Large acute myocardial infarctions are the most frequent cause of subsequent systolic heart failure. Some evidence exists on the improvement after intracoronary administration of bone marrow cells in patients with a recente acute myocardial infarction. Although subgroup analyses suggest that patients with the largest myocardial infarctions have the largest increase in ejection fraction after intracoronary bone marrow administration, there is no published trial including only large myocardial infarctions. Therefor we sought to confirm the subgroup analyses by conducting a trial in only large first acute myocardial infarction patients.