Ticagrelor Monotherapy Versus Ticagrelor With Aspirin in Patients With ST-Segment Elevation Myocardial Infarction

Objectives: The aim of this study was to assess whether the effects of ticagrelor monotherapy after 3-month dual-antiplatelet therapy (DAPT) are consistent among patients presenting with ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction, and unstable angina treated with drug-eluting stents.

Background: Ticagrelor monotherapy after short-term DAPT has not been investigated in patients with STEMI.

Methods: This was a pre-specified, stratified, subgroup analysis of the STEMI cohort from the TICO (Ticagrelor Monotherapy After 3 Months in the Patients Treated With New Generation Sirolimus Stent for Acute Coronary Syndrome) trial, which constituted 36% of the total population. The primary outcome was a composite of major bleeding and major adverse cardiac and cerebrovascular events (MACCE; death, myocardial infarction, stent thrombosis, stroke, or target vessel revascularization). The secondary outcomes were major bleeding and MACCE.

Results: The incidence of the primary outcome was 4.4% in patients with STEMI (n = 1,103), 6.0% in those with non-ST-segment elevation myocardial infarction (n = 1,027), and 4.1% in those with unstable angina (n = 926), without statistical significance (p = 0.09). Compared with ticagrelor-based 12-month DAPT, ticagrelor monotherapy after 3-month DAPT showed consistent effects on the primary outcome across clinical presentations (p for interaction [p_int] = 0.64). Furthermore, the effect of ticagrelor monotherapy on the reduction of major bleeding was consistent across clinical presentations (p_int = 0.36). The effect of ticagrelor monotherapy on MACCE was also consistent in patients with STEMI, without evidence of a higher risk for MACCE (p_int = 0.14).

Conclusions: This pre-specified subgroup analysis revealed no heterogeneity in the effects of ticagrelor monotherapy after 3-month DAPT, compared with 12-month DAPT, for the primary outcome, major bleeding, and MACCE across clinical presentations including STEMI, though larger studies are needed to demonstrate these findings with adequate power. (Ticagrelor Monotherapy After 3 Months in the Patients Treated With New Generation Sirolimus Stent for Acute Coronary Syndrome [TICO Study]; NCT02494895).