BackgroundFree fatty acids (FFA), oxidized low-density lipoprotein (LDL) and its antibodies, lipid profile markers, which are formed under oxidative stress, play an important role in atherosclerotic disease. Assess the levels of these markers in myocardial infarction patients depending on the extent of coronary artery disease (CAD).MethodsST-elevation MI patients with hemodynamically significant stenoses of ≥75% in one, two, three, or more coronary arteries were examined. The patients were divided into three groups according to the severity of coronary lesions. Patients had a ≥75% stenotic lesion in one coronary artery (group 1, n = 135), two coronary arteries (group 2, n = 115), or three or more coronary arteries (group 3, n = 150). The control group comprised healthy subjects (n = 33).ResultsFFA levels on day 1 from MI onset were higher in groups 1, 2, and 3 compared with controls. On day 1 from MI onset, oxidized LDL levels were significantly higher in groups 2 and 3 than those in controls (both р = 0.001). Oxidized LDL levels were significantly higher in patients with multivessel CAD compared with those with single-vessel CAD on days 1 and 12. Antibody levels increased with the number of affected arteries.ConclusionHigh levels FFA, oxidized LDL and its antibody, lipid profile markers, and parameters of the pro/antioxidant systems persist during the subacute phase of MI.