Meta-analysis of the impact of mitral regurgitation on outcomes after transcatheter aortic valve implantation.

Significant mitral regurgitation (MR) constitutes an important co-existing valvular heart disease burden in the setting of aortic valve stenosis. There are conflicting reports on the impact of significant MR on outcomes after transcatheter aortic valve implantation (TAVI). We evaluated the impact of MR on outcomes after TAVI by performing a meta-analysis of 8 studies involving 8,927 patients reporting TAVI outcomes based on the presence or absence of moderate-severe MR. Risk ratios (RRs) were calculated using the inverse variance random-effects model. None-mild MR was present in 77.8% and moderate-severe MR in 22.2% of the patients. The presence of moderate-severe MR at baseline was associated with increased mortality at 30 days (RR 1.35, 95% confidence interval [CI] 1.14 to 1.59, p = 0.003) and 1 year (RR 1.24, 95% CI 1.13 to 1.37, p <0.0001). The increased mortality associated with moderate-severe MR was not influenced by the cause of MR (functional or degenerative MR; RR 0.90, 95% CI 0.62 to 1.30, p = 0.56). The severity of MR improved in 61 ± 6.0% of patients after TAVI. Moderate-severe residual MR, compared with none-mild residual MR after TAVI, was associated with significantly increased 1-year mortality (RR 1.48, 95% CI 1.31 to 1.68, p <0.00001). In conclusion, baseline moderate-severe MR and significant residual MR after TAVI are associated with an increase in mortality after TAVI and represent an important group to target with medical or transcatheter therapies in the future.