Background: The relevance of this study is determined by the search for reserves to improve and increase the quality of life of patients undergoing open-heart surgery, especially the elderly and patients in their later life, due to an increase in life expectancy and the absence in the literature of data concerning the prevention of postoperative cognitive dysfunction disorders, since cognitive impairments are a frequent consequence of cardiac surgery and are due to a number of factors, among which microemboliation cerebral vessels, transient cerebral ischemia due to cerebral hypoperfusion during use of the artificial circulation (IC), the development of systemic inflammatory response, brain edema. The aim of the study: To study the impact of operational stress on the cognitive field in patients of middle and advanced age with IHD or valvular insufficiency. Materials and methods: The object of the study included 30 patients aged 46 to 80 years (mean age 60.3±10.3 years) with coronary heart disease (stable angina of stress) and valvular heart disease treated in the cardiosurgery department of the cardiosurgical center of Belgorod Regional Clinical Hospital. The patients were examined prior to surgical treatment and in the early postoperative period at 7.1±2.1 days, depending on the severity of the patient's condition. The study used: the Mini-Cog scale and the Clock drawing test. Results: The results of our study showed that in elderly patients with valvular pathology and coronary heart disease there is a significant decrease in cognitive abilities and memory in the early postoperative period. Conclusion: The increase in cognitive dysfunction in elderly patients in the early postoperative period shows the need for using preventive programs in the pre- and pre-operative period.