Ticagrelor monotherapy after short-term dual antiplatelet therapy (DAPT) reduces major bleeding events without increasing ischemic events in patients with ST-segment elevation myocardial infarction (STEMI), according to a substudy from the TICO ACS trial released Monday.
Seung-Jun Lee, MD, of Severance Cardiovascular Hospital, Seoul, South Korea, Jae Young Cho, MD, of Wonkwang University Hospital, Iksan, South Korea, and colleagues reported their findings in a manuscript published in the Feb. 22 issue of JACC: Cardiovascular Interventions.
The primary TICO (Ticagrelor Monotherapy After 3 Months in the Patients Treated With New Generation Sirolimus Stent for Acute Coronary Syndrome) trial showed that ticagrelor monotherapy after 3 months of DAPT is superior to 12-month DAPT for net adverse clinical events.
The TICO study included all the subsets of acute coronary syndrome. The main aim of the newly reported substudy is to evaluate the safety and efficacy of ticagrelor monotherapy after short-term DAPT in STEMI patients. The primary outcome was net adverse cardiac events, defined as a composite of major bleeding and major adverse cardiac and cerebrovascular events (MACCE) within 1 year.
A total of 1,103 patients out of 3,056 patients presented with STEMI; 546 patients were randomly assigned to ticagrelor monotherapy after 3 months of DAPT, and 557 patients were assigned to ticagrelor-based 12-month DAPT. Patients with STEMI were younger and had a lower prevalence of comorbidities than those with non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina. Also, the total number and length of implanted stents were lower in STEMI patients than were those with NSTEMI or unstable angina.
During the 1-year follow-up, the primary endpoint of net adverse clinical events occurred in 4.4% of patients with STEMI and 6% of patients with NSTEMI. In STEMI patients, net adverse events were similar in both groups (3.7% in ticagrelor monotherapy after 3 months of DAPT vs. 5% in patients who received ticagrelor based 12-month DAPT; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.41-1.29; p=0.27). Major bleeding was significantly lower in the ticagrelor monotherapy group (0.9% vs. 2.9%; HR, 0.32; 95% CI, 0.12-0.87; p=0.02). The effect of ticagrelor monotherapy on MACCE was also consistent in patients with STEMI, without evidence of a higher risk for MACCE (pinteration=0.14).
The authors noted some limitations to this analysis. The study was not individually powered for the primary outcome, and larger studies with adequate power are required. Bleeding outcomes in the early period, open-label design of the trial and lower-than-expected rate of adverse events in the primary trial are other major limitations of this study.
In an accompanying editorial, by Michel Zeitouni, MD, and Paul Guedeney, MD, of Sorbonne University, Paris, stated that a recent meta-analysis of major trials evaluating aspirin-free strategies does not suggest an increase in ischemic event rates. The editorialists also noted that premature ticagrelor discontinuation reported in 15% to 25% of patients is also a major problem if patients are treated with ticagrelor monotherapy.
Lee, Cho and colleagues concluded that that this substudy analysis showed no heterogeneity in the effects of ticagrelor monotherapy after 3-month DAPT as compared with 12-month DAPT. Ticagrelor monotherapy after short DAPT is beneficial in STEMI patients. The authors added that future prospective trials targeting patients with STEMI are required to clarify the benefits of ticagrelor monotherapy in this high-risk population.
Lee SJ, Cho JY, Kim BK et al. Ticagrelor Monotherapy Versus Ticagrelor With Aspirin in Patients With ST-Segment Elevation Myocardial Infarction. JACC Cardiovasc Interv 2021;14:431–40.
Zeitouni M, Guedeney P. Aspirin-Free Strategies in ACS: Is It the Drug or the Stent? JACC Cardiovasc Interv 2021;14:441–3.