Asymptomatic vs. symptomatic atrial fibrillation: Clinical outcomes in heart failure patients

•The impact of asymptomatic atrial fibrillation (AF) in different types of clinical heart failure (HF) is not well established•We analysed real-world AF patients stratified according to symptomatic status, clinical HF and left ventricular ejection fraction (LVEF).•Asymptomatic AF accounts for a substantial percentage of patients (43-48%), with similar proportions among the groups stratified for HF status and LVEF•Asymptomatic AF in patients with HF and reduced LVEF had clear negative implications for outcomes at long-term. : The outcome implications of asymptomatic vs. symptomatic atrial fibrillation (AF) in specific groups of patients according to clinical heart failure (HF) and left ventricular ejection fraction (LVEF) need to be clarified. : In a prospective observational study, patients were categorized according to overt HF with LVEF≤40%, or with LVEF>40%, or without overt HF (with LVEF40%≤ or > 40%), as well as according to the presence of asymptomatic or symptomatic AF. A total of 8096 patients, divided into 8 groups according to HF and LVEF, were included with similar proportions of asymptomatic AF (ranging from 43 to 48%). After a median follow-up of 730 [699 -748] days, the composite outcome (all-cause death and MACE) was significantly worse for patients with asymptomatic AF associated with HF and reduced LVEF vs. symptomatic AF patients of the same group (p=0.004). On adjusted Cox regression analysis, asymptomatic AF patients with HF and reduced LVEF were independently associated with a higher risk for the composite outcome (aHR 1.32, 95% CI 1.04-1.69) and all-cause death (aHR 1.33, 95% CI 1.02-1.73) compared to symptomatic AF patients with HF and reduced LVEF. Kaplan-Meier curves showed that HF-LVEF≤40% asymptomatic patients had the highest cumulative incidence of all-cause death and MACE (p