Antiplatelet therapy in acute coronary syndromes: ticagrelor

Ticagrelor is a direct-acting, oral, reversibly binding P2Y(12) receptor antagonist. As a cyclopentyltriazolopyrimidine, ticagrelor represents a new chemical class of agents that do not require metabolic activation and have consistent ability to inhibit platelet aggregation. The phase III PLATO study evaluated ticagrelor compared with clopidogrel in 18,624 patients with acute coronary syndromes, and demonstrated a significant reduction in the risk of death from vascular causes/myocardial infarction (MI)/stroke with ticagrelor (9.8 vs. 11.7% with clopidogrel; HR: 0.84; 95% CI: 0.77-0.92; p < 0.001) without a significant increase in PLATO-defined major bleeding (11.6 vs. 11.2%, respectively; p = 0.43). MI and death from vascular causes were separately significantly reduced, and death from any cause and stent thrombosis reductions achieved nominal statistical significance. Ticagrelor showed benefit over clopidogrel in almost all patient subgroups, including patients who had received clopidogrel at randomization, patients with both planned invasive or noninvasive treatment; patients with ST elevation myocardial infarction (STEMI) referred for primary percutaneous coronary intervention, patients with non-STEMI, and patients who underwent bypass surgery. Hence, the PLATO population reflected specifically those patients who would ordinarily receive thienopyridine-based antiplatelet therapy in a clinical setting.