Cilostazol Versus Aspirin for Primary Prevention of Atherosclerotic Events

Inclusion Criteria: 1. Type 2 diabetes mellitus with high risk of macrovascular complications; high risk is one or more as follows: * Hypertension (≧ 140/90 or anti-hypertensive therapy) * Hypercholesterolemia (LDL-C \> 130 mg/dL or anti-hyperlipidemic therapy) * TG \> 200 mg/dL * Non proliferative retinopathy or macular edema * Microalbuminuria or macroalbuminuria * Smoker 2. Patients on no anti PLT drug history 3. Patients who are agree with this research Exclusion Criteria: 1. Type 1 diabetes mellitus 2. Macrovascular complication history 3. Uncontrolled hypertension, unstable angina history 4. Congestive heart failure 5. Bleeding tendency 6. Chronic liver disease (ALT \> 100 or AST \> 100) or Chronic renal disease creatinine \> 3.0 mg/dl) 7. Anemia (hemoglobin \< 10 mg/dl) or thrombocytopenia (platelet count less than 100,000/mm3) 8. Pregnant or lactation women 9. Plan to be revascularized in 4 weeks 10. Plan to go to surgery or invasive intervention in 4 weeks 11. Plan to need to admission for acute cardiovascular disease in 4 weeks 12. Contraindication of this medication 13. Other anti-PLT drug therapy