Abstract 1077: Decreased Progenitor Cell Homing into Healed Myocardial Infarction is Associated with Reduced Contractile Recovery Following Intracoronary Administration of Progenitor Cells in Patients with Ischemic Cardiomyopathy
Background: Initial clinical pilot trials indicate a beneficial effect of intracoronary (i.c.) infusion of progenitor cells on myocardial function in patients with acute myocardial infarction. However, it is unknown whether healing of the infarct may modify the therapeutic efficacy of i.c. progenitor cell administration.Therefore, in 14 patients with a previous myocardial infarction occurring 5 days to 15 years (mean 40±60 months) prior to the examination, ex-vivo Indium-111 labelled endothelial progenitor cells (EPC) were administered into the infarct related artery, and gamma camera total body imaging was performed to quantify the amount of Indium-111 radioactivity within the heart reflecting homing of the administered EPC.
Results: 1 hour after i.c. administration of Indium-111 labelled EPC, 7.0±4.9% of total radioactivity was detected in the heart. There was a close inverse correlation between the age of the previous infarct and cardiac Indium-111 uptake (r=-0.63; p=0.02), indicating that infarct healing is associated with significantly decreased EPC homing following i.c. administration. Most importantly, in a series of 76 patients receiving i.c. EPC administration between 5 days and 288 months after myocardial infarction, recovery of regional contractile function in the infarcted area supplied by the infused artery as assessed by LV angiography demonstrated a close inverse correlation with infarct age (r = -0.64; p<0.001).
Conclusions: In patients with ischemic heart disease, infarct healing is associated with decreased homing of i.c. administered progenitor cells. Decreased progenitor cell homing appears to contribute to the significantly reduced contractile recovery following progenitor cell administration in patients with healed, old infarcts.