Ticagrelor : clinical development and future potential

Platelets participate centrally in atherothrombosis, resulting in vessel occlusion and ischaemia. Consequently, optimisation of antiplatelet regimens has the potential to further reduce the residual burden of morbidity and mortality associated with atherosclerosis. Ticagrelor is a potent oral platelet P2Y12 receptor antagonist that (1) inhibits a central amplification pathway of platelet activation directly as well as via an active metabolite, (2) has a rapid onset and offset of antiplatelet action that remains consistent in the circulation during twice-daily administration and is amenable to reversal, (3) has inverse agonist properties, and (4) demonstrates pleiotropic effects that contribute to anti-thrombotic, anti-inflammatory and vasodilatory properties. These advantageous characteristics of ticagrelor have translated to beneficial clinical outcomes in patients with acute coronary syndromes or ischaemic stroke, during prolonged maintenance therapy in specific high-risk populations, and following percutaneous coronary intervention but not definitively following coronary artery bypass graft surgery or in peripheral artery disease patients. Novel innovative strategies aim to reduce the risk of bleeding during dual antiplatelet therapy via shortening the duration of treatment and replacing the standard-of-care with ticagrelor monotherapy. In cases where aspirin is an essential component in secondary prevention, dose modification when combined with ticagrelor may hypothetically provide desirable clinical outcomes following appropriate clinical assessment as predicted by pharmacological studies. Overall, the future management of acute coronary syndromes could potentially involve the dichotomisation of antithrombotic therapies, whereby only those with high-risk of ischaemia, without a high-risk of bleeding, receive ticagrelor plus very-low-dose aspirin, while ticagrelor monotherapy is administered to the remaining majority.