Clinical Comparison of a Novel Balloon-Expandable Versus a Self-Expanding Transcatheter Heart Valve for the Treatment of Patients with Severe Aortic Valve Stenosis: The EVAL Registry

Transcatheter aortic valve replacement (TAVR) has been developed as a successful treatment option for a broad range of patients affected by severe, symptomatic aortic stenosis (AS). Prior studies have demonstrated device success with lower paravalvular leak (PVL) using the balloon-expandable (BE) Sapien/XT transcatheter heart valve (THV) vs. a self-expanding (SE) THV. Yet, very limited data are available concerning this pioneering THV.

The aim of this study was to compare early safety and clinical performance of the newly available BE Myval THV compared to the SE THV which is a commonly used valve, in a cohort of intermediate–low-risk profile patients with severe, symptomatic AS, undergoing TAVR.

This study is the first of its kind to provide a clinical comparison between the well-known SE THV and the novel BE Myval THV with features that ease procedural aspects, while theoretically maintaining favourable clinical outcomes.

The study confirms a comparable clinical performance and rates of overall mortality and disabling stroke between the two THV methods, while showing superior benefits with the BE Myval THV in reducing the risk of pacemaker implantation (PPI) and ≥ mild PVL within 30 days and 6 months after the implantation.

From March 2019 to March 2021, a single-centre, retrospective cohort analysis was performed with patients undergoing TAVR for severe symptomatic AS. Patients were treated with either the BE Myval or the SE Evolut R (ER) bioprosthesis.

• Device success at day 30 according to the Valve Academic Research Consortium-3 composite outcome of technical success

• 30-day all-cause mortality, cardiovascular mortality, ≥ mild PVL, and PPI rates
• A composite of all-cause mortality and disabling stroke at 6 months

• Symptomatic, severe, native aortic valve stenosis
• Indications for TAVR  

• Patients with a prior permanent pacemaker who were not at risk for the outcome

• In total 166 patients were included; 108 patients received the SE ER THV and 58 patients received the BE Myval THV
• The two groups demonstrated similar baseline clinical characteristics
• Early device success transpired in 55 patients (94.8%) in the BE Myval group vs. 90 patients (83.3%) in the SE ER group (odds ratio [OR], 3.667; 95% confidence interval [CI], 1.094–12.14; p = 0.048)
• There were significantly lower incidences of ≥ moderate PVL (3.45% vs. SE ER 14.8%; OR, 0.2, 95% CI, 0.05–0.8; p = 0.0338), and PPI (11% vs. SE ER 24.2%; OR, 0.38, 95% CI, 0.15–0.99; p = 0.0535) in the BE Myval THV group at day 30
• No significant differences were found in the incidences of all-cause mortality and disabling stroke between the two groups, 6-month post-implantation
• At the 6-month follow-up, the BE Myval THV was significantly associated with lower rates of PPI (11% vs. SE ER 27.5%; OR, 0.32, CI, 95% 0.1273–0.8; p = 0.02) and ≥ moderate PVL (6.9% vs. SE ER 19.8%; OR, 0.31; 95% CI, 0.1–0.94; p = 0.0396)

This observational experience, comparing the BE THV with the SE ER THV, showed a similar clinical and haemodynamic performance of the two devices and equivalent clinical performance. Promising clinical results were delivered by the newer generation BE Myval THV as shown to be associated with a lower incidence of mild PVL and the less frequent need for PPI in patients implanted with this device.

• Lack of randomisation and the small sample size
• Short-term follow-up time and the single-centre experience