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Evevident
Original paper
2002NEJMCardiology

MADIT-II

Prophylactic Implantation of a Defibrillator in Patients with Myocardial Infarction and Reduced Ejection Fraction

RCTICD primary prevention after MI

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Overview

In prior MI with LVEF <=30%, prophylactic ICD implantation reduced all-cause mortality versus conventional therapy.

Clinical takeaway

MADIT-II simplified primary-prevention ICD selection by showing benefit in post-MI severe LV dysfunction without requiring inducible VT testing.

Key result

Mortality: 14.2% with ICD vs 19.8% with conventional therapy over average 20-month follow-up; HR 0.69.

Practice impact

Use primary-prevention ICDs in eligible post-MI patients with persistently reduced EF after the waiting period and optimized therapy.

Evidence

Study design

Randomized, open-label, multicenter trial.

Enrollment

1,232

Follow-up

Average 20 months.

Geography

Multinational

Clinical question

Does prophylactic ICD implantation improve survival in patients with prior MI and severe LV systolic dysfunction?

Population

  • Patients with prior myocardial infarction and left ventricular ejection fraction of 30% or less.

Intervention

Implantable cardioverter-defibrillator.

Comparator

Conventional medical therapy.

Primary outcome

Death from any cause.

Prophylactic ICD implantation reduced all-cause mortality compared with conventional medical therapy.

Hazard ratio / 0.69 / CI 95% CI 0.51-0.93 / p=0.016

Key results

  • Mortality: 14.2% with ICD vs 19.8% with conventional therapy.
  • Hazard ratio for death with ICD: 0.69; 95% CI 0.51-0.93; p=0.016.
  • Electrophysiology-study inducibility was not required for enrollment.

Harms

  • ICD therapy carries procedural, inappropriate shock, infection, and device-complication risks not captured by the headline mortality result.

Clinical Use

When to cite

  • When explaining primary-prevention ICD indications in ischemic cardiomyopathy.

Practice impact

  • Helped establish primary-prevention ICD therapy for ischemic cardiomyopathy with severe LV dysfunction.

Applicability

  • Most applicable to post-MI patients with persistently reduced EF after appropriate waiting period and guideline-directed therapy.

Limitations

  • Device technology and heart failure medical therapy have evolved.
  • Requires sufficient life expectancy and functional status to benefit.
  • Does not apply immediately after acute MI before reassessment.

Common misinterpretations

  • Do not implant immediately after MI based solely on MADIT-II; reassess EF after the recommended waiting period.

Related evidence

SCD-HeFT - Context

Citation

Moss AJ, Zareba W, Hall WJ, et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med. 2002;346(12):877-883. doi:10.1056/NEJMoa013474

Prophylactic implantation of a defibrillator improves survival.