%0 Journal Article
%T The influence of CYP 2C19*2 polymorphism on platelet function testing during single antiplatelet treatment with clopidogrel
%A Alf-Aage R Pettersen
%A Harald Arnesen
%A Trine B Opstad
%A Ingebjorg Seljeflot
%J Thrombosis Journal
%D 2011
%I BioMed Central
%R 10.1186/1477-9560-9-4
%X Patients with symptomatic coronary artery disease, all on chronic single aspirin treatment were randomized to continue on aspirin or change to clopidogrel. In 219 randomly selected clopidogrel treated patients, platelet reactivity was evaluated by VASP-PRI determination and by use of VerifyNow P2Y12-PRU. The CYP 2C19*2 G/A polymorphism was further determined.The total frequency of clopidogrel resistance was 29.0% by VASP-PRI and 31.6% by VerifyNow-PRU. The number of patients being hetero- and homozygous combined for the CYP 2C19*2 polymorphism (GA/AA) was 64 (29%). Platelet reactivity was significantly higher in patients with the polymorphism compared to wild-type patients (GG). VASP-PRI was 50.9% (SD19) in patients having the polymorphism compared to 38.3% (SD21) in patients with the GG genotype (p = 0.001). Correspondingly, the mean PRU was 165 (SD67) compared to 124 (SD69) (p < 0.001). The frequency of clopidogrel resistance in patients with the polymorphism was 32% compared to 16% in wild-type patients when defined by VASP-PRI (p = 0.006). When defined by PRU (VerifyNow), the corresponding frequencies were 53% and 22% (p < 0.001).Clopidogrel treated patients with the CYP 2C19*2 polymorphism have significantly increased platelet reactivity compared to patients with the wild-type, evaluated with the VASP determination, and even more pronounced with the VerifyNow P2Y12 method.ClinicalTrials.gov: NCT00222261Antiplatelet therapy is widely used in patients with a high risk of atherothrombosis and has become a cornerstone in treatment of coronary artery disease (CAD) [1]. Aspirin has been the primary choice for decades, whereas the benefit of adding clopidogrel in high-risk patients has been demonstrated in several trials [2,3]. Despite improvement in antiplatelet regimens, patients on-treatment run a considerable risk for new thrombotic events [4].Although clinical benefit has been shown with clopidogrel, interindividual variation of platelet inhibition has been focus
%K Clopidogrel resistance
%K Functional tests
%K VerifyNow method
%K VASP method
%K Genetic polymorphisms
%U http://www.thrombosisjournal.com/content/9/1/4