Effect of clopidogrel loading dose on brachial flow mediated vasodilation in patients with coronary artery disease

INTERVENTION: Single dose of 300 mg versus 600 mg of clopidogrel orally. CONDITION: Stable coronary artery disease ; Circulatory System ; Ischaemic heart diseases PRIMARY OUTCOME: Effect of treatment on the absolute change in % Flow‐Mediated Dilation (FMD). SECONDARY OUTCOME: Effects of treatment on:; 1. Platelet superoxide production; 2. Platelet basal VAsodilator‐Stimulated Phosphoprotein (VASP)‐phosphorylation ; 3. Platelet P2V12‐receptor inhibition INCLUSION CRITERIA: 1. Men or women, older than 18 years of age 2. Angiographically documented, clinically stable coronary artery disease (defined as at least one coronary artery stenosis more than 50% or general wall irregularities) 3. Endothelial dysfunction, defined as a Flow‐Mediated Vasodilatation (FMD) of less than 8% 4. Ability of subject to understand character and individual consequences of clinical trial 5. Written informed consent must be available before enrolment in the trial 6. Current therapy with acetylsalicylic acid 100 mg/d