Meta-analysis of mortality outcomes and mitral regurgitation evolution in 4,839 patients having transcatheter aortic valve implantation for severe aortic stenosis

Transcatheter aortic valve implantation (TAVI) is an effective alternative therapy in selected patients with severe aortic stenosis. The role and effects of coexistent moderate to severe mitral regurgitation (msMR) in patients who undergo TAVI remain unclear. Thirteen studies enrolling 4,839 patients who underwent TAVI, including patients with msMR, were considered in a meta-analysis and analyzed for all-cause-mortality; a further meta-analysis was performed to assess mitral regurgitation (MR) evolution after TAVI. In patients with msMR, all-cause-mortality after TAVI was significantly increased at 30-day (effect size [ES] -0.18, 95% confidence interval [CI] -0.31 to -0.04, I(2) = 46.51, Q = 7.48), 1-year (ES -0.22, 95% CI -0.36 to -0.08, I(2) = 56.20, Q = 11.41), and 2-year (ES -0.15, 95% CI -0.27 to -0.02, I(2) = 0.00, Q = 2.64) follow-up compared with patients with absent or mild MR, independent of baseline left ventricular ejection fraction. Interestingly, the impact of msMR on outcomes was statistically stronger when the CoreValve system was used. TAVI was also associated with an improvement in MR entity at 3- and 6-month follow-up (overall ES -0.19, 95% CI -0.37 to -0.01, I(2) = 61.52, Q = 10.39). In conclusion, the presence of preoperative msMR in patients with severe, symptomatic aortic stenosis who undergo TAVI negatively affects outcomes after TAVI. In addition, in the same group of patients, a trend toward a reduction in MR severity was observed. Whether the decrease in MR severity affects mortality after TAVI remains to be defined