Amiodarone for resuscitation after out-of-hospital cardiac arrest due to ventricular fibrillation

Background Whether antiarrhythmic drugs improve the rate of successful resu scitation after out-of-hospital I cardiac arrest has not been determined in randomized clinical trials. Methods We conducted a randomized, double-blind, placebo-controlled study o f intravenous amiodarone in patients with out-of-hospital cardiac arrest. P atients who had cardiac arrest with ventricular fibrillation (or pulseless ventricular tachycardia) and who had not been resuscitated after receiving three or more precordial shocks were randomly assigned to receive 300 mg of intravenous amiodarone (246 patients) or placebo (258 patients). Results The treatment groups had similar clinical profiles. There was no si gnificant difference between the amiodarone and placebo groups in the mean (+/-SD) duration of the resuscitation attempt (42+/-16 and 43+/-16 minutes, respectively), the number of shocks delivered (4+/-3 and 6+/-5), or the pr oportion of patients who required additional antiarrhythmic drugs after the administration of the study drug (66 percent and 73 percent). More patient s in the amiodarone group than in the placebo group had hypotension (59 per cent vs. 48 percent, P=0.04) or bradycardia (41 percent vs. 25 percent, P=0 .004)after receiving the study drug. Recipients of amiodarone were more lik ely to survive to be admitted to the hospital (44 percent, vs. 34 percent o f the placebo group; P=0.03). The benefit of amiodarone was consistent amon g all subgroups and at all times of drug administration. The adjusted odds ratio for survival to admission to the hospital in the amiodarone group as compared with the placebo group was 1.6 (95 percent confidence interval, 1. 1 to 2.4; P=0.02). The trial did not have sufficient statistical power to d etect differences in survival to hospital discharge, which differed only sl ightly between the two groups. Conclusions In patients with out-of-hospital cardiac arrest due to refracto ry ventricular arrhythmias, treatment with amiodarone resulted in a higher rate of survival to hospital admission. Whether this benefit extends to sur vival to discharge from the hospital merits further investigation. (N Engl J Med 1999; 341:871-8.) (C) 1999, Massachusetts Medical Society.