In patients undergoing transcatheter aortic valve implantation (TAVI), patient–prosthesis mismatch is associated with increased mortality. Findings from the SMART trial now show that in patients with symptomatic aortic stenosis and a small aortic annulus, a self-expanding valve has similar rates of clinical outcomes at 1 year and lower rates of bioprosthetic dysfunction compared with a balloon-expandable valve. These findings were presented at the ACC.24 conference.

The multicentre SMART trial involved 716 patients (mean age 80 years, 87% women) with symptomatic severe aortic stenosis and an aortic valve annulus area of ≤430 mm2 who were randomly assigned to undergo TAVI with a self-expanding supra-annular valve or a balloon-expandable valve. At 1 year, the self-expanding valve was non-inferior to the balloon-expandable valve for the composite end point of stroke, heart failure rehospitalization and death, and superior with respect to bioprosthetic valve dysfunction. Furthermore, the self-expanding valve was also superior to the balloon-expandable valve for numerous hypothesis-tested secondary end points, including mean gradient and mean effective orifice area. Moderate or severe patient–prosthesis mismatch at 30 days was observed in 11.2% of the self-expanding valve group compared with 35.3% of the balloon-expandable valve group (P < 0.001).