Background: We sought to compare the antiplatelet effects of the glycoprotein IIb-IIIa receptor blockers abciximab or tirofiban, combined with an adjuvant therapy with clopidogrel and aspirin.
Study design and methods: Twenty patients undergoing coronary stenting were randomly assigned to receive either abciximab or tirofiban combined with aspirin and clopidogrel. Serial blood samples were taken to assess platelet aggregation, P-selectin expression, thrombin generation, and platelet-induced endothelial cell expression of MCP-1, uPAR, and ICAM-1. Results and conclusions The therapy with aspirin plus clopidogrel attenuated agonist-induced platelet aggregation and P-selectin surface exposure (P <.05 vs aspirin monotherapy). Both tirofiban and abciximab further reduced agonist-induced platelet aggregation (P <.05), and decreased thrombin generation but had no effect on platelet alpha-granule release. None of the antithrombotic strategies significantly affected platelet-induced endothelial cell activation. Since platelet adhesion/degranulation initiates an inflammatory/mitogenic response in the vascular wall, future therapeutic strategies will have to be aimed at the inhibition of platelet release reactions.