Medical therapy

Catheter ablation VS medical therapy for atrial fibrillation

Observational studies implicated that catheter ablation may be safe and effective for treating atrial fibrillation in young and old people. It had not been studied in a large randomized experiment. The report summarizes the results of the CABANA trial by age at enrollment (catheter ablation versus antiarrhythmic drug therapy for atrial fibrillation). Patients with atrial fibrillation aged 65 or older with a risk factor for stroke were randomly assigned to catheter ablation or drug therapy. The primary outcome was a combination of death, debilitating stroke, major bleeding, or cardiac arrest. Secondary outcomes were all-cause mortality, composite of cardiovascular mortality or hospitalization, and recurrence of atrial fibrillation. Proportional hazards regression models were used to modify the treatment effect estimates for the baseline covariates.

Approximately 766 (34.8%) of the 2204 randomized patients in CABANA were 65 years old, 1130 (51.3%) were between 65 and 74 years old, and 308 (14.0%) were 75 years old. Catheter ablation was associated with a 43% reduction in primary outcome for patients aged 65-74 years (aHR, 0.57 [95% CI, 0.30–1.09]), a 21% reduction for patients aged 65-74 years (aHR, 0.79 [95% CI, 0.54–1.16]), and an indeterminate effect for patients aged 75 years (aHR, 1.39 [95% CI, 0.75–2.58]). The four-year incident rates for ablation versus drug treatment were 3.2% versus 7.8%, 7.8% versus 9.6%, and 14.8% versus 9.0%, respectively . The primary endpoint aHR increased (i.e. became less favorable to ablation) by 27% on average for each 10-year age group (interaction P value=0.215). A similar trend was observed in all-cause mortality: for each 10-year age group, aHR increased by 46% on average (interaction P value=0.111). In all age categories, ablation was associated with reduced rates of atrial fibrillation recurrence compared to drug treatment (aHR 0.47, 0.58, and 0.49, respectively). Treatment-related problems were rare in both groups (3%), regardless of age. The researchers found age-related differences in the clinical outcomes of catheter ablation compared to pharmacological treatment, with younger patients experiencing the greatest relative and absolute benefits from catheter ablation. In older patients, there was no prognostic improvement from ablation.