β-Blockers in Atrial Fibrillation Patients With or Without Heart Failure: Association With Mortality in a Nationwide Cohort Study.

Background: Recent data suggest that β-blockers are associated with prognostic advantages in heart failure (HF) patients without concomitant atrial fibrillation (AF), but not in HF patients with concomitant AF. We aimed to investigate associations between β-blocker treatment and cardiovascular outcome and mortality in AF patients with and without HF.
Methods and Results: Three nationwide registries were used to identify patients with nonvalvular AF patients with or without concomitant HF. Patients were stratified into β-blocker users and β-blocker nonusers, and according to the presence of a HF diagnosis. We followed the patients ≤ 5 years after baseline. Six different cardiovascular outcomes were investigated, including all-cause mortality and fatal thromboembolic events. Crude event rates were ascertained and propensity-matched Cox regression was used to compare event rates according to β-blocker usage status. A total of 205,174 patients were included, where 39,741 patients had prevalent HF. In the latter subgroup of patients, the 1-year propensity-matched hazard ratio (HR) for all-cause mortality was 0.75 (95% confidence interval, 0.71-0.79; nontreated used as reference). For patients without concomitant HF, the propensity-matched HR for all-cause mortality was 0.78 (95% confidence interval, 0.71-0.76).
Conclusions: In this large nationwide cohort study, evidence of a lower mortality with β-blocker therapy in AF patients with concomitant HF was observed. In addition, this association was accompanied with indications that β-blocker treatment is also associated with a better prognosis in AF patients without concomitant HF.
(© 2016 American Heart Association, Inc.)