Background: Several clinical trials are underway to determine whether autologous skeletal myoblast transplantation is an effective and safe therapeutic strategy for severe heart failure due to myocardial infarction (MI). It remains unclear whether repeated skeletal myoblast implantation is a feasible and effective cell delivery method for the infarcted myocardium.
Methods and results: Four weeks after a coronary ligation, male syngeneic Lewis rats were assigned to 3 treatment groups: 3 episodes of skeletal myoblasts (6x10(6)) transplantation (group I), a bolus transplantation of myoblasts (18x10(6)) (group II), or culture medium injection (group III). Eight weeks after the first treatment, echocardiography, cardiac catheterization and histological examination were performed to compare the therapeutic effects on left ventricular (LV) systolic and diastolic functions, and the engrafted myoblast volume. Repeated myoblast implantation significantly improved LV function and resulted in significantly larger engrafted volume and LV contractility compared with a bolus transplantation with the same number of myoblasts.
Conclusions: Repeated skeletal myoblast transplantation is a safe and effective therapeutic strategy for the infarcted myocardium.