• Patients ≥19 years

• Symptomatic patients with carotid artery stenosis\* greater than 50% and asymptomatic patients with carotid artery stenosis\* greater than 70% who are scheduled to undergo or who have undergone carotid artery stenting

• High bleeding risk is defined as a Bleeding Academic Research Consortium type 3 or 5 bleeding risk of ≥4% at 1 year or a risk of an intracranial hemorrhage (ICH) of ≥1% at 1 year, Patients who meet at least one of the criteria for high bleeding risk\*\* below

⁃ The degree of stenosis is determined using the method performed in the North American Symptomatic Carotid Endarterectomy Trial.

‣ Criteria for high bleeding risk (≥ 1)

• Incidence of non-access site bleeding within 12 months prior to stenting (gastrointestinal tract or hematuria)

∙ Presence of BARC type 3 or 5 bleeding regardless of the onset time, but the cause has not been completely cured.

∙ Adults aged ≥75 years

∙ Thrombocytopenia \< 100,000/mm3 (based on the screening test)

∙ Blood clotting disorders that increase bleeding (Von Willebrand disease, factor VII, VIII, IX, and XI deficiency)

∙ Patients with anemia defined as hemoglobin \<12g/dL in men and \<11g/dL in women or patients who donated blood within 4 weeks (based on the screening test)

∙ Patients received steroids or NSAIDs for ≥4 weeks

∙ Patients with active malignancy (except for nonmelanoma skin cancer)

∙ Renal disease (dialysis, transplantation, Estimated Glomerular Filtration Rate \< 60ml/min per 1.73m2)

∙ Liver disease (cirrhosis with portal hypertension)

∙ Cerebral microbleeds ≥ 5

∙ Stroke or transient ischemic attacks within 6 months or Transient amaurosis fugax

∙ Incidence of nontraumatic intracerebral hemorrhage regardless of duration or incidence of traumatic intracerebral hemorrhage within 12 months