Lack of effect of amiodarone on survival after extensive infarction

Background The purpose of this study was to elucidate whether the reduction of mortality with amiodarone after myocardial infarction depended on ejection fraction. Methods The data from the Polish Amiodarone Trial were analysed retrospectively. Patients with acute myocardial infarction and contraindications to betablockers were randomized on days 5-7 after admission to receive amiodarone (n = 305) or placebo (n = 308). Short and long-term (46 months) mortality were analysed comparing the groups with impaired (ejection fraction < 40%) and preserved (ejection fraction greater than or equal to 40%) left ventricular function. A subset of patients (n = 523) with available echocardiograms were subjected to this analysis. Results Long-term and sudden cardiac mortality were significantly reduced with amiodarone in the group of patients with ejection fraction greater than or equal to 40% (amiodarone versus placebo, respectively: 9.1 versus 16.5%, P < 0.05; 3.4 versus 8.2, P < 0.05). No beneficial effect of amiodarone was observed in the group with low ejection fraction (cardiac and sudden cardiac mortality: amiodarone versus placebo, 20.8 versus 19.3% and 7.8 versus 5.7% respectively). One-year mortality also revealed a favourable trend only in amiodarone-allocated patients with ejection fraction greater than or equal to 40%. Conclusion Amiodarone decreased long-term and sudden cardiac mortality after myocardial infarction only in patients with preserved left ventricular function. No benefit was observed in patients with decreased ejection fraction.