CASTLE-AF was a randomized, open-label, multicenter trial evaluating differences in mortality and morbidity by catheter ablation vs medical therapy in patients with a history of symptomatic paroxysmal or permanent atrial fibrillation and concomitant heart failure with an ejection fraction <35%.
Patients were randomized to receive catheter ablation or guideline-recommended medical therapy for afib, with recommendations to maintain sinus rhythm.
The trial demonstrated fewer incidences of death from any cause or hospitalization for worsening heart failure (primary endpoint) in the ablation group, 51 (28.5%) vs. 82 (44.6%) patients, log-rank test <0.01.
The NNT to prevent all-cause death was 9, with the greatest mortality benefit seen at 3 years.
Why this matters:
This trial highlights the benefit of maintaining sinus rhythm in HF and AF. At 60 months, the catheter ablation group had remained in sinus rhythm longer compared to medical therapy (63.1% vs 21%, p<0.01); with the caveat recurrence of afib were recommended for repeat ablation during scheduled follow up.
In addition to meeting the primary endpoint, the ablation group exhibited lower incidence of cardiovascular death.
The trial adds to growing evidence of efficacy of ablation over medication alone, and importantly, the mortality benefit gained. Criticisms include lack of blinding, and that the sinus rhythm was recommended over rate control in the medication alone group.
Marrouche NF, Brachmann J, Andresen D, et al. Catheter Ablation for Atrial Fibrillation with Heart Failure. N Engl J Med. 2018;378(5):417-427.