title: Influence of heparin coating of coronary stents and ex vivo efficacy of different doses of acetylsalicylic acid and ticlopidine in a pulsed floating model of recirculating human plasma.
abstract: Acute occlusion of stented coronary vessels still occurs in up to 3%. Activated platelets have been found to play a major role in the pathogenesis of these complications. We therefore analyzed the efficacy of a heparin coating of coronary stents and investigated the ex vivo efficacy of different antiplatelet drugs. Each of seven healthy volunteers was treated with each of the following medications for 7 days: ASA 100 mg/day, ASA 300 mg/day, ticlopidine 250 mg/day, and ticlopidine 500 mg/day. Three standardized in vitro silicon tubing models, one of them containing an uncoated stent, one a heparin-coated stent, and one without a stent (control) were filled with PRP and circulation was started. TOS in systems with heparin-coated stents was 2.4-times longer compared to systems with uncoated stents (P<0.001), and 1.5-times longer compared to the control (P<0.01). The increase of CD62p expression within the first 5 min was 2.5-times higher in systems with uncoated stents and 1.7-times higher in the control than in systems with heparin-coated stents (P<0.05). Aggregometry revealed significant medication- and dose-dependent inhibition of platelet aggregability for all medications. Heparin-coating of coronary stents reduces their thrombogenicity significantly. ASA and ticlopidine effectively reduce platelet activation ex vivo. The used in vitro system facilitates a reproducible method to estimate the thrombogenicity of coronary stents prior to in vivo trials.
authors.affiliation: Department of Transfusion Medicine and Transplantation Immunology, University Hospital Hamburg-Eppendorf, Hamburg, Germany. brockmann@gmx.de
authors.forename: Marc A
authors.initials: MA
authors.lastname: Brockmann
authors.forename: Kai
authors.initials: K
authors.lastname: Gutensohn
authors.forename: Juliane
authors.initials: J
authors.lastname: Bau
authors.forename: Peter
authors.initials: P
authors.lastname: Kuehnl
authors.forename: Thomas
authors.initials: T
authors.lastname: Meinertz
authors.forename: Christian
authors.initials: C
authors.lastname: Nienaber
authors.forename: Christian
authors.initials: C
authors.lastname: Beythien
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000494:pharmacology / Q000627:therapeutic use; D001241:Aspirin / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D012016:Reference Values; D015607:Stents; D013988:Ticlopidine / Q000494:pharmacology*
chemical_list: D000925:Anticoagulants; D020099:Coated Materials, Biocompatible; D010975:Platelet Aggregation Inhibitors; D006493:Heparin; D013988:Ticlopidine; D001241:Aspirin