Intracoronary Infusion of Mononuclear Bone Marrow-Derived Stem Cells is Associated with a Lower Plaque Burden After Four Years

Aim: To assess the long-term effects of intracoronary stem cell (SC) infusion following acute myocardial infarction (AMI) on the local atherosclerotic process at the site of infusion after four years of follow-up. Methods: We evaluated 18 post-AMI patients. Group 1 consisted of nine patients given an intracoronary injection of autologous mononuclear SC, and group 2 consisted of nine patients given a placebo injection. The plaque count, plaque burden (PB) and coronary calcium score (CCS) were assessed using multislice 64 CT angiography of the coronary tree four years after SC injection. Results: The total PB and CCS along the entire coronary segment distal to the site of infusion were significantly lower in the SC group (PB -702 mm(3) vs. 1.465 mm(3), p=0.0006; CCS -295 vs. 796, p < 0.0001). The mean PB per coronary artery was 112.12 mm(3)+/- 16.82 mm(3) for the treated arteries vs. 189.56 mm(3) +/- 20.98 mm(3) for the untreated arteries (p < 0.0001), while the mean CCS was 53.12 +/- 16.4 vs. 106.43 +/- 10.86 (p < 0.0001). In the SC group, there were significant differences in the mean PB (87.75 mm(3) vs. 112.12 mm(2), p=0.005) and mean CCS (36.87 vs. 53.12, p=0.04) between the coronary segment infused with SC and the entire coronary artery. Conclusions: Multislice CT angiography of atheromatous plaques in the coronary tree four years after SC infusion in post-AMI patients indicates a significantly lower atheromatous plaque burden, as demonstrated by a lower plaque volume and lower CCS at the site of stem cell infusion compared with other coronary territories.