BACKGROUND: The widespread use of coronary computed tomographic angiography has increased the number of cases of coronary stenosis in asymptomatic individuals. In this population, we aimed to analyze the net benefit of aspirin, which is currently recommended for secondary cardiovascular prevention. METHODS: This propensity score-matching study screened 41,441 asymptomatic individuals who underwent coronary computed tomographic angiography during health checkups between 2007 and 2022. Ultimately, 1483 patients with incidentally diagnosed coronary stenosis were enrolled after excluding ineligible individuals. Using a 1:1 propensity score matching, data from 636 individuals (318 new aspirin users and 318 controls) were analyzed. The primary outcome variable was composite cardiovascular events (cardiovascular death, nonfatal myocardial infarction, and nonfatal ischemic stroke/transient ischemic attack), with/without major bleeding. RESULTS: At a median follow-up of 6.3 years, 11 and 18 individuals experienced composite events in the aspirin and control groups (2.1 and 3.2/1000 person-years
hazard ratio 0.62
P = .20), respectively. Conversely, composite events and major bleeding occurred in 26 and 23 individuals in the aspirin and control groups (4.9 and 4.1/1000 person-years
hazard ratio 1.16
P = .60), with a higher bleeding risk in the aspirin group. Kaplan-Meier curves demonstrated no significant difference in composite events without (log-rank P = .21) or with major bleeding (P = .61). Furthermore, age, chronic kidney disease, and low high-density lipoprotein cholesterol were identified as predictors of composite events and bleeding. CONCLUSIONS: Aspirin showed no benefit for composite events and bleeding in asymptomatic individuals with coronary stenosis. Thus, personalized aspirin use rather than universal aspirin use may be more appropriate for this population.