Sinus rhythm versus atrial fibrillation in elderly patients with chronic heart failure--insight from the Cardiac Insufficiency Bisoprolol Study in Elderly.

Background: It has been suggested that patients with chronic HF and atrial fibrillation (AF) may respond differently to beta-blockers than those in sinus rhythm (SR).
Methods: In this predefined analysis of the CIBIS-ELD trial, a total of 876 chronic HF patients (164 patients with AF) were randomized to bisoprolol or carvedilol. During the 12-week-treatment phase, beta-blockers were doubled fortnightly up to the target dose or maximally tolerated dose, which was maintained for 4 weeks.
Results: Patients with AF had lower left ventricular ejection fraction (LVEF), exercise capacity, self-rated health, quality of life (QoL) scores for both SF36 physical and psychosocial component, and higher NYHA class than those in SR. Beta-blocker titration was associated with clinical improvement in both AF and SR patients: LVEF, 6-minute walk distance, physical and psychosocial components of QoL scores, self-rated health and NYHA class (p<0.05, for all). The extent of improvement did not differ between patients with AF and in SR and did not differ between bisoprolol and carvedilol. Heart rate (HR) at baseline was higher in the AF group, and remained higher until the end of the trial. Patients with higher baseline HR had larger reductions in HR, regardless of rhythm. AF patients more frequently reached target beta-blocker dose compared to those in SR (p<0.005).
Conclusions: Elderly patients with chronic HF and AF derive comparable clinical benefits from beta-blocker titration as those in SR. Patients with AF tolerate higher beta-blocker doses than those in SR, which appears to be related to higher baseline HR.
(Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)