- Question
- Does suppressing ventricular arrhythmias with antiarrhythmic drugs reduce mortality in patients with asymptomatic or mildly symptomatic arrhythmia after myocardial infarction?
- Design
- Randomized, placebo-controlled trial with a preceding drug-titration phase; this preliminary report included 1727 randomized patients with an average follow-up of 10 months.
- Population
- Myocardial infarction survivors with asymptomatic or mildly symptomatic ventricular arrhythmia (six or more ventricular premature beats per hour) whose arrhythmia was suppressed by one of the study drugs, as assessed by Holter recording.
- Intervention
- Active antiarrhythmic drug (encainide, flecainide or moricizine) after arrhythmia suppression was shown during the titration phase.
- Control
- Placebo.
- Primary outcome
- Death from arrhythmia and nonfatal cardiac arrest; this report also analyzed total mortality and arrhythmic deaths in the encainide and flecainide groups versus placebo.
- Results
- Arrhythmic death or nonfatal cardiac arrest: 33 of 730 patients on encainide or flecainide (4.5%) versus 9 of 725 on placebo (1.2%); relative risk 3.6 (95% CI, 1.7 to 8.5). Total mortality: 56 of 730 (7.7%) versus 22 of 725 (3.0%); relative risk 2.5 (95% CI, 1.6 to 4.5).
- Conclusion
- Encainide and flecainide should not be used in patients with asymptomatic or minimally symptomatic ventricular arrhythmia after myocardial infarction, even though they initially suppress the arrhythmia.
- Why it matters
- It showed that suppressing an arrhythmia with a drug does not equal improved survival and that some antiarrhythmics can cause harm. It changed the approach to post-infarction ventricular arrhythmias and led to the discontinuation of that part of the trial.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 7, 2026