P Fontana1, S Nolli, G Reber, P de Moerloose. 1. Department of Internal Medicine, Faculty of Medicine, Division of Angiology and Hemostasis, University Hospitals of Geneva, Geneva, Switzerland. pierre.fontana@medecine.unige.ch
Abstract
BACKGROUND: Some data suggest that biological 'resistance' to aspirin or clopidogrel may influence clinical outcome. OBJECTIVE: The aim of this study was to evaluate the relationship between aspirin and clopidogrel responsiveness in healthy subjects. METHODS:Ninety-six healthy subjects were randomly assigned to receive a 1-week course of aspirin 100 mg day(-1) followed by a 1-week course of clopidogrel (300 mg on day 1, then 75 mg day(-1)), or the reverse sequence, separated by a 2-week wash-out period. The drug effects were assessed by means of serum TxB2 assay, platelet aggregation tests, and the PFA -100 and UltegraRPFA -Verify Now methods. RESULTS: Only one subject had true aspirin resistance, defined as a serum TxB2 level > 80 pg microL(-1) at the end of aspirin administration and confirmed by platelet incubation with aspirin. PFA-100 values were normal in 29% of the subjects after aspirin intake, despite a drastic reduction in TxB2 production; these subjects were considered to have aspirin pseudo-resistance. Clopidogrel responsiveness was not related to aspirin pseudo-resistance. Selected polymorphisms of platelet receptor genes were not associated with either aspirin or clopidogrel responsiveness. CONCLUSIONS: In healthy subjects, true aspirin resistance is rare and aspirin pseudo-resistance is not related to clopidogrel responsiveness.
RCT Entities:
BACKGROUND: Some data suggest that biological 'resistance' to aspirin or clopidogrel may influence clinical outcome. OBJECTIVE: The aim of this study was to evaluate the relationship between aspirin and clopidogrel responsiveness in healthy subjects. METHODS: Ninety-six healthy subjects were randomly assigned to receive a 1-week course of aspirin 100 mg day(-1) followed by a 1-week course of clopidogrel (300 mg on day 1, then 75 mg day(-1)), or the reverse sequence, separated by a 2-week wash-out period. The drug effects were assessed by means of serum TxB2 assay, platelet aggregation tests, and the PFA -100 and Ultegra RPFA -Verify Now methods. RESULTS: Only one subject had true aspirin resistance, defined as a serum TxB2 level > 80 pg microL(-1) at the end of aspirin administration and confirmed by platelet incubation with aspirin. PFA-100 values were normal in 29% of the subjects after aspirin intake, despite a drastic reduction in TxB2 production; these subjects were considered to have aspirin pseudo-resistance. Clopidogrel responsiveness was not related to aspirin pseudo-resistance. Selected polymorphisms of platelet receptor genes were not associated with either aspirin or clopidogrel responsiveness. CONCLUSIONS: In healthy subjects, true aspirin resistance is rare and aspirin pseudo-resistance is not related to clopidogrel responsiveness.
Authors: Markus Schmugge; Oliver Speer; Sabine Kroiss; Walter Knirsch; Oliver Kretschmar; Margaret L Rand; Manuela Albisetti Journal: Eur J Pediatr Date: 2015-01-16 Impact factor: 3.183
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