Differential Effects of Progenitor Cell Populations on Left Ventricular

Objectives We compared biological repair after acute myocardial infarction (AMI) with selected porcine progenitor cell populations. Background Cell types and mechanisms responsible for myocardial repair after AMI remain uncertain. Methods In a blinded, randomized study, we infused autologous late-outgrowth endothelial progenitor cells (EPC) (n! 10, 34 " 22 # 106 CD29-31-positive, capable of tube formation), allogeneic green fluorescent peptide–labeled mesenchymal stem cells (MSC) (n! 11, 10 " 2 # 106 CD29-44-90-positive, capable of adipogenic and osteo-genic differentiation), or vehicle (CON) (n! 12) in the circumflex artery 1 week after AMI. Systolic function (ejec-tion fraction), left ventricular (LV) end-diastolic and end-systolic volumes, and infarct size were assessed with magnetic resonance imaging at 1 week and 7 weeks. Cell engraftment and vascular density were evaluated on postmortem sections