Prevalence, clinical characteristics, and outcome of atrial functional mitral regurgitation in hospitalized heart failure patients with atrial fibrillation

Background: Functional mitral regurgitation (MR) caused by reduced left ventricular ejection fraction (EF) and tethering, termed ventricular functional MR (VFMR), is associated with worse outcomes. Atrial functional MR (AFMR) caused by left atrial enlargement and annular dilatation was also recently described in patients with atrial fibrillation (AF). However, the clinical profiles of AFMR in hospitalized heart failure (HF) patients are unclear. We investigated the prevalence, clinical characteristics, and prognosis of AFMR in hospitalized HF patients with AF. Methods: We analyzed 189 hospitalized HF patients with AF. The prevalence, clinical characteristics, and prognosis were compared between 4 groups: patients with EF >= 50% and no/mild MR (pEFnoMR), patients with EF <50% and no/mild MR (rEFnoMR), patients with EF >50% and moderate/severe MR (AFMR), and patients with EF >= 50% and moderate/severe MR (VFMR). Results: The prevalence of AFMR was 15.9% in hospitalized HF patients with AF. AFMR patients were older and more likely to have an enlarged left atrium, lower tenting height, and moderate/severe tricuspid regurgitation than VFMR patients. There were no differences in all-cause death after discharge among pEFnoMR, rEFnoMR, and AFMR patients. AFMR patients were associated with a higher rate of a composite of cardiac death and readmission for HF compared with pEFnoMR and rEFnoMR patients (log-rank p = 0.046 and p = 0.004). There were no differences in composite endpoints between AFMR and VFMR patients (log-rank p = 0.507). Conclusions: AFMR was present in a proportion of elderly hospitalized HF patients with AF, and was a condition requiring attention because of readmission for HF in a hospitalized HF cohort. (C) 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.