A randomized trial of prophylactic antiarrhythmic agents (amiodarone and sotalol) in patients with atrial fibrillation for whom direct current cardioversion is planned

Antiarrhythmic agents enhance maintenance of sinus rhythm (SR) after direct current cardioversion (DCC) for atrial fibrillation but there are few comparative trials. Background The aims of the study were (1) to establish whether patients successfully cardioverted to SR are more likely to stay in SR over 6 months if taking amiodarone or sotalol, and if so, to establish whether one agent is better than the other; (2) to establish whether taking amiodarone or sotalol is better at achieving chemical cardioversion within the 6 weeks before DCC; and (3) to establish whether DCC is more likely to be successful on a drug. Methods Randomized, prospective, nonblinded, controlled study of treatment with either amiodarone (n = 27), sotalol (n = 36), or no antiarrhythmic agent (n = 31). Results Chemical cardioversion occurred in 7 patients in the amiodarone group (A), 7 patients in the sotalol group (S), but none in the no-antiarrhythmic group (N). A total of 33 (92%) patients in the sotalol group, 22 (81%) patients in the amiodarone group, and 23 (74%) patients in the no-antiarrhythmic group were in SR after cardioversion. Of the original cohort of patients, 17 (63%) patients in the amiodarone group remained in SR at 6-month follow-up, compared with 14 (39%) in the sotalol group and 5 (16%) in the no-antiarrhythmic group (A vs N, P < .0002, P < .0006B [after Bonferroni correction]; A vs S, P = .05, P = .15B; and S vs N, P = .03, P = .09B). Conclusions Amiodarone and sotalol achieved chemical cardioversion before planned electrical cardioversion in 26% and 19% of patients, respectively. After successful cardioversion, amiodarone appears better than sotalol at maintaining SR at 6 months.