title: Comparison of Platelet Reactivity in Black Versus White Patients With Acute Coronary Syndromes After Treatment With Ticagrelor.
abstract: Ticagrelor, a potent platelet inhibitor, has primarily been studied in white patients. Platelet reactivity among black patients with acute coronary syndrome (ACS) on ticagrelor, however, is unknown. Our objective was to compare platelet reactivity in black versus white patients with ACS treated with ticagrelor. We conducted a prospective, pharmacodynamic study of 29 black patients with ACS treated with ticagrelor. Platelet reactivity was assessed at 1, 4, and 8 hours after a loading dose of ticagrelor 180 mg and at 30 days on a maintenance dose of ticagrelor 90 mg twice daily. Assays included light transmission aggregometry, VerifyNow P2Y12, and vasodilator-stimulated phosphoprotein. We provided comparison with a historical white cohort. Platelet reactivity among blacks with ACS on ticagrelor was similar to that in whites, except that blacks had lower values at 4 hours, 8 hours, and on maintenance therapy for light transmission aggregometry with 20 μmol/L adenosine diphosphate. Among blacks, high-on-treatment platelet reactivity for all 3 assays was uncommon at 1 hour and nonexistent at 4 hours, 8 hours, and while on maintenance therapy. Blacks preloaded with clopidogrel (n = 17) had significantly lower results of VerifyNow (64 ± 65 vs 198 ± 86, p <0.001) and vasodilator-stimulated phosphoprotein (12.8 ± 21.6 vs 58.9 ± 19.9, p <0.001) at 1 hour compared with those with no clopidogrel preload. In conclusion, among patients with ACS receiving ticagrelor, levels of platelet reactivity in blacks are similar to that in whites. This suggests that the cardiovascular benefits of ticagrelor observed in the platelet inhibition and patient outcomes (PLATO) trial are likely to be observed in blacks and whites.
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gaglia
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lipinski
authors.affiliation: Division of Cardiology, Centre Hospitalier Universitaire de Toulouse, Toulouse, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Lhermusier
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC.
authors.forename: Arie
authors.initials: A
authors.lastname: Steinvil
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC.
authors.forename: Sarkis
authors.initials: S
authors.lastname: Kiramijyan
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC.
authors.forename: Shreejana
authors.initials: S
authors.lastname: Pokharel
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Torguson
authors.affiliation: Division of Cardiology, University of Florida College of Medicine-Jacksonville, Jacksonville, Florida.
authors.forename: Dominick J
authors.initials: DJ
authors.lastname: Angiolillo
authors.affiliation: Division of Cardiology, Uppsala University, Uppsala, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Wallentin
authors.affiliation: Division of Cardiology, University of Sheffield, Sheffield, United Kingdom.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Storey
authors.affiliation: Division of Cardiology, Medstar Heart and Vascular Institute, Washington, DC. Electronic address: ron.waksman@medstar.net.
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
mesh_terms: D054058:Acute Coronary Syndrome / Q000188:drug therapy*; D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D000368:Aged; D044383:Black People; D001792:Blood Platelets / Q000187:drug effects*; D000077144:Clopidogrel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D010979:Platelet Function Tests; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D000077486:Ticagrelor; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D044465:White People
chemical_list: D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D000077144:Clopidogrel; D000077486:Ticagrelor; D000241:Adenosine; D013988:Ticlopidine