Clinical characteristics and prognostic impact of atrial fibrillation among older patients with heart failure with preserved ejection fraction hospitalized for acute heart failure.

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are often coexisting conditions, but their interrelationship has not yet been clarified. This study investigated the clinical characteristics and prognostic impact of AF among older patients with HFpEF hospitalized for acute HF (AHF). The study included patients 65 years of age and older who were admitted to the Emergency Department due to AHF from 1 January 2016 to 31 December 2019. Patients were divided into two groups according to the presence of AF. The primary endpoint was all-cause, in-hospital mortality. Overall, 770 patients with HFpEF were included, mean age 82 years, 53% were females. Nearly, a third (30%) of these patients had a concomitant AF and they were significantly older and had higher N-Terminal pro-B-type natriuretic peptide (NT-proBNP) values. Overall, the in-hospital mortality rate was much higher among HFpEF patients with AF compared to those without AF (11.4% vs 6.9%, respectively; p = 0.037). At multivariate analysis, AF emerged as an independent risk factor for death (OR 1.73 [1.03-2.92]; p = 0.038). Among older patients with HFpEF admitted for AHF, the coexistence of AF was associated with a nearly twofold increased risk of all-cause in-hospital mortality. Patients with HFpEF and AF describe a phenotype of older and more symptomatic patients, with higher NT-proBNP, left atrial enlargement, right ventricular dysfunction, and higher CV mortality.