INTRODUCTION: Several factors, including device design, annulus size, and sizing strategies, influence transcatheter heart valve (THV) hemodynamic outcomes in patients with aortic stenosis(AS). This substudy evaluates early (30-day) echocardiographic outcomes of the Myval, Sapien, and Evolut THV series, focusing on hemodynamic performance and valve durability.

METHODOLOGY: The LANDMARK trial is a prospective, randomised, multicentre, open-label, non-inferiority trial comparing 384 patients implanted with Myval THV series to 384 receiving Sapien and Evolut THV series. Hemodynamic assessments followed Valve Academic Research Consortium-3 recommendations.

RESULTS: At 30-day, hemodynamic device success rates were 85.9%, 77.8, and 85.4% for Myval, Sapien, and Evolut THV series, respectively (PMyval-Sapien=0.02 and PMyval-Evolut>0.99). Significant improvements in peak aortic flow velocity, pressure gradients, effective orifice area(EOA), Doppler velocity index(DVI), and cardiac indices were observed across all groups, except for unchanged left ventricular ejection fraction. Moderate prosthesis-patient mismatch (PPM) was less frequent with Myval THV series(10.7%) versus Sapien THV series(22.5%), but higher than Evolut THV series (6.0%)(PMyval-Sapien=0.0006, PMyval-Evolut=0.12), while severe PPM showed no significant differences(4.3% vs 6.5% vs 1.8%; PMyval-Sapien=0.40, PMyval-Evolut=0.23). Total aortic regurgitation (≥moderate) showed no significant difference for Myval (2.6%), Sapien(1.8%) or Evolut THV series (6.3%)(PMyval-Sapien=0.76, PMyval-Evolut=0.06). Myval THV series required minimal oversizing compared to Evolut THV series (P<0.0001).

CONCLUSION: The Myval THV series demonstrates short-term hemodynamic performance comparable to Evolut THV series and superior to Sapien THV series in moderate PPM incidence. Including intermediate sizes minimizes oversizing, underscoring its potential as an alternative for TAVI patients. Long-term follow-up is necessary to confirm these findings.