Repair of myocardial infarction by epicardial deposition of bone marrow cell-coated muscle patch in a murine model

Background. Myocardial infarction results in irreversible myocyte loss. In a murine model, we tested the feasibility of a novel repair technique combining bone marrow cell (BMC) transplantation and cardiomyoplasty. Methods. Myocardial infarction was induced cryogenically in backcrossed ROSA 26 transgenic X C57BL/6J mice (n = 75). Thirty days later, surviving mice (n = 69) were randomized to sham treatment (rethoracotomy only; n = 11), patch only treatment (n = 29), or patch + BMC treatment (n = 29). Abdominal muscle patches were harvested from donor littermates not expressing the beta-galactosidase reporter gene and sutured on the epicardium directly above the infarct zone. Patch only-treated mice received uncoated patches. Patch + BMC-treated mice received patches coated with 5 X 10(6) beta-galactosidase-expressing BMCs embedded in a collagen-rich three-dimensional matrix. Results. Mortality rate was 52% after muscle patch implantation. Bone marrow cells were able to migrate from muscle patch into the infarct zone, as demonstrated by P-galactosidase immunostaining, and ultimately constituted 8% of all cells in scar tissue (mean +/- standard deviation, 219 +/- 111/mm(2)). Angiogenesis and cell survival in the scar were improved by patch + BMC treatment. Left ventricular geometry and cardiac function were improved by patch treatment, with or without BMC, although the effects were stronger after patch + BMC treatment. Conclusions. Epicardial deposition of a BMC-coated muscle patch is a promising approach to restoring cardiac function after myocardial infarction. (C) 2004 by The Society of Thoracic Surgeons.