Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis: Early Success But Concerning Red Flags

Transcatheter aortic valve implantation complexity score

BACKGROUND

Increasing demand for transcatheter aortic valve implantation (TAVI) places greater emphasis on the efficiency of pathways and services. A significant limitation to increasing TAVI capacity is the availability of cardiac catheterisation laboratory time. We have developed a novel complexity scoring system (TAVI ComplEXity; TEX score) which can aid in planning lists with appropriate case selection. To validate the TEX score, we have undertaken a retrospective analysis of TAVI cases. The hypothesis is that increasing TEX score correlates with increased procedural duration and reduced valve academic research consortium (VARC) 3 technical and device success.

METHODS

The TEX score assigns patients to a complexity level of 1 (low), 2 (intermediate) or 3 (high) based on the presence of specific clinical and anatomical variables. For validation purposes, comparisons were made between patients in the three complexity levels with respect to procedural duration as well as VARC-3 technical success, device success and early safety.

RESULTS

The validation study included 1034 consecutive patients who underwent TAVI between June 2021 and October 2023. Of these, 582 (56.3%) were classified as level 1 complexity, 377 (36.5%) level 2 and 75 (7.3%) level 3. Significant differences were observed between the three groups with respect to procedural duration (73.7 min vs 85.6 min vs 136 min; p<0.001), VARC-3 technical success (97.9% vs 96.6% vs 92%; p<0.05) and VARC-3 device success (96.2% vs 92.3% vs 86.6%; p<0.001).

CONCLUSION

The TEX score is a simple tool which allows stratification of patients into three levels of complexity. Increasing complexity levels correlate with increasing procedural duration and reduced VARC-3 technical and device success. This is potentially useful for scheduling patients onto appropriate lists.

Comparable efficacy and safety for bicuspid aortic valve stenosis patients undergoing transcatheter aortic valve replacement with balloon-expandable or self-expanding valves using Wei's sizing method

BACKGROUND

The present study aimed to investigate whether proper sizing can improve the procedural and clinical outcomes of transcatheter aortic valve replacement (TAVR) with new-generation self-expanding valves (SEVs) and balloon-expandable valves (BEVs) for treating bicuspid aortic stenosis (BAS).

METHODS

We retrospectively evaluated consecutive patients who underwent TAVR with Sapien 3 valves (Edwards Lifesciences, Irvine, CA) or Evolut R/PRO valves (Medtronic, Minneapolis, MN) for severe BAS from 2017 to 2022. The primary endpoints were device success rate and major adverse cardiac and cerebral events (MACCEs), including mortality, nonfatal myocardial infarction or disabling stroke, transcatheter heart valve failure, or clinically relevant valve thrombosis during follow-up. Our team used a complementary approach of supraannular sizing in addition to the conventional annular sizing method (Wei's method) to guide the TAVR procedures.

RESULTS

We recruited a total of 75 consecutive patients, of whom 43 (57%) were treated with BEVs from October 2017 to June 2021, and 32 (43%) were treated with SEVs from July 2021 to December 2022. Device success was similar between the BEV and SEV groups (93% vs 94%; p > 0.99), and no cases of annular rupture occurred in either group. Similar rates of moderate-to-severe paravalvular leak were observed in the BEV and SEV groups (5% vs 6%, p > 0.99). At a median follow-up of 464 days, the MACCE rates were comparable between the two groups. In multivariate analysis, the presence of previous percutaneous coronary interventions (hazard ratio: 5.43; p = 0.039) and New York Heart Association functional class III/IV heart failure at 30 days of follow-up after TAVR (hazard ratio: 9.90; p = 0.037) were independently associated with long-term MACCEs.

CONCLUSION

Our results demonstrated comparable efficacy and safety for BAS patients undergoing TAVR using either BEVs or SEVs when using Wei's sizing method.

Bicuspid Aortic Valve Disease: Classifications, Treatments, and Emerging Transcatheter Paradigms

Bicuspid aortic valve (BAV) is a common congenital valvular malformation, which may lead to early aortic valve disease and bicuspid-associated aortopathy. A novel BAV classification system was recently proposed to coincide with transcatheter aortic valve replacement being increasingly considered in younger patients with symptomatic BAV, with good clinical results, yet without randomized trial evidence. Procedural technique, along with clinical outcomes, have considerably improved in BAV patients compared with tricuspid aortic stenosis patients undergoing transcatheter aortic valve replacement. The present review summarizes the novel BAV classification systems and examines contemporary surgical and transcatheter approaches.

Impact of Pacemaker Implantation After Transcatheter Aortic Valve Replacement on Long-Term Survival in Patients With Bicuspid Aortic Valve

Limited data are available about the impact of permanent pacemaker (PPM) implantation on long-term survival in patients with a bicuspid aortic valve (BAV) and severe aortic stenosis (AS) treated with transcatheter aortic valve replacement (TAVR). We aimed to evaluate the long-term clinical outcomes of patients with BAV with AS who underwent periprocedural PPM implantation after TAVR with a self-expandable prosthesis. Data from patients with BAV and severe AS who underwent TAVR between April 2009 and January 2022 and followed in the framework of the One Hospital ClinicalService-CoreValve Project were collected. Patients were categorized in 2 groups according to PPM implantation after TAVR ("PPM" group) or not ("no PPM" group). The coprimary end points were all-cause death and a composite of cardiac mortality, rehospitalization because of cardiac causes, stroke, and myocardial infarction. Overall, 106 patients were considered (74 in the "no PPM" group and 32 in the "PPM" group). No statistically significant difference was found between the groups in terms of follow-up and baseline characteristics. Patients in the PPM group were more likely to show baseline conduction abnormalities (p = 0.023). Patients in the PPM group were more often treated with older generation prosthesis than those in the no PPM group (28.1% vs 5.4%, respectively, p = 0.013). At 2 years of follow-up, all-cause death in the no PPM and PPM groups occurred in 20.0% and 10.0% of patients, respectively (hazard ratio 0.37, 95% confidence interval 0.08 to 1.67). Similarly, no difference was evident for the composite end point between the 2 groups (no PPM vs PPM: 8 [14.6%] vs 6 [19.3%], hazard ratio 1.67, 95% CI 0.58 to 4.81). In conclusion, patients with severe AS and BAV treated with TAVR complicated by PPM implantation are not exposed to an increased risk of major adverse events at 2 years of follow-up.

Long-Term Mortality After TAVI for Bicuspid vs. Tricuspid Aortic Stenosis: A Propensity-Matched Multicentre Cohort Study

Objectives

Patients with bicuspid aortic valve (BAV) stenosis were excluded from the pivotal trials of transcatheter aortic valve implantation (TAVI). We compared the in-hospital and long-term outcomes between patients undergoing TAVI for bicuspid and tricuspid aortic valve (TAV) stenosis.

Methods

We performed a retrospective registry-based analysis on patients who underwent TAVI for BAV and TAV at five different centers between January 2009 and August 2017. The primary outcome was long-term all-cause mortality. Secondary outcomes were in-hospital mortality, procedural complications, and valve performance.

Results

Of 1,451 consecutive patients who underwent TAVI, two propensity-matched cohorts consisting of 130 patients with BAV and 390 patients with TAV were analyzed. All-cause mortality was comparable in both groups up to 10 years following TAVI (HR 1.09, 95% CI: 0.77–1.51). Device success and in-hospital mortality were comparable between the groups (96 vs. 95%, p = 0.554 and 2.3 vs. 2.1%, p = 0.863, respectively). Incidence of procedural complications was similar in both groups, with a trend toward a higher rate of stroke in patients with BAV (5 vs. 2%, p = 0.078). Incidence of moderate or severe paravalvular leak (PVL) at discharge was comparable in both groups (2 vs. 2%, p = 0.846). Among patients with BAV, all-cause mortality was similar in self-expanding and balloon-expandable prostheses (HR 1.02, 95% CI: 0.52–1.99) and lower in new-generation devices compared to old-generation valves (HR 0.27, 95% CI 0.12–0.62).

Conclusion

Patients who had undergone TAVI for BAV had comparable mortality to patients with TAV up to 10 years after the procedure. The device success, in-hospital mortality, procedural complications, and PVL rate were comparable between the groups. The high rate of neurological complications (5%) in patients with BAV warrants further investigation.

Treatment of Bicuspid Aortic Valve Stenosis Using Transcatheter Heart Valves

The paucity of data regarding the use of transcatheter aortic valve replacement (TAVR) in bicuspid aortic valve (BAV) anatomy due to exclusion from pivotal studies and lack of studies assessing the long-term outcomes and valve performance continue to present a significant challenge as we expand TAVR to patients with BAV anatomy. This article discusses the important anatomic and clinical considerations in the selection and management of patients with BAV with TAVR and reviews the emerging evidence that increasingly suggests this procedure is safe, device success is excellent, and procedural outcomes are improving.

Challenging Anatomies for TAVR-Bicuspid and Beyond

Transcatheter aortic valve replacement has emerged as the standard treatment for the majority of patients with symptomatic aortic stenosis. As transcatheter aortic valve replacement expands to patients across all risk groups, optimal patient selection strategies and device implantation techniques become increasingly important. A significant number of patients referred for transcatheter aortic valve replacement present with challenging anatomies and clinical indications that had been historically considered a contraindication for transcatheter aortic valve replacement. This article aims to highlight and discuss some of the potential obstacles that are encountered in clinical practice with a particular emphasis on bicuspid aortic valve disease.

Surgical challenges in retrieval of an embolized transcatheter valve from the aorta

Embolization of a transcatheter aortic valve is a rare complication. Surgery is required if percutaneous retrieval is not possible. We present a case of embolization of an evolut R device (Medtronic, Minneapolis, Minnesota) into the ascending aorta. This device due to its taller profile presents unique surgical challenges in retrieval with respect to arterial access and cross clamping of the aorta. Prior knowledge of the profile of the various devices is critical in order to ensure a safe retrieval and smooth conduct of the operation.

Patient-Specific Computer Simulation of Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Morphology

Background:

A patient-specific computer simulation of transcatheter aortic valve replacement (TAVR) in tricuspid aortic valve has been developed, which can predict paravalvular regurgitation and conduction disturbance. We wished to validate a patient-specific computer simulation of TAVR in bicuspid aortic valve and to determine whether patient-specific transcatheter heart valve (THV) sizing and positioning might improve clinical outcomes.

Methods:

A retrospective study was performed on TAVR in bicuspid aortic valve patients that had both pre- and postprocedural computed tomography imaging. Preprocedural computed tomography imaging was used to create finite element models of the aortic root. Finite element analysis and computational fluid dynamics was performed. The simulation output was compared with postprocedural computed tomography imaging, cineangiography, echocardiography, and electrocardiograms. For each patient, multiple simulations were performed, to identify an optimal THV size and position for the patient’s specific anatomic characteristics.

Results:

A total of 37 patients were included in the study. The simulations accurately predicted the THV frame deformation (minimum-diameter intraclass correlation coefficient, 0.84; maximum-diameter intraclass correlation coefficient, 0.88; perimeter intraclass correlation coefficient, 0.91; area intraclass correlation coefficient, 0.91), more than mild paravalvular regurgitation (area under the receiver operating characteristic curve, 0.86) and major conduction abnormalities (new left bundle branch block or high-degree atrioventricular block; area under the receiver operating characteristic curve, 0.88). When compared with the implanted THV size and implant depth, optimal patient-specific THV sizing and positioning reduced simulation-predicted paravalvular regurgitation and markers of conduction disturbance.

Conclusions:

Patient-specific computer simulation of TAVR in bicuspid aortic valve may predict the development of important clinical outcomes, such as paravalvular regurgitation and conduction abnormalities. Patient-specific THV sizing and positioning may improve clinical outcomes of TAVR in bicuspid aortic valve.

Clinical outcomes of the Lotus Valve in patients with bicuspid aortic valve stenosis: An analysis from the RESPOND study

AIMS

Patients with bicuspid valves represent a challenging anatomical subgroup for transcatheter aortic valve implantation (TAVI). This analysis evaluated the clinical outcomes of the fully repositionable and retrievable Lotus Valve System in patients with bicuspid aortic valves enrolled in the RESPOND post-market registry.

METHODS AND RESULTS

The prospective, open-label RESPOND study enrolled 1,014 patients at 41 centers in Europe, New Zealand, and Latin America, 31 (3.1%) of whom had bicuspid aortic valves. The mean age in the bicuspid patient cohort was 76.4 years, 64.5% were male, and the baseline STS score was 6.0 ± 10.2. Procedural success was 100%, with no cases of malpositioning, valve migration, embolization, or valve-in-valve. Repositioning was attempted in 10 cases (32.3%). There was one death (3.2%) and one stroke (3.2%) at 30-day follow-up. Mean AV gradient was reduced from 48.7 ± 17.0 mmHg at baseline to 11.8 ± 5.1 mmHg at hospital discharge (P < 0.001); mean effective orifice area (EOA) was increased from 0.6 ± 0.2 cm² to 1.7 ± 0.4 cm² (P < 0.001). There were no cases of moderate or severe paravalvular leak (PVL) adjudicated by the core laboratory; four subjects (13.8%) had mild PVL, 5 (17.2%) had trace PVL. The rate of pacemaker (PM) implantation for PM-naïve patients was 22.2% (6/27).

CONCLUSIONS

Data from the RESPOND registry demonstrate good clinical and echocardiographic outcomes up to 1 year postimplantation in patients with bicuspid aortic valves using the repositionable Lotus Valve.

Principles of TAVR valve design, modelling, and testing

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has emerged as an effective minimally-invasive alternative to surgical valve replacement in medium- to high-risk, elderly patients with calcific aortic valve disease and severe aortic stenosis. The rapid growth of the TAVR devices market has led to a high variety of designs, each aiming to address persistent complications associated with TAVR valves that may hamper the anticipated expansion of TAVR utility.

AREAS COVERED

Here we outline the challenges and the technical demands that TAVR devices need to address for achieving the desired expansion, and review design aspects of selected, latest generation, TAVR valves of both clinically-used and investigational devices. We further review in detail some of the up-to-date modeling and testing approaches for TAVR, both computationally and experimentally, and additionally discuss those as complementary approaches to the ISO 5840-3 standard. A comprehensive survey of the prior and up-to-date literature was conducted to cover the most pertaining issues and challenges that TAVR technology faces.

EXPERT COMMENTARY

The expansion of TAVR over SAVR and to new indications seems more promising than ever. With new challenges to come, new TAV design approaches, and materials used, are expected to emerge, and novel testing/modeling methods to be developed.

Transcatheter Treatment of Bicuspid Aortic Valve Disease: Imaging and Interventional Considerations

Patients with bicuspid aortic valve disease have systematically been excluded from large randomized clinical trials investigating transcatheter aortic valve implantation (TAVI) due to their younger age, lower surgical risk and complex aortic anatomy. The asymmetric nature of the bicuspid valve orifice often accompanied by heavy regional calcification has led to concerns regarding valve positioning and expansion. Bicuspid aortic valve disease patients are at heightened risk of TAVI-related complications including coronary occlusion, aortic dissection and annular rupture, as well as the known risks of progressive aortopathy in these patients. These unique anatomical characteristics pose challenges for TAVI operators. However, with recent and ongoing refinements in implantation technique, improvements in pre-procedural imaging and iterations in device design, TAVI is emerging as a safe and feasible treatment option in this population. Paravalvular aortic regurgitation and high pacemaker rates have been the Achilles Heel for TAVI in bicuspid valve patients, yet newer generation devices are yielding promising results. Further studies are required before TAVI ultimately emerges as a viable option in low and intermediate surgical-risk patients with bicuspid valve disease. This review comprehensively summarizes the epidemiology, pathology and current evidence for TAVI in patients with bicuspid aortic valve disease. We also outline some practical tips for performing TAVI in these patients.

Transcatheter aortic valve implantation in bicuspid aortic valve stenosis

Bicuspid aortic stenosis (AS) is not rare in patients treated with transcatheter aortic valve implantation (TAVI). Bicuspid valves have unique anatomy which could affect the results of TAVI; however, multiple recent reports have shown that TAVI is safe and effective in this population. Paravalvular aortic regurgitation was initially found to be more frequent in bicuspid patients, but newer-generation devices have shown superior results in this respect. Higher rates of pacemaker implantation after TAVI in bicuspid AS do require further investigation. Current data suggest that bicuspid valves should not be a contraindication for TAVI, but future specific trials are needed to support this assertion.

Transcatheter aortic valve implantation: new hope in the management of valvular heart disease

Severe calcific aortic stenosis is relatively common, and unless treated with valve replacement it carries an adverse prognosis. A large number of patients, however, are denied surgery due to their advanced age or coexistent medical conditions that increase perioperative cardiovascular risks. Transcatheter aortic valve implantation (TAVI), a technique in which a bioprosthetic valve is inserted via a catheter and implanted within the diseased native aortic valve, is a new therapeutic modality for treatment of older patients with severe symptomatic aortic stenosis and other comorbidities, who have an inherently high surgical risk. This review will provide an overview of the pivotal trials in the development of TAVI; while also investigating important complications and limitations of the procedure and evaluating how new valves are being designed and clinically evaluated, with the ultimate goal of reducing potential complications and expanding the use of TAVI to lower-risk patient cohorts.