Severity of Functional Mitral Regurgitation on Admission for Acute Decompensated Heart Failure Predicts Long‐Term Risk of Rehospitalization and Death

BACKGROUND: Functional mitral regurgitation (FMR) has emerged as a therapeutic target in patients with chronic heart failure and left ventricular systolic dysfunction. The significance of FMR in acute decompensated heart failure remains obscure. We systematically investigated the prevalence and clinical significance of FMR on admission in patients admitted with acute decompensated heart failure and left ventricular systolic dysfunction. METHODS AND RESULTS: The study was a single‐center, retrospective review of patients admitted with acute decompensated heart failure and left ventricular systolic dysfunction between 2012 and 2017. Patients were divided into 3 groups of FMR: none/mild, moderate, and moderate‐to‐severe/severe FMR. The primary outcome was 1‐year post‐discharge all‐cause mortality. We also compared these groups for 6‐month heart failure hospitalization rates. Of 2303 patients, 39% (896) were women. Median left ventricular ejection fraction was 25%. Four hundred and fifty‐three (20%) patients had moderate‐to‐severe/severe FMR, which was independently associated with 1‐year all‐cause mortality. Moderate or worse FMR was found in 1210 (53%) patients and was independently associated with 6‐month heart failure hospitalization. Female sex was independently associated with higher severity of FMR. CONCLUSIONS: More than half of patients hospitalized with acute decompensated heart failure and left ventricular systolic dysfunction had at least moderate FMR, which was associated with increased readmission rates and mortality. Intensified post‐discharge follow‐up should be undertaken to eliminate FMR amenable to pharmacological therapy and enable timely and appropriate intervention for persistent FMR. Further studies are needed to examine sex‐related disparities in FMR.