BACKGROUND Among patients with severe aortic stenosis (AS) un- dergoing transcatheter aortic valve implantation (TAVI), nearly one third have a small aortic annulus. These patients are at higher risk of prosthetic valve dysfunction. Recently, the SMART trial reported that the self-expanding Evolut series was superior to balloon-expandable Sapien series with respect to echocardiographic hemodynamic out- comes at one year. The Myval series is a novel balloon-expandable transcatheter heart valve (THV) whose clinical non-inferiority at 30 days compared to the Evolut and Sapien series was recently demon- strated in the LANDMARK trial. However, the performance of Myval series in patients with a small aortic annulus is unknown. METHODS The LANDMARK trial is a randomized, non-inferiority trial conducted in 16 countries, which compares the safety and effective ness between Myval THV series and contemporary THV series (Sapien and Evolut) in accordance with the third Valve Academic Research Consortium recommendations. The primary endpoint was a compos- ite of all-cause death, all stroke, bleeding (type 3 or 4), acute kidney injury stage 2-4, major vascular complication, moderate or severe prosthetic valve regurgitation (PVR), and permanent pacemaker implantation at 30 days. This sub-study compared the clinical and echocardiographic outcomes at 30 days in patients with a small aortic annulus (aortic valve annulus area &430 mm 2 ). RESULTS Out of 768 patients randomized in the trial, 245 (32%) patients had a small aortic annulus (125 patients in Myval, 64 in Sapien and 56 in Evolut). The proportions of female in patients with a small annulus were 86%, 81% and 88% in Myval, Sapien and Evolut, respectively. At 30 days, the primary composite endpoint occurred in 24 (20%), 13 (21%) and 18 (33%) patients in Myval, Sapien and Evolut, respectively (Myval vs Sapien: p¼1.00, Myval vs Evolut: p¼0.08). Myval had a lower aortic valve mean pressure gradient (MPG, Myval: 9.3mmHg; Sapien: 11.8mmHg, p<0.01) and a higher effective orifice area (EOA) compared to Sapien (1.75cm 2, 1.53cm 2 , p<0.01), while having a higher MPG (Evolut: 5.8mmHg, p<0.01) and lower EOA than Evolut (2.27cm 2 , p<0.01). CONCLUSIONS At 30 days, Myval THV series had a lower aortic valve mean pressure gradient and a higher effective orifice area than Sapien. TAVI with the Myval THV series in small annulus patients with severe aortic stenosis is comparable to both the Sapien and Evolut series in terms of primary composite endpoint at 30 days.