Balloon-Expandable Versus Self-Expanding Valves in Patients With Small Aortic Annuli Undergoing Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is a widely accepted treatment option for patients with severe aortic valve stenosis. However, approximately one-third of patients undergoing TAVR present with a small aortic annulus, which is associated with impaired valve performance. The primary objective of this study was to evaluate 2-year mortality after transfemoral TAVR in patients with a small aortic annulus (valve size ≤23 mm for balloon-expandable valves and ≤26 mm for self-expanding valves), comparing balloon-expandable with self-expanding valves. The CENTER2-study includes data from 25,771 patients undergoing TVR. Patients were propensity score-matched and compared on clinical outcomes. A total of 8,827 (37.2%) patients had a small aortic annulus. Mean age was 81.9 ± 6.3 years, 76.9% were female, and the median STS-PROM score was 4.8% (IQR 2.3 to 5.6). In the matched cohort of 2,692 patient pairs, patients receiving a balloon-expandable valve had higher rates of life-threatening bleeding at 30 days (3.6% vs 2.4%, p = 0.01) and two-year mortality (19.1% vs 15.3%, HR 1.23, 95% CI 1.07 to 1.43, p = 0.004). However, permanent pacemaker implantation was more frequent in patients receiving a self-expanding valve (21.6% vs 8.7%, p < 0.001). In conclusion, in this large real-world cohort of patients undergoing transfemoral TAVR, 37.2% of patients had a small aortic annulus. Patients with a small aortic annulus receiving a balloon-expandable valve had higher 2-year mortality rates. Patients receiving a self-expanding valve had higher rates of permanent pacemaker implantation.