The impact of functional vs degenerative mitral regurgitation on clinical outcomes among patients undergoing transcatheter aortic valve implantation

Abstract

Among patients undergoing transcatheter aortic valve implantation (TAVI), concomitant mitral regurgitation (MR) has been associated with adverse prognosis. We aimed to assess long-term clinical outcomes according to MR etiology. In a single-center registry of consecutive patients undergoing TAVI, we investigated the impact of functional (FMR) vs degenerative (DMR) MR on cardiovascular (CV) mortality throughout 2years of follow-up. Among 603 patients (mean age 82.4±5.7years, 55% female) undergoing TAVI, 149 patients had moderate or severe MR (24.7%). Functional MR and DMR were documented in 53 (36%) and 96 (64%) patients, respectively. At 2years, patients with FMR and DMR had higher rates of CV mortality (30.2% vs 32.4%) as compared with patients with no MR (14.6%; FMR vs no MR: hazard ratio [HR] 2.32, 95% CI 1.34-4.02, P=.003; DMR vs no MR: HR 2.56, 95% CI 1.66-3.96, P<.001). In adjusted analyses, DMR was associated with an increased risk of CV mortality throughout the 2-year follow-up (adjusted HR 2.21, 95% CI 1.4-3.49, P=.001) as compared with FMR (adjusted HR 1.13, 95% CI 0.59-2.18, P=.707). Relevant MR was postprocedurally significantly reduced in both the DMR and FMR groups, whereas improvement of a decreased left ventricular ejection fraction was predominantly seen in the FMR group as compared with baseline. Patients with severe, symptomatic aortic stenosis undergoing TAVI complicated by moderate or severe MR portend impaired prognosis. Particularly, patients with DMR are at increased risk for CV mortality during long-term follow-up.