Abstract 4132498: Hemodynamic and Clinical Outcomes with Balloon-Expandable Valves Versus Self-Expanding Valves in Patients with Small Aortic Annulus Undergoing Transcatheter Aortic Valve Implantation: A Meta-Analysis of Randomized Controlled Trials

Background: Transcatheter aortic valve implantation (TAVI) is thought to be more effective than surgery for patients with small aortic annulus (SAA), however, the comparative efficacy of different transcatheter heart valves (THVs) remains uncertain. The objective of this meta-analysis was to compare the effects of balloon-expandable valves (BEVs) and self-expanding valves (SEVs) on hemodynamic parameters and clinical outcomes in patients with SAA who underwent TAVI. Methods: A thorough literature search was performed across PubMed/MEDLINE, Embase, and the Cochrane Library from their inception until May 2024 to identify eligible randomized controlled trials (RCTs) and propensity-score matched (PSM) studies. Clinical outcomes were evaluated using a random-effects model to pool risk ratios (RRs) with 95% confidence intervals (CIs). Results: The analysis included 8 studies; 2 RCTs and 6 PSM studies, with a total of 2,180 patients with SAA. BEVs were associated with a smaller indexed effective orifice area (MD: -0.18, 95% CI: -0.31 to -0.05) and a higher transvalvular mean pressure gradient (MD: 5.23, 95% CI 3.44 to 7.02) than SEVs. The risk for prosthesis-patient mismatch (PPM) (RR= 1.82, 95% CI: 1.27 to 2.60) and severe PPM (RR= 2.77, 95% CI: 1.93 to 3.98) was significantly higher for patients receiving BEVs than those receiving SEVs. However, no significant difference was observed between BEVs and SEVs regarding the risk of paravalvular leak (RR= 0.98, 95% CI: 0.57 to 1.69) and the permanent pacemaker implantation (RR= 0.78, 95% CI: 0.50 to 1.23). Although patients receiving BEVs showed a slightly lower risk of major bleeding events (RR= 0.69, 95% CI: 0.49 to 0.99), BEVs were associated with a significantly increased risk of 1-year cardiovascular mortality (RR= 1.61, 95% CI: 1.05 to 2.47) compared to those receiving SEVs. However, no significant differences were observed between BEVs and SEVs regarding 30-day all-cause mortality (RR= 1.19, 95% CI: 0.57 to 2.49), 1-year all-cause mortality (RR= 1.17, 95% CI: 0.89 to 1.53), stroke rates (RR= 0.83, 95% CI: 0.52 to 1.31) and any vascular complication (RR= 1.13, 95% CI: 0.72 to 1.75). Conclusion: In patients with SAA, SEVs showed reduced risks of PPM and severe PPM compared to BEVs, along with a larger indexed effective orifice area. Moreover, SEVs were associated with a lower risk of 1-year cardiovascular mortality.