The Defibrillator in Acute Myocardial Infarction Trial (DINAMIT): Study protocol

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 Trio ( DINAMIT) is a randomized, open label, parallel-group comparison of ICD ther apy versus no ICD therapy in selected survivors of acute myocardial infarct ion. It will test the hypothesis that reduction of sudden arrhythmogenic de ath by means of the ICD will result in reduction of overall mortality rates in patients at high risk after acute myocardial infarction. Accordingly, t his international multicenter study aims to enroll patients shortly after t heir infarction (day 6 to day 40) who have reduced left ventricular functio n (left ventricular ejection fraction less than or equal to0.35) and impair ment of cardiac autonomic function shown by depressed heart rate variabilit y (standard deviation of normal-to-normal R-R intervals less than or equal to 70 ms) or elevated average 24-hour heart rate (mean 24-hour R-R interval less than or equal to 750 ms, assessed by Holter monitoring). Patients wil l be followed for approximately 3 years on average with subsequent data ana lysis 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 ia evaluate the benefit of ICD therapy for the primary prevention of sudden cardiac death in patien ts at high risk after acute myocardial infarction.