To examine the efficacy and safety of dual antiplatelet therapy (DAPT) including cilostazol (Pletaal OD Tablet ®) in comparison with antiplatelet monotherapy (excluding cilostazol) for secondary prevention of ischemic stroke in high-risk patients for stroke

Inclusion Criteria:

• Patients with a diagnosis of noncardioembolic IS that developed between 8 and 180 days before the start of the protocol treatment

• Patients with a responsible lesion identified by MRI

• Patients aged 20 to 85 years old when providing informed consent

• Patients taking clopidogrel or aspirin alone as antiplatelet therapy when providing informed consent

• Patients meeting at least one of the following criteria a-c:

  1. at least 50% stenosis of a major intracranial artery (to the level of A2, M2, or P2)

  2. at least 50% stenosis of an extracranial artery (the common carotid artery，internal carotid artery，vertebral artery，brachiocephalic artery，or subclavian artery)

  3. Two or more of the following risk factors

     • Aged 65 years or more
     • Diabetes mellitus
     • Hypertension
     • Peripheral arterial disease
     • Chronic kidney disease
     • History of IS (excluding the index IS for this study)
     • History of ischemic heart disease
     • Smoking (only current smokers)

• Patients considered to be able to visit the study site for ambulatory care throughout the observation period

• Patients who provided written informed consent

Exclusion Criteria:

• Patients with emboligenic heart disease

• Patients taking any anticoagulant agents

• Patients who cannot undergo MRI examination for reasons such as claustrophobia and implanted pacemaker

• Patients scheduled to undergo any surgery, such as percutaneous angioplasty, stent placement, and bypass grafting, during the study period

• Patients with a drug-eluting coronary stent implanted within one year

• Patients with a history of symptomatic non-traumatic intracranial hemorrhage, any other hemorrhagic disease (eg, active peptic ulcer), bleeding predisposition, or blood clotting disorders

• Patients with a history of hypersensitivity to cilostazol

• Patients with congestive heart failure or uncontrolled angina pectoris

• Patients with thrombocytopenia (platelet count ≦ 100,000/mm3)

• Patients with severe liver or renal dysfunction

• Women who are pregnant, breast-feeding, or of child-bearing potential

• Patients with a malignant tumor requiring treatment

• Patients who are taking aspirin, and meet any of the following criteria:

  • History of hypersensitivity to aspirin or salicylic acid analogues
  • Current peptic ulcer
  • Aspirin-induced asthma or its history

• Patients who are taking clopidogrel, and meet the following criterion:

  ・History of hypersensitivity to clopidogrel

• Patients who are participating in any other clinical studies

• Patients considered by the investigator/subinvestigator to be unsuitable for participating in this study