The aim of the studyThe aim of the study was the analysis of HDL- C, its subfractions (LpA-I i LpA-I/A-II) and apoprotein AI (Apo A I) in the setting of acute myocardial infarction and in relation to: clinical course, myocardial tissue injury degree, inflammatory response intensity, atherosclerosis severity and early high platelet reactivity (HPR) on clopidogrel and acetylsalicylic acid (ASA) therapy. The prognostic value of the aforementioned parameters and their changes in 12-month follow-up were also assessed. As well as the influence of the changes on the atherosclerotic process.The study population comprised of 52 patients aged 46-76 years old with no history of hypercholesterolemia who were hospitalized due to STEMI as the first manifestation of the coronary heart disease.Conclusions:1. Traditional clinical and laboratory parameters only to a small extent determine the acute MI phase concentrations of Apo A I, HDL-C and its subfractions: LpA-I i LpA-I/A-II.2. The acute MI phase LpA-I concentration is independently associated with HPR on clopidogrel therapy.3. The acute MI phase concentrations of Apo A I, HDL-C and its subfractions: LpA-I and LpA-I/A-II are not associated with in-hospital course, but high basal HDL-C and LpA-I levels indicate the higher risk of future major adverse cardiovascular events.4. Low HDL-C as well as high LpA-I/A-II concentrations persistent after the acute phase of MI on long term hypolipidemic therapy are associated with better clinical outcome. However the changes in concentrations of all evaluated parameters did not influenced atherosclerosis progression in 12-month follow-up.