Heparin Coating of Coronary Stents Increases Time Until Stent Occlusion Due to Delayed Platelet Activation in an In Vitro Circulating Model

Acute and subacute reocclusion of stented coronary vessels are still a major risk factor after coronary stent implantation. Implanted stents have been discussed to be a major trigger for platelet activation. Coating of coronary stents has been found to improve clinical outcome after stent implantation due to decreased platelet activation. Therefore, in this study we monitored the time until stent occlusion (TSO) in an in vitro circulation model, filled with platelet-rich plasma (PRP) and containing uncoated or heparin coated stents (Hepamed, Medtronic, Germany). Furthermore, the extent of platelet activation within PRP during circulation in the in vitro model was measured using flow cytometry.