Effect of amiodarone on mortality after myocardial infarction: a double-blind, placebo-controlled, pilot study.
OBJECTIVES: The goal of this study was to evaluate the effect of amiodarone on mortality, ventricular arrhythmias and clinical complications in high risk postinfarction patients. BACKGROUND: No therapy has been shown to reduce sudden death in patients ineligible to receive beta-adrenergic blocking agents after myocardial infarction. METHODS: Patients who were not eligible to receive beta-blockers were randomized to receive amiodarone (n = 305) or placebo (n = 308) for 1 year. RESULTS: There were 21 deaths in the amiodarone group compared with 33 in the placebo group (odds ratio 0.62, 95% confidence interval [CI] 0.35 to 1.08, p = 0.095). There were two noncardiac deaths in the amiodarone group and none in the placebo group; thus, the difference in cardiac mortality (19 vs. 33, respectively) was statistically significant (odds ratio 0.55, 95% CI 0.32 to 0.99, p = 0.048). There was a significant decrease in Lown class 4 ventricular arrhythmias (7.5% vs. 19.7%, respectively, p < 0.001). Adverse effects developed in 30% of amiodarone-treated patients and 10% of placebo-treated patients. Pulmonary toxicity, which was mild and reversible, occurred in only one patient in the amiodarone group but in no patient in the placebo group. CONCLUSIONS: This trial demonstrated a significant reduction in cardiac mortality and ventricular arrhythmias with amiodarone treatment. However, given the wide confidence intervals and borderline statistical significance of our trial, larger trials are needed to confirm or refute this view.