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

AIMS: 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.

CONCLUSION

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.