Early outcomes of the novel Myval THV series compared to SAPIEN THV series and Evolut THV series in individuals with severe aortic stenosis

Abstract

Background: There are limited head-to-head randomised trials comparing the performance of different transcatheter heart valves (THVs).

Aims: We aimed to evaluate the non-inferiority of the balloon-expandable Myval THV series compared to the balloon-expandable SAPIEN THV series or the self-expanding Evolut THV series.

Methods: The LANDMARK trial randomised 768 patients in a 1:1 ratio, (Myval THV series [n=384] vs contemporary series with 50% SAPIEN THV series [n=192] and 50% Evolut THV series [n=192]). The non-inferiority of Myval over the SAPIEN or Evolut THV series in terms of the 30-day primary composite safety and effectiveness endpoint as per the third Valve Academic Research Consortium (VARC-3) was tested in an intention-to-treat population with a predefined statistical power of 80% (1-sided alpha of 5%) for a non-inferiority margin of 10.44%.

Results: The Myval THV series achieved non-inferiority for the primary composite endpoint over the SAPIEN THV series (24.7% vs 24.1%, risk difference [95% confidence interval {CI}]: 0.6% [not applicable {NA} to 8.0]; p=0.0033) and the Evolut THV series (24.7% vs 30.0%, risk difference [95% CI]: –5.3% [NA to 2.5]; p<0.0001). The incidences of pacemaker implantation were comparable (Myval THV series: 15.0%, SAPIEN THV series: 17.3%, Evolut THV series: 16.8%). At 30 days, the mean pressure gradient and effective orifice area were significantly better with the Myval THV series compared to the SAPIEN THV series (p<0.0001) and better with the Evolut THV series than with the Myval THV series (p<0.0001). At 30 days, the proportion of moderate to severe prosthetic valve regurgitation was numerically higher with the Evolut THV series compared to the Myval THV series (7.4% vs 3.4%; p=0.06), while not significantly different between the Myval THV series and the SAPIEN THV series (3.4% vs 1.6%; p=0.32).

Conclusions: The Myval THV series is non-inferior to the SAPIEN THV series and the Evolut THV series in terms of the primary composite endpoint at 30 days. Clinical trial registration: ClinicalTrials.gov: NCT04275726; EudraCT number 2020-000,137-40.