Transcatheter aortic valve replacement outcomes in bicuspid compared to trileaflet aortic valves

Transcatheter Aortic Valve Replacement Versus Surgical Aortic Valve Replacement in Bicuspid Aortic Valve Stenosis-We Need a Well-Designed Randomized Control Trial

Bicuspid aortic stenosis is a common pathology, typically seen in patients a decade younger than those with tricuspid valves. Surgical aortic valve replacement has been the mainstay treatment for bicuspid disease, especially considering the prevalence of concomitant aortic aneurysmal pathology. Transcatheter aortic valve replacement has shown equivalent results in bicuspid compared to tricuspid pathology in highly selected patient populations in single-arm registries and observational studies. For older patients with favorable bicuspid pathology, TAVR is reasonable. However, as younger patients with longer life expectancy are now being treated with TAVR, what is "best" is a question only answered by a well-designed randomized controlled trial. Herein, we describe the current evidence for treating bicuspid aortic stenosis and provide a framework for future trials. Yet, the question of equipoise remains, and who will we enroll?

Bicuspid aortic stenosis: National three-year outcomes of transcatheter versus surgical aortic valve replacement among Medicare beneficiaries

OBJECTIVE

Randomized trials of transcatheter versus surgical aortic valve replacements have excluded bicuspid anatomy. We compared 3-year outcomes of transcatheter aortic valve replacement versus surgical aortic valve replacement in patients aged more than 65 years with bicuspid aortic stenosis.

METHODS

The Centers for Medicare and Medicaid data were used to identify 6450 patients undergoing isolated surgical aortic valve replacement (n = 3771) or transcatheter aortic valve replacement (n = 2679) for bicuspid aortic stenosis (2012-2019). Propensity score matching with 21 baseline characteristics including frailty created 797 pairs.

RESULTS

Unmatched patients undergoing transcatheter aortic valve replacement were older than patients undergoing surgical aortic valve replacement (78 vs 70 years), with more comorbidities and frailty (all P < .001). After matching, transcatheter aortic valve replacement was associated with a similar mortality risk compared with surgical aortic valve replacement within the first 6 months (hazard ratio [HR], 1.08, 95% CI, 0.67-1.69) but a higher mortality risk between 6 months and 3 years (HR, 2.16, 95% CI, 1.22-3.83). Additionally, transcatheter aortic valve replacement was associated with a lower risk of heart failure readmissions before 6 months (HR, 0.51, 95% CI, 0.31-0.87) but a higher risk between 6 months and 3 years (HR, 4.78, 95% CI, 2.21-10.36). The 3-year risks of aortic valve reintervention (HR, 1.03, 95% CI, 0.30-3.56) and stroke (HR, 1.21, 95% CI, 0.75-1.96) were similar.

CONCLUSIONS

Among matched Medicare beneficiaries undergoing transcatheter aortic valve replacement or surgical aortic valve replacement for bicuspid aortic stenosis, 3-year mortality was higher after transcatheter aortic valve replacement. However, transcatheter aortic valve replacement was associated with a similar risk of mortality and a lower risk of heart failure readmissions during the first 6 months after the intervention. Randomized comparative data are needed to best inform treatment choice.

Sex differences in transcatheter aortic valve replacement outcomes among patients with bicuspid aortic stenosis

BACKGROUND

Despite comprising almost half of all patients undergoing valvular repair, data on transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic stenosis (BAS) are limited.

OBJECTIVE

We aimed to evaluate whether there are any sex differences in trends and outcomes of TAVR in this population.

METHODS

We utilized the National Inpatient Sample from 2012 to 2020 to identify admissions with BAS who underwent TAVR and analyzed trends and outcomes. Our primary outcome was in-hospital mortality and secondary outcomes were in-hospital complications. We used two models to adjust for demographics (A) and interventions (B).

RESULTS

Between 2012 to 2020, there were 76,540 hospitalizations for BAS patients who underwent AVR, among which 6,010 (7.9 %) underwent TAVR. There was an overall increasing trend in number of TAVR cases with a decreasing trend in mortality (2013: 8.7 %, 2020: 1.3 %). TAVR was performed more in males (61.1% vs 38.9 %). Despite the worse baseline characteristics in males, in-hospital mortality (2.4% vs. 1.5 %; OR: 1.584; 95 % CI: 0.621-4.038; p = 0.335) and secondary outcomes were similar across both sexes, even after adjusting for demographics and interventions.

CONCLUSION

TAVR in BAS has grown rapidly in the last decade. Males comprised the majority and had more comorbidities, but mortality and complications were similar in both sexes. Despite the increasing number of cases, a decreasing trend in mortality was observed for both sexes ultimately approaching that of SAVR, suggesting that TAVR may be a safe alternative among eligible males and females with bicuspid AS.

Bicuspid Aortic Valve Disease: From Pathophysiology to Treatment

The Bicuspid Aortic Valve (BAV) is the most common congenital anomaly in adults, with a global incidence of 1.3%. Despite being well documented, BAV presents significant clinical challenges due to its phenotypic heterogeneity, diverse clinical manifestations, and variable outcomes. Pathophysiologically, BAV differs from tricuspid valves in calcification patterns and hemodynamic effects, leading to increased shear stress and aortic root dilatation, while it is influenced by genetic and hemodynamic factors. This is why therapeutically, BAV presents challenges for both surgical and transcatheter interventions, with surgical approaches being traditionally preferred, especially when aortopathy is present. However, transcatheter aortic valve implantation (TAVI) has emerged as a viable option, with studies showing comparable outcomes to surgery in selected patients, while advancements in TAVI and a better understanding of BAV's genetic and pathophysiological nuances are expanding treatment options. The choice between mechanical and bioprosthetic valves also presents considerations, particularly regarding long-term durability and the need for anticoagulation. Future research should focus on long-term registries and genetic studies to refine therapeutic strategies and improve patient outcomes. This review aims to evaluate current approaches in the surgical and interventional management of BAV, focusing on its anatomy, pathogenesis, pathophysiology, and therapeutic strategies.

Mechanical behaviors of a new elliptical valve stent in bicuspid aortic valve

BACKGROUND AND OBJECTIVE

The conventional valve stents that are cylindrical in shape will become elliptical when implanted in bicuspid aortic valve, thereby reducing the durability of the artificial valve. In this study, a new design of valve stent is presented where valve stents have elliptical cross-section at the annulus and it is expected to have better expandability and circle shape during the interaction between the stent and bicuspid aortic valve, thereby extending the durability of artificial valve.

METHODS

Finite element method (FEM) is used to study the mechanical behavior of the novel valve stent in the bicuspid aortic valve. The effects of three matching relationship between the ellipticity of the stents and the ellipticity of the annulus (i.e., the ellipticity of the stent is greater than, equal to and less than the annulus ellipticity, respectively) on the mechanical behavior of stent expansion are studied. In addition, the expansion mechanical behavior of the novel valve stent at different implantation depths is also compared.

RESULTS

Results indicate that novel valve stent implantation with elliptical features is superior to conventional circular valve stent. When the novel valve stent ellipticity is less than the annulus ellipticity, the ellipticity of the novel valve stent after implantation is smaller than that of the conventional circular valve stent. This indicated that the novel valve stent has better expandability and post-expansion shape, making artificial valve to have better durability. The risk of paravalvular leak after implantation is lowest when the novel valve stent ellipticity is less than annulus ellipticity. When the novel valve stent ellipticity coincides with annulus ellipticity, the aortic wall is subjected to greatest stress. With the increase of implantation depth, the stress on the novel valve stent decrease.

CONCLUSIONS

This study might provide insights for improving stent design for bicuspid aortic valve.

Clinical outcomes and the impact of valve morphology for transcatheter aortic valve replacement in bicuspid aortic valves: A systematic review and meta-analysis

BACKGROUND

Bicuspid aortic valve (BAV) is present in approximately 0.5%-2% of the general population, causing significant aortic stenosis (AS) in 12%-37% of affected individuals. Transcatheter aortic valve replacement (TAVR) is being considered the treatment of choice in patients with symptomatic AS across all risk spectra.

AIM

Aim Our study aims to compare TAVR outcomes in patients with BAV versus tricuspid aortic valves (TAV).

METHODS

A comprehensive literature search was performed in PubMed, Web of Science, and Cochrane trials. Studies were included if they included BAV and TAV patients undergoing TAVR with quantitative data available for at least one of our predefined outcomes. Meta-analysis was performed by the random-effects model using Stata software.

RESULTS

Fifty studies of 203,288 patients were included. BAV patients had increased 30-day all-cause mortality (odds ratio [OR] = 1.23 [1.00-1.50], p = 0.05), in-hospital stroke (OR = 1.39 [1.01-1.93], p = 0.05), in-hospital and 30-day PPI (OR = 1.13 [1.00-1.27], p = 0.04; OR = 1.16 [1.04-1.13], p = 0.01) and in-hospital, 30-day and 1-year aortic regurgitation (AR) (OR = 1.48 [1.19-1.83], p < 0.01; OR = 1.79 [1.26-2.52], p < 0.01; OR = 1.64 [1.03-2.60], p = 0.04). Subgroup analysis on new-generation valves showed a reduced 1-year all-cause mortality (OR = 0.86 [CI = 0.75-0.98], p = 0.03), despite higher in-hospital and 30-day PPI (OR = 0.1.21 [1.04-1.41], p = 0.01; OR = 1.17 [1.05-1.31], p = 0.01) and in-hospital AR (OR = 1.62 [1.14-2.31], p = 0.01) in the BAV group. The quality of included studies was moderate-to-high, and only three analyses presented high heterogeneity.

CONCLUSION

TAVR is associated with comparable outcomes in patients with BAV and TAV. Careful selection of BAV cases by preprocedural assessment of valve anatomy and burden of calcification, pre- and post-procedural dilation, and implementing newer generations of valves may improve the safety and efficacy of TAVR in BAV patients.

Transcatheter and Surgical Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Stenosis

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is not widely used in patients with bicuspid aortic valve (BAV) disease and has not yet been studied in randomized clinical trials. We characterized the rate of use and outcomes of TAVR and surgical aortic valve replacement (SAVR) in patients with BAV.

METHODS

Adults with BAV stenosis receiving SAVR or TAVR procedures were abstracted from the 2012 to 2019 Nationwide Readmissions Database (NRD). Risk-adjusted analyses were performed with NRD-provided weights and inverse probability of treatment weights (IPTW) to examine the association of treatment strategy on inpatient mortality, complications, and hospitalization resource utilization. Nonelective readmissions within 90 days of discharge and reintervention at the first readmission were also examined.

RESULTS

Of an estimated 56 331 patients with BAV requiring aortic valve replacement, 6.8% underwent TAVR. Unadjusted analysis demonstrated higher index hospitalization mortality for TAVR compared with SAVR. Upon risk adjustment using NRD-provided weights, the odds of pacemaker implantation remained significantly higher for TAVR patients compared with SAVR, with no significant difference in mortality. When NRD-provided survey weights were applied, TAVR had higher rates of 90-day readmission. Adjustment with inverse probability of treatment weights resolved these differences between the 2 groups. Regardless of the risk-adjustment method, the odds of reintervention were consistently higher among BAV TAVR patients compared with SAVR.

CONCLUSIONS

The present analysis demonstrates comparable in-hospital mortality and morbidity for TAVR and SAVR patients in the moderate-risk era. With increasing TAVR use in BAV, surgeons must further refine selection criteria with consideration of concomitant aortopathy and implications of reintervention.

Bicuspid Aortic Valves: an Up-to-Date Review on Genetics, Natural History, and Management

PURPOSE OF REVIEW

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality. It has a wide spectrum of clinical manifestations including aortic regurgitation (AR), aortic stenosis, and an associated aortopathy with a small but increased risk of aortic dissection. This review describes current knowledge of BAV, from anatomy and genetics to a discussion of multifaceted strategies utilized in the management of this unique patient population. This review will also highlight critical knowledge gaps in areas of basic and clinical research to enhance further understanding of this clinical entity.

RECENT FINDINGS

The current knowledge regarding pathophysiologic mechanisms, screening, and surveillance guidelines for BAV and the associated aortopathy is discussed. We also discuss current management techniques for aortic valve repair versus replacement, indications for aortic surgery (root or ascending aorta), and the emergence of the Ross procedure as a viable management option not only in children, but also in adolescents and adults. The varied clinical phenotype of the BAV, resulting in its specific complex hemodynamic interactions, renders it an entity which is separate and distinct from the tricuspid aortic valve pathologies. While various aortic histopathologic and protein alterations in BAV patients have been described, it remains unclear if these changes are causal or the result of hemodynamic alterations imposed by sheer stress on the intrinsically dysfunctional BAV. Medical management for patients with BAV with AS, AI, or dilated aortic roots/ascending aortas remains challenging and needs further investigation. More than 50% of patients with BAV will undergo AVR during their lifetime, and more than 25% of patients with BAV undergo aortic surgery performed for dilation of the aortic root or ascending aorta, often concurrently with AVR. The search for the ultimate genetic or epigenetic cause of the different bicuspid phenotypes will ultimately be facilitated by the next-generation sequencing tools that allow for study of large populations at low cost. Improvements in diagnostic and stratification criteria to accurately risk assess BAV patients are critical to this process.

Patients With Bicuspid Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

Objective

We sought to conduct a systematic review and meta-analysis of clinical adverse events in patients undergoing transcatheter aortic valve replacement (TAVR) with bicuspid aortic valve (BAV) vs. tricuspid aortic valve (TAV) anatomy and the efficacy of balloon-expandable (BE) vs. self-expanding (SE) valves in the BAV population. Comparisons aforementioned will be made stratified into early- and new-generation devices. Differences of prosthetic geometry on CT between patients with BAV and TAV were presented. In addition, BAV morphological presentations in included studies were summarized.

Method

Observational studies and a randomized controlled trial of patients with BAV undergoing TAVR were included according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline.

Results

A total of 43 studies were included in the final analysis. In patients undergoing TAVR, type 1 BAV was the most common phenotype and type 2 BAV accounted for the least. Significant higher risks of conversion to surgical aortic valve replacement (SAVR), the need of a second valve, a moderate or severe paravalvular leakage (PVL), device failure, acute kidney injury (AKI), and stroke were observed in patients with BAV than in patients with TAV during hospitalization. BAV had a higher risk of new permanent pacemaker implantation (PPI) both at hospitalization and a 30-day follow-up. Risk of 1-year mortality was significantly lower in patients with BAV than that with TAV [odds ratio (OR) = 0.85, 95% CI 0.75–0.97, p = 0.01]. BE transcatheter heart valves (THVs) had higher risks of annular rupture but a lower risk of the need of a second valve and a new PPI than SE THVs. Moreover, BE THV was less expanded and more elliptical in BAV than in TAV. In general, the rates of clinical adverse events were lower in new-generation THVs than in early-generation THVs in both BAV and TAV.

Conclusions

Despite higher risks of conversion to SAVR, the need of a second valve, moderate or severe PVL, device failure, AKI, stroke, and new PPI, TAVR seems to be a viable option for selected patients with severe bicuspid aortic stenosis (AS), which demonstrated a potential benefit of 1-year survival, especially among lower surgical risk population using new-generation devices. Larger randomized studies are needed to guide patient selection and verified the durable performance of THVs in the BAV population.

Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Stenosis

After 15 years of successive randomized, controlled trials, indications for transcatheter aortic valve replacement (TAVR) are rapidly expanding. In the coming years, this procedure could become the first line treatment for patients with a symptomatic severe aortic stenosis and a tricuspid aortic valve anatomy. However, randomized, controlled trials have excluded bicuspid aortic valve (BAV), which is the most frequent congenital heart disease occurring in 1% to 2% of the total population and representing at least 25% of patients 80 years of age or older referred for aortic valve replacement. The use of a less invasive transcatheter therapy in this elderly population became rapidly attractive, and approximately 10% of patients currently undergoing TAVR have a BAV. The U.S. Food and Drug Administration and the "European Conformity" have approved TAVR for low-risk patients regardless of the aortic valve anatomy whereas international guidelines recommend surgical replacement in BAV populations. Given this progressive expansion of TAVR toward younger and lower-risk patients, heart teams are encountering BAV patients more frequently, while the ability of this therapy to treat such a challenging anatomy remains uncertain. This review will address the singularity of BAV anatomy and associated technical challenges for the TAVR procedure. We will examine and summarize available clinical evidence and highlight critical knowledge gaps regarding TAVR utilization in BAV patients. We will provide a comprehensive overview of the role of computed tomography scans in the diagnosis, and classification of BAV and TAVR procedure planning. Overall, we will offer an integrated framework for understanding the current role of TAVR in the treatment of bicuspid aortic stenosis and for guiding physicians in clinical decision-making.

Temporal Trends and Outcomes of Transcatheter Versus Surgical Aortic Valve Replacement for Bicuspid Aortic Valve Stenosis

OBJECTIVES

The purpose of this study was to assess the temporal trends of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic stenosis (AS), and to compare the outcomes between TAVR and surgical aortic valve replacement (SAVR) in this population.

BACKGROUND

Randomized trials comparing TAVR to SAVR in AS with bicuspid valve are lacking.

METHODS

The study queried the National Inpatient Sample database (years 2012 to 2016) to identify hospitalizations for bicuspid AS who underwent isolated aortic valve replacement. A propensity-matched analysis was used to compare outcomes of hospitalizations for TAVR versus SAVR for bicuspid AS and TAVR for bicuspid AS versus tricuspid AS.

RESULTS

The analysis included 31,895 hospitalizations with bicuspid AS, of whom 1,055 (3.3%) underwent TAVR. TAVR was increasingly utilized during the study period for bicuspid AS (ptrend = 0.002). After matching, TAVR and SAVR had similar in-hospital mortality (3.1% vs. 3.1%; odds ratio: 1.00; 95% confidence interval: 0.60 to 1.67). There was no difference between TAVR and SAVR in the rates of cardiac arrest, cardiogenic shock, acute kidney injury, hemopericardium, cardiac tamponade, or acute stroke. TAVR was associated with lower rates of acute myocardial infarction, post-operative bleeding, vascular complications, and discharge to nursing facility as well as a shorter length of hospital stay. On the contrary, TAVR was associated with a higher incidence of complete heart block and permanent pacemaker insertion. TAVR for bicuspid AS was associated with similar in-hospital mortality compared with tricuspid AS.

CONCLUSIONS

This nationwide analysis showed similar in-hospital mortality for TAVR and SAVR in patients with bicuspid AS. TAVR for bicuspid AS was also associated with similar in-hospital mortality compared with tricuspid AS. Further studies are needed to evaluate long-term outcomes of TAVR for bicuspid AS.

Outcomes of transcatheter aortic valve replacement in bicuspid aortic valve stenosis

Background

Due to abnormal valve geometry, patients with bicuspid aortic valve (BAV) have been excluded in many transcatheter aortic valve replacement (TAVR) trials resulting in very limited data with regards to its safety and efficacy.

Methods

We searched electronic databases including Cochrane Database of Systematic Reviews, MEDLINE and EMBASE for all studies including case series, and original reports published before December 2018 that assessed outcomes following TAVR in BAV stenosis. We also included studies that had patients with TAV for comparison. Pooled effect size was calculated with a random-effect model and weighted for the inverse of variance, to compare outcomes post-TAVR between BAV and TAV. The heterogeneity of effect estimates across the studies was assessed using I2. Publication bias was assessed with funnel plots. Statistical analysis was performed using SPSS version 24 (IBM Corp., SPSS Statistics for Windows, Version 24.0. Armonk, NY.).

Results

A total of 19 studies describing 1,332 patients with BAV and 3,610 with TAV. There was no significant difference in the30-day mortality between patients with BAV and TAV [odds ratio (OR): 1.18, 95% confidence interval (CI): 0.7-1.7, P=0.41, I²=0]. One-year mortality rate in the BAV population was 13.1% compared to 15.4% in the TAV patients (P=0.75). Patients with BAV had significantly more moderate to severe paravalvular leak (PVL) post TAVR (PVL ≥3) 8.8% vs. 4.2% in TAV patients (OR: 1.478, 95% CI: 1.000-2.184, P=0.050, I²=0. Device success was significantly higher in TAV patients compared to BAV patients 93.5% vs. 87% (OR: 0.63, 95% CI: 0.49-0.86, P=0.003).

Conclusions

TAVR in patients with BAV is associated with a high incidence of paravalvular regurgitation with a comparable 30-day mortality rate to TAV patients. The use of newer generation valve prosthesis improved outcomes.