Progressive calcification of bioprosthetic mitral valve observed during pregnancy resulting from in vitro fertilization: a case report.

BACKGROUND: Women with pre-existing cardiac conditions who undergo assisted reproductive technologies (ART) are believed to be at a heightened risk of cardiovascular events during both the treatment and pregnancy phases. An unresolved question within this context pertains to whether the ART procedure itself constitutes a risk factor for individuals with bioprosthetic heart valves (BHV). Additionally, there is ongoing controversy regarding whether pregnancies expedite the process of structural valve degeneration (SVD) in BHV. The purpose of this study is to present the developmental process of BHV calcification, which is considered the primary cause of SVD, during a pregnancy resulting from in vitro fertilization and embryo transfer (IVF-ET), an ART modality, and to elucidate the underlying mechanisms. CASE PRESENTATION: At 7 + 3 weeks of gestation in a twin pregnancy resulting from IVF-ET, a 27-year-old woman with a bioprosthetic mitral valve manifesting severe mitral stenosis and moderate pulmonary arterial hypertension, was suspected of SVD. Despite undergoing fetal reduction, she experienced progressive calcification of the bioprosthetic valve, increasing pulmonary arterial pressure and ultimately deteriorated into heart failure. An elective cesarean section and redo valve replacement was subsequently administered to improve her cardiovascular condition. As a result, a healthy young boy was delivered and the dysfunctional BHV was replaced with a mechanical valve. She did not report any discomfort during the 3-month follow-up. CONCLUSION: The progressive calcification of the BHV was observed during IVF pregnancy, indicating a potential connection between fertility therapy, pregnancy and calcification of BHV. Pregnant women with pre-implanted BHV should be treated with caution, as any medical interventions during ART and pregnancy can have a significant impact on both maternal and fetal outcomes. Thus, involving a multidisciplinary team in decision-making early on, starting from the treatment of the original heart disease, throughout the entire process of ART and pregnancy, is crucial.

Emergency and Prophylactic Extracorporeal Membrane Oxygenation for Patients Undergoing Valve-in-Valve Transcatheter Aortic Valve Implantation With Small Surgical Bioprosthesis: A Report of Four Cases.

Mechanical circulatory support (MCS) using veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is widely implemented as a rescue device in transcatheter aortic valve implantation (TAVI). Although prophylactic VA-ECMO (pECMO) in TAVI is preferable to emergency VA-ECMO (eECMO) in terms of overall survival, there is currently no consensus on the introduction criteria for pECMO. Here, we report four cases of eECMO and pECMO performed in valve-in-valve TAVI (ViV-TAVI) with a small surgical bioprosthesis to consider the validity of the current pECMO indications. In the two cases that were placed on eECMO, a 19 mm and 21 mm Carpentier-Edwards perimount bioprosthesis (CEP), a stented bioprosthetic valve, were sewn. After the transcatheter heart valve (THV) passed through the surgical aortic valve, acute aortic regurgitation developed, thus leading to hemodynamic instability requiring cardiopulmonary resuscitation, and therefore VA-ECMO was introduced. In the two cases using pECMO, 19 mm of CEP were sewn, and the THV was safely placed once MCS had been established. In all four cases, the patients were removed from VA-ECMO in the operating room following ViV-TAVI. The eECMO patients were discharged on postoperative days 12 and 20, while the pECMO patients were discharged on postoperative days 7 and 9, respectively. From our experience and based on the findings of some published reviews, ViV-TAVI with a small surgical bioprosthesis is considered to belong to a high-risk patient group demonstrating hemodynamic instability. The introduction of pECMO for such cases may therefore be an effective option for obtaining a better prognosis.

Rates and Predictors of Structural Valve Degeneration and Failure of Trifecta Bioprosthetic Valve Over a 5-year Follow-up Period: A Single-center Experience.

Introduction: The Trifecta bioprosthetic valve has been commonly used for surgical aortic valve replacement (SAVR). Multiple studies have been done to define the rate of structural valve degeneration (SVD) and failure (SVF), but the outcomes are still debatable. Therefore, we aim to conduct this single-center study to estimate the rate and predictors of SVD/SVF. Methodology: This retrospective observational cohort single-center study was conducted between 2014 and 2019 among Trifecta SAVR patients. Data were patient's characteristics collected from electronic medical records at baseline and follow-up (3-5 years). Statistical analysis was performed with a significance level of P ≤ 0.05. Results: A total of 271 eligible patients were identified. Most of our sample were males (57.9%), with a mean age of 71.1 ± 10.6 years. The mean baseline preoperative ejection fraction (EF) was 53.0%, with no change (P = 0.88) in the immediate postoperative EF (53.6%). A most recent follow-up EF revealed a significant increase of EF (55.2%), P = 0.01. Furthermore, there was a significant increase from peak velocity to PVMRE (mean difference [MD] ± standard error of mean (SEM) [0.15 ± 0.04], P < 0.01), an increase in pressure gradient (PGIPE) to PGMRE (MD ± SEM [1.70 ± 0.49], P < 0.01), and a decrease in Doppler velocity index (DVIIPE) to DVIMRE (MD ± SEM [-0.037 ± 0.01], P = 0.01). Regarding the SVF rate, 13 (4.8%) patients had failed valves requiring replacement throughout the study period. Conclusions: Over a 5-year follow-up period, 4.8% had SVF with an SVD of 23.2%, with the majority of SVD not being clinically significant except in six patients. These results corroborate with a previously published study suggesting a bad clinical outcome of Trifecta valve placement.

Calcification of surgical aortic bioprostheses and its impact on clinical outcome.

AIMS: Aortic valve calcification (AVC) of surgical valve bioprostheses (BPs) has been poorly explored. We aimed to evaluate in vivo and ex vivo BP AVCs and its prognosis value. METHODS AND RESULTS: Between 2011 and 2019, AVC was assessed using in vivo computed tomography (CT) in 361 patients who had undergone surgical valve replacement 6.4 ± 4.3 years earlier. Ex vivo CT scans were performed for 37 explanted BPs. The in vivo CT scans were interpretable for 342 patients (19 patients [5.2%] were excluded). These patients were 77.2 ± 9.1 years old, and 64.3% were male. Mean in vivo AVC was 307 ± 500 Agatston units (AU). The AVC was 562 ± 570 AU for the 183 (53.5%) patients with structural valve degeneration (SVD) and 13 ± 43 AU for those without SVD (P < 0.0001). In vivo and ex vivo AVCs were strongly correlated (r = 0.88, P < 0.0001). An in vivo AVC > 100 AU (n = 147, 43%) had a specificity of 96% for diagnosing Stage 2-3 SVD (area under the curve = 0.92). Patients with AVC > 100 AU had a worse outcome compared with those with AVC ≤ 100 AU (n = 195). In multivariable analysis, AVC was a predictor of overall mortality (hazard ratio [HR] and 95% confidence interval = 1.16 [1.04-1.29]; P = 0.006), cardiovascular mortality (HR = 1.22 [1.04-1.43]; P = 0.013), cardiovascular events (HR = 1.28 [1.16-1.41]; P < 0.0001), and re-intervention (HR = 1.15 [1.06-1.25]; P < 0.0001). After adjustment for Stage 2-3 SVD diagnosis, AVC remained a predictor of overall mortality (HR = 1.20 [1.04-1.39]; P = 0.015) and cardiovascular events (HR = 1.25 [1.09-1.43]; P = 0.001). CONCLUSION: CT scan is a reliable tool to assess BP leaflet calcification. An AVC > 100 AU is tightly associated with SVD and it is a strong predictor of overall mortality and cardiovascular events.

Early and mid-term outcomes after aortic valve replacement using a novel tissue bioprosthesis: a systematic review.

OBJECTIVES: While current data show a clear trend towards the use of bioprosthetic valves during aortic valve replacement (AVR), durability of bioprosthetic valves remains the most important concern. We conducted a 1st systematic review of all available evidence that analysed early and mid-term outcomes after AVR using the Inspiris RESILIA™ bioprosthesis. METHODS: A systematic literature search was performed to identify all relevant studies evaluating early and mid-term outcomes after AVR using the Inspiris RESILIA bioprosthesis and including at least 20 patients with no restriction on the publication date. Subgroup meta-analysis was performed to compare Inspiris RESILIA and PERIMOUNT Magna Ease bioprosthesis and to pool the early postoperative mortality and stroke rates. RESULTS: A total of 416 studies were identified, of which 15 studies met the eligibility criteria. The studies included a total of 3202 patients with an average follow-up of up to 5.3 years. The average age of patients across the studies was 52.2-75.1 years. Isolated AVR was performed in 39.0-86.4% of patients. In-hospital or 30-day postoperative mortality was 0-2.8%. At the mid-term follow-up, freedom from all-cause mortality was up to 85.4%. Among studies with mid-term follow-up, trace/mild paravalvular leak was detected in 0-3.0%, while major paravalvular leak was found only in up to 2.0% of patients. No statistically significant differences in terms of mortality (P = 0.98, odds ratio 1.02, 95% confidence interval 0.36-2.83) and stroke (P = 0.98, odds ratio 1.01, 95% confidence interval 0.38-2.73) between the Inspiris RESILIA bioprosthesis and PERIMOUNT Magna Ease bioprosthesis were observed in the subgroup meta-analysis. CONCLUSIONS: Mid-term data on the safety and haemodynamic performance of the novel aortic bioprosthesis are encouraging. Further comparative studies with other bioprostheses and longer follow-up are still required to endorse durability and safety of the novel bioprosthesis.

Two-Year Outcomes of Valve-in-Valve Using New-Generation Transcatheter Devices Compared With Redo-SAVR.

Few studies have compared the clinical outcomes between valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) with new-generation valves and re-operative surgical aortic valve replacement (Redo-SAVR). We compared the clinical outcomes of patients who underwent ViV-TAVR with those of patients who underwent Redo-SAVR at Cedars-Sinai Medical Center between 2015 and 2021. New-generation valves were used for ViV-TAVR. A propensity score-matched (PSM) analysis was performed to adjust for differences in baseline characteristics. The primary end point was all-cause mortality at 30 days and 2 years. In-hospital procedural and clinical outcomes were also compared between the groups. A total of 256 patients (140 who underwent ViV-TAVR and 116 who underwent Redo-SAVR) were eligible for PSM. In the unmatched cohort, patients in the ViV-TAVR group were older and had more co-morbidities than those in the Redo-SAVR group. After PSM, there were no significant differences in all-cause death between the ViV-TAVR and Redo-SAVR groups at 30 days (3.9% vs 2.6%, p = 0.65) or 2 years (6.5% vs 7.8%, p = 0.75). The incidences of stroke and heart failure rehospitalization were similar at 30 days and 2 years. The cumulative complication rates during hospitalization were significantly lower in the ViV-TAVR group than in the Redo-SAVR group (11.7% vs 28.6% p = 0.015). The long-term outcomes of ViV-TAVR using new-generation valves were similar to those of Redo-SAVR, although ViV-TAVR was associated with lower rates of in-hospital complications.

Early Biological Valve Failure: Structural Valve Degeneration, Thrombosis, or Endocarditis?

Biological valve failure (BVF) is an inevitable condition that compromises the durability of biological heart valves (BHVs). It stems from various causes, including rejection, thrombosis, and endocarditis, leading to a critical state of valve dysfunction. Echocardiography, cardiac computed tomography, cardiac magnetic resonance, and nuclear imaging play pivotal roles in the diagnostic multimodality workup of BVF. By providing a comprehensive overview of the pathophysiology of BVF and the diagnostic approaches in different clinical scenarios, this review aims to aid clinicians in their decision-making process. The significance of early detection and appropriate management of BVF cannot be overstated, as these directly impact patients' prognosis and their overall quality of life. Ensuring timely intervention and tailored treatments will not only improve outcomes but also alleviate the burden of this condition on patients' life. By prioritizing comprehensive assessments and adopting the latest advancements in diagnostic technology, medical professionals can significantly enhance their ability to manage BVF effectively.

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.

In-Series Transcatheter Aortic Valve Replacement-in-Transcatheter Aortic Valve Replacement: ACURATE neo Transcatheter Heart Valve Degeneration Successfully Managed with Myval, Avoiding Coronary Flow Obstruction-A Case Report.

•Durability is vital for transcatheter aortic valve replacement in younger patients.•Aortic insufficiency is one of the features of structural valve degeneration.•Degenerated ACURATE neo can be treated with low implantation of an oversized Myval.

Soft Biomimetic Approach for the Development of Calcinosis-Resistant Glutaraldehyde-Fixed Biomaterials for Cardiovascular Surgery.

Pathological aseptic calcification is the most common form of structural valvular degeneration (SVD), leading to premature failure of heart valve bioprostheses (BHVs). The processing methods used to obtain GA-fixed pericardium-based biomaterials determine the hemodynamic characteristics and durability of BHVs. This article presents a comparative study of the effects of several processing methods on the degree of damage to the ECM of GA-fixed pericardium-based biomaterials as well as on their biostability, biocompatibility, and resistance to calcification. Based on the assumption that preservation of the native ECM structure will enable the creation of calcinosis-resistant materials, this study provides a soft biomimetic approach for the manufacture of GA-fixed biomaterials using gentle decellularization and washing methods. It has been shown that the use of soft methods for preimplantation processing of materials, ensuring maximum preservation of the intactness of the pericardial ECM, radically increases the resistance of biomaterials to calcification. These obtained data are of interest for the development of new calcinosis-resistant biomaterials for the manufacture of BHVs.

One-year clinical outcomes following Edwards INSPIRIS RESILIA aortic valve implantation in 487 young patients with severe aortic stenosis: a single-center experience.

Introduction: The use of an aortic bioprosthesis is on the rise in younger patients with severe aortic stenosis despite the risk of accelerated structural valve degeneration (SVD). In the search for an optimal valve substitute that would not be prone to SVD, the INSPIRIS bioprosthesis represents a promising solution to lowering the risk of SVD. Here, we report the 1-year outcomes of the INSPIRIS RESILIA aortic bioprosthesis in a population of young patients who underwent aortic valve replacement. Methods: In this prospective single-center study, we included all consecutive patients receiving INSPIRIS RESILIA bioprosthesis between June 2017 and July 2021. Patients with isolated severe aortic regurgitation were excluded. Clinical assessment and transthoracic echocardiography were performed preoperatively and at 1 year post-operatively. The primary outcome was overall mortality at one year. Results: A total of 487 patients were included. The mean age was 58.2 ± 11.5 years, 75.2% were men. Most of the interventions were elective, with a mean EuroSCORE II of 4.8 ± 7.9. The valve annulus size in most cases was either 23 mm or 25 mm. Overall mortality at 1-year was 4.1%. At 1-year, 7 patients (1.4%) had a stroke, 4 patients (0.8%) had a myocardial infarction, and 20 patients (4.1%) were hospitalized for congestive heart failure. The Kaplan-Meier estimated survival rates and survival without major adverse cardiac events at 1-year were 96.4% and 96.7%, respectively. At 1-year follow-up, 10 patients (2.1%) had endocarditis and 1 patient (0.2%) had partial prosthetic thrombosis. Pacemaker implantation at 1-year post-operative was necessary in 27 patients (5.5%). Severe patient prosthesis mismatch and severe intra valvular regurgitation were 1.2% and 0.6%, respectively. The Kaplan-Meier estimated survival rates at 1-year of no infective endocarditis preoperative and infective endocarditis preoperative were 97.9 ± 0.7% and 89.5 ± 3.3%, respectively (P < 0.001). Excluding endocarditis-related complication, no structural valve deterioration and no valve failure requiring redo surgery were reported. Conclusion: This is the largest single-center descriptive study of the 1-year outcomes after INSPIRIS RESILIA bioprosthesis implantation. The EDWARDS INSPIRIS RESILIA bioprosthesis provides encouraging clinical outcomes with an excellent 1- year survival rates and good hemodynamic performance. Long-term studies are mandatory to assess valve durability.

Durability of bioprosthetic aortic valve replacement in patients under the age of 60 years - 1-year follow-up from the prospective INDURE registry.

OBJECTIVES: We report 1-year safety and clinical outcomes in patients <60 years undergoing bioprosthetic surgical aortic valve intervention. METHODS: The INSPIRIS RESILIA Durability Registry is a prospective, multicentre registry to assess clinical outcomes of patients <60 years. Patients with planned SAVR with or without concomitant replacement of the ascending aorta and/or coronary bypass surgery were included. Time-related valve safety, haemodynamic performance and quality of life (QoL) at 1 year were assessed. RESULTS: A total of 421 patients were documented with a mean age of 53.5 years, 76.5% being male and 27.2% in NYHA class III/IV. Outcomes within 30 days included cardiovascular-related mortality (0.7%), time-related valve safety (VARC-2; 5.8%), thromboembolic events (1.7%), valve-related life-threatening bleeding (VARC-2; 4.3%) and permanent pacemaker implantation (3.8%). QoL was significantly increased at 6 months and sustained at 1 year. Freedom from all-cause mortality at 1 year was 98.3% (95% confidence interval 97.1; 99.6) and 81.8% were NYHA I versus 21.9% at baseline. No patient developed structural valve deterioration stage 3 (VARC-3). The mean aortic pressure gradient was 12.6 mmHg at 1 year and the effective orifice area was 1.9 cm2. CONCLUSIONS: The 1-year data from the INSPIRIS RESILIA valve demonstrate good safety and excellent haemodynamic performance as well as an early QoL improvement. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov: NCT03666741.

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.

Transcatheter aortic valve durability: a contemporary clinical review.

Encouraged by randomized controlled trials demonstrating non-inferiority of transfemoral transcatheter aortic valve implantation (TAVI) compared to surgical aortic valve replacement (SAVR) across all surgical risk categories, there has been a dramatic increase in the use of TAVI in a younger patient cohort with severe aortic stenosis, endorsed by both European and American Cardiac Societies. However, the standard use of TAVI in younger, less co-morbid patients with a longer life expectancy can only be supported if there is sound data demonstrating long-term durability of transcatheter aortic valves (TAVs). In this article, we have reviewed available randomized and observational registry clinical data pertaining to TAV long-term durability, placing emphasis on trials and registries using the new standardized definitions of bioprosthetic valve dysfunction (BVD) and bioprosthetic valve failure (BVF). Despite inherent difficulties in interpreting the available data, the determination reached is that the risk of structural valve deterioration (SVD) is potentially lower after TAVI than SAVR at 5 to 10 years, and that the two treatment modalities have a similar risk of BVF. This supports the adoption of TAVI in younger patients evident in current practice. However, the routine use of TAVI in younger patients with bicuspid aortic valve stenosis should be cautioned due to insufficient long-term TAV durability data in this particular patient population. Finally, we highlight the importance of future research into the unique potential mechanisms that can potentially contribute to TAV degeneration.

Explant vs Redo-TAVR After Transcatheter Valve Failure: Mid-Term Outcomes From the EXPLANTORREDO-TAVR International Registry.

BACKGROUND: Valve reintervention after transcatheter aortic valve replacement (TAVR) failure has not been studied in detail. OBJECTIVES: The authors sought to determine outcomes of TAVR surgical explantation (TAVR-explant) vs redo-TAVR because they are largely unknown. METHODS: From May 2009 to February 2022, 396 patients in the international EXPLANTORREDO-TAVR registry underwent TAVR-explant (181, 46.4%) or redo-TAVR (215, 54.3%) for transcatheter heart valve (THV) failure during a separate admission from the initial TAVR. Outcomes were reported at 30 days and 1 year. RESULTS: The incidence of reintervention after THV failure was 0.59% with increasing volume during the study period. Median time from index-TAVR to reintervention was shorter in TAVR-explant vs redo-TAVR (17.6 months [IQR: 5.0-40.7 months] vs 45.7 months [IQR: 10.6-75.6 months]; P < 0.001], respectively. TAVR-explant had more prosthesis-patient mismatch (17.1% vs 0.5%; P < 0.001) as the indication for reintervention, whereas redo-TAVR had more structural valve degeneration (63.7% vs 51.9%; P = 0.023), with a similar incidence of ≥moderate paravalvular leak between groups (28.7% vs 32.8% in redo-TAVR; P = 0.44). There was a similar proportion of balloon-expandable THV failures (39.8% TAVR-explant vs 40.5% redo-TAVR; P = 0.92). Median follow-up was 11.3 (IQR: 1.6-27.1 months) after reintervention. Compared with redo-TAVR, TAVR-explant had higher mortality at 30 days (13.6% vs 3.4%; P < 0.001) and 1 year (32.4% vs 15.4%; P = 0.001), with similar stroke rates between groups. On landmark analysis, mortality was similar between groups after 30 days (P = 0.91). CONCLUSIONS: In this first report of the EXPLANTORREDO-TAVR global registry, TAVR-explant had a shorter median time to reintervention, with less structural valve degeneration, more prosthesis-patient mismatch, and similar paravalvular leak rates compared with redo-TAVR. TAVR-explant had higher mortality at 30 days and 1 year, but similar rates on landmark analysis after 30 days.

Genetically engineered sheep: A new paradigm for future preclinical testing of biological heart valves.

BACKGROUND: Heart valve implantation in juvenile sheep to demonstrate biocompatibility and physiologic performance is the accepted model for regulatory approval of new biological heart valves (BHVs). However, this standard model does not detect the immunologic incompatibility between the major xenogeneic antigen, galactose-α-1,3-galactose (Gal), which is present in all current commercial BHVs, and patients who universally produce anti-Gal antibody. This clinical discordance leads to induced anti-Gal antibody in BHV recipients, promoting tissue calcification and premature structural valve degeneration, especially in young patients. The objective of the present study was to develop genetically engineered sheep that, like humans, produce anti-Gal antibody and mirror current clinical immune discordance. METHODS: Guide RNA for CRISPR Cas9 nuclease was transfected into sheep fetal fibroblasts, creating a biallelic frame shift mutation in exon 4 of the ovine α-galactosyltransferase gene (GGTA1). Somatic cell nuclear transfer was performed, and cloned embryos were transferred to synchronized recipients. Cloned offspring were analyzed for expression of Gal antigen and spontaneous production of anti-Gal antibody. RESULTS: Two of 4 surviving sheep survived long-term. One of the 2 was devoid of the Gal antigen (GalKO) and expressed cytotoxic anti-Gal antibody by age 2 to 3 months, which increased to clinically relevant levels by 6 months. CONCLUSIONS: GalKO sheep represent a new, clinically relevant advanced standard for preclinical testing of BHVs (surgical or transcatheter) by accounting for the first time for human immune responses to residual Gal antigen that persists after current BHV tissue processing. This will identify the consequences of immune disparity preclinically and avoid unexpected past clinical sequelae.

Comparison of modes of failure and clinical outcomes between explanted porcine and bovine pericardial bioprosthetic valves.

OBJECTIVE: To compare pathological and hemodynamic modes of failure and operative outcomes between explanted porcine and bovine pericardial bioprosthetic valves. METHODS: Patients who underwent explantation of their bioprosthetic valves at Toronto General Hospital from 2007 to 2019 were identified. Retrospective chart review was conducted to attain demographic information, operative outcomes, and echocardiography and pathology reports. RESULTS: A total of 278 patients underwent explantation of their porcine (n=183) or bovine pericardial (n=95) valves. A greater proportion of the porcine group had severe regurgitation, compared to the bovine group (45.3% vs. 19.8%, p<.001). Porcine valves had higher rates of cusp flail (19.4% vs. 3.3%, p<.001). The rates of moderate or worse stenosis were higher among bovine pericardial valves (37.9% vs. 15.8%, p<.001). On pathologic examination, the porcine valves exhibited more cusp tears (67.6% vs. 50.5%, p=.006), while higher incidences of calcification were found in the bovine group (p<.001). Rate of stroke was higher during the explantation procedure of the bovine valves (5.3% vs. 0.5%, p=.040). CONCLUSIONS: The primary mode of failure was regurgitation in porcine valves due to cusp tears and stenosis in bovine valves due to calcification. Establishing a clear understanding of failure modes based on valve material may improve design and guide valve selection at the time of surgery.

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

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

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.

A Case of Valve-in-Valve-in-Valve for Severe Aortic Regurgitation: Is Lifetime Management Upon Us?

BACKGROUND: The incremental use of transcatheter aortic valve replacement will inexorably lead to structural valve deterioration and the need for both a second and third valvular interventions, raising the question of feasibility. CASE SUMMARY: We present the case of a 76-year-old man that presented with cardiogenic shock refractory to inotropic support. His workup revealed severe bioprosthetic aortic regurgitation 5 years after undergoing transcatheter aortic valve-in-valve implantation. After confirming anatomical suitability with multimodality imaging, he underwent uncomplicated valve-in-valve-in-valve (ViViV) implantation of a 23 mm Edwards S3 Ultra valve with rapid clinical improvement. CONCLUSIONS: Whether in the form of stenosis or severe regurgitation as in our patient, ViViV is feasible. Careful preprocedural planning and confirmation of anatomical suitability with multimodality imaging are key for success and safety.