Self-expanding or balloon-expandable transcatheter aortic valve replacement in patients with small aortic annulus: A systematic review and meta-analysis

Abstract

Background: A small aortic annulus presents unique hemodynamic challenges during transcatheter aortic valve replacement (TAVR), increasing the risk of prosthesis-patient mismatch (PPM) and suboptimal valve performance. This study aimed to compare the efficacy and safety of self-expanding valves (SEVs) versus balloon-expandable valves (BEVs) in patients with a small aortic annulus. Methods: A systematic search using 4 databases, including PubMed, Embase, Web of Science, and Cochrane CENTRAL, was conducted from inception to June 1, 2025. Studies comparing clinical outcomes of SEVs and BEVs in patients with a small aortic annulus were included. Results: Thirty-eight studies involving 19,421 participants were included. No significant difference in all-cause mortality was observed between SEVs and BEVs from in-hospital to 5-year follow-up. SEVs were associated with a significantly lower risk of PPM at discharge (OR 0.34, 95 % CI 0.28–0.42), 30 days (OR 0.31, 95 % CI 0.21–0.47), and 1 year (OR 0.25, 95 % CI 0.15–0.42). However, SEVs were associated with a higher risk of in-hospital paravalvular leakage (PVL) (OR 1.95, 95 % CI 1.39–2.74), moderate-to-severe PVL (OR 2.48, 95 % CI 1.91–3.22), and permanent pacemaker implantation (PPI) both in-hospital and at 30 days. These findings remained consistent across sensitivity analyses limited to new-generation valves and propensity score-matched or randomized studies. Conclusions: SEVs offer favorable hemodynamic advantages and lower risks of PPM and valve dysfunction compared to BEVs, with no difference in survival. However, these benefits must be weighed against the increased risks of PVL and PPI. Individualized valve selection remains essential to optimizing outcomes in TAVR patients.