The aim of the study is to evaluate platelet function variations according to the delay since last aspirin intake (12 vs 24 hours)in a population of diabetic patients with previous Coronary Artery Disease.

We have previously demonstrated that there was a time-dependant efficacy of aspirin on platelet function. In this study, we investigate platelet function (fundamental research) according to the delay since last aspirin intake (12 vs 24 hours)in a population of diabetic patients with previous Coronary Artery Disease routinely treated with aspirin. In order to eliminate any variation linked to a cumulative dose effect of aspirn, platelet function is assessed 24 hours after a single 150 mg aspirin intake or 12 hours after a 75 mg aspirin intake given twice per day (corresponding to the same total dose of 150 mg /day). Light transmission aggregometry triggered by arachidonic acid 0.5mg/mL (LTA-AA) is the main endpoint of the study (intensity and velocity of agregation following exposure to arachidonic acid 0.5 mg/ml).

Inclusion Criteria:

• type 2 diabetes mellitus
• documented coronary artery disease
• treatment with aspirin for at least 7 days before randomization
• one of the following additional criteria defined from our previous study9: current smoking, hs-CRP > 4mg/L, fibrinogen > 4g/L and/or platelet count > 270 103/mm3

Exclusion Criteria:

• oral anticoagulants, heparin, thrombolytic agents, non-steroidal anti-inflammatory drugs, prasugrel
• family or personal history of bleeding or thrombophilic disorders
• platelet count > 600x103/mm3 or < 150x103/mm3
• hematocrit > 50% or < 25%
• creatinine clearance < 30mL/min
• low compliance before enrollment
• cancer considered not in remission or those having undergone major surgery within the month prior to enrollment.

Consecutive stable DM patients presenting to the Department of Cardiology, Lariboisiere Hospital. Patients are eligible if they have DM and documented CAD and are treated for at least 7 days with a non-enteric-coated aspirin.