Impact of left ventricular function on clinical outcomes of functional mitral regurgitation patients undergoing transcatheter mitral valve repair.

Abstract

To evaluate the impact of baseline left ventricular (LV) function on the clinical outcomes of patients with functional mitral regurgitation (FMR) treated with MitraClip. It is unknown whether patients with significant FMR and severe LV dysfunction benefit from MitraClip. A cohort of 77 patients with significant FMR undergoing MitraClip procedure between December 2010 and January 2015 was categorized by baseline LV ejection fraction (LVEF) into tertiles: LVEF <27% (n = 27), LVEF 27-37% (n = 25), and LVEF >37% (n = 25). We sought to evaluate the impact of LVEF on all-cause mortality at follow-up. There were no significant differences in baseline comorbidities, medical treatment and MR severity among tertiles of LVEF. Overall procedural success was 94%, with no differences among groups (LVEF <27%: 89%; LVEF 27-37%: 100%; LVEF >37%: 92%; P = 0.25). Median follow-up was 372 days (interquartile range: 128-627 days). MR severity improved in all three groups, as compared to baseline. There were no differences in the prevalence of MR ≤2+ on follow-up (P = 0.40). Mortality was highest in patients with LVEF <27% (41%), as compared with LVEF 27-37% (16%) and LVEF >37% (4%), P = 0.004. Patient who died had a lower baseline LVEF compared to those who survived (24.8 ± 7.7% versus 35.5 ± 13.7%, P < 0.001). An LVEF <27% was an independent predictor of mortality after adjusting for procedural success: hazard ratio 3.4 (95% CI: 1.1 to 10.0; P = 0.030). MitraClip is effective in FMR patients regardless of the severity of LV dysfunction. However, low baseline LVEF is associated with increased mortality, despite procedural success. © 2016 Wiley Periodicals, Inc.