Bone-marrow-derived progenitor cell therapy in need of proof of concept: design of the REPAIR-AMI trial.

Early reperfusion of occluded coronary arteries has significantly reduced early mortality and improved the long-term prognosis of patients with an acute myocardial infarction. However, the development of postinfarction heart failure remains a major challenge. Initial experimental studies indicated that mononuclear progenitor cells derived from the bone marrow may contribute to the functional regeneration of freshly infarcted myocardium and increase neovascularization of ischemic areas. A number of clinical pilot trials have now transferred the experimental approach into the clinical arena, aiming at regenerating myocardial function with infusion of bone-marrow-derived progenitor cells in patients after an acute myocardial infarction. While these initial trials using intracoronary infusion of bone-marrow-derived progenitor cells indeed suggested that such a strategy appears to be feasible and safe in patients with an acute myocardial infarction, there is definitely a pressing need for a proof-of-concept study documenting a potentially beneficial effect of progenitor cell therapy on cardiac function.