The assessment of endothelial function is relatively simple and non-invasive method of short duration. Implementing this simple method to comprehend the platelet function will enable clinicians to better monitor and control the platelet inhibition in healthy subjects (for primary prevention) and in CAD patients (for secondary prevention). In addition, the FMD method can be useful in the evaluation of the success of the (antithrombocytic) treatment, the prognosis and the risk-stratification in hospitalized patients with acute coronary syndromes.