The purpose of the study is to determine whether administration of 150 mg clopidogrel is effective in reducing the one-year incidence of thromboischemic events in patients with high on-clopidogrel platelet reactivity compared to 75 mg clopidogrel in the patient population overweight or obese with a body mass index (BMI) ≥ 27 kg.m-2.

The goal is to evaluate the effect of the double maintenance dose of clopidogrel versus single dose in patients with proven coronary and with BMI ≥ 27 kg.m-2 1 - Biologically: study and compare the respective effects of the double dose and single dose of clopidogrel on platelet aggregation.

2 - Clinically: to study and compare the cardiovascular events and adverse effects depending on the dose of clopidogrel.

Inclusion Criteria:

• Male or female,
• Old (e) of more than 20 years
• BMI ≥ 27kg.m-2
• Patients hospitalized for acute coronary syndrome (Whatever the ST segment and troponin dosage)
• Patients with proven coronary candidates for treatment with Clopidogrel (who received a loading dose of 600mg over 2 hours or treated with 75 mg/day or 150mg / day of clopidogrel for longer than 7 days)

Exclusion Criteria:

• Patients unwilling.
• Patient participating in another study.
• Patients with cardiogenic shock
• Patient on anti GpIIbIIIa or stopped less than 72 hours before the test aggregability
• Patients scheduled for surgery in less than 6 months
• ischemic stroke older than 6 weeks.
• History of hemorrhagic stroke (any time)
• Patients on or candidates for AVK
• Patients with a different anti ADP (ticlopidine, prasugrel)
• Patients with an indication against clopidogrel (side effects, bleeding ...)
• Thrombocytopenia < 100000/mm3
• anemia (Ht < 30%)
• Thrombocythaemia (Ht > 52%)
• Pregnancy