Background: In contrast to a cytotoxic or cytostatic pharmacotherapy, promoting the vascular healing response by capturing and sequestering circulating endothelial progenitor cells (EPC) to the stent surface by a CD34 antibody coating (Genous
™
stent) may accelerate stent reendo-thelialization and prevent restenosis formation, as well as stent thrombosis (ST)
Methods: The HEALING IIB study was a multi-center, prospective trial designed to assess the safety and efficacy of the Genous
™
bio-engineered stent in conjunction with HmG CoA reductase inhibitors (statins) to stimulate EPC recruitment, in the treatment of patients with de novo coronary artery lesions (n=100 pts). The primary safety endpoint was major adverse cardiac events (MACE) at 30 days, whereas the primary efficacy endpoint was late luminal loss by QCA at 6 months follow-up.
Results: At interim analysis of the first 45 patients that completed the 6-month angiographic follow-up, the composite MACE rate was 11.1%, whereas 6.6% clinically justified target lesion revascularizations were observed. 2 Patients died within the first 30 days after stent implantation due to angiographically verified stent thrombosis. Low circulating EPC titers were previously associated with a poor response to the EPC capture stent with TLR events and high late loss. Therefore, patients were pre-treated with Atorvastatin 80 mg qd prior to the PCI in order to augment EPC levels. Statin therapy stimulated the levels of committed EPCs by +294%, but failed to increase the titer of CD34+cells (+25%). Although statin pretreatment stimulated EPC levels, the angiographic outcome of the EPC capture stent was not improved in these patients: in-stent late luminal loss was 0.77±0.46 mm. We anticipate to complete analysis of the 6 month angiographic follow-up of all 100 patients by the time of the AHA2008.
Conclusions: The HEALING-IIB study suggests that the EPC capture coronary stent in combination with statin therapy does not sufficiently impede stent restenosis formation for the treatment of de novo coronary artery disease. Although concomitant statin therapy was able to stimulate EPC recruitment, it failed to stimulate CD34+ stem cell levels and did not improve the angiographic outcome of the bioengineered EPC capture stent.
INCREASE IN ENDOTHELIAL PROGENITOR CELLS AFTER ACUTE MYOCARDIAL INFARCTION MAY REDUCE LATE LUMINAL LOSS IN THE STENT DEPLOYED IN INFARC RELATED CORONARY ARTERY
