"Mortality and Morbidity in Patients Receiving Encainide, Flecainide, or Placebo". The New England Journal of Medicine. 1991. 324(12):781-788.

## Clinical Question
Does implantable cardioverter-defibrillator (ICD) therapy improve survival among patients early after myocardial infarction with reduced left ventricular function and impaired cardiac autonomic function?

## Bottom Line
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.

## Major Points


## Guidelines
Current guidelines do not recommend routine prophylactic ICD implantation early after myocardial infarction.

## Design
- 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

## Population
### 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

## Interventions
- ICD implantation within one week after randomization in the ICD group
- Optimal medical therapy for all patients

## Outcomes
### 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)

## Criticisms
- 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

## Funding
Supported by St. Jude Medical, grant holder.

## Further Reading
- 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.