IMPORTANCE Catheter ablation is effective in restoring sinus rhythm in atrial fibrillation (AF), but its effects on long-term mortality and stroke risk are uncertain. OBJECTIVE To determine whether catheter ablation is more effective than conventional medical therapy for improving outcomes in AF. DESIGN, SETTING, AND PARTICIPANTS The Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation trial is an investigator-initiated, open-label, multicenter, randomized trial involving 126 centers in 10 countries. A total of 2204 symptomatic patients with AF aged 65 years and older or younger than 65 years with 1 or more risk factors for stroke were enrolled from November 2009 to April 2016, with follow-up through December 31, 2017. INTERVENTIONS The catheter ablation group (n = 1108) underwent pulmonary vein isolation, with additional ablative procedures at the discretion of site investigators. The drug therapy group (n = 1096) received standard rhythm and/or rate control drugs guided by contemporaneous guidelines. MAIN OUTCOMES AND MEASURES The primary end point was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Among 13 prespecified secondary end points, 3 are included in this report: all-cause mortality; total mortality or cardiovascular hospitalization; and AF recurrence. RESULTS Of the 2204 patients randomized (median age, 68 years; 37.2% female; 42.9% had paroxysmal AF and 57.1% had persistent AF), 89.3% completed the trial. Of the patients assigned to catheter ablation, 1006 (90.8%) underwent the procedure. Of the patients assigned to drug therapy, 301 (27.5%) ultimately received catheter ablation. In the intention-to-treat analysis, over a median follow-up of 48.5 months, the primary end point occurred in 8.0% (n = 89) of patients in the ablation group vs 9.2% (n = 101) of patients in the drug therapy group (hazard ratio [HR], 0.86 [95% CI, 0.65-1.15]; P = .30). Among the secondary end points, outcomes in the ablation group vs the drug therapy group, respectively, were 5.2% vs 6.1% for all-cause mortality (HR, 0.85 [95% CI, 0.60-1.21]; P = .38), 51.7% vs 58.1% for death or cardiovascular hospitalization (HR, 0.83 [95% CI, 0.74-0.93]; P = .001), and 49.9% vs 69.5% for AF recurrence (HR, 0.52 [95% CI, 0.45-0.60]; P < .001). CONCLUSIONS AND RELEVANCE Among patients with AF, the strategy of catheter ablation, compared with medical therapy, did not significantly reduce the primary composite end point of death, disabling stroke, serious bleeding, or cardiac arrest. However, the estimated treatment effect of catheter ablation was affected by lower-than-expected event rates and treatment crossovers, which should be considered in interpreting the results of the trial.

Background: In patients with heart failure (HF) and atrial fibrillation (AF), several clinical trials have reported improved outcomes, including freedom from AF recurrence, quality of life (QOL), and survival, with catheter ablation. This report describes the treatment-related outcomes of the AF patients with HF enrolled in the Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial. Methods: CABANA randomized 2204 patients with AF who were ≥65 years old or <65 with ≥1 risk factor for stroke at 126 sites to ablation with pulmonary vein isolation or drug therapy including rate/rhythm control drugs. Of these, 778 (35%) had NYHA class ≥ II at baseline and form the subject of this report. The CABANA primary endpoint was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Results: Of the 778 HF patients enrolled in CABANA, 378 were assigned to ablation and 400 to drug therapy. Ejection fraction (EF) at baseline was available for 571 patients (73%) and 9.3% of these had an EF <40%, while 11.7% had EFs between 40-50%. In the intention-to-treat analysis, the ablation arm had a 36% relative reduction in the primary composite endpoint (hazard ratio [HR] 0.64; 95% confidence interval [CI], 0.41 to 0.99) and a 43% relative reduction in all-cause mortality (HR 0.57; 95% CI, 0.33 to 0.96) compared to drug therapy alone over a median follow-up of 48.5 months. AF recurrence was decreased with ablation (HR 0.56; 95% CI, 0.42 to 0.74). The adjusted mean difference for the AF Effect on QOL (AFEQT) summary score averaged over the entire 60-month follow-up was 5.0 points favoring the ablation arm (95% CI, 2.5 to 7.4 points), and the Mayo AF-specific Symptom Inventory (MAFSI) frequency score difference was -2.0 points favoring ablation (95% CI, -2.9 to -1.2). Conclusions: In patients with atrial fibrillation enrolled in CABANA who had clinically diagnosed stable heart failure at trial entry, catheter ablation produced clinically important improvements in survival, freedom from AF recurrence, and quality of life relative to drug therapy. These results, obtained in a cohort most of whom had preserved left ventricular function, require independent trial verification. Clinical Trial Registration: URL: https://www.clinicaltrials.gov Unique Identifier: NCT00911508

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