Clinical characteristics and prognostic impact of atrial fibrillation in patients with chronic heart failure

AIMS: To assess the prevalence, clinical characteristics and independent prognostic impact of atrial fibrillation (AF) in chronic heart failure (CHF) patients, and the potential protective effect of disease-modifying medications, particularly beta-blockers (BB). METHODS: We retrospectively reviewed the charts of patients referred to our center since January 2004, and collected all clinical information available at their first visit. We assessed mortality to the end of June 2015. We compared patients with and without AF, and assessed the association between AF and all-cause mortality by multivariate Cox regression and Kaplan-Meyer analysis, particularly accounting for ongoing treatment with BB. RESULTS: A total of 903 patients were evaluated (mean age 68±12 years, 73% male). Prevalence of AF was 19%, ranging from 10% to 28% in patients ≤60 and ≥77 years, respectively. Besides the older age, patients with AF had more symptoms (NYHA II-III 60 vs. 44%), lower prevalence of dyslipidemia (23 vs. 37%), coronary artery disease (28 vs. 52%) and left bundle branch block (9 vs. 16%). On the contrary, they more frequently presented with an idiopathic etiology (50 vs. 24%), a history of valve surgery (13 vs. 4%) and received overall more devices implantation (31% vs. 21%). The use of disease-modifying medications (i.e. BB and ACE inhibitors/angiotensin receptor blockers) was lower in patients with AF (72 vs. 80% e 71 vs. 79%, respectively), who on the contrary were more frequently treated with symptomatic and antiarrhythmic drugs including diuretics (87 vs. 69%) and digoxin (51 vs. 11%). At a mean follow-up of about 5 years, all-cause mortality was significantly higher in patients with AF as compared to those in sinus rhythm (45% vs. 34%, p value <0.05 for all previous comparisons). However, in a multivariate analysis including the main significant predictors of all-cause mortality, the univariate relationship between AF and death (HR 1.49, 95% CI 1.15-1.92) became not statistically significant (HR 0.98, 95% CI 0.73-1.32). Nonetheless, patients with AF not receiving BB treatment were found to have the worst prognosis, followed by patients with sinus rhythm not receiving BB therapy and patients with AF receiving BB therapy, who both had similarly worse survival when compared to patients with sinus rhythm receiving BB therapy. CONCLUSIONS: AF was highly prevalent and associated with older age, worse clinical presentation and underutilization of disease-modifying medications such as BB in a population of elderly patients with CHF. AF had no independent impact on mortality, but the underutilization of BB in this group of patients was associated to a worse long-term prognosis.