Randomized double-blind study comparing the efficacy and safety between antazoline and propafenone for conversion of paroxysmal atrial fibrillation to sinus rhythm (AnProAF study)

INTRODUCTION: Antazoline is a frequently used antiarrhythmic drug (AAD); however, to date, no randomized controlled trial has evaluated its efficacy and safety for cardioversion of recent‑onset atrial fibrillation (AF) in comparison with other approved AADs. OBJECTIVES: This study aimed to compare clinical efficacy and safety of antazoline and propafenone for a rapid conversion of nonvalvular paroxysmal AF to sinus rhythm in patients without heart failure. PATIENTS AND METHODS: This was a single‑center, randomized, double‑blind study. It included patients with AF (lasting <48 hours) who were in a stable cardiopulmonary condition and eligible for cardioversion. The individuals who fulfilled the inclusion criteria were randomly assigned to receive either antazoline (up to 300 mg) or propafenone (up to 140 mg) intravenously. The primary end point was conversion of AF to sinus rhythm confirmed on electrocardiography. RESULTS: Overall, 94 participants (46 [48.9%] in the antazoline group and 48 [51.1%] in the propafenone group) were included. The mean (SD) age was 67.5 (14) years, and 40 participants (42.5%) were men. Successful AF conversion was observed in 29 patients (63%) from the antazoline group and 25 individuals (52.1%) from the propafenone group (P = 0.39). The median time to conversion was 10 minutes in the antazoline group and 30 minutes in the propafenone group (P = 0.03). Severe adverse events were observed in 5 patients (10.8%) treated with antazoline and 5 individuals (10.4%) who received propafenone. CONCLUSIONS: Intravenous antazoline demonstrated efficacy and safety comparable to those of intravenous propafenone for acute conversion of nonvalvular paroxysmal AF to sinus rhythm in patients without heart failure.