Intracoronary Delivery of Autologous Cardiac Stem Cells Improves Cardiac Function in a Porcine Model of Chronic Ischemic Cardiomyopathy
Background—Relevant preclinical models are necessary for further mechanistic and translational studies of c-kit+ cardiac stem cells (CSCs). The present study was undertaken to determine whether intracoronary CSCs are beneficial in a porcine model of chronic ischemic cardiomyopathy.
Methods and Results—Pigs underwent a 90-min coronary occlusion followed by reperfusion. Three months later, autologous CSCs (n=11) or vehicle (n=10) were infused into the infarct-related artery. At this time, all indices of LV function were similar in control and CSC-treated pigs, indicating that the damage inflicted by the infarct in the two groups was similar; one month later, however, CSC-treated pigs exhibited significantly greater LV ejection fraction (echocardiography) (51.7 ± 2.0% vs. 42.9 ± 2.3 %, P<0.01), systolic thickening fraction in the infarcted LV wall, and max LV dP/dt, as well as lower LVEDP. Confocal microscopy showed clusters of small α-sarcomeric actin positive cells expressing Ki67 in the scar of treated pigs, consistent with cardiac regeneration. The origin of these cycling myocytes from the injected cells was confirmed in four pigs that received EGFP-labeled CSCs, which were positive for the cardiac markers troponin I, troponin T, myosin heavy chain, and connexin-43. Some engrafted CSCs also formed vascular structures and expressed α-smooth muscle actin.
Conclusions—Intracoronary infusion of autologous CSCs improves regional and global LV function and promotes cardiac and vascular regeneration in pigs with old MI (scar). The results mimic those recently reported in humans (SCIPIO trial) and establish this porcine model of ischemic cardiomyopathy as a useful and clinically-relevant model for studying CSCs.
- Received January 2, 2013.
- Revision received May 9, 2013.
- Accepted May 16, 2013.