This cohort study will evaluate the relatiobship of stroke recurrence and anti-platelet resistance in ischemic stroke patients

Inclusion Criteria:

1. Men and women over 60 years old at the time of written consent
2. Those admitted to the hospital within 72 hours after acute cerebral infarction and treated with Aspirin 100 mg and Clopidogrel 75 mg
3. Written informed consent voluntarily signed

Exclusion Criteria:

1. Those with evidence other brain lesions such as brain tumors
2. Those who need oral anticoagulants other than vitamin K antagonists or anticoagulant therapy of warfarin
3. Contraindicate to Aspirin or Clopidogrel or allergic to the drug
4. Subjects who are at risk of active pathological bleeding such as digestive ulcer and intracranial hemorrhage
5. Cancer disease that can shorten life expectancy
6. Patient's condition that may interfere with participation in study such as mental illness, mental retardation, dementia, drug abuse, and alcoholism
7. Subjects other than the above unsuitable for this clinical study identified by Investigator

Stroke patient