There were 6 amiodarone studies (315 patients) and 2 flecainide studies (163 patients).
Amiodarone.
After 3 months of therapy, the proportion of amiodarone-treated patients remaining in normal sinus rhythm (NSR) was significantly greater than that expected with the quinidine standard: 72.6% compared with 70%. The pooled rate difference was 3.5% (SD 2.7, z 9.5, p<0.0001).
After 6 months of therapy (5/6 studies, 226 patients), 71% of those treated with amiodarone remained in NSR compared to 58% on the quinidine standard. The pooled rate difference was 13.8% (SD 2.3, z 31.4, p<.0001).
After 12 months of therapy (2 studies, 107 patients), 60% of those treated with amiodarone remained in NSR compared with 50% on the quinidine standard. The pooled rate difference was 10.4% (SD 1.5, z 15.7, p<.0001).
There was a 29% incidence of adverse effects with approximately 9.5% of patients requiring discontinuation of therapy.
Flecainide.
After 3 months of therapy, 48.5% of patients treated with flecainide remained in NSR compared to 70% on the quinidine standard. The pooled rate difference was -21.4% (SD 1.9, z 40.5, p<.0001).
After 12 months of therapy, 34% of patients treated with flecainide remained in NSR compared to 50% on the quinidine standard. The pooled rate difference was -15.7% (SD 1.3, z 29.8, p<.0001).
The total incidence of adverse effects was not reported; however 8.6% of patients discontinued therapy.