Overview of platelet functional testing methods and their controversial role in the clopidogrel-treated patient

Platelet functional testing has been available to clinicians for several decades. Despite certain limitations, it has proven useful in several arenas, including diagnosing bleeding disorders, assessment of platelet-derived hemostasis and for monitoring response to antiplatelet medication. Special attention has recently been paid to high residual platelet reactivity in patients undergoing percutaneous coronary interventions and being treated with antiplatelet medications, largely because of the increased risk of major cardiovascular events and stent thrombosis. In keeping with this, determining high residual platelet reactivity in patient appropriately taking aspirin and P2Y12 inhibitor therapy has focused attention on tests aimed at diagnosing poor antiplatelet, and specifically clopidogrel response. Based on this, attempts to predict and intervene on poor response and its potential outcomes are prominent in the current literature, with the assistance of both platelet functional analysis and genetic deter...