Cognitive impairment in patients with cardiovascular diseases is regarded as one of the most clinically significant complications affecting disease course, rehabilitation outcomes, and social adaptation. At the same time, existing studies predominantly focus on biomedical factors and fail to fully explain the pronounced interindividual variability in cognitive trajectories following cardiac surgery, which highlights the need for a systemic analysis of cognitive functioning that takes into account clinical, clinical-psychological, and socio-psychological determinants. The aim of the present study was to develop and empirically validate a systemic model of cognitive functioning in patients with ischemic heart disease who underwent coronary artery bypass grafting. The study was conducted across five stages covering the entire period of treatment and rehabilitation: before surgery, 12–14 days after surgery, and 3, 6, and 12 months postoperatively. Neuropsychological and pathopsychological assessments, clinical-psychological interviews, and analysis of medical records were employed. Statistical data processing included principal component factor analysis, repeated-measures multivariate analysis of variance, and multiple regression analysis. The results demonstrated that cognitive functioning represents a system of differentiated but interrelated domains– attention, memory, thinking, and visual recognition– characterized by differing sensitivity to factors of various origins. Clinical characteristics of the disease and comorbid pathology determine the baseline level and constraints of cognitive functioning, whereas clinical-psychological and socio-psychological factors modify individual trajectories of cognitive dynamics and define compensatory capacities. Cognitive changes were shown to be determined not only by the severity of somatic condition but also by premorbid cognitive level, social activity, occupational engagement, and treatment adherence. The findings allow cognitive impairment in patients with cardiovascular diseases to be conceptualized as the result of a systemic interaction between biological, psychological, and social factors and substantiate the necessity of a comprehensive approach to diagnosis and rehabilitation following surgical treatment of cardiovascular pathology.