Background: The number of circulating Endothelial Progenitor Cells(EPCs) and their migratory activity have been reported to be reduced in patients with ischemic cardiovascular disease. The measurement of brachial artery flow-mediated dilation (FMD) by ultrasound is a noninvasive and indirect method representing EPCs��� number and function. We investigated that dysfunction of EPCs had any influence on improvement of left ventricular function in Cardiac stem cell therapy group(MAGIC-III).
Methods & Results: A total of 43 subjects was enrolled as one of five groups; healthy G-CSF(20), old MI (OMI)-G-CSF (8), acute MI(AMI)-G-CSF (11), OMI-control (2), and AMI-control(2). The flow-mediated dilation (FMD) was used to evaluate endothelial function by high-resolution brachial artery ultrasound before and after G-CSF. C-reactive protein (CRP), interleukin-6 (IL-6) were measured as biomarkers of inflammation. In AMI & OMI-G-CSF group, double PACS about EPCs marker(esp. CD34 & KDR) was done to identify mobilized EPCs. LVEF was measured by myocardial SPECT, dobutamine stress echocardiography and MRI at 24 weeks after enrolled day. Baseline FMD of healthy G-CSF group was higher than that of disease group(14.61짹5.42 & 6.06짹3.72, p<0.01). In all three G-CSF groups, G-CSF did not significantly alter FMD. In disease group(N=23), baseline FMD and ��FMD between pre and post G-CSF injection did not have any statistically significant correlation with LVEF improvement after 24weeks. Baseline CRP, IL-6 level and EPC mobilization confirmed by double PACS showed similar results.
Conclusions: Although FMD is a useful method to estimate the EPCs��� number and function, our study showed that the FMD results could not predict the improvement of LV function in cardiac stem cell therapy. For the more appropriate cardiac stem cell therapy, a useful method to predict LV functional improvement is required.