This study explores the hypothesis that wearable defibrillators can impact mortality by reducing sudden death during the first three months after a heart attack in persons with high risk for life-threatening arrhythmias.

In patients with ventricular dysfunction immediately following myocardial infarction, sudden death may be responsible for up to 50% of total mortality. Wearable defibrillators may reduce sudden death by providing immediate detection and treatment of ventricular arrhythmias. This study is design to demonstrate a reduction in sudden death measured at three months following myocardial infarction among patients who have ventricular dysfunction.

Inclusion Criteria:

• Patients identified in the hospital or within 7 days after discharge with a diagnosis of an acute MI (STEMI or Non-STEMI)

• LV ejection fraction ≤35% determined at the following time point:

  1. If no PCI within the first 8 hours following the MI: ≥ 8 hours after MI
  2. If acute PCI occurs within 8 hours of MI: ≥8 hours after PCI
  3. If CABG is planned (before or within 7 days of discharge), wait to enroll and then use the most recent assessment at least 48 hours post CABG

• Age ≥ 18 years

Exclusion Criteria:

• Existing ICD or indication for an ICD at the time of screening
• Existing unipolar pacemakers/leads
• Chronic renal failure requiring hemodialysis after hospital discharge
• Chest circumference too small or too large for LifeVest garment*
• Participants discharged to an institutional setting with an anticipated stay > 7 days
• Pregnancy
• Inability to consent
• Any other condition or circumstance that in the judgment of the clinician makes the participant unsuitable for the study.