mm Hg or greater from discharge or at 30 days to last echocardiography with a final mean gradient of 20 mm Hg or greater or (2) new-onset moderate or severe intraprosthetic aortic regurgitation or an increase of 1 grade or more.

Results

Of 4762 included patients, 2605 (54.7%) were male, and the mean (SD) age was 82.1 (7.4) years. A total of 2099 RCT patients, including 1128 who received TAVI and 971 who received surgery, and 2663 non-RCT patients who received TAVI were included. The cumulative incidence of SVD treating death as a competing risk was lower in patients undergoing TAVI than surgery (TAVI, 2.20%; surgery, 4.38%; hazard ratio [HR], 0.46; 95% CI, 0.27-0.78; P = .004). This lower risk was most pronounced in patients with smaller annuli (23 mm diameter or smaller; TAVI, 1.32%; surgery, 5.84%; HR, 0.21; 95% CI, 0.06-0.73; P = .02). SVD was associated with increased 5-year all-cause mortality (HR, 2.03; 95% CI, 1.46-2.82; P < .001), cardiovascular mortality (HR, 1.86; 95% CI, 1.20-2.90; P = .006), and valve disease or worsening heart failure hospitalizations (HR, 2.17; 95% CI, 1.23-3.84; P = .008). Predictors of SVD were developed from multivariate analysis.

Conclusions and Relevance

This study found a lower rate of SVD in patients undergoing self-expanding TAVI vs surgery at 5 years. Doppler echocardiography was a valuable tool to detect SVD, which was associated with worse clinical outcomes.

Trial Registration

ClinicalTrials.gov Identifiers: NCT01240902, NCT01586910, and NCT01531374.

Transcatheter Aortic Valve Implantation: Long-Term Outcomes and Durability

Transcatheter aortic valve implantation (TAVI) has become the standard of care in symptomatic older patients with severe aortic stenosis regardless of surgical risk. With the development of newer generation transcatheter bioprostheses, improved delivery systems, better preprocedure planning with imaging guidance, increased operator experience, shorter hospital length of stay, and low short- and mid-term complication rates, TAVI is gaining popularity among younger patients at low or intermediate surgical risk. Long-term outcomes and durability of transcatheter heart valves have become substantially important for this younger population due to their longer life expectancy. The lack of standardized definitions of bioprosthetic valve dysfunction and disagreement about how to account for the competing risks made comparison of transcatheter heart valves with surgical bioprostheses challenging until recently. In this review, the authors discuss the mid- to long-term (≥ 5 years) clinical outcomes observed in the landmark TAVI trials and analyze the available long-term durability data emphasizing the importance of using standardized definitions of bioprosthetic valve dysfunction.

Computed tomography imaging for subclinical leaflet thrombosis following surgical and transcatheter aortic valve replacement

Subclinical leaflet thrombosis (LT) may occur following surgical and transcatheter aortic valve replacement. Computed tomography (CT) has become an established imaging modality to diagnose subclinical LT following bioprosthetic aortic valve replacement. Even so, there is a limited (but growing) experience in utilizing CT imaging for this indication. This review emphasizes a systematic approach to acquiring and analysing CT imaging for subclinical LT, highlighting evidence surrounding clinical sequelae of subclinical LT and anti-thrombotic implications following diagnosis.

Patient-Specific Immersed Finite Element-Difference Model of Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) first received FDA approval for high-risk surgical patients in 2011 and has been approved for low-risk surgical patients since 2019. It is now the most common type of aortic valve replacement, and its use continues to accelerate. Computer modeling and simulation (CM&S) is a tool to aid in TAVR device design, regulatory approval, and indication in patient-specific care. This study introduces a computational fluid-structure interaction (FSI) model of TAVR with Medtronic's CoreValve Evolut R device using the immersed finite element-difference (IFED) method. We perform dynamic simulations of crimping and deployment of the Evolut R, as well as device behavior across the cardiac cycle in a patient-specific aortic root anatomy reconstructed from computed tomography (CT) image data. These IFED simulations, which incorporate biomechanics models fit to experimental tensile test data, automatically capture the contact within the device and between the self-expanding stent and native anatomy. Further, we apply realistic driving and loading conditions based on clinical measurements of human ventricular and aortic pressures and flow rates to demonstrate that our Evolut R model supports a physiological diastolic pressure load and provides informative clinical performance predictions.

Long-term survival after surgical or transcatheter aortic valve replacement for low or intermediate surgical risk aortic stenosis: Comparison with general population

BACKGROUND

Long-term survival after surgery for severe aortic stenosis (AS) provides important information regarding the choice between surgical (SAVR) and transcatheter (TAVR) aortic valve replacement. This study investigated the long-term survival of AS patients with low or intermediate surgical risk who underwent SAVR or TAVR in our institution versus that of the Japanese general population.

METHODS

From 2009 to 2019, 1276 consecutive patients underwent SAVR or TAVR for severe AS. Among them, we retrospectively investigated those with low (n = 383) or intermediate (n = 137) surgical risk treated with SAVR and those with low (n = 86) or intermediate (n = 333) surgical risk treated with TAVR. Their post-intervention survival was compared with that of an age- and gender-matched Japanese general population.

RESULTS

The overall 5-year survival rate of SAVR for patients with low surgical risk (mean age, 72 ± 9 years) was not significantly different from that of the general population (90 % vs. 89 %, respectively; p = 0.58), whereas that of patients with intermediate surgical risk (77 ± 6 years) was significantly lower than that of the general population (77 % vs. 84 %, respectively; p = 0.03). After TAVR, the 5-year survival of patients with low (78 ± 8 years) or intermediate (83 ± 5 years) surgical risk was significantly lower than that of the general population (low risk, 64 % vs. 81 %, p < 0.01; intermediate risk, 66 % vs. 71 %, respectively, p = 0.01).

CONCLUSIONS

Our study demonstrated that long-term survival after SAVR for AS patients with low surgical risk was as good as that of the age- and gender-matched general population, while the long-term survival after SAVR for intermediate-risk or TAVR for low- or intermediate-risk patients was lower than that of the general population. These findings suggest that SAVR is an appropriate option for AS patients with low surgical risk and good life expectancy, especially in Japan, where the life expectancy is the longest worldwide.

Proteolytic Degradation Is a Major Contributor to Bioprosthetic Heart Valve Failure

Background Whereas the risk factors for structural valve degeneration (SVD) of glutaraldehyde-treated bioprosthetic heart valves (BHVs) are well studied, those responsible for the failure of BHVs fixed with alternative next-generation chemicals remain largely unknown. This study aimed to investigate the reasons behind the development of SVD in ethylene glycol diglycidyl ether-treated BHVs. Methods and Results Ten ethylene glycol diglycidyl ether-treated BHVs excised because of SVD, and 5 calcified aortic valves (AVs) replaced with BHVs because of calcific AV disease were collected and their proteomic profile was deciphered. Then, BHVs and AVs were interrogated for immune cell infiltration, microbial contamination, distribution of matrix-degrading enzymes and their tissue inhibitors, lipid deposition, and calcification. In contrast with dysfunctional AVs, failing BHVs suffered from complement-driven neutrophil invasion, excessive proteolysis, unwanted coagulation, and lipid deposition. Neutrophil infiltration was triggered by an asymptomatic bacterial colonization of the prosthetic tissue. Neutrophil elastase, myeloblastin/proteinase 3, cathepsin G, and matrix metalloproteinases (MMPs; neutrophil-derived MMP-8 and plasma-derived MMP-9), were significantly overexpressed, while tissue inhibitors of metalloproteinases 1/2 were downregulated in the BHVs as compared with AVs, together indicative of unbalanced proteolysis in the failing BHVs. As opposed to other proteases, MMP-9 was mostly expressed in the disorganized prosthetic extracellular matrix, suggesting plasma-derived proteases as the primary culprit of SVD in ethylene glycol diglycidyl ether-treated BHVs. Hence, hemodynamic stress and progressive accumulation of proteases led to the extracellular matrix degeneration and dystrophic calcification, ultimately resulting in SVD. Conclusions Neutrophil- and plasma-derived proteases are responsible for the loss of BHV mechanical competence and need to be thwarted to prevent SVD.

Management Challenges in Patients Younger Than 65 Years With Severe Aortic Valve Disease

Importance

The management of aortic valve disease, including aortic stenosis and aortic regurgitation (AR), in younger adult patients (age &amp;lt;65 years) is complex, and the optimal strategy is often unclear, contingent on multiple anatomic and holistic factors.

Observations

Traditional surgical approaches carry significant considerations, including compulsory lifelong anticoagulation for patients who receive a mechanical aortic valve replacement (AVR) and the risk of structural valvular deterioration and need for subsequent valve intervention in those who receive a bioprosthetic AVR. These factors are magnified in young adults who are considering pregnancy, for whom issues of anticoagulation and valve longevity are heightened. The Ross procedure has emerged as a promising alternative; however, its adoption is limited to highly specialized centers. Valve repair is an option for selected patients with AR. These treatment options offer varying degrees of durability and are associated with different risks and complications, especially for younger adult patients. Patient-centered care from a multidisciplinary valve team allows for discussion of the optimal timing of intervention and the advantages and disadvantages of the various treatment options.

Conclusions and Relevance

The management of severe aortic valve disease in adults younger than 65 years is complex, and there are numerous considerations with each management decision. While mechanical AVR and bioprosthetic AVR have historically been the standards of care, other options are emerging for selected patients but are not yet generalizable beyond specialized surgical centers. A detailed discussion by members of the multidisciplinary heart team and the patient is an integral part of the shared decision-making process.

Infrared Spectroscopic Verification of a α-Helical Collagen Structure in Glutaraldehyde-Free Crosslinked Bovine Pericardium for Cardiac Implants

The degeneration of heart valve bioprostheses due to calcification processes is caused by the intercalation of calciumhydroxyapatite in pericardium collagen bundles. Variations of the protein secondary structure of biomaterials according to preparation are relevant for this mineralization process and thus the structural characterization of innovative bioprostheses materials is of great importance. The gold standard for prostheses preparation is glutaraldehyde (GA)-fixation of bovine pericardium that adversely promotes calcification. The novel GA-free SULEEI-treatment of bovine pericardium includes decellularization, UV-crosslinking, and electron beam sterilization. The aim of this study is the structural characterization of SULEEI-treated and GA-fixed bovine pericardium. IR spectroscopic imaging combined with multivariate data and curve fit analysis was applied to investigate the amide I and amide II regions of SULEEI-treated and GA-fixed samples. The spectroscopic images of GA-fixed pericardial tissue exhibited a generally high content of amine groups and side chains providing nucleation points for calcification processes. In contrast, in SULEEI-treated tissue, the typical α-helical structure was retained and was supposed to be less prone to deterioration.

Multicenter experience with valve-in-valve transcatheter aortic valve replacement compared with primary, native valve transcatheter aortic valve replacement

BACKGROUND

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) offers an alternative to reoperative surgical aortic valve replacement. The short- and intermediate-term outcomes after ViV TAVR in the real world are not entirely clear.

PATIENTS AND METHODS

A multicenter, retrospective analysis of a consecutive series of 121 ViV TAVR patients and 2200 patients undergoing primary native valve TAVR from 2012 to 2017 at six medical centers. The main outcome measures were in-hospital mortality, 30-day mortality, stroke, myocardial infarction, acute kidney injury, and pacemaker implantation.

RESULTS

ViV patients were more likely male, younger, prior coronary artery bypass graft, "hostile chest," and urgent. 30% of the patients had Society of Thoracic Surgeons risk score <4%, 36.3% were 4%-8% and 33.8% were >8%. In both groups many patients had concomitant coronary artery disease. Median time to prosthetic failure was 9.6 years (interquartile range: 5.5-13.5 years). 82% of failed surgical valves were size 21, 23, or 25 mm. Access was 91% femoral. After ViV, 87% had none or trivial aortic regurgitation. Mean gradients were <20 mmHg in 54.6%, 20-29 mmHg in 30.6%, 30-39 mmHg in 8.3% and ≥40 mmHg in 5.87%. Median length of stay was 4 days. In-hospital mortality was 0%. 30-day mortality was 0% in ViV and 3.7% in native TAVR. There was no difference in in-hospital mortality, postprocedure myocardial infarction, stroke, or acute kidney injury.

CONCLUSION

Compared to native TAVR, ViV TAVR has similar peri-procedural morbidity with relatively high postprocedure mean gradients. A multidisciplinary approach will help ensure patients receive the ideal therapy in the setting of structural bioprosthetic valve degeneration.

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.

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.

Understanding aortic valve repair through Ozaki procedure: A review of literature evidence

BACKGROUND

Aortic valve neocuspidization (AV Neo) using glutaraldehyde-treated autologous pericardium was first reported by Ozaki et al. in 2007. This technique has become an alternative to tissue and mechanical valve in selected patients as long-term anticoagulation is not required and shows promising midterm results and durability.

METHOD

A comprehensive search was performed on the major database using the search terms "Ozaki technique" AND "Aortic Valve Neocuspidization" AND "AV Neocuspidization" AND "Autologous pericardium" AND "glutaraldehyde-treated autologous pericardium." Articles up to August 1st, 2021 were included in this study.

RESULTS

A total of nine studies with a total of 1342 patients were included. The mean age was 67.36 and 54.23% were male. 66.32% and 23.92% of patients had aortic stenosis and aortic regurgitation, respectively. 66% of patients had a native tricuspid aortic valve (AV) and 31.37% of patients' native AV was bicuspid. Three studies reported their experience performing AV Neo via ministernotomy.

CONCLUSION

AV Neo can be a suitable alternative to surgical AV replacement in selected patients. The short- and midterm outcomes are comparable without the need for long-term oral anticoagulation. Long-term follow-up data are required for this novel approach to be widely adopted.

Structural valve deterioration of bioprosthesis in the aortic position: A single-center experience

BACKGROUND

Aortic valve replacement (AVR) is one of the most common open-heart surgical procedures. The durability of the tissue valve in the aortic position is crucial in AVR and transcatheter AVR. We reviewed structural valve deterioration using echocardiographic follow-up in three types of surgical aortic tissue valves.

METHODS

A retrospective analysis was conducted where hemodynamic deterioration was evaluated and compared using transthoracic echocardiography, including pressure gradients and effective orifice area. Kaplan-Meier analyses were used to summarize the time to failure.

RESULTS

The study included 133 Trifecta, 156 Epic, and 321 Magna Ease valves. Seventy-six percent (1941/2551) of patients had to be excluded due to insufficient echo data. Through univariate analysis, 34% (216/610) of valves met deterioration criteria after 24 months. Unadjusted survival curves showed a significant difference between valves (p ≤ .001), with a longer mean time to deterioration for the Magna Ease versus Trifecta and Epic of 68.9 versus 50.1 and 38.2 months, respectively. A Cox proportional hazard analysis found worse hazard ratios of 1.69 (p ≤ .04) and 2.4 (p ≤ .01) for Trifecta versus Magna and Epic versus Trifecta, respectively.

CONCLUSION

All three valve types demonstrated structural valve deterioration on echocardiographic follow-up with significant differences in rate. The Magna Ease appeared to have the highest durability, and the Epic the lowest. Further investigation is warranted to confirm the results in a larger multicenter study.

Looking Back to Look Forward: What to Expect in a Redo Surgery for a Bioprosthesis Replacement

Redo surgeries are becoming more common because of an increased rate of bioprosthesis implantation. We performed a retrospective study on patients who underwent redo replacement of an aortic and/or mitral bioprosthesis between 2005 and 2018 to evaluate intra-hospital mortality and morbidity. Univariate analysis was performed on the propensity score variables to determine predictors of mortality. A total of 180 patients were enrolled in the study: Group A (replacement of aortic bioprosthesis) with 136 patients (75.56%) and group B (replacement of mitral bioprosthesis ± aortic bioprosthesis) with 44 patients (24.44%). NYHA class ≥ 3 and female sex were significantly more common in group B. Cardiopulmonary-bypass time and aortic cross-clamping time in group A and group B were, respectively, 154.95 ± 74.35 and 190.25 ± 77.44 (p = 0.0005) and 115.99 ± 53.54 and 144.91 ± 52.53 (p = 0.0004). Overall mortality was 8.89%. After propensity score adjustment, Group B was confirmed to have an increased risk of death (OR 3.32 CI 95% 1.02−10.88 p < 0.0001), gastrointestinal complications (OR 7.784 CI 95% 1.005−60.282 p < 0.0002) and pulmonary complications (OR 2.381 CI 95% 1.038−5.46 p < 0.0001). At the univariate analysis, endocarditis, cardiopulmonary-bypass and aortic cross clamping time, NYHA class ≥ 3 and urgency setting were significantly associated to death. Intra-hospital outcomes were acceptable regarding mortality and complications. Patients who need redo surgery on mitral bioprosthesis have an increased risk of post-operative pulmonary and gastrointestinal complications and mortality. Therefore the choice of mitral bioprosthesis at time of first surgery should be carefully evaluated.

Utilization of Two- and Three-Dimensional Transesophageal Echocardiography in Successfully Guiding Transcatheter Mitral Valve in Bioprosthetic Mitral Valve/Mitral Ring Implantation without Complications in Patients with Thrombus in Left Atrium/Left Atrial Appendage

BACKGROUND

The aim of this study is to describe, for the first time to our knowledge, the utilization of both two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) in successfully performing transcatheter mitral valve (MV) in bioprosthetic MV/MV annulopasty ring implantation using the apical approach in 12 patients (pts) with co-existing left atrial appendage (LAA) and/or LA (left atrium) body thrombus, which is considered a contraindication for this procedure.

METHODS AND RESULTS

All pts were severely symptomatic with severe bioprosthetic MV stenosis/regurgitation except one with a previous MV annuloplasty ring and severe native MV stenosis. Thrombus in LAA and/or LA body was noted in all by 2D and 3DTEE. All were at high/prohibitive risk for redo operation and all refused surgery. Utilizing both 2D and 3DTEE, especially 3DTEE, guidewires and the prosthesis deployment system could be manipulated under direct vision into the LA avoiding any contact with the thrombus. The procedure was successful in all with amelioration of symptoms and no embolic or other complications over a mean follow-up of 21 months.

CONCLUSION

Our study demonstrates the feasibility of successfully performing this procedure in pts with thrombus in LAA and/or LA body without any complications.

Bioprosthetic Aortic Valve on the Move

• Acute bioprosthetic aortic valve regurgitation can present with cardiogenic shock. • Echocardiography is critical in the assessment of bioprosthetic aortic valve function. • In up to 6% of patients with infectious endocarditis, no microbiologic agent is identified. • Surgery is the mainstay of treatment for prosthetic acute aortic regurgitation.

Recellularized bovine pericardium with autologous mesenchymal stem cells reduces immune activation

INTRODUCTION

Current bioprosthetic heart valve replacement options are limited by structural valvular deterioration (SVD) due to an immune response to the xenogenic scaffold. Autologous mesenchymal stem cell (MSC) recellularization is a method of concealing xenogenic scaffolds, preventing recipient immune recognition of xenogenic tissue heart valves, and potentially leading to reduction in SVD incidence. The purpose of this study is to examine the effects of autologous MSC recellularized tissue on the immune response of human whole blood to bovine pericardium (BP). We hypothesized that autologous MSC recellularization of BP will result in reduced pro-inflammatory cytokine production equivalent to autologous human pericardium.

METHODS

Bone marrow, human pericardium, and whole blood were collected from adult patients undergoing elective cardiac surgery. Decellularized BP underwent recellularization with autologous MSCs, followed by co-incubation with autologous whole blood. Immunohistochemical, microscopic, and quantitative immune analysis approaches were used.

RESULTS

We demonstrated that native BP, exposed to human whole blood, results in significant TNF-α and IL1β production. When decellularized BP is recellularized with autologous MSCs and exposed to whole blood, there is a significant reduction in TNF-α and IL1β production. Importantly, recellularized BP exposed to whole blood had similar production of TNF-α and IL1β when compared to autologous human pericardium exposed to human whole blood.

CONCLUSION

Our results suggest that preventing initial immune activation with autologous MSC recellularization may be an effective approach to decrease the recipient immune response, preventing recipient immune recognition of xenogeneic tissue engineered heart valves, and potentially leading to reduction in SVD incidence.

Transcatheter Aortic Valve Implantation for Bioprosthetic Valve Failure: Placement of Aortic Transcatheter Valves 3 Aortic Valve-in-Valve Study

Background

Transcatheter aortic valve implantation is safe and effective for high-risk patients with bioprosthetic valve failure (BVF) but has not been studied in low- and intermediate-risk patients. One year outcomes of the PARTNER 3 Aortic Valve-in-valve (AViV) Study were evaluated.

Methods

This prospective, single-arm, multicenter study enrolled 100 patients from 29 sites with surgical BVF. The primary endpoint was a composite of all-cause mortality and stroke at 1 year. The key secondary outcomes included mean gradient, functional capacity, and rehospitalization (valve-related, procedure-related, or heart failure related).

Results

A total of 97 patients underwent AViV with a balloon-expandable valve from 2017 to 2019. Patients were 79.4% male with a mean age of 67.1 years and Society of Thoracic Surgeons score of 2.9%. The primary endpoint occurred in 2 patients (2.1%) who had strokes; there was no mortality at 1 year. Five patients (5.2%) had valve thrombosis events, and 9 patients (9.3%) had rehospitalizations, including 2 (2.1%) for strokes, 1 (1.0%) for heart failure, and 6 (6.2%) for aortic valve reinterventions (3 explants, 3 balloon dilations, and 1 percutaneous paravalvular regurgitation closure). From baseline to 1 year, New York Heart Association class III/IV decreased from 43.3% to 4.5%, mean gradient from 39.1 ± 18.2 mm Hg to 19.7 ± 7.6 mm Hg, and ≥moderate aortic regurgitation from 41.1% to 1.1%.

Conclusions

AViV with a balloon-expandable valve improved hemodynamic and functional status at 1 year and can provide an additional therapeutic option in selected low- or intermediate-risk patients with surgical BVF, although longer term follow-up is necessary.

Emergency Transcatheter Aortic Valve Implantation in a Surgical Aortic Bioprosthetic Valve for Acute Decompensated Heart Failure Caused by Sudden Progression of Structural Valve Deterioration

Bioprosthetic aortic valves have limited durability. We herein report sudden progression of structural valve deterioration (SVD) and a successful case of emergency transcatheter aortic valve (TAV) implantation for acute decompensated heart failure (ADHF) caused by SVD. A 79-year-old man who had undergone a Bentall operation 11 years prior was diagnosed with ADHF due to suddenly progressive SVD. Emergency TAV implantation in the surgical bioprosthetic valve was selected based on the surgical risk. Ours and previous case reports suggest that SVD can progress suddenly, even after months of stability, and that emergency TAV implantation is effective.

Two-year outcomes after transcatheter aortic valve-in-valve implantation in degenerated surgical valves

BACKGROUND

Transcatheter aortic valve-in-valve implantation (ViV-TAVI) has emerged in recent years as a safe alternative to redo surgery in high-risk patients. Although early results are encouraging, data beyond short-term outcomes are lacking. Herein, we aimed to assess the 2-year outcomes after ViV-TAVI.

METHODS

Patients undergoing ViV-TAVI for degenerated surgical valves between 2013 and 2019 at the Cleveland Clinic were reviewed. The coprimary endpoints were all-cause mortality and congestive heart failure (CHF) hospitalizations. We used time-to-event analyses to assess the primary outcomes. Further, we measured the changes in transvalvular gradients and the incidence of structural valve deterioration (SVD).

RESULTS

One hundred and eighty-eight patients were studied (mean age = 76 years; 65% males). At 2 years of follow-up, all-cause mortality and CHF hospitalizations occurred in 15 (8%) and 28 (14.9%) patients, respectively. On multivariable analysis, the postprocedural length of stay was a significant predictor for both all-cause mortality (hazard ratio [HR] = 1.1; 95% confidence interval [CI]: 1.01, 1.19) and CHF hospitalization (HR = 1.16; 95% CI: 1.07, 1.27). However, the internal diameter of the surgical valve was not associated with significant differences in both primary endpoints. For hemodynamic outcomes, nine patients (4.8%) developed SVD. The mean and peak transvalvular pressure gradients remained stable over the follow-up period.

CONCLUSION

ViV-TAVI for degenerated surgical valves was associated with favorable 2-year clinical and hemodynamic outcomes. Further studies are needed to better understand the role of ViV-TAVI as a treatment option in the life management of aortic valve disease.

Outcomes of Surgical Aortic Valve Replacement After Transcatheter Aortic Valve Implantation

Few studies have reported their experience in explantation of a transcatheter heart valve. We found 2,100 patients who underwent transcatheter aortic valve implantation (TAVI) from 2013 through 2021. Of 2,100, a total of 17 patients underwent surgical aortic valve replacement after TAVI, including surgical bailout. The mean age was 78.3 years. Co-morbidities were very frequent, including coronary artery disease (70.6%), atrial fibrillation (52.9%), cerebrovascular disease (47.1%), and pulmonary hypertension (41.2%). A history of cardiac surgery was observed in 6 patients (35.3%). The mean predicted risk of mortality at the time of TAVI was 7.7%. Surgical bailout was the most common indication of valve explantation (n = 8, 47.1%), followed by infective endocarditis (n = 4, 23.5%) and paravalvular leak (n = 2, 11.8%). The valve-in-valve TAVI was not feasible because of endocarditis, paravalvular leak, and history of valve-in-valve TAVI. Overall, 13 (76.5%) were performed urgently or emergently, and 10 (58.9%) required aortic root reconstruction. The mean cardiopulmonary bypass time was 158.5 minutes. In-hospital mortality was 41.2%. Transcatheter heart valve explantation continues to be rare; however, these data will continue to be informative as TAVI explantations will become more common with time.

Durability of a bovine pericardial aortic bioprosthesis based on Valve Academic Research Consortium-3 echocardiographic criteria

Objectives

The Carpentier-Edwards Perimount Magna Ease (Edwards Lifesciences) pericardial bioprosthesis has demonstrated satisfying hemodynamics at midterm follow-up, but its durability remains unclear. We report our 10-year experience with this third-generation valve implanted in the aortic position, with particular attention to structural valve deterioration.

Methods

From 2007 to 2016 at our center, 338 patients underwent aortic valve replacement using the Perimount Magna Ease pericardial bioprosthesis. Patients were prospectively followed (mean 6.6 ± 2.6 years) with clinical evaluation and yearly echocardiography. Follow-up was 98% complete (7 patients lost) for a total of 2238 valve-years. Bioprosthesis structural valve deterioration was determined by strict echocardiographic assessment based on the Valve Academic Research Consortium 3 criteria.

Results

Overall operative mortality was 1.2%. Actuarial survival including early deaths averaged 80.9% ± 2.2% and 66.7% ± 4.4% after 5 and 10 years of follow-up, respectively. Actuarial freedom from explantation due to structural valve deterioration at 5 and 10 years was 99.6% ± 0.4% and 88.8% ± 5.0%, respectively, and actuarial freedom of structural valve deterioration at 5 and 10 years was 98.5% ± 0.7% and 44.0% ± 6.4%, respectively. More precisely, actuarial freedom of structural valve deterioration stage 3 was 99.6% ± 0.4% at 5 years and 88.3% ± 5.0% at 10 years, whereas freedom of structural valve deterioration stage 2/3 was 98.5% ± 0.7% and 60.9% ± 7.0%, respectively.

Conclusions

With a low rate of explantation due to structural valve deterioration events at 10 years, and particularly a low rate of moderate or severe structural valve deterioration based on echocardiographic Valve Academic Research Consortium 3 criteria, the Carpentier-Edwards Perimount Magna Ease pericardial bioprosthesis remains a reliable choice for a tissue valve in the aortic position.

Video Abstract

Technical Aspects and Development of Transcatheter Aortic Valve Implantation

Aortic stenosis is the most common valve disease requiring surgery or percutaneous treatment. Since the first-in-man implantation in 2002 we have witnessed incredible progress in transcatheter aortic valve implantation (TAVI). In this article, we review the technical aspects of TAVI development with a look at the future. Durability, low thrombogenicity, good hydrodynamics, biocompatibility, low catheter profile, and deployment stability are the attributes of an ideal TAVI device. Two main design types exist-balloon-expandable and self-expanding prostheses. Balloon-expandable prostheses use a cobalt-chromium alloy frame providing high radial strength and radiopacity, while the self-expanding prostheses use a nickel-titanium (Nitinol) alloy frame, which expands to its original shape once unsheathed and heated to the body temperature. The valve is sewn onto the frame and consists of the porcine or bovine pericardium, which is specially treated to prevent calcinations and prolong durability. The lower part of the frame can be covered by polyethylene terephthalate fabric or a pericardial skirt, providing better sealing between the frame and aortic annulus. The main future challenges lie in achieving lower rates of paravalvular leaks and new pacemaker implantations following the procedure, lower delivery system profiles, more precise positioning, longer durability, and a good hemodynamic profile. Patient-specific design and the use of autologous tissue might solve these issues.

Standardized Definitions for Bioprosthetic Valve Dysfunction Following Aortic or Mitral Valve Replacement: JACC State-of-the-Art Review

Bioprosthetic valve dysfunction (BVD) and bioprosthetic valve failure (BVF) may be caused by structural or nonstructural valve dysfunction. Both surgical and transcatheter bioprosthetic valves have limited durability because of structural valve deterioration. The main objective of this summary of experts participating in a virtual workshop was to propose standardized definitions for nonstructural and structural BVD and BVF following aortic or mitral biological valve replacement with the goal of facilitating research reporting and implementation of these terms in clinical practice. Definitions of structural BVF, based on valve reintervention or death, underestimate the true incidence of BVF. However, definitions solely based on the presence of high transprosthetic gradient at a given echocardiogram during follow-up overestimate the incidence of structural BVD and BVF. Definitions of aortic or mitral structural BVD must therefore include the confirmation by imaging of permanent structural changes to the leaflets alongside evidence of deterioration in valve hemodynamic function at echocardiography follow-up.

Bioprosthetic Aortic Valve Hemodynamics: Definitions, Outcomes, and Evidence Gaps: JACC State-of-the-Art Review

A virtual workshop was organized by the Heart Valve Collaboratory to identify areas of expert consensus, areas of disagreement, and evidence gaps related to bioprosthetic aortic valve hemodynamics. Impaired functional performance of bioprosthetic aortic valve replacement is associated with adverse patient outcomes; however, this assessment is complicated by the lack of standardization for labelling, definitions, and measurement techniques, both after surgical and transcatheter valve replacement. Echocardiography remains the standard assessment methodology because of its ease of performance, widespread availability, ability to do serial measurements over time, and correlation with outcomes. Management of a high gradient after replacement requires integration of the patient's clinical status, physical examination, and multimodality imaging in addition to shared patient decisions regarding treatment options. Future priorities that are underway include efforts to standardize prosthesis sizing and labelling for both surgical and transcatheter valves as well as trials to characterize the consequences of adverse hemodynamics.

TAVR for All? The Surgical Perspective

In spite of the noninferiority of transcatheter aortic valve replacement (TAVR) in high- and intermediate-risk patients, there are still obstacles that need to be overcome before the procedure is further expanded and clinically integrated. The lack of evidence on the long-term durability of the bioprostheses used for TAVR remains of particular concern. In addition, surgery may be preferred over TAVR in patients with bicuspid aortic valve (BAV) or with concomitant pathologies such as other valve diseases (mitral regurgitation/tricuspid regurgitation), aortopathy, and coronary artery disease. In this review, we discuss and summarize relevant data from clinical trials, current trends, and remaining obstacles, and provide our perspective on the indications for the expansion of TAVR.

Bioprosthetic valve dysfunction and failure after TAVI in bicuspid aortic valve stenosis during one-year follow-up according to VARC-3

BACKGROUND

Transcatheter aortic valve implantation (TAVI) in bicuspid aortic valve (BAV) stenosis has become more frequent in the last years. This may pose challenges for long-time valve durability. Therefore, we aimed to evaluate the prevalence of bioprosthetic valve dysfunction (BVD) with the newest-generation devices in BAV stenosis up to one-year follow-up (FU).

METHODS

The primary endpoint was defined as the prevalence of BVD during the first procedural year according to Valve Academic Research Consortium (VARC)-3 criteria. Secondary endpoints were defined as failure in device success and clinical endpoints according to VARC-3.

RESULTS

A total of 107 patients were included. Of these, 34 subjects (31.8%) met the criteria for BVD during a mean FU of 263 ± 180 days, of which 20.2% were already documented after thirty days. Device success after one year was lower in the + BVD cohort (57.6% vs. 98.7%, p < 0.0001*). The rates of structural valve deterioration were 6.5%, non-structural valve deterioration (NSVD) 17.8%, subclinical leaflet thickening 10.3%, and endocarditis 0.9%. NSVD was foremost triggered by patient prosthesis mismatch in balloon-expandable valves. Hemodynamic valve deterioration stage 1 and 2 was confirmed in 16.8% of + BVD patients, while stage 1 and 3 bioprosthetic valve failure occurred in 1.9%. There was no impact of BVD on mortality.

CONCLUSION

There is critical evidence of early BVD after TAVI in BAV during one-year FU in one-third of patients, also lowering device success. The most frequently observed bioprosthetic valve dysfunction was NSVD due to patient prosthesis mismatch following TAVI with a balloon-expandable valve.

Subclinical Leaflet Thrombosis and Anticoagulation After Transcatheter Aortic Valve Replacement: A Review

Importance

Subclinical leaflet thrombosis affects approximately 15% of patients after transcatheter aortic valve replacement (TAVR). The pathophysiology and clinical significance of leaflet thrombosis remain incompletely understood. Defining the optimal management strategy in patients who are asymptomatic, including the role for oral anticoagulation (OAC), is a key challenge for the field.

Observations

Three recent randomized trials have evaluated the role of OAC in patients after TAVR. These studies have confirmed prior observational data suggesting that OAC is effective at prevention of subclinical leaflet thrombosis. Overall, however, OAC does not lead to a clinical benefit over the period studied, and in some patients may be harmful owing to bleeding risk.

Conclusions and Relevance

Strategies for identification of patients in whom the benefit of OAC outweighs the risks are required for optimization of long-term outcome after TAVR. This requires clearer insights into the mechanisms of asymptomatic leaflet thrombosis, its clinical significance, and patient-specific risks of bleeding and structural valve degeneration.

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.

Current surgical bioprostheses: Looking to the future

The utilization of bioprostheses for surgical heart valve replacement has been increasing across all age groups. For patients, the appeal of the bioprosthetic valve rests with the avoidance of anticoagulation, fewer thrombotic and hemorrhagic events, and the increasing availability of transcatheter valve-in-valve interventions -both in the aortic and mitral positions- allowing for lower morbidity reinterventions. While improvements in valve hemodynamics and long-term durability have made bioprostheses a reasonable choice for a growing number of patients, challenges do remain. With increasing usage of bioprostheses, especially in younger patients, there will be an increase in the projected number of failing bioprosthetic valves. This trend will bring even more emphasis to maximizing long-term durability, optimizing anticoagulation, and promoting patient-level decision making around prosthesis choice.

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.