Thromb Haemost 2008; 100(04): 618-625
DOI: 10.1160/TH08-01-0033
Platelets and Blood Cells
Schattauer GmbH

ADP-induced platelet aggregation frequently fails to detect impaired clopidogrel-responsiveness in patients with coronary artery disease compared to a P2Y12-specific assay

Authors

  • Andreas Schäfer

    1   Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Sarah Weinberger

    1   Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Ulrike Flierl

    1   Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Martin Eigenthaler

    2   Institut für Klinische Biochemie und Pathobiochemie, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Stefan Störk

    1   Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Ulrich Walter

    2   Institut für Klinische Biochemie und Pathobiochemie, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Georg Ertl

    1   Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
  • Johann Bauersachs

    1   Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Julius-Maximilians-Universität Würzburg, Germany
Further Information

Publication History

Received 15 January 2008

Accepted 07 July 2008

Publication Date:
22 November 2017 (online)

Preview

Summary

Incomplete P2Y12-inhibition during clopidogrel treatment is associated with increased cardiovascular events and mortality after coronary intervention. We investigated the incidence of impaired individual clopidogrel-responsiveness using a P2Y12-specific and pre-treatment-independent assay in a real world situation. One hundred consecutive patients with coronary artery disease (CAD) on combined acetylsalicylic acid and clopidogrel treatment (75 mg/d) and 33 patients on aspirin only were screened for platelet ADP-induced signalling by conventional aggregometry, platelet P-selectin expression and the platelet reactivity index (PRI). Impaired P2Y12-specific inhibition by clopidogrel was defined as a PRI>50%. Functional platelet reactivity was significantly lower in clopidogrel-treated patients compared to controls. Impaired individual response to treatment was diagnosed in 69% of clopidogrel-treated patients. Conventional assessment of maximum ADP-induced platelet aggregation failed to detect impaired P2Y12 inhibition in 36% of patients identified by PRI to have an impaired clopidogrel response. Impaired clopidogrel response was associated with lower HDL levels and a history of hyperlipidaemia. In conclusion, PRI as a P2Y12-specific assay to evaluate the treatment effect of clopidogrel in patients with CAD revealed insufficient P2Y12-inhibition in two thirds of patients in a real-world scenario indicating a markedly higher incidence than previously assumed. PRI detected significantly more patients with impaired response than conventional platelet aggregation.