Withdrawing aspirin therapy and switching to ticagrelor monotherapy after 3 months of dual antiplatelet therapy (DAPT) lowers the incidence of bleeding without increasing ischaemic events compared with continuation of ticagrelor plus aspirin therapy in patients who have undergone percutaneous coronary intervention (PCI) and are at high risk of bleeding or ischaemic events. This finding comes from the TWILIGHT trial, presented at TCT 2019 and simultaneously published in The New England Journal of Medicine.

This double-blind, placebo-controlled trial included 9,006 patients who had undergone PCI and were at high risk of bleeding or ischaemic events. All patients received DAPT with the P2Y12 inhibitor ticagrelor plus aspirin and, after 3 months, those who had not had a major bleeding or ischaemic event continued with ticagrelor therapy (n = 7,119) and were randomly assigned to receive aspirin or placebo.

At 1 year, patients receiving ticagrelor alone had a lower incidence of the primary end point of clinically relevant bleeding (Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding) than those receiving ticagrelor plus aspirin (4.0% versus 7.1%; HR 0.56, 95% CI 0.45–0.68, P < 0.001). The benefit of ticagrelor monotherapy over DAPT was observed for the more severe BARC type 3 or 5 bleeding events (1.0% versus 2.0%; HR 0.49, 95% CI 0.33–0.74) and with alternative bleeding scores. Importantly, no differences were observed between the groups for the composite secondary end point of all-cause death, nonfatal myocardial infarction or nonfatal stroke (3.9% versus 3.9%; HR 0.99, 95% CI 0.78–1.25, P < 0.001 for noninferiority). Analysis of prespecified subgroups showed consistent benefits of ticagrelor monotherapy on bleeding and ischaemic end points regardless of patient characteristics, including age, sex, diabetes mellitus status or stent length.

Taken together, these findings suggest that aspirin can be dropped after 3 months of DAPT in this high-risk patient population.