Self-Expandable Versus Balloon-Expandable Transcatheter Aortic Valve Replacement for Treatment of Patients With Small Aortic Annulus: An Updated Meta-Analysis of Reconstructed Individual Patient Data

Transcatheter aortic valve replacement has emerged as an effective alternative to surgery in selected patients with aortic stenosis. It needs to be made clear which type of valve has better results in patients with small aortic annulus. We searched PubMed, Scopus, Embase, Cochrane Library, and Web of Science, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A total of 27 articles were included, including 10,378 patients [5989 in balloon-expanding valve (BEV) and 4389 in the self-expanding valve (SEV) groups] with small aortic annulus. Our meta-analysis demonstrated no significant difference between SEVs and BEVs for 1-year all-cause mortality. There was a statistically significant increased risk of permanent pacemaker implantation (PPI) within 30 days and ischemic stroke at 1 year with SEVs [risk ratio (RR) = 1.69, 95% confidence interval (CI) = 1.18-2.42, P < 0.01, and RR = 1.83, 95% CI = 1.03-3.26, P = 0.04, respectively]. Our meta-analysis showed that SEVs are favored over BEVs in terms of 1-year change from baseline in effective orifice area (mean difference = 0.45, 95% CI = 0.19-0.71, P < 0.01). Moreover, after 1-year follow-up, severe patient-prosthesis mismatch was significantly lower in the SEV group (RR = 0.24, 95% CI = 0.11-0.53, P < 0.01). In conclusion, SEVs were associated with better echocardiographic outcomes from baseline. Patients with SEVs were more likely to develop stroke and require PPI but were less likely to have patient-prosthesis mismatch. The benefit of a larger effective aortic valve area with SEVs has to be balanced against higher PPI and stroke rates.