- Current clinical guidelines advocate implantable cardioverter defibrillator (ICD) therapy for the prevention of sudden cardiac death among post myocardial infarction (MI) patients. However, there are scarce data regarding compliance with the guidelines and utilization of this life-saving treatment. We aimed to assess the rate of ICD utilization among post MI patients with left ventricular ejection fraction (LVEF) ≤ 35%. Methods All patients admitted with a ST-elevation MI at a single tertiary care center from 2005 to 2009, discharged alive with LVEF ≤ 35% and surviving 40 days were included. Patients already implanted with an ICD and whose residence was outside the hospital's area of coverage were excluded. ICD utilization, LVEF re-assessment and mortality were assessed during mean follow up time of 2 years. Results Of the 285 subjects, only 26 (9%) received an ICD. There were significant differences in ICD use among different medical health organizations (insurers). Among the 259 subjects not implanted with an ICD, repeat echocardiography study for the re-assessment of LVEF was performed in only 176 (68%). Of those, LVEF remained severely impaired in 47%. After excluding subject whose LVEF improved at follow up, the ICD utilization rate was 14%. In a multi-variable analysis, significant predictors of ICD utilization were age below the median of 61 years, and a repeat echocardiography. Using propensity score and matching of subjects implanted with ICD with those not implanted, ICD implantation was found to be associated with survival benefit. Conclusions ICDs are underutilized in post MI patients and compliance with current guidelines is insufficient. Failure to re-assess LVEF is a barrier for this life-saving treatment. Withholding ICD therapy among unselected post MI patients with depressed LVEF is associated with a markedly increased mortality.