Outcomes and predictors of patients with moderate or severe functional mitral regurgitation and nonischemic dilated cardiomyopathy

Abstract

Background: Patients with functional mitral regurgitation (FMR) and nonischemic dilated cardiomyopathy (DCM) are associated with high mortality.

Objectives: Our study aimed to compare the clinical outcomes between different treatment strategies and identify predictors associated with the adverse outcomes.

Methods: A total of 112 patients with moderate or severe FMR and nonischaemic DCM were included in our study. The primary composite outcome was all-cause death or unplanned hospitalization for heart failure. The secondary outcomes were individual components of the primary outcome and the cardiovascular death.

Results: In this study, the primary composite outcome occurred in 26 patients (44.8%) in mitral valve repair (MVr) group and 37 patients (68.5%) in medical group (hazard ratio [HR], 0.28; 95% confidence interval [CI], 0.14-0.55; p < .001). The 1-, 3-, and 5-year survival rates for patients with MVr were 96.6%, 91.8%, and 77.4%, respectively, which were significantly higher than that of medical group: 81.2%, 71.9%, and 65.1%, respectively (HR, 0.32; 95% CI, 0.12-0.87; p = .03). Left ventricular ejection fraction (LVEF) < 41.5% (p < .001) and atrial fibrillation (p = .02) were independently associated with the primary outcome. LVEF < 41.5% (p = .007), renal insufficiency (p = .003), and left ventricular end-diastolic diameter > 66.5 mm (p < .001) were independently associated with heightened risk for all-cause death.

Conclusion: Compared with medical therapy, MVr was associated with a better prognosis in patients with moderate or severe FMR and nonischemic DCM. We observed that LVEF < 41.5% was the only independent predictor of the primary outcome and all individual components of secondary outcomes.

Keywords: functional mitral regurgitation; medical therapy; mitral valve repair; nonischemic dilated cardiomyopathy; prognosis; risk factors.