Catheter ablation reduces mortality for patients with heart failure and atrial fibrillation (CASTLE-AF)

Reference

Marrouche NF, Brachmann J, Andresen D, et al, for the CASTLE-AF Investigators. Catheter ablation for atrial fibrillation with heart failure. N Engl J Med 2018;378(5):417-427.

Synopsis

Previous studies have shown that in patients with comorbid heart failure and atrial fibrillation, rhythm control using medications was not superior to rate control. This study identified 397 patients with moderate to severe heart failure with an ejection fraction of less than or equal to 35% and paroxysmal or persistent atrial fibrillation. Their mean age was 64 years, 87% were men, 70% had persistent atrial fibrillation, and 60% had New York Heart Association Class II heart failure. Approximately 10% in each group withdrew after the baseline evaluation (most commonly for withdrawal of consent after randomization) and 28 patients in the catheter ablation group and 18 patients in the medical therapy group did not receive the assigned intervention. The number was larger in the catheter ablation group since some patients had conditions that precluded ablation, such as left atrial scarring. Analysis was by intention to treat, though, and the final groups were balanced with regard to age, sex, and comorbidities at baseline. All patients initially went through a 5-week run-in period in which their treatment of heart failure was optimized. The median follow-up was just more than 3 years, and outcomes were assessed by study team members masked to treatment assignment. At the end of the study period, deaths due to any cause (13.4% vs 25.0%; P = .01; number needed to treat [NNT] = 9), heart failure hospitalizations (20.7% vs 35.9%; P = .004; NNT = 7), cardiovascular hospitalizations (35.8% vs 48.4%; P = .04; NNT = 8), and cardiovascular deaths (11.2% vs 22.3%; P = .009; NNT = 9) were all improved in the catheter ablation group. There was no effect on the likelihood of hospitalization due to any cause or the risk of stroke. In terms of disease-oriented outcomes, left ventricular ejection fraction increased by 8% in the catheter ablation group and 0.2% in the medical therapy group (P = .005). Regarding subgroup analyses, patients with an ejection fraction of at least 25% had a greater benefit than those with an ejection fraction of less than 25%. The study was sponsored by Biotronik.