Abstract 596: Platelet inhibition by Ticagrelor in African American versus Caucasian patients after Percutaneous Coronary Intervention
PLATO study showed that in acute coronary syndromes, treatment with Ticagrelor as compared with Clopidogrel significantly reduced the rate of death, myocardial infarction or stroke. In subgroup analysis based on race, no significant difference in primary end point was noted. However, African Americans (AA) comprised only 1.1% of study population. AA have greater mortality from coronary artery disease (CAD) and more likely to have high on-treatment platelet reactivity. Aim of our study is to compare the extent of platelet inhibition achieved by Ticagrelor and Clopidogrel in AA versus Caucasian patients undergoing percutaneous coronary intervention (PCI). Methods: 72 patients undergoing PCI during September to November 2014 were included in this study. All received Aspirin 325mg loading dose (LD) followed by 81mg maintenance dose, along with either Ticagrelor 180 mg LD followed by 90 mg twice-daily MD or Clopidogrel 600 mg LD followed by 75 mg once-daily MD. Platelet reactivity (PRU) was measured using the VerifyNow P2Y12 function assay 12-24h following MD and the average values calculated for each group. Results: 40 African American (55%) and 32 Caucasian (45%) patients were included. Ticagrelor was used in 45 (62.5%) and Clopidogrel was used in 27 patients (37.5%). Among Caucasians, 16 (50%) received Ticagrelor and 16 (50%) received Clopidogrel. Among AA, 27 patients (67%) received Ticagrelor, 13 patients (33%) received Clopidogrel. In the total study population, the average PRU achieved was lower for Ticagrelor (44) compared with Clopidogrel (183). Among patients who received Ticagrelor, significantly lower average PRU was seen in AA (33) compared to Caucasians (63). Among patients who received Clopidogrel, similar average PRU was seen in AA (181) and Caucasian (185) groups. After combining Ticagrelor and Clopidogrel groups, lower average PRU was achieved in AA (76) compared to Caucasians (126), the difference primarily attributable to Ticagrelor. Conclusion: Ticagrelor achieved greater platelet inhibition in AAs compared to Caucasians, while Clopidogrel achieved similar platelet inhibition in both racial groups. This potentially greater platelet inhibition by Ticagrelor in high risk AA group merits investigation in large-scale studies.
Author Disclosures: P.K. Katikaneni: None. K. Modi: None.
- © 2015 by American Heart Association, Inc.