Grant: CIHR Fellowship

Blood-thinning therapy is important among patients at an increased risk of acute ischemic events, such as a heart attack or stroke. Numerous studies have shown that responses to antithrombotic therapy are variable. Patients who are "resistant" to such drugs are at an increased risk of acute ischemic events, while those responding too strongly to the drugs may be at an increased risk of bleeding. Platelet function testing holds the promise of individualizing antithrombotic treatment to the specific needs of individual patients, allowing precise dosing of medications so to prevent clot formation in blood without needlessly increasing the risk of bleeding. However, how to interpret platelet function testing results remains an unresolved issue, particularly in patients suffering from peripheral artery disease, chronic kidney disease or diabetes, in whom the clinical efficacy of antithrombotic drugs remains largely understudied, despite a significantly increased risk of suffering from acute ischemic events. This project aims to increase knowledge about antithrombotic therapy in peripheral artery disease, chronic kidney disease and diabetes, and the usefulness of point-of-care platelet function testing in the clinic to identify poor and pronounced responders to antithrombotic therapy. The efficacy of alternative treatments in selected patients with a poor response will be evaluated. Whether functional platelet testing can identify individuals at an increased risk of bleeding during antithrombotic therapy will be assessed. As antithrombotic therapy involves balancing thrombosis (an insufficient effect) and bleeding (an excessive effect), testing of antithrombotic drug efficacy in order to individualize dosages is attractive. The outcomes of this project may provide means to improve the efficacy and safety of antithrombotic therapy in all patients, and most particularly in those at the highest ischemic and bleeding risks.