Safety and Effectiveness of Electrical and Pharmacological Cardioversion in Persistent Atrial Fibrillation. Part I: Study Rationale, Design and Assessment of Effectiveness

Abstract

Aim. We aimed to compare effectiveness of new class III antiarrhythmic drug Refralon with direct current cardioversion (DCC) in patients with persistent atrial fibrillation (AF). Material and methods. 60 patients with persistent AF were randomized to groups of DCC (n=30) and pharmacologic conversion (PCV; n=30). There were no differences in age, sex, AF duration, concomitant cardiovascular diseases, CHA2DS2-VASc score and echocardiographic parameters between the groups compared. Initial assessment excluded contraindications to restore sinus rhythm (SR). In DCC group two attempts using biphasic synchronized shocks of 150 J and 170 J were performed. In PCV group patients received up to three subsequent intravenous injections of Refralon 10 μg/kg (maximal dose 30 μg/kg). Results. SR was restored in 27 of 30 patients (90%) in DCC group and in 28 of 30 patients (93.3%) in PCV group. 95% confidence interval (CI) for primary effectiveness criterion was [-0.1 – 0.16]. AF recurred in 1 patient after successful DCC. There were no AF recurrences in PCV group. 26 of 30 patients (86.7%) in DCC group and 28 of 30 patients (93.3%) in PCV group remained in SR 24 hours after cardioversion. 95%CI for secondary effectiveness criterion was [-0.07 – 0.19]. Conclusion. Effectiveness of Refralon is noninferior to DCC in patients with persistent AF.