Abstract Background Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of death worldwide. The ASCVD risk score can be a great tool for preventing ASCVD in the future. There is a mediation recommendation depending on calculated risk called United States Prevention Services Task Force (USPSTF) aspirin (ASA) recommendation. However, the validation studies of long-term clinical outcomes in Korean population using the ASCVD risk score and of the effect of ASA in Korean patients using USPSTF recommendation are limited. Methods A total of 7,249 patients with any chest pain who underwent coronary spasm provocation tests between January 2004 and December 2021 were enrolled. Patients were divided into four groups, based on the ASCVD risk score: < 5% group (Low Risk, n = 2,534), 5 - 10% group (Borderline Risk, n=1,681), 10 - 20% group (Intermediate Risk, n = 1,896) and ≥ 20% group (High Risk, n = 1,138). The primary endpoint was Major Adverse Cerebral and Cardiovascular Event (MACCE1), including stroke and MACE. The secondary endpoint was MACCE 2, defined as composite of MACE and recurrent angina requiring follow-up coronary angiography (CAG). The third endpoint was the effect of aspirin in patients who have over 20% ASCVD risk. Results Long term (10-year) ASCVD risk score was well-validated from the "Low Risk" group to the "High Risk" group by 1.87%, 7.44%, 14.09%, and 30.61%, respectively (P < 0.001). In baseline characteristics, the calculation factors of ASCVD risk score is also well-stratified, showing the more adverse clinical profiles in the "High Risk" group than the "Low Risk" group. In 10-year clinical outcomes, although MACCE1 and MACCE2 showed an increasing trend numerically, stroke was observed to significantly increase according to ASCVD risk score. There was no effect of ASA prescribed in accordance with USPSTF recommendation. The group with the highest rate of 20% or more failed to show the aspirin prevent effect on the occurrence of CV events, but also increased the incidence (MACCE1; HR: 1.647, P-Value: 0.283, 95% CI: 0.662 - 4.100, MACCE2; HR: 1.819, P-Value: 0.025, 95% CI: 1.078 - 3.068). Conclusion Long term ASCVD risk score was associated with higher risk of stroke. However, MACCE1 and MACCE2 only showed an increasing trend numerically. Furthermore, the effect of ASA prescribed based on the USPSTF ASA use recommendation statement were not observed in Korean population. Consequently, additional research is needed to ensure the utility of ASCVD risk score and the effect of ASA in high-risk patients to prevent future CV events in Korean population.