Time-dependent dynamic mobilization of circulating progenitor cells during percutaneous coronary intervention in diabetics

Background: Circulating progenitor cells (CPC) especially endothelial progenitor cell (EPC) levels and functions are attenuated in diabetic patients. This may explain the poorer outcome of diabetics undergoing percutaneous coronary intervention (PCI). We aim to study the dynamic changes of these cells in these patients. Methods: Blood of 8 diabetics with stable coronary artery disease who underwent elective PCI, were obtained at baseline, 1, 4 and 24 h after PCI. Fluorescence activated cell sorting (FACS) analysis was performed to quantitate CD34+ and CD34+/ KDR+ cells. Patients with recent acute coronary syndrome were excluded. Results: After PCI, decreases in CPC from baseline were detected in 7 out of the 8 patients. In these 7 patients, mean CD34+ and CD34+/KDR+ cells were 182 ± 99/1 × 10⁵ and 18 ± 16/1 × 10⁵ cells respectively. Maximal decrease of CD34+ and CD34+/KDR+ cells were 47.8% and 53.3% at 1 h and 4 h respectively. At 24 h, CPC levels returned to baseline but were not elevated. The only patient with raised cardiac enzymes has instead, 2 to 3 fold increase in CPCs at 1 and 4 h. Conclusions: We found a transient dip in circulating progenitors early during PCI. This suggests incorporation of the cells into the sites of vascular denudation. The absence of subsequent CPC elevation post-PCI in diabetes may be associated with known poorer outcome of these patients. With myocardial injury, more progenitors may be mobilized from the bone marrow into the circulation and abolish the hyperacute reduction in circulating levels.