Author + information
- S1936879815020828-ac14e90e572706f0fe6bf870ea481014Michael Joseph Lipinski1,
- S1936879815020828-5537c24c174de8b528bbeea792cddba0Michael A. Gaglia1,
- S1936879815020828-a79033d94483ffa83e69315f45649c25Thibault Lhermusier1,
- S1936879815020828-b41fe52590ef8bb393cebb8b291037bfArie Steinvil1,
- S1936879815020828-22ca6bb575feb9b0401e73b8ef13bd3aSarkis Kiramijyan1,
- S1936879815020828-43188b297454714a1e633ce32956ff39Rebecca Torguson1,
- S1936879815020828-716872d786d814660b960e91668b613fJohanna Kim1,
- S1936879815020828-b6b710f6bfd763713db79a5a2fd2a82eNina Chandra1,
- S1936879815020828-6865824349f2da4826787c395cd600e2Dominick J. Angiolillo2,
- S1936879815020828-da137d3be59c694cbb10a2b45116eb6eLars Wallentin3,
- S1936879815020828-0454b02a8e7505e5a04285fe536606dbRobert F. Storey4 and
- S1936879815020828-772b1cb1fca98a9f26e1e7f8bddc725bRon Waksman1
Little is known regarding the ability of ticagrelor to inhibit platelet reactivity in African Americans (AA) with acute coronary syndrome (ACS). Thus, we performed pharmacodynamic studies of platelet reactivity following treatment with ticagrelor in AA with ACS.
We prospectively enrolled AA with ACS who did not have contraindication to ticagrelor. Blood samples were collected 1, 4, and 8 hours following loading with ticagrelor and again at 30 days. Platelet reactivity was assessed with maximal platelet aggregation (MPA) to 20 or 5 μM adenosine diphosphate (ADP) on light transmission aggregometry, VerifyNow P2Y12 reaction units (PRU), and platelet reactivity index vasodilator-stimulated phosphoprotein phosphorylation (PRI-VASP).
We enrolled 24 AA patients with a mean age of 67±13 and 54% were men. Twenty-one were admitted for NSTEMI, 1 for STEMI, 2 patients for UA, and 58% of patients received clopidogrel before ticagrelor. Platelet reactivity was significantly inhibited after loading with ticagrelor and remained inhibited on maintenance therapy (Figure). Platelet inhibition was significantly greater at 4 and 8 hours compared with 1 hour for all tests (p<0.05). Importantly, patients that received clopidogrel prior to ticagrelor had significantly greater platelet inhibition at 1 hour than patients who did not receive clopidogrel (PRU 201±72 vs 70±69, p<0.001; PRI 63±19 vs 14±24, p<0.001). However, there was no difference in PRU values by 4 hours (PRU 33±44 vs 31±33). The degree of platelet inhibition following loading with ticagrelor and on maintenance therapy appears comparable to that seen in Caucasian patients enrolled in the PLATO trial.
Ticagrelor significantly inhibits platelet reactivity measured by LTA, VerifyNow PRU, and VASP in AA with ACS.
|1 Hour||4 Hours||8 Hours||30 Days|
|MPA (%) to 20 μM ADP||26±21||9±8||8±8||17±11|
|MPA (%) to 5 μM ADP||17±16||3±4||4±5||8±7|