Maintenance of sinus rhythm with metoprolol CR initiated before cardioversion and repeated cardioversion of atrial fibrillation: a randomized double-blind placebo-controlled study.
OBJECTIVE
To assess the effect of metoprolol in combination with repeated cardioversion on maintenance of sinus rhythm (SR).


RESULTS
Consecutive outpatients with persistent atrial fibrillation (AF) were randomized to treatment with metoprolol CR or placebo in a double-blind fashion. Study treatment was started at least one week before direct current (DC) cardioversion. Patients were followed once a week during the first 6 weeks after cardioversion. In case of relapse during this period, a second cardioversion was performed. Total treatment time was 6 months. A total of 168 patients were randomized to metoprolol (n = 83) or placebo (n = 85). The dose of study treatment at cardioversion was 169 +/- 47 mg in the metoprolol group and 180 +/- 40 mg in the placebo group (P = 0.12). In an intention-to-treat analysis, 46 patients (55%) in the metoprolol group and 34 patients (40%) in the placebo group (P = 0.04) had SR 1 week after cardioversion, and 38 patients (46%) in the metoprolol group compared with 22 patients (26%) in the placebo group had SR after 6 months (P < 0.01).


CONCLUSIONS
A treatment strategy of metoprolol CR started before cardioversion in combination with prompt second cardioversion in case of early relapse (1-6 weeks) significantly increases the proportion of patients in SR during six months of follow-up.
Nergårdh
Anna K
AK
Department of Cardiology, Karolinska Institutet at Stockholm South Hospital, Stockholm S-118 83, Sweden. anna.nergardh@sodersjukhuset.se
Rosenqvist
Mårten
M
Nordlander
Rolf
R
Frick
Mats
M
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000628:therapy*; D003131:Combined Modality Therapy; D004311:Double-Blind Method; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D012008:Recurrence; D019233:Retreatment; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D008790:Metoprolol