Aims: In patients with persistent atrial fibrillation (AF), the efficacy and safety of two anti-arrhythmic drugs in preventing the recurrence of AF after successful direct current (DC) cardioversion was prospectively assessed in a multi-centre double-blind, placebo-controlled, randomised trial using daily trans-telephonic monitoring.
Methods and results: 1182 patients with persistent AF were prospectively enrolled, 848 patients were successfully cardioverted and then randomised to either sotalol (383 patients), quinidine plus verapamil (377 patients) or placebo (88 patients). The primary outcome parameter was AF recurrence or death. All patients received an event recorder (Tele-ECG) and had to record and transmit via telephone at least one ECG per day during follow-up. The mean follow-up period was 266 days. A total of 191,103 Tele-ECGs were recorded and transmitted. The primary outcome parameter (AF recurrence of any kind or death) was observed in 572 patients (67%) in whom at least one episode of AF recurrence was documented during follow-up, in 348 patients (41%) AF recurrence was persistent. The recurrence rates after one year for any AF were 83% for placebo, 67% for sotalol and 65% for quinidine plus verapamil, the latter being statistically superior to placebo but not different from sotalol. The recurrence rates for the secondary outcome parameter persistent AF were 77%, 49% and 38%, respectively. Quinidine plus verapamil was significantly superior to placebo and to sotalol. About 95% of all AF recurrences were initially detected in the daily Tele-ECG, about 70% of all AF recurrences occurred completely asymptomatic. Adverse events on sotalol and quinidine plus verapamil were comparable with the exception that all torsade de pointes tachycardias occurred on sotalol.
Conclusion: Anti-arrhythmic treatment after DC cardioversion of persistent AF significantly decreases the recurrence rates of persistent AF compared to placebo with superiority of quinidine plus verapamil compared to sotalol. Symptoms were not reliable as clinical surrogates to detect episodes of AF.