Diabetes mellitus (DM) and essential hypertension (EH) complicate the course of disease and lead to poor prognosis in patients with very high cardiovascular risk. The aim of the investigation was to study the factors leading to progression of atherosclerosis in patients with acute myocardial infarction (MI). 105 patients (pts) with acute myocardial infarction were investigated: the 1st group was consisted of 15 pts without concomitant diseases; in the 2nd group were 52 pts with EH and in the 3rd group – 38 pts with combination of EH and DM. Worse results during bicycle exercise test were obtained in pts with MI and EH, especially in pts with MI, concomitant EH and DM. However, EH preceding MI was associated with better myocardial contractility in early period of MI because of left ventricular hyperthrophy, inhibiting dilatation and having compensatory function. Significant increase of proatherogenic modification of low and very low density lipoproteins was found in all pts, but the greatest disturbances were recorded in pts with concomitant DM. These results may explain the worse prognosis in such category of pts.