Role of platelet function testing in clinical practice: current concepts and future perspectives

Oral antiplatelet therapy is routinely administered to ACS patients as well as to patients undergoing percutaneous coronary intervention (PCI) with the primary aim of inhibiting platelet-mediated thrombus formation and subsequent abrupt vessel occlusion. Individual platelet response to aspirin and especially to clopidogrel is highly variable and evidence has grown in recent years linking an attenuated response to therapy with the occurrence of ischemic events. At present, the antiplatelet therapy landscape is changing with the emergence of prasugrel and ticagrelor as alternative and more potent treatment options. In addition, tests for near-patient monitoring of platelet function in clinical practice are available and are being increasingly employed for the optimization of antiplatelet treatment. It is hypothesized that platelet function testing may prove useful for achieving an optimized balance of proven platelet inhibition at a cost of moderate bleeding risk. This is also why first centers have already included testing in day-to-day routine. Extensive clinical evaluations with a range of currently-available assays for platelet function testing are ongoing and the current and future role of platelet function testing in clinical practice is a topic of much debate. Widespread adoption of this practice and its incorporation into clinical guidelines awaits the results of ongoing trials where treatment is changed based on platelet function testing data. This review paper summarizes the key characteristics of platelet function tests available, presents an overview of relevant studies and examines the present role of platelet function testing in clinical practice with a focus on antiplatelet therapy in patients undergoing coronary stent placement.