Multicenter Automatic Defibrillator Implantation Trial (MADIT)


Status: Completed in 2001

The first trial to show the lifesaving benefits of Implantable Cardiac Defibrillators (ICD) without requiring patients to have a documented history of abnormal heart rhythms.
Results | Design | Patient Population | Clinical Relevance

Mortality over an average follow-up of 20 months

  • There was a 31% reduction in the risk of death at any interval among patients in the defibrillator group as compared with patients in the conventional-therapy group. 
  • The cumulative survival curves represent a relative decrease in death rates in the defibrillator group (95% confidence limits) of 12% at 1 year (-27 to 40%), 28% at 2 years (4 to 46%), and 29% at 3 years (5 to 46%).
Patients were randomized into two treatment arms in a 3:2 ratio.

Patients in the first arm were treated with conventional drug treatment and also implanted with an ICD.

The second group was treated exclusively with conventional drug treatment, as prescribed by the patient's attending physician (control arm).

Patients were seen in the follow-up clinic at 1 month after randomization, and then at 3-month intervals until the termination date of the study or death.

Eligible study participants included both male and female patients over 21 years of age that had experienced an MI at least 30 days prior to study enrollment and demonstrated an ejection fraction (EF) ≤ 30%.

Some of the exclusion criteria were

  • Prior cardiac arrest
  • Syncope unrelated to an acute MI
  • NYHA Class IV
  • CABG or non-CABG revascularization less than 3 months prior to enrollment
  • Use of antiarrhythmic agents, except for atrial arrhythmias
  • Comorbidity associated with decreased survival for trial duration.

76 Centers worldwide

  • 71 U.S.
  • 5 European

1232 patients enrolled

To evaluate the effect of prophylactic ICD therapy on survival in patients with prior MI and LV dysfunction.

The primary endpoint was death from any cause

First trial to show the lifesaving benefits of ICDs without requiring patients to have a documented history of abnormal heart rhythms