 All patients with stable coronary artery disease and successful DES implantation in native coronary arteries including high risk features, eg, left main stenosis, bifurcations or in-stent restenosis will be eligible. They will be stratified at entry according to their metabolic status DM, MS, or no DMMS. Measurements will be performed both 6-24 hours after clopidogrel loading dose acute effects and 4 months later under clopidogrel maintenance dose chronic effects. 