Functional testing methods for the antiplatelet effect of P2Y12 receptor antagonists.

Dual antiplatelet therapy with aspirin and a P2Y(12) receptor antagonist is the cornerstone of management in patients with acute coronary syndrome and those with coronary artery disease who have undergone coronary stent implantation. Clopidogrel is the most commonly used P2Y(12) antagonist. Despite clopidogrel's clinical effectiveness in reducing recurrent cardiovascular events in patients with coronary artery disease, the pharmacodynamic effect of clopidogrel is heterogeneous. Various platelet function tests that provide a quantitative measure of the downstream effects of clopidogrel on the P2Y(12) receptor are available. The consistent observation that a lack of clopidogrel effect based on these tests is associated with poor clinical outcome has led to the promise of an individualized, patient-centered approach to antiplatelet therapy. Over the past few years, a wealth of data have helped bring this promise closer to reality, and upcoming clinical trials of platelet function testing could at last bring personalized medicine into routine clinical practice.