A Cochrane review on antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation[Abstract] 1 included 59 studies with a total of 20 981 subjects. Dronedarone was included in 5 of the studies with a total of 6 675 subjects, and 3 of them compared dronedarone with placebo.
Compared to placebo dronedarone reduced atrial fibrillation recurrence (RR 0.85, 95% CI 0.80 to 0.91; 2 studies, n=1 443). This corresponded to a recurrence rate of 76.6% in people treated with placebo and 65.1% (95% CI 61.3% to 69.7%) in people treated with dronedarone; NNTB for dronedarone was 9 (95% CI 7 to 15) for one year. Dronedarone reduced risk of stroke (RR 0.66, 95% CI 0.47 to 0.95; 2 studies, n=5 872) corresponding to a risk of stroke of 27 per 1000 people in the placebo group and 18 per 1000 (13 to 25) people in the dronedarone group; NNTB was 109 (95% CI 70 to 741) for one year.
Dronedarone showed no significant difference in mortality compared with placebo (RR 0.86, 95% CI 0.68 to 1.09; 3 studies, n=6 071), and increased withdrawals due to adverse effects (RR 1.58, 95% CI 1.34 to 1.85; 3 studies, n=6 071; NNTH 22, 95% CI 15 to 38). There seemed to be an increase of proarrhythmia with dronedarone compared with placebo, but the CIs included the possibility of no difference or even a benefit on this outcome (RR 1.95, 95% CI 0.77 to 4.98; 2 studies, n=5 872; I2 = 78%). In sensitivity analysis, there was only one study rated at low risk of bias or including more than 200 participants, and this study found an increased risk of proarrhythmia with dronedarone compared to placebo (RR 2.94, 95% CI 2.08 to 4.15; 1 study, n=4 628).
In direct comparisons between antiarrhythmics amiodarone reduced recurrences of atrial fibrillation significantly more than dronedarone (RR 0.69, 95% CI 0.59 to 0.82; 1 study, n=504).
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