EMPIRIC LONG-TERM AMIODARONE PROPHYLAXIS FOLLOWING MYOCARDIAL-INFARCTION - A METAANALYSIS

Background: The prophylactic administration of amiodarone following ac ute myocardial infarction has been investigated in several small trial s. This study combined the results of these small trials in a metaanal ysis to determine the effects of prophylactic low-dose amiodarone on m ortality following acute myocardial infarction. Methods: Four prospect ive, randomized, placebo-controlled trials, which investigated the pro phylactic administration of low-dose amiodarone (200 to 400 mg/d) to p atients after acute myocardial infarction, were selected from the curr ent literature according to strict inclusion criteria. A total of 1140 patients, 566 in the amiodarone-treated group and 574 in the placebo- treated group, were included in the analysis. Sudden cardiac death, ca rdiac mortality, and total mortality were the end points of interest. In addition, the effect of impaired left ventricular function (ejectio n fraction, <45%) on total mortality was assessed. Data were aggregate d by using the Mantel-Haenszel method to obtain final summary statisti cs for these end points. Results: Patients treated with low-dose amiod arone exhibited a lower incidence of sudden cardiac death (3.1%) and t otal mortality (6.1%) when compared with patients treated with placebo (6.9% and 11.2%, respectively; both P<.01; and 95% confidence interva l [CI], 0.011 to 0.065 and 0.013 to 0.082, respectively). There was no significant difference between the amiodarone- and placebo-treated gr oups with respect to cardiac mortality(2.6% vs 3.7%, respectively; P=. 26; and 95% CI, -0.012 to 0.032). For patients with a left ventricular ejection fraction of less than 45%, total mortality was 5.5% in the a miodarone-treated group and 9.4% in the placebo-treated group (P=.30; CI, -0.023 to 0.101). Conclusions: Although further data from ongoing large, randomized trials are needed, this meta-analysis suggests that the prophylactic administration of low-dose amiodarone to patients fol lowing acute myocardial infarction reduces the incidence of both sudde n cardiac death and total mortality. The benefits of low-dose amiodaro ne may be limited to patients with preserved left ventricular function .