Abstract
Background: Although intracardiac injection or intracoronary delivery of mesenchymal stem cells (MSCs) has been reported, there have been few studies on the intravenous injection of MSCs, particularly in Japan. Methods and Results: Five patients with left ventricular ejection fraction (LVEF) ≤45% received 1.0×10(8) MSCs intravenously. The procedure did not induce significant changes in vital signs. One patient had an elevated body temperature after 1 day, but recovered spontaneously. Laboratory tests remained normal for 1 month after cell delivery. Computed tomography was performed after 1-2 years, and there was no evidence of malignancy. Conclusions: In this pilot study of patients with reduced LVEF, intravenous MSC delivery had no adverse effects.