Recurrence of atrial fibrillation (AF) following catheter ablation remains a clinical challenge, and short-term antiarrhythmic drug therapy during the 3-month blanking period is commonly used to reduce early arrhythmia recurrence. This open-label, randomized controlled trial published in Europace compared dronedarone and amiodarone administered for 12 weeks after AF ablation to evaluate differences in efficacy and safety.

A total of 280 patients undergoing AF ablation were randomized, with 273 included in the modified intention-to-treat (mITT) analysis. Participants received either dronedarone or amiodarone during the blanking period, with therapy discontinued thereafter as per protocol. The primary endpoint was recurrence of atrial tachyarrhythmia lasting more than 30 seconds beyond the blanking period.

In the mITT analysis, atrial tachyarrhythmia recurrence rates were not significantly different between dronedarone and amiodarone groups (23.4% vs 16.9%; p=0.184). Secondary efficacy outcomes were comparable between treatment arms. However, safety outcomes differed significantly.

The incidence of adverse effects was lower with dronedarone compared with amiodarone (40.9% vs 64.0%; p<0.001), primarily due to lower rates of QTc prolongation (5.8% vs 15.4%; p=0.01) and hypothyroidism (8.8% vs 26.5%; p<0.001). Intention-to-treat analysis results were consistent with the mITT findings.

Dronedarone showed a comparable effect on arrhythmia recurrence with a more favorable safety profile compared with amiodarone.