Evaluation of platelet aggregability in patients with coronary artery disease treated with clopidogrel: a comparison between VerifyNow P2Y12®, impedance aggregometry and PFA-100®

Abstract

Clopidogrel is the medication of choice, associated with acetylsalicylic acid (ASA), on the medical therapy of patients suffering of Acute Coronary Syndromes, and also on those submitted to percutaneous coronary intervention with stents. Despite this, several studies have demonstrated great variability in individual response to the drug, with special interest in drug interaction with the proton pump inhibitors and the polymorphisms of the cytochrome CYP2C19. The ideal method to evaluate this effect is not yet established, although there is the great popularity of the VerifyNow® because it is a point of care assay. So, the end-point of this study will be the comparison between VerifyNow® and two other methods of platelet aggregability evaluation: impedance aggregometry and PFA-100. The sample size include 100 (one hundred) subjects, consisting of patients with chronic coronary artery disease taking ASA and clopidogrel. The blood samples will be withdrawn in three moments - visit 1: patients only on ASA; visit 2: ASA with clopidogrel; and visit 3: clopdiogrel with ranitidin or omeprazole (in a double-blind design). (AU)