Impact of atrial fibrillation on long-term clinical outcomes in outpatients with heart failure

BackgroundAtrial fibrillation (AF) is a common arrhythmia in patients with heart failure (HF); however, its impact on unselected outpatients with HF remains unclear.MethodsWe followed 2024 symptomatic outpatients with HF who visited the Cardiovascular Institute Hospital (The Shinken Database: 2004–2011, N=17,517). We examined the prevalence, clinical characteristics, and outcomes of AF in these outpatients with HF.ResultsAF was observed in 310 of the patients (15%). Patients with AF were older; more likely to be female; and had lower rates of hypertension, diabetes mellitus, and ischemic heart disease. However, they also had higher rates of New York Heart Association grades III/IV, lower left ventricular ejection fraction (EF), renal dysfunction, and dilated cardiomyopathy. The use of cardiovascular drugs including beta-blockers, renin-angiotensin-system inhibitors, diuretics, digitalis, and antiarrhythmic drugs was more common in patients with AF. Kaplan–Meier curves revealed that the incidences of all-cause death, cardiovascular disease death, and HF-related admission were significantly higher in patients with AF. Kaplan–Meier curves and an unadjusted Cox regression analysis showed that AF was associated with a significantly higher risk of all-cause death, cardiovascular death, and HF-related admission. However, the adjusted Cox regression model showed that AF was no longer an independent risk factor for all-cause death, cardiovascular death, and HF death but remained an independent risk factor of HF-related admission (hazard ratio, 1.781; 95% confidence interval, 1.172–2.704; p=0.007).ConclusionsAF was frequently observed in outpatients with HF. AF was not associated with long-term mortality but was independently associated with HF-related admission in this outpatient population.