Maintenance of sinus rhythm after electrical cardioversion of persistent atrial fibrillation; sotalol vs bisoprolol.

Objective: The purpose of the study was to compare the efficacy and safety of sotalol and bisoprolol in the maintenance of sinus rhythm after electrical cardioversion of atrial fibrillation.

Methods: Patients (n=128) were randomized to sotalol (80 mg b.i.d.) or bisoprolol (5 mg x day(-1)). Patients with contraindications to beta-blockers, class III antiarrhythmic drugs or prior treatment with use of study medication for prevention of atrial fibrillation were excluded. Follow-up clinical evaluation was performed 1 day and 1 month after cardioversion and thereafter at 3-month intervals.

Results: There were no group differences in baseline clinical characteristics. After a follow-up of 12 months, 59% of all patients were still in sinus rhythm. The fraction remaining in sinus rhythm was calculated for the two groups by Kaplan--Meier analysis. During follow-up, 41% of patients on sotalol and 42% on bisoprolol developed atrial fibrillation (ns). In two patients (3.1%) on sotalol, life-threatening proarrhythmias (torsade de pointes tachycardias) occurred, whereas none were found in the bisoprolol group. Symptomatic bradycardias occurred in two patients on sotalol and three on bisoprolol.

Conclusions: This study demonstrates that sotalol (160 mg x day(-1)) and bisoprolol (5 mg x day(-1)) are equally effective in maintaining sinus rhythm. Because of the side effects of sotalol, bisoprolol seems to be advantageous for maintenance of sinus rhythm after cardioversion of atrial fibrillation.