Abstract 4540: Mobilization of Endothelial Progenitor Cells After Implantation of Different Drug-eluting Stents
Implantation of drug-eluting stents (DES) can lead to delayed endothelial healing and impaired vasodilation. Exact mechanisms are unknown but reduced homing of circulating endothelial progenitor cells (EPC) is probably involved. Impaired endothelial healing in first-generation DES.
Aim: comparison of the EPC mobilization, expression of vascular and endothelial developmental markers in circulating EPC and levels of chemotactic and inflammatory cytokines after implantation of different types of DES in correlation with neointima formation and strut endothelialization.
Methods and results: 50 patients with stable CAD undergoing the elective PCI with implantation of paclitaxel- (PES), sirolimus- (SES), everolimus- (EES) and zotarolimus-eluting (ZES) as well as bare metal stents (BMS) were enrolled. Number of EPC was measured using FACS, and chemoattractans using ELISA before PCI, 24 hours and 4 weeks later. Number of circulating CD34+CD133+VEGFR2+ EPC (1.6±1.1 cells/μL) increased 24 hours after PCI in patients with BMS (4.1±1.5 cells/μL), ZES (3.7±1.4 cells/μL) and EES (4.3±1.8 cells/μL), but not with PES (2.0±0.9 cells/μL) and SES (1.7±1.3 cells/μL). No differences in levels of chemoattractants SCF, G-CSF, VEGF and SDF-1 were found after 24 hours and 4 weeks after PCI. 24 hrs after implantation of BMS levels of MCP-1, IL-10, sCD40L and hsCRP were increased in comparison to baseline, and did not change in any of DES groups [MCP-1 (510±112 vs. 362±71 pg/mL, p<0.05); IL-10 (4.4±2.1 vs. 3.1±1.3 pg/mL, p<0.05); sCD40L (4.97±2.4 vs. 3.2±1.5 pg/mL, p<0.03); hsCRP (3.4±1.1 vs. 2.8±0.9 pg/mL, p<0.05). No differences in levels of cytokines and EPC were found after 4 weeks between DES and BMS. CD133+ EPC were isolated 24 hours after PCI using magnetic beads. Similar levels of mRNA for endothelial (VE-cadherin, von Willebrand factor, CD31) were found between all types of DES. Rate of apoptotic EPC was the same in all groups. Number of EPC was negatively correlated with increase of neointima volume in IVUS after 6 months in BMS.
Conclusion: Implantation of paclitaxel- and sirolimus-euting stent is associated with suppression of the mobilization of endothelial progenitor cells in comparison to BMS and new-generation zotarolimus- and everolimus-eluting stents.