Comparative Real-Time Effects on Platelet Adhesion and Aggregation Under Flowing Conditions of In Vivo Aspirin, Heparin, and Monoclonal Antibody Fragment Against Glycoprotein IIb-IIIa

Background A real-time in vitro system of human platelet thrombosis under arterylike flowing conditions similar to those produced in vivo by angioplasty would be useful for the evaluation of potential antiarterial thrombotic agents in association with in vivo trials. Aspirin, heparin, and the chimeric monoclonal antibody antigen-binding fragment 7E3 (c7E3 Fab) directed against platelet glycoprotein (GP) IIb-IIIa have been used in attempts to delay or prevent thrombotic reocclusion of coronary arteries after angioplasty. We compared the effects of these agents administered in vivo on GPIb-mediated platelet adhesion to von Willebrand factor (vWF)/collagen type I (as in atherosclerotic subendothelium) and on subsequent GPIIb-IIIa–fibrinogen/vWF–mediated platelet aggregation under flowing conditions analogous to those in constricted coronary arteries. Methods and Results Citrated whole blood containing mepacrine-labeled platelets from patients and healthy donors was perfused for 1 minute at an abnormally elev...