This investigation will be conducted in patients 18-75 years of age with multiple coronary artery disease risk factors (antiplatelet naïve patients) and patients with prior MI or PVD on antiplatelet therapy. Pharmacodynamics will be assessed at multiple time points to assess onset-, maintenance-, and offset-effect of vorapaxar on thrombin generation, platelet reactivity, and plasma/platelet endothelial and inflammatory biomarkers. Safety assessment will be assessed throughout the study.