Inhibition of platelet thrombosis using an activated protein C-loaded stent: In vitro and in vivo results

In high-risk and complicated coronary intervention, the risk of acute closu re is unpredictable. Thrombus and platelet deposition at the intervention s ite: may also have further effects on subsequent restenosis. In vivo infusi on of activated protein C has previously been shown to achieve potent antic oagulation without any haemostatic side effects. We now evaluated the in vi tro and in vivo efficacy of polymer-coated coronary stents loaded with puri fied rabbit Activated Protein C (APC). By measuring I-125-fibrinogen/fibrin deposition APC-loaded stent-wires were antithrombotic compared to albumin- loaded. inhibited-APC-loaded. plain polymer-coated and stainless steel sten t-wires. In a balloon injury rabbit iliac artery model, APC-loaded stents d id not occlude (0/14) compared to plain stents (9/15) and SSA-loaded stents (2/4). Relative In-111-labelled platelet deposition showed a similarly sig nificant degree of inhibition. In conclusion. APC-loading could render sten ts significantly less thrombotic. Whether an effective anti-thrombogenic st ent like this effectively reduces restenosis rates warrants further evaluat ion.