In summary, the disrupted oxidant–antioxidant system, specifically lower glutathione peroxidase and higher malondialdehyde, superoxide dismutase, and catalase activities, in patients with asymptomatic carotid artery stenosis compared to healthy volunteers highlight the potential role of oxidative stress in the development and progression of carotid artery stenosis. This evidence concerns the gene CAT and coronary atherosclerosis measurement.