Hemodynamic and clinical outcomes with balloon-expandable valves versus self-expanding valves in patients with small aortic annulus undergoing transcatheter aortic valve replacement: A meta-analysis of randomized controlled trials and propensity score matched studies

Transcatheter aortic valve replacement (TAVR) is considered more effective than surgical aortic valve implantation for patients with a small aortic annulus (SAA), however, the comparative efficacy of different transcatheter heart valves (THVs) remains uncertain. A literature search was performed across databases from their inception until June 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). The analysis included 10 studies with 2,960 patients. BEVs were associated with a significantly smaller indexed effective orifice area (MD: -0.18, 95 % CI: -0.27 to -0.10), and a higher transvalvular mean pressure gradient (MD: 5.07, 95 % CI 3.43 to 6.71) than SEVs. The risk for prosthesis-patient mismatch (PPM) (RR = 1.89, 95 % CI: 1.42 to 2.51) and severe PPM (RR = 2.80, 95 % CI: 1.96 to 4.0) was significantly higher for patients receiving BEVs than those receiving SEVs. Although nonsignificant differences were observed between BEVs and SEVs regarding 30-day and 1-year all-cause mortality, 30-day stroke rates, vascular complication, paravalvular leak, and permanent pacemaker implantation (p > 0.05), patients receiving 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. In patients with SAA, BEVs demonstrated worse hemodynamic performance as determined by the higher risk of moderate and severe PPM compared to SEVs. Moreover, the use of BEVs was associated with a higher risk of 1-year cardiovascular mortality.