European Heart Journal (2001) 22: 1504–1510 doi:10.1053/euhj.2000.2546, available online at http://www.idealibrary.com on

Maintenance of sinus rhythm after electrical cardioversion of persistent atrial fibrillation Sotalol vs bisoprolol A. Plewan, G. Lehmann, G. Ndrepepa, J. Schreieck, E. U. Alt, A. Scho¨mig and C. Schmitt German Heart Center and 1, Medizinische Klinik, Klinikum rechts der Isar, Technische Universita¨t Mu¨nchen, Munich, Germany

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.

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.

Methods Patients (n=128) were randomized to sotalol (80 mg b.i.d.) or bisoprolol (5 mg . 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.

Conclusion This study demonstrates that sotalol (160 mg . day
1) and bisoprolol (5 mg . 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. (Eur Heart J 2001; 22: 1504–1510, doi:10.1053/ euhj.2000.2546)  2001 The European Society of Cardiology

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-

Introduction Persistent atrial fibrillation is one of the most common cardiac arrhythmias. Its prevalence increases with age and concomitant heart disease[1,2]. The risk of thrombembolic events in patients with persistent atrial fibrillation is up to three times higher compared to those in sinus rhythm[3]. By the loss of effective atrial contractions in the failing heart, stroke volume and cardiac output are decreased up to 25%[4]. Furthermore, Revision submitted 13 November 2000, and accepted 22 November 2000. Correspondence: Dr Andreas Plewan, 1. Medizinische Klinik Klinikum rechts der Isar, Ismaninger Strasse 22, D-81675 Mu¨nchen, Germany. 0195-668X/01/221504+07 $35.00/0

Key Words: Atrial fibrillation, cardioversion, sotalol, bisoprolol. See page 1370 for the Editorial comment on this article

cardiopulmonary exercise capacity is reduced, especially in the presence of an underlying structural heart disease[5]. Thus, in principle, restoration and maintenance of sinus rhythm appears worthwhile. Although cardioversion, treated pharmacologically, is successful in 40%–70% of subjects[6–8], electrical external and transvenous internal cardioversion is an established method for treating atrial fibrillation, with primary success rates up to 95%[9,10]. However, the long-term results for maintenance of sinus rhythm are more discouraging without prophylactic antiarrhythmic therapy. Only 25% of patients remain in sinus rhythm 12 months after successful cardioversion[6]. Various antiarrhythmic drugs, such as amiodarone, flecainide, propafenone and sotalol have been used to increase stability of sinus rhythm[11–14]. All of them bear the risk of proarrhythmic adverse effects[15,16].  2001 The European Society of Cardiology

Maintenance of sinus rhythm: sotalol vs bisoprolol

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Sotalol is a beta-blocker with class III antiarrhythmic properties[17]. In patients with recent onset atrial fibrillation after coronary artery bypass grafting, sotalol has been shown to be superior to a mere beta-blocking agent in the early postoperative phase[14], but it has not yet been confirmed whether sotalol is also superior to conventional beta-blockers in the maintenance of sinus rhythm in the long-term and in an unselected patient population. The purpose of our study was to compare the efficacy and safety of sotalol and bisoprolol in the prevention of relapse into atrial fibrillation after successful electrical cardioversion to sinus rhythm.

rate 480 ms or a corrected QT interval of >400 ms, in proarrhythmias (e.g. torsades de pointes) or symptomatic hypotension (systolic blood pressure 400 ms), sinus bradycardia