Balloon-versus self-expandable transcatheter aortic valve implantation in small aortic annuli: a meta-analysis of randomized and propensity studies.

The hemodynamic and clinical differences between balloon- (BEV) and self-expandable valves (SEV) are critical for patients with a small aortic annulus (SAA). This meta-analysis aims to evaluate the clinical and hemodynamic performance of these two systems in patients with severe aortic stenosis and SAA. A systematic review was conducted from inception to June 2024 for randomized and propensity-score studies comparing BEV and SEV outcomes in patients with a SAA. Reconstructed individual patient data (IPD) from Kaplan Meier curves was pooled for overall survival and rehospitalization for heart failure. Nine studies with 2856 patients met our inclusion criteria: 1427 in the BEV group and 1429 in the SEV group. SEV demonstrated superior hemodynamic performance, including improved iEOA (Standardized Mead Difference [SMD]: 0.52, p = 0.0012), lower mean gradients (SMD: - 0.89, p < 0.0001), and reduced PPM (Odds Ratio [OR]: 0.38, p < 0.0001) compared to BEV. BEV presented lower new pacemaker rates compared to SEV (OR: 1.52, p = 0.0447). There were no significant differences between SEV and BEV in terms of rates of > mild paravalvular leaks, early stroke, and Valve Academic Research Consortium-defined outcomes. Reconstructed IPD showed no significant differences in overall survival (Hazard Ratio [HR]: 0.95, p = 0.584) and rehospitalization for heart failure (HR: 1.05, p = 0.828) during follow-up. In patients with SAA undergoing TAVI the use of BEV was associated with higher frequency of PPM and/or pressure gradients. Similar early stroke, survival and rehospitalization rates were reported. Pacemaker rates were higher with SEV. Long-term follow-up studies are required, especially with newer-generation devices.