Trial Synopsis REFINE ICD is testing whether an implantable cardioverter defibrillator (ICD), in addition to usual care, will alter mortality as compared to usual care alone. A total of 700 patients with an LVEF 36% to 50% plus impaired HRT and abnormal TWA, measured at least 2 months after MI, are being randomized. Patients with normal HRT +/- TWA are not eligible for randomization but are followed in a registry. 

Primary hypothesis. An ICD in addition to usual care will increase the probability of survival in subjects with LVEF values of 36% to 50%, impaired HRT and abnormal TWA measured at least 2 months after the index MI. 

Outcome. Mortality is the standard by which most cardiac interventions are judged since it is unbiased and unambiguous. In the event of a positive outcome, quality of life should be assessed to aid in the overall interpretation of the results. As such, these outcomes comprise secondary outcomes and will only be assessed if the primary outcome is positive. 

Inclusion Criteria: 18-80 years old, clinically appropriate ICD candidate, LVEF 36% to 50% measured 2 months post-MI and at least 3 months after angioplasty or bypass surgery, revascularization where clinically indicated, appropriate medical therapy, sinus rhythm in the 8 weeks prior to the Holter assessment, and abnormal HRT and TWA on the Holter assessment performed 2 months after MI (core lab with expert over-read). The trial is registered at (NCT00673842)