Supplement articlePotential clinical utility of genetic and platelet function tests in patients on treatment with clopidogrelCattaneo, MarcoAuthor Information Medicina III Ospedale San Paolo, Dipartimento di Medicina, Chirurgia e Odontoiatria, Università degli Studi di Milano, Milan, Italy Correspondence to Dr Marco Cattaneo, Unità di Medicina 3, Ospedale San Paolo, Dipartimento di Medicina, Chirurgia e Odontoiatria - Università degli Studi di Milano, Via di Rudinì 8, 20142 Milano, Italy Tel: +390250323095; fax: +390250323089; e-mail: [email protected] Received 18 June, 2013 Accepted 26 June, 2013 Journal of Cardiovascular Medicine: December 2013 - Volume 14 - Issue - p S16-S21 doi: 10.2459/JCM.0b013e328364bd3a Buy Metrics Abstract Clopidogrel, a pro-drug whose active metabolite is an inhibitor of the platelet P2Y12 receptor, is used mostly for the prevention of cardiovascular events in patients with acute coronary syndromes undergoing percutaneous coronary interventions. However, clopidogrel is associated with great variability in antiplatelet response, mostly caused by variable efficacy of cytochrome P450 (CYP) isoforms, which convert clopidogrel to its active metabolite in a two-step process. Tailored treatment regimens that aim to transform all poor responders into responders have been proposed as a solution to poor responsiveness to clopidogrel. This tailored treatment is based on laboratory tests of platelet function (such as platelet aggregometry, the vasodilator-stimulated phosphoprotein phosphorylation assay and the VerifyNow P2Y12 assay) or genotyping of CYP. However, currently there is no agreement among platelet function tests in the identification of poor responders; moreover, no standardization of these tests or guidance on how to tailor treatment effectively based on their results is available. The alternative of identifying poor responders based on CYP genotyping is also unsatisfactory, as CYP genotypes account for only about 10% of individual response to the drug. Therefore, tailoring treatment of clopidogrel should not be implemented in the clinical setting yet. © 2013 Italian Federation of Cardiology. All rights reserved.