A Cochrane review [Abstract] 1 included 59 studies with a total of 20 981 subjects. Flecainide was included in 8 of the studies (n=1 258), and 4 of them compared flecainide with placebo or no treatment.
Flecainide reduced recurrence of atrial fibrillation by about a third (RR 0.65, 95% CI 0.55 to 0.77; 4 studies, n=511) compared to placebo or no treatment corresponding to a recurrence rate of 69.8% in people not treated or receiving placebo and 45.4% (38.4% to 53.8%) in people receiving flecainide. The NNTB for flecainide was 4 (95% CI 3 to 6).
Risk of proarrhythmia (counting both tachyarrhythmias and bradyarrhythmias attributable to treatment) was over 4 times higher among people receiving flecainide than placebo or no treatment (RR 4.80, 95% CI 1.30 to 17.77; 4 studies, n=511) corresponding to a risk of 6 per 1000 among people in the placebo/no treatment group compared with a risk of 30 (95% CI 8 to 112) per 1000 people in the flecainide group. The NNTH for flecainide was 44 (95% CI 10 to 556). Flecainide increased withdrawals due to adverse effects compared to placebo or no treatment (RR 15.41, 95% CI 0.91 to 260.19; 1 study, n=73). Seven people receiving flecainide withdrew due to adverse events, compared with none in the control arm.
Very few data on mortality with flecainide was available; none of the 4 studies (n=511) reported any death from any cause. Thus, it was impossible to make any reliable estimation what the effect of long-term treatment with flecainide on mortality might be. Flecainide has been shown to induce an excess of mortality in some studies in other heart conditions 2.
Primary/Secondary Keywords