Background: The implantable cardioverter/defibrillator (ICD) has been shown to be superior to antiarrhythmic drug therapy for the secondary prevention of sudden cardiac death. Its role in the primary prevention of sudden death after myocardial infarction is unknown. Methods and Results The Defibrillator in Acute Myocardial Infarction Trial (DINAMIT) is a randomized, open-label, parallel-group comparison of ICD therapy versus no ICD therapy in selected survivors of acute myocardial infarction. It will test the hypothesis that reduction of sudden arrhythmogenic death by means of the ICD will result in reduction of overall mortality rates in patients at high risk after acute myocardial infarction. Accordingly, this international multicenter study aims to enroll patients shortly after their infarction (day 6 to day 40) who have reduced left ventricular function (left ventricular ejection fraction </=0. 35) and impairment of cardiac autonomic function shown by depressed heart rate variability (standard deviation of normal-to-normal R-R intervals </=70 ms) or elevated average 24-hour heart rate (mean 24-hour R-R interval </=750 ms, assessed by Holter monitoring). Patients will be followed for approximately 3 years on average with subsequent data analysis based on the intent-to-treat principle. Primary outcome is all-cause death. The trial is expected to be completed in 2003.
Conclusions: DINAMIT is the first prospective study to evaluate the benefit of ICD therapy for the primary prevention of sudden cardiac death in patients at high risk after acute myocardial infarction.