Delivery route in bone marrow cell transplantation should be optimized according to the etiology of heart disease.

Background: Recent studies have revealed that bone marrow cell (BMC) transplantation is effective not only for myocardial infarction (MI), but also for dilated cardiomyopathy (DCM). However, the method of administering donor cells remains unknown, and may differ between MI and DCM. In the present study, intramyocardial (IM) injection and intravenous (IV) delivery of BMC were compared in each etiological model.

Methods And Results: MI was induced in 72 mice and DCM in another 36 mice by doxorubicin. BMCs were administered IV or IM in an acute MI (AMI), old MI (OMI) or DCM model. In the AMI model, left ventricular (LV) remodeling was reduced in both the IM- and IV-groups, but only in the IM-group in the OMI model. In the DCM model, the LV dimension of the IV-group was smaller than that of the IM-group. Histological examination showed that green fluorescent protein (GFP) cells were equally distributed in the infarct area of the IV- and IM-groups in AMI, and in the IM-group in the OMI model. In the DCM model, GFP cells were diffusely scattered throughout the ventricular wall in the IV-group, but were confined to the injection site in the IM-group.

Conclusions: In OMI, IM delivery of BMCs was more effective than IV; however, IV delivery was superior in DCM. Delivery route should be selected according to the etiology of heart disease to optimize the efficacy of BMC transplantation.