Features of cognitive status in patients over 65 years of age after high-risk cardiac surgery

Objective. To evaluate early postoperative cognitive changes in patients older than 65 years following cardiac surgery and to identify factors associated with cognitive impairment. Materials and methods. The study included 76 patients with coronary artery disease, significant coronary artery involvement, or heart valve defects. The mean age was 68.5 years (range: 66.2—72.0). Cognitive function was assessed using the Mini-Mental State Examination (MMSE) before surgery and at discharge. Intraoperative cerebral oxygenation (rSO2, %) was monitored. Regression analysis was performed to identify factors associated with postoperative cognitive decline. Results. Cognitive impairment was generally mild both before surgery and in the early postoperative period, with MMSE scores of 28.2 (25.5—29.0) and 28.5 (24.2—29.0), respectively. Before surgery, 50% of patients exhibited no or mild cognitive impairment, 38.2% had moderate impairment, and 11.8% had mild dementia. By the seventh postoperative day, the proportion of patients with moderate cognitive impairment increased. A decline in cognitive function was observed in 40.7% of patients. Deterioration in cognitive function was associated with intraoperative rSO2 levels below 40% during cardiopulmonary bypass (OR 2.14; 1.65—4.63, p=0.03), chronic kidney disease stage C3a or higher (OR 2.11; 1.17—6.42, p=0.02), and atrial fibrillation or ventricular extrasystole (OR 1.96; 1.23–5.71, p=0.01). Conclusions. Postoperative cognitive decline occurred in 40.7% of patients and was associated with cerebral desaturation during bypass, chronic kidney disease stage C3a or higher, and life-threatening arrhythmias. Intraoperative monitoring of cerebral oxygenation is recommended for high-risk cardiac surgery patients to prevent cognitive impairment.