NEW YORK (Reuters Health) – German investigators report in Heart that intramyocardial transfer of cord blood-derived stem cells improves left-ventricular function and prevents scar formation in a porcine model of acute MI.

Senior author Dr. Arjang Ruhparwar, at the University of Heidelberg, and colleagues used human cord blood-derived unrestricted somatic stem cells because of their relatively low immunogenicity, their high levels of pluripotency and expansion potential, and their ability to release “a multitude of cytokines.”

Immediately after ligature of the coronary artery of month-old domestic pigs treated with immunosuppressants, the scientists injected cultured cord-blood stem cells in10 animals or culture medium in 8 animals into the free wall of the left ventricle. After 48 hours, there was no difference between groups in apoptosis, recruitment of macrophages, or mitosis;and after 8 weeks, the authors detected no evidence of donor cell engraftment. Thus, they exclude the theory that “functional recovery is simply based on improved neovascularization or modified tissue remodeling.”

Eight weeks post-MI, transesophageal echocardiography showed that the “left ventricular ejection fraction had dramatically improved” in stem cell-treated animals, recovering to 88% of baseline levels, whereas ejection fraction remained severely impaired at 45% of pre-MI levels in control animals.

Left ventricular end diastolic volume significantly increased in the control animals and there was significant scarring in the infarction areas. By contrast, there was no evidence of scarring or ventricular dilation in the pigs treated with stem cells.

Reference:
Heart 2009;95:27-35.