Pharmacological rhythm versus rate control in patients with atrial fibrillation and heart failure: the CASTLE-AF trial

Background: The value of antiarrhythmics to maintain normal sinus rhythm in patients with atrial fibrillation (AF) and heart failure (HF) is still being debated. We aimed to determine whether rhythm control using antiarrhythmic drugs (AADs) is more effective than rate control in improving outcomes in this population. Method: In this sub-analysis of the CASTLE-AF study, we included patients that were treated pharmacologically either to maintain sinus rhythm or to achieve rate control. The primary endpoint was defined as a composite of death from any cause or worsening of HF that led to an unplanned overnight hospitalization. Result: Among 210 patients (mean age of 64.1 ± 10.8 years, 83.3% male) treated pharmacologically, 60 patients were in the rhythm control group and 150 were in the rate control group. Patients in the rhythm control group were less likely to be assigned a beta-blocker (53 (88.3%) vs 141 (97.9%), P = 0.004) and digitalis (8 (13.3%) vs 53 (36.8%), P < 0.001). Over a median follow-up of 3.76 (95% confidence interval (CI), 3.23, 4.48) years, the primary composite endpoint of all-cause mortality and HF admissions occurred in 23 patients (38.3%) in the rhythm control arm vs 67 (44.7%) in the rate control arm (hazard ratio, 0.99; 95% CI, 0.62 to 1.60; P = 0.976). Conclusion: In CASTLE-AF among AF patients with HF, rhythm control with AADs did not significantly reduce the primary composite endpoint of all-cause mortality and HF hospitalization when compared with a pharmacological rate control strategy.