No impact of atrial fibrillation on mortality risk in optimally treated heart failure patients

Background: Several studies have shown that atrial fibrillation (AF) is associated with increased risk of death in heart failure (HF) patients. However, it is not clear whether this increased risk is independent of other risk factors. Hypothesis: We hypothesized that AF would be an independent risk factor for death in a large cohort of HF patients. Methods: Patients referred to Norwegian HF outpatient clinics were enrolled between October 2000 and February 2008. Patients with heart rhythm other than AF or sinus rhythm were excluded. Mortality data were obtained from the National Statistics Bureau, Statistics Norway with the last update February 2008. Results: There were 4048 patients included in the analysis, with a median follow-up of 28 months. Adherence to guidelines regarding medical treatment was high. In univariate analysis, AF patients (n = 1391) had a higher risk of death than patients in sinus rhythm (n = 2657) (hazard ratio [HR] 1.181; 95% confidence interval (CI), 1.044–1.336; P = 0.008). However, after adjusting for confounding factors (age, New York Heart Association class, coronary artery disease as the main cause of HF, use of any loop diuretic, hemoglobin level, and serum creatinine), AF was no longer associated with increased risk of death (HR 1.037; 95% CI, 0.901–1.193; P = 0.619). Conclusions: In this cohort of heart failure patients receiving optimal medical treatment at specialized HF clinics, AF was not associated with increased risk of death after adjusting for confounding factors. © 2011 Wiley Periodicals, Inc. AstraZeneca Norway provided secretarial assistance in maintaining the Norwegian heart failure registry by financing an independent IT consultant. The authors have received research grants, consultancy fees, and/or honoraria for lectures from several pharmaceutical companies. The authors have no other funding, financial relationships, or conflicts of interest to disclose.