Abstract
BACKGROUND: Dual antiplatelet therapy (DAPT) with aspirin and ticagrelor is standard treatment for ST-elevation myocardial infarction (STEMI). While the optimal ticagrelor dose is established, the ideal aspirin maintenance dose remains debatable, particularly in East Asian populations who demonstrate enhanced bleeding sensitivity with standard antiplatelet regimens compared to Western populations. METHODS: The Low-dose Evaluation of Aspirin in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention (LEAST) trial is a multicenter, randomized, double-blind, placebo-controlled trial comparing low-dose (50 mg/d) versus standard-dose (100 mg/d) aspirin combined with ticagrelor (90 mg twice daily) in Chinese STEMI patients post-percutaneous coronary intervention. A total of 3612 patients will be enrolled from 34 centers across China using stratified randomization by age and multivessel disease status. The primary endpoint is 12-month composite of cardiac death, non-fatal myocardial infarction, non-fatal stroke, and ischemia-driven target vessel revascularization (non-inferiority testing with 1.5% absolute difference margin). The key secondary endpoint is Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding (superiority testing). A hierarchical testing strategy ensures bleeding benefits are only claimed when ischemic safety has been established. RESULTS: This trial will provide evidence regarding optimal aspirin maintenance dose in Chinese STEMI patients receiving DAPT with ticagrelor. The findings may support development of population-specific antithrombotic strategies that better balance efficacy and safety in East Asian populations. CONCLUSION: The LEAST trial addresses an important knowledge gap regarding optimal aspirin dosing in Chinese STEMI patients and may influence future guideline recommendations for acute coronary syndrome management in Asian populations. TRIAL REGISTRATION: ClinicalTrials.gov (NCT06756945).