Mortality following ventricular arrhythmia suppression by encainide, flecainide, and moricizine after myocardial infarction. The original design concept of the Cardiac Arrhythmia Suppression Trial (CAST).
Epstein AE, Hallstrom AP, Rogers WJ, Liebson PR, Seals AA, Anderson JL, Cohen JD, Capone RJ, Wyse DG
Journal of the American Medical Association JAMA. 1993 Nov 24;270:2451­5: Issue: 20
A total of 3549 patients with myocardial infarction and left ventricular dysfunction.

Administration of encainide, flecainide, moricizine to suppress ventricular premature depolarizations showed that the suppression of asymptomatic or mildly symptomatic ventricular arrhythmias after myocardial infarction does not improve survival and can increase mortality when compared with placebo. Treatment strategies designed solely to suppress these arrhythmias should no longer be followed.

At 1 year from the time of randomization to blinded therapy, 95% of placebo­treated patients vs 90% of active drug­treated patients remained alive (P = .0006). Similarly, at 1 year, 96% of placebo­treated patients vs 93% of active drug­treated patients remained free of cardiac arrest or arrhythmic death (P = .003).