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

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.

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