Effects of stent coating on platelets and endothelial cells after intracoronary stent implantation

Abstract

Background: Adhesion molecules are known to be important in the regulation of endothelial cell and platelet functions. Increased platelets P-selectin expression is a marker of stent thrombosis after uncoated stent placement. Hypothesis: The aim of this study was to compare the effects of intracoronary placement of phosphorylcholine (PC)-coated, versus heparin-coated, versus uncoated stents on platelets and endothelial activity. Methods: Thirty patients (age 55 ± 10, 27 men) with significant proximal left anterior descending coronary artery stenoses were randomized to elective implantation of PC-coated, versus heparin-coated, versus uncoated stents. Following stent placement, intravenous heparin and aspirin plus ticlopidine were administered. Venous plasma soluble E-selectin, sP-selectin, and intercellular adhesion molecule-1 levels were measured before the procedure and 24 and 48 h thereafter as markers of platelet and endothelial cell activation. Patients were excluded if they had a disease known to influence platelet and endothelial cell function. Results: Plasma sP-selectin levels decreased significantly after implantation of PC- and heparin-coated stents (p = 0.04), but remained unchanged in patients randomized to uncoated stents. Plasma sE-selectin levels increased significantly after uncoated stent placement (p = 0.04) and remained unchanged after coated stent implantation. Conclusion: In patients treated with combined antiplatelet therapy, implantation of PC- and heparin-coated stents decreased platelet activity without activating endothelial cells, whereas placement of uncoated stents led to endothelial activation without changing platelet activity. These results suggest that PC-coated and heparin-coated stents may be advantageous in limiting thrombotic complications.