Autologous Stem Cells and Transmyocardial Laser Revascularization for Ischemic Heart

ABSTRACT

Myogenic stem cells and transmyocardial laser revascularization (TMR) have been used independently to treat patients with coronary heart disease. We assessed the hypothesis that implantation of autologous myogenic stem cells during TMR will augment ventricular function by new muscle formation and will improve perfusion by neovascularization. Thirty two mini-swine were subjected to myocardial ischemia by applying an ameroid constrictor on the left anterior descending coronary artery. Pigs were randomly assigned into four equal size groups of Ischemia, Ischemia+TMR, Ischemia+ Cell and Ischemia+TMR+Cell. Myocardial blood flow was estimated using colored microspheres, 12 lead ECG was recorded, and ventricular function was determined by the hemodynamic system coupled with sonomicrometry. Three weeks after ameroid constrictor application, ECG changes indicated myocardial infarction of left anterior and apical areas in all pigs. Significant decreases (P<.01) in systolic % wall thickening fraction and % segmental shortening fraction were also observed. At 9 weeks after initial surgery a dramatic decrease (P<.01) in scar areas, a marked improvement (P<.05) in myocardial perfusion and significant better hemodynamic functions were observed for cell implantation groups. Labeled muscle tissue was observed at the implantation sites. Systolic % wall thickening fraction and % segmental shortening fraction were also clearly improved in the cell implanted groups. Stem cells alone or TMR+Cell significantly reduced scar areas, developed new muscle tissue, improved myocardial perfusion, and enhanced contractile function after myocardial infarction.