Impact of Concomitant Mitral Regurgitation on Cardiovascular Events and Mortality After Transcatheter Aortic Valve Replacement: A Meta-Analysis

Abstract

Mitral regurgitation (MR) is common in patients undergoing transcatheter aortic valve replacement (TAVR). However, it is unclear how MR severity affects prognosis. This meta-analysis evaluated the associations among baseline MR severity, cardiovascular outcomes, and mortality after TAVR. Eligible studies included adult patients undergoing TAVR with stratified MR severity (MR >/= 2 or MR >/= 3) and reported the post-TAVR clinical outcomes. Sensitivity analyses stratified by follow-up duration, leave-one-out sensitivity, and meta-regression were also conducted. Forty-two studies (n = 67,257 patients) were included. MR >/= 2 was associated with increased all-cause mortality during follow-up (> 30 days) (hazard ratio HR: 1.40; 95% confidence interval CI: 1.26, 1.55) and cardiovascular mortality (risk ratio RR: 1.80; 95% CI: 1.05, 3.08), but not with stroke, transient ischemic attack, myocardial infarction (MI), or heart failure hospitalization. MR >/= 3 conferred an even higher risk of all-cause mortality during follow-up (RR: 1.55; 95% CI: 1.24, 1.94) and rehospitalization (RR: 1.40; 95% CI: 1.17, 1.67), but not for stroke and MI. MR improvement occurred in 41% of patients within < 1-year post-TAVR, declined to 15% at > 1-year post-TAVR. Baseline moderate-to-severe MR (MR >/= 2) predicts all-cause mortality during follow-up and cardiovascular mortality after TAVR, particularly severe MR (MR >/= 3). While no consistent associations were found with nonfatal outcomes such as stroke, TIA, MI, or heart failure hospitalization, the prognostic impact of MR appears to be predominantly mortality-centered.