Citation: American Heart Journal. 166(2):266-72, 2013 Aug..Journal: American heart journal.ISSN: 0002-8703.Full author list: Pendyala LK; Torguson R; Loh JP; Devaney JM; Chen F; Kitabata H; Minha S; Barbash IM; Suddath WO; Satler LF; Pichard AD; Waksman R.UI/PMID: 23895809.Subject(s): *African Americans/ge [Genetics] | Aged | *Aryl Hydrocarbon Hydroxylases/ge [Genetics] | *Blood Platelets/de [Drug Effects] | Female | Humans | Logistic Models | Male | Middle Aged | Mutation | *Percutaneous Coronary Intervention | *Platelet Aggregation Inhibitors/pd [Pharmacology] | Platelet Aggregation Inhibitors/tu [Therapeutic Use] | Platelet Function Tests | Polymorphism, Genetic | *Ticlopidine/aa [Analogs & Derivatives] | Ticlopidine/pd [Pharmacology] | Ticlopidine/tu [Therapeutic Use]Institution(s): MedStar Heart & Vascular Institute | MedStar Health Research InstituteActivity type: Journal Article.Medline article type(s): Journal ArticleOnline resources: Click here to access onlineDigital Object Identifier: http://dx.doi.org/10.1016/j.ahj.2013.04.008 (Click here)Abbreviated citation: Am Heart J. 166(2):266-72, 2013 Aug.Local Holdings: Available online from MWHC library: 1995 - present, Available in print through MWHC library: 1999 - 2006.Abstract: BACKGROUND: On-treatment platelet reactivity to clopidogrel is variable and in part genetic dependent. In African American (AA) patients, the relation between on-treatment platelet reactivity to clopidogrel and the factors that influence this interaction is unknown. The present study aims to evaluate on-treatment platelet reactivity to clopidogrel in AA patients and its interaction to race and CYP2C19*2 loss of function mutation.Abstract: METHODS: The study cohort included 289 consecutive patients presenting for percutaneous coronary intervention who were entered into a prospective observational registry. High on-treatment platelet reactivity (HTPR) was defined as P2Y12 reaction units (PRU) >=208 with VerifyNow P2Y12 assay and >50% by vasodilator-stimulated phosphoprotein phosphorylation assay platelet reactivity index (VASP PRI) measured 6 to 24 hours postprocedure. CYP2C19*2 (rs4244285) genotype was analyzed by real-time polymerase chain reaction.Abstract: RESULTS: The prevalence of HTPR by both PRU (56% vs 35%, P = .003) and VASP PRI (67% vs 45%, P = .002) is more common in AAs compared with whites, respectively. African American patients had higher on-treatment mean PRU (207 +/- 110 vs 160 +/- 102, P = .002) and VASP PRI (49 +/- 26 vs 38 +/- 26, P = .004). African Americans also had a higher prevalence of CYP2C19*2 allele carrier status compared with whites (43% vs 29%, P = .04). African American race (P = .008) and CYP2C19*2 allele status (P = .02) independently had significant effects on PRU and VASP. Multivariable logistic regression analysis has shown that both CYP2C19*2 allele carrier status and AA race were independent correlates of HTPR for PRU >=208.Abstract: CONCLUSIONS: African American patients undergoing percutaneous coronary intervention not only have a higher prevalence of HTPR to clopidogrel but also have higher CYP2C19*2 allele carrier status compared with whites. Careful selection of antiplatelet agents should be considered in an AA population at higher risk for ischemic complications. Copyright 2013 Mosby, Inc. All rights reserved.