"Mortality and Morbidity in Patients Receiving Encainide, Flecainide, or Placebo". The New England Journal of Medicine. 1991. 324(12):781-788.
Links to original sources: Wiki Journal Post Full Journal Article
Does implantable cardioverter-defibrillator (ICD) therapy improve survival among patients early after myocardial infarction with reduced left ventricular function and impaired cardiac autonomic function?
Prophylactic ICD therapy does not reduce overall mortality among high-risk patients who have recently had a myocardial infarction. Although ICD therapy was associated with a reduction in the rate of death due to arrhythmia, this benefit was offset by an increase in the rate of death from nonarrhythmic causes.
The Defibrillator in Acute Myocardial Infarction Trial (DINAMIT) demonstrated that the use of an ICD in the early period after an MI in patients with reduced left ventricular ejection fraction and impaired autonomic function did not result in reduced overall mortality.
Current guidelines do not recommend routine prophylactic ICD implantation early after myocardial infarction.
- Multicenter, randomized, open-label trial - N=674 patients with a recent MI (6 to 40 days previously) - Intervention: ICD therapy (n=332) - Control: No ICD therapy (n=342) - Mean follow-up: 30±13 months - Primary outcome: Mortality from any cause - Secondary outcome: Death from arrhythmia
### Inclusion Criteria - Age 18 to 80 years - Recent MI (6 to 40 days prior) - Left ventricular ejection fraction ≤0.35 - Impaired cardiac autonomic function (SDNN ≤70 ms or mean RR interval ≤750 ms over 24 hours)
### Exclusion Criteria - Congestive heart failure or NYHA class IV at randomization - Expected pacemaker requirement
### Baseline Characteristics - Age: 61.7 years - Male: 74.7% - Mean left ventricular ejection fraction: 0.28
- ICD implantation within one week after randomization in the ICD group - Optimal medical therapy for all patients
### Primary Outcome - No significant difference in overall mortality between groups (ICD 7.5% vs Control 6.9% annual mortality rates) ### Secondary Outcomes - Decreased deaths from arrhythmia in the ICD group (ICD 1.5% vs Control 3.5% annual rates) - Increased nonarrhythmic deaths in the ICD group (ICD 7.6% vs Control 4.4% annual rates)
- The reason for the increased nonarrhythmic deaths in the ICD group is unclear - The trial did not support an ICD benefit in this patient population despite previous studies suggesting a potential survival advantage
Supported by St. Jude Medical, grant holder.
- Hohnloser SH, Kuck KH, Dorian P, et al. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial infarction. N Engl J Med. 2004;351(24):2481-2488.