Clinical studies have demonstrated that intracoronary or intramyocardial transplantation of bone marrow mononuclear cells (BMMNCs) into ischemic myocardium improves cardiac function. The objective of the present study was to evaluate the safety and feasibility of intramyocardial BMMNC transplantation into nongraftable areas in combination with off-pump coronary artery bypass grafting in patients with ischemic cardiomyopathy.
Five male patients with myocardial infarction lasting for more than 1 month and with nongraftable myocardium received autologous mononuclear cell transplantation during off-pump coronary artery bypass grafting. Autologous bone marrow was aspirated from the iliac crest. BMMNCs (mean 1.6, standard error [SE] 0.3 × 109) including CD34-positive cells (mean 6.8, SE 1.1 × 106) and AC133-positive cells (mean 3.1, SE 1.7 × 106) were injected into the nongraftable ischemic myocardium. Heart function was evaluated with the use of echocardiography, and myocardial perfusion was examined with single photon emission computed tomography technetium-99mTc sestamibi scans.
Two months after cell transplantation, the mean ejection fraction had increased by 7.4%, SE 1.9% (p = 0.016) compared with that before cell transplantation and off-pump coronary artery bypass grafting. The increase in ejection fraction was not correlated with the number of transplanted total mononuclear cells, CD34-positive cells and AC133-positive cells. Myocardial perfusion at the cell-transplanted area increased after cell transplantation and off-pump coronary artery bypass grafting. No arrhythmia was observed.
The present clinical study suggests that intramyocardial transplantation of autologous BMMNCs into the ischemic area during off-pump coronary artery bypass grafting is both feasible and safe and has beneficial effects on cardiac function.