Platelet function testing in practice: a case study.

ABSTRACT

Dual antiplatelet therapy with aspirin and a thienopyridine reduces ischemic cardiovascular events following percutaneous coronary intervention. However, despite this treatment, residual risk of ischemic events persists. Among other factors, enhanced platelet reactivity after thienopyridine therapy is associated with an increased risk of ischemic cardiovascular events. A heterogeneous and variable patient response to the thienopyridine clopidogrel exists and has been attributed to a number of genetic, pharmacologic, and clinical factors. Developments in point-of-care platelet function testing allow for the assessment of on-treatment platelet reactivity after thienopyridine therapy and thus identify poor responders. We report two cases of stent thrombosis in which the bedside rapid platelet function VerifyNow P2Y12 Assay® (Accumetrics, San Diego, CA) was used to determine on-treatment platelet reactivity and identify potential etiologies of the thrombotic events.