Atrial fibrillation ablation in practice: assessing CABANA generalizability.

Abstract

The Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial aimed to assess the impact of ablation on morbidity and mortality. This observational study was conducted in parallel to CABANA to assess trial generalizability. Using a large US administrative database, we identified 183760 patients with atrial fibrillation (AF) treated with ablation or medical therapy (antiarrhythmic or rate control drugs) between 1 August 2009 and 30 April 2016 (CABANA enrolment period). Propensity score weighting was used to balance patients treated with ablation (N = 12032) or medical therapy alone (N = 171728) on 90 dimensions. Ablation was associated with a reduction in the composite endpoint of all-cause mortality, stroke, major bleeding, and cardiac arrest [hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.70-0.81; P < 0.001]. The majority of patients (73.8%) were potentially trial eligible; among whom the risk reduction associated with ablation was greatest (HR 0.70, 95% CI 0.63-0.77; P < 0.001). Among the 3.8% of patients who failed to meet the inclusion criterion, i.e. patients under 65 years without stroke risk factors, the event rates were low and there was no significant relationship with ablation (HR 0.67, 95% CI 0.29-1.56; P = 0.35). Among the 22.4% patients who met at least one of the trial exclusion criteria, there was a lesser but statistically significant reduction associated with ablation (HR 0.85, 95% CI 0.75-0.95; P = 0.01). In routine clinical care, ablation was associated with a reduction in the primary CABANA composite endpoint of all-cause mortality, stroke, major bleeding, and cardiac arrest, particularly in patients who were eligible for the trial.