Pretreatment with transmyocardial revascularization might improve ischemic myocardial function performed with cell transplantation

Background: Cells transplanted into the myocardial infarct areas might be lost because of the lack of blood supply to these myocardium areas. The hypothesis that pretreatment with angiogenic therapy induced by transmyocardial revascularization (TMR) might improve ischemic myocardial function, followed by cell transplantation was tested. Methods and Results: After the ligation of the left anterior descending coronary artery, rats were treated with TMR. Two weeks, embryonic stem cells were transplanted into an injured heart. Four weeks after cell transplantation, cardiac function was assessed by homodynamic measurements. Capillary density and infarct size in the infarct myocardium were measured by using a previous experimental method. Graft histology and morphology was also evaluated. Four weeks after the operation, myocardial infarct (MI) rats treated with TMR and cell transplantation showed significantly higher cardiac function in hemodynamic measurements (p<0.01) than that of MI rats receiving cell transplantation or TMR alone. A significant increase in capillary density and reduction in infarct size was observed in the MI rats that received a combined therapy (p<0.01). Conclusion: Pretreatment of an infarct region of the heart with angiogenesis induced by TMR can enhance the efficacy of a cell graft and attenuate the progression of cardiac dysfunction in the rat model.