Abstract
Background: Atrial fibrillation (AF) and mitral regurgitation (MR) are frequently combined in patients with heart failure (HF). However, the effect of AF on the prognosis of patients with HF and MR remains unknown. Methods and Results: We studied 867 patients (mean age 73 years; 42.7% female) with acute decompensated HF (ADHF) in the NARA-HF registry. Patients were divided into 4 groups based on the presence or absence of AF and MR at discharge. Patients with severe MR were excluded. The primary endpoint was the composite of cardiovascular (CV) death and HF-related readmission. During the median follow-up of 621 days, 398 patients (45.9%) reached the primary endpoint. In patients with MR, AF was associated with a higher incidence of the primary endpoint regardless of left ventricular function; however, in patients without MR, AF was not associated with CV events. Cox multivariate analyses showed that the incidence of CV events was significantly higher in patients with AF and MR than in patients with MR but without AF (hazard ratio 1.381, P=0.036). Similar findings were obtained in subgroup analysis of patients with AF and only mild MR. Conclusions: The present study demonstrated that AF is associated with poor prognosis in patients with ADHF with mild to moderate MR, but not in those without MR.