Monitoring platelet inhibition after clopidogrel with the VerifyNow-P2Y12(R) rapid analyzer: the VERIfy Thrombosis risk ASsessment (VERITAS) study.

Introduction: Clopidogrel inhibits platelet P2Y12 ADP receptors, while ADP, as an inductor of aggregation, stimulates both P2Y12 and P2Y1 platelet receptors. Despite a clinical loading dose routine with clopidogrel, some patients still experience coronary stent thrombosis suggesting persistent platelet activation. The VerifyNow-P2Y12 is a rapid assay that test platelet activity over 3 min and uses of the combination of ADP and prostaglandin E1 (PGE1) to directly measure the effects of clopidogrel on the P2Y12 receptor.

Assessing aspirin responsiveness in subjects with multiple risk factors for vascular disease with a rapid platelet function analyzer.

Aspirin, compared with placebo, reduces the risk of cardiovascular events by 25% in populations of patients with and without known arterial vascular disease. However, the phenomena of 'aspirin resistance' that has been described in 5'--50% of this population may critically reduce aspirin's efficacy. One study has suggested that aspirin-resistant patients have a 3.