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