The novel balloon-expandable Myval transcatheter heart valve (THV) demonstrated noninferiority to contemporary THVs in patients with severe native aortic stenosis, new randomized trial results show. Patrick W. Serruys, MD, PhD, of the University of Galway, Ireland, presented these findings during a late-breaking trials session Wednesday at EuroPCR 2024 in Paris. The LANDMARK trial randomized 768 patients with severe native aortic valve stenosis at 31 sites in 16 countries on a 1:1 basis to undergo TAVR according to the 2021 European guidelines with either the Myval THV (Meril Life Sciences Pvt. Ltd.) or a contemporary commercially available THV (Sapien [Edwards Lifesciences] or Evolut [Medtronic] series). The trial was designed to enroll real-world patients, including those with small aortic annuli and bicuspid aortic valves. The primary composite endpoint, measured at 30 days, is as defined by the Valve Academic Research Consortium 3: all-cause mortality, any stroke, major bleeding, acute kidney injury, major vascular complications, moderate or severe prosthetic valve regurgitation, and conduction system disturbances resulting in a new permanent pacemaker implantation. The Myval series is the only valve with intermediate sizes. Myval valve sizes included in the LANDMARK trial are 20, 21.5, 23, 24.5, 26, 27.5, 29, 30.5 and 32 mm. The Sapien 3 and Sapien 3 Ultra THVs are available in four sizes: 20, 23, 26 and 29 mm, and the Evolut series valves are available in 23, 26, 29 and 34 mm. The primary endpoint occurred in 24.7% of the Myval group and 27.0% of the contemporary valve group. The absolute risk difference was -2.3%, and the upper bound of the one-sided 95% confidence interval (CI) was 3.8%, which was well below the prespecified 10.44% noninferiority margin, meaning the Myval series demonstrates noninferiority to the contemporary valves (p-noninferiority < 0.0001). The components of the primary endpoint were all similar, with neither arm reporting any death or all-cause stroke through 30-days, and all other components showing low incidence rates in both arms. The Myval series also demonstrated larger effective orifice area (EOA) than the Sapien series at the 23 mm (Myval 1.8 mm2 vs. Sapien 1.58 mm2; p=0.01), 26 mm (2.13 mm2 vs. 1.9 mm2; p=0.01) and 29 mm (2.43 mm2 vs. 2.05 mm2; p=0.01). There was no difference in EOA between the Myval and Evolut series valves at comparable sizes, 26 mm (2.13 mm2 vs. 2.22 mm2; p=1.00) and 29 mm (2.43 mm2 vs. 2.27 mm2; p=0.48). Serruys said the Myval’s favorable EOA profile “may impact the durability and the long-term clinical outcomes.” He added that the “hypothetical benefit” of the larger availability of valve sizes with the Myval THV “still needs to be investigated in future trials with specific predefined endpoints or by superior clinical outcomes in the long-term follow-up.” The LANDMARK trial is planned to follow patients through 10 years. Photo Credit: Screenshot by Jason Wermers/CRTonline.org Photo Caption: Patrick W. Serruys, MD, PhD, discusses the LANDMARK trial during a news conference at EuroPCR 2024.