Detection of individual responses to clopidogrel: validation of a novel, rapid analysis using TEG 6s.

IntroductionThere is potential value in testing individual response to P2Y12 inhibitors to predict ischemic and bleeding risk in patients undergoing percutaneous coronary intervention. The aims of this study were: (1) to validate the ability of a novel point of care (POC) assay, thrombelastography (TEG) 6s, to detect changes in adenosine diphosphate (ADP)-induced whole blood clotting in volunteers and patients given clopidogrel using TEG 5000 as a reference and (2) to compare a novel, rapid parameter, area under the curve at 15minutes (AUC15), with the traditional maximum clot amplitude (MA) in TEG 6s. MethodsA total of 25 participants were included in whom ADP-induced clotting was measured at 4 time points: (1) 12 healthy volunteers given 600mg of clopidogrel; (2) 12 patients with ACS given 600mg of clopidogrel; (3) 1 healthy volunteer given 600mg of clopidogrel on 5 separate occasions. All samples were tested using conventional TEG 5000 and the new POC TEG 6S, and a new parameter called AUC15 was compared with MA in TEG 6s. Results(1) TEG 5000 and TEG 6s both detected changes in ADP-induced platelet activation. Bland-Altman analysis demonstrated a good level of agreement between them. (2) For TEG 6S, correlation between MA and the novel AUC15 was strong for both thrombin and ADP channels (R-2=0.867, R=.936, P<.001), and the AUC15 result was available on average 13.3minutes earlier. ConclusionsThrombelastography 6s is a rapid, easy to use and accurate test of ADP-induced clotting using TEG 5000 as a reference. A novel parameter, AUC15, is a viable, time-saving option for this test and has potential value in personalized P2Y12 inhibitor therapy.