The intermediate changes (IC) in coronary arteries (stenosis 40-70%) are a substantial clinical issue. The aims of the thesis were as follows: analysis of the clinical view of the patients with IC in the coronary arteries, estimation of a frequency of the occurrence of end points such as an exacerbation of the angina, hospitalization, an acute coronary syndrome, heart death among the patients who were subjected to pharmacological or invasively treatment and establishing the risk factors of an appearance of the above mentioned end points. Retrospective trial affected 232 patients –171 men (the average 58 ± 9,1 years old). There were two groups analyzed: group A - 165 patients treated pharmacologically, group B – 67 patients treated invasively. The whole period of observation was 12 months. Conclusions: the exacerbation of the angina occurred more frequently among those patients who were treated invasively, the necessity of performing coronary angioplasty in the IC among the patients treated preservative affected 4% of the sick; reinterventions among the patients treated invasively most frequently referred to the IC located in the LAD, likelihood of restenosis of the IC amounted to 14%, risk factors of the reintervention in the IC were: a state after past coronary angioplasty, obesity and the presence of persistent elevation of the ST section of ECG, the likelihood of death or the arising of myocardial infarction among the patients treated preservative and invasively does not differ essentially; risk factors that lead to the occurrence of the composite end point are: past coronary angioplasty procedure, diabetes, persistent elevation of the ST section, disorder of the heart rhythm, raise of the CPK, stenosis of the LAD and disorders of the contractility of the left ventricular.