Thromb Haemostasis
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Randomized Controlled Trial Clinical Trial
Monitoring of aspirin (ASA) pharmacodynamics with the platelet function analyzer PFA-100.
Anti-platelet drug therapy is currently performed without monitoring, because the established method of platelet aggregometry is cumbersome. The recently developed platelet function analyzer PFA-100 measures shear stress dependent, collagen epinephrine (CEPI) and collagen adenosine diphosphate (CADP) induced platelet plug formation. As the PFA-100 provides a valuable tool to detect patients with platelet dysfunction more efficiently and cost-effectively than aggregometry, we investigated its potential to monitor the efficacy of aspirin treatment. ⋯ Thus, the PFA-100 system appears suitable to demonstrate an aspirin-induced platelet effect in a longitudinal study, and may be adequate to monitor a patient's compliance. However, prospective trials have to be conducted to demonstrate whether the EPI-CT achieved under ASA-intake has predictive value for cardiovascular outcome.
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The c7E3 Fab reduces ischemic complications in patients undergoing high-risk coronary angioplasty or atherectomy. The present study investigated how c7E3 Fab inhibition of the platelet receptor glycoprotein IIb/IIIa and the endothelial vitronectin receptor affected platelet adhesion to endothelium and surface adsorbed fibrinogen under flow conditions. Platelet adhesion was examined using a stagnation point flow device with shear stress and shear rates up to 2.2 dynes/cm2 and 170 s(-1), respectively. ⋯ In spite of ADP stimulation c7E3 Fab completely blocked platelet adhesion to adsorbed fibrinogen and, moreover, to intact endothelium. Preincubation of endothelial cells with c7E3 (fc = 20 [microg/ml) blocked adhesion of ADP-stimulated platelets by approximately 50%. Apart from the inhibition of platelet aggregation, c7E3 Fab added in vitro and given therapeutically in patients effectively blocks platelet adhesion to components of the injured as well as intact vessel wall under stagnation point flow conditions.