The full text was published simultaneously in the Lancet.

Patients with acute coronary syndrome are at risk of morbidity and mortality compared to those with chronic coronary syndrome. The prognosis of these patients can be improved with early revascularization. After revascularization, international guidelines recommend that patients take ticagrelor or prasugrel together with aspirin for 12 months to reduce the risk of myocardial infarction and stent thrombosis.

This study investigated the effectiveness and safety of continuing with ticagrelor alone after one month of dual antiplatelet therapy (ticagrelor plus aspirin).

Patients who had acute coronary syndrome (unstable angina, NSTEMI, STEMI) in the last 30 days and had an indication for percutaneous coronary intervention were included in this randomized, placebo-controlled, double-blind clinical study. After the percutaneous intervention, all patients (n=3505) were given ticagrelor + aspirin for one month. Patients who did not experience major bleeding (BARC 3 or 5) or ischemic event (MI, stroke, stent thrombosis, target vessel revascularization for clinical reasons) at the end of the first month and did not interrupt dual antiplatelet therapy for more than 48 hours were randomized into two groups as ticagrelor + aspirin (n = 1700) and ticagrelor + placebo (n=1700).

Three thousand three hundred ninety-nine patients were followed for 12 months between September 2019 and October 2022. The primary superiority endpoint of the study was clinically significant bleeding (BARC 2, 3, or 5), which occurred at a rate of 2.1% (n = 35) in the ticagrelor group and 4.6% (n = 78) in the ticagrelor + aspirin group (HR = 0.45, 95% CI). 0.30-0.66, p<0.0001). The primary non-inferiority outcome, MACCE (cardiac death, MI, ischemic stroke, stent thrombosis, target vessel revascularization events), was 3.6% (n=61) in the ticagrelor group and 3.7% (n=63) in the ticagrelor + aspirin group. (HR=0.98, 95% CI 0.69-1.39, Pnon-inferiority <0.0001, Psuperiority=0.89).

In patients with acute coronary syndrome, who remained event-free for one month on dual antiplatelet therapy, treatment with ticagrelor alone between month one and month 12 after the intervention resulted in a lower rate of clinically relevant bleeding and a similar rate of MACCE compared with ticagrelor plus aspirin.

Contemporary drug-eluting stents have an impact on achieving these results. Furthermore, these data suggest that a 12-month dual antiplatelet course is not only necessary but also harmful in the majority of ACS patients. The results may also affect the guidelines. The issue of the appropriate treatment will be 12 months after percutaneous intervention remains a question mark.