Transcoronary Implantation of Bone Marrow Stromal Cells Improves Heart Function After Myocardial Infarction

Objective: To test the therapeutic effectiveness of transcoronary implanted stromal cells using a canine model. Methods; The canine acute coronary occlusion model was created by ligating the left anterior descending artery ( LAD). After LAD ligation, bone-marrow derived stromal cells were injected into the ligated coronary artery. Results; Six weeks later, lots of 4' ,6-Diamidino-2-phenyindole( DAPI) labelled stromal cells were identified in the scar tissue , expressing myogenic-specific protein ofα-actin. Some stromal cells were found to be connected to the adjacent host cardio-myocytes with gap junction (connexin 43 staining positive). Cardiac function was evaluated by echocardiography at 6 weeks after implantation. Left Ventricular Ejection Fraction (LVEF) was improved(0.48±0. 09 vs 0. 35±0.05,P 0. 01). The hemody-namic parameters including±dp/dtmax and cardiac output were increased in the cell therapy group (P 0. 05 ). Stromal cell transplantation induced angiogenesis in the scar, and the number of capillary vessels per high-power field (0. 2mm2) in the cell therapy group was 5. 49±0. 50 (and 2. 03±0. 46 for control group, P 0. 01). Conclusions: This study demonstrated for the first time that bone-marrow stromal cell delivered via coronary artery are capable of targeted migration,differentiation into cardiomyocytes in the scar tissue and improvement of heart function.