His research interests include lipid metabolism, severe forms of genetic dyslipidemias, especially familial hypercholesterolemia and HDL deficiency, non-alcoholic fatty liver disease and imaging in atherosclerosis especially detection of vascular calcification. He also studies newer therapies to reduce cholesterol in patients with genetic dyslipidemias. He has published more than 400 papers in peer-review journals like the Lancet, NEJM, Lancet Diabetes & Endocrinology, Atherosclerosis, ATVB, Circulation, The European Heart Journal, JACC, JACC Cardiovascular Imaging, Journal of Lipid Research and Current Opinion of Lipidology among others. He was considered as a Highly Cited Author according to Clarivate Analytics in 2021, 2022 and 2023. Dr. Santos has coordinated and participated in many Brazilian and International guidelines on dyslipidemia and atherosclerosis prevention, metabolic syndrome, obesity, diabetes and coronary heart disease. He is a former president of the Department of Atherosclerosis of the Brazilian Society of Cardiology and past president of the International Atherosclerosis Society (IAS) (2019-2021). Dr. Santos is member of the Guidelines Writing Committee of the European Atherosclerosis Society and one of the associate editors of Atherosclerosis, the Journal of Clinical Lipidology and the European Journal of Preventive Cardiology.