Midterm outcomes after postoperative delirium on cognition and mood in patients after cardiac surgery

Delirium is a common neurologic complication after cardiac surgery. Our primary objective was to determine the impact of delirium on self-reported problems with midterm cognitive functioning and mood postcardiac surgery.

A single-center, prospective cohort study was conducted, enrolling 197 patients undergoing coronary artery bypass grafting or valve replacement. Baseline cognition and mood were assessed preoperatively in elective patients as a part of routine care using the Montreal Cognitive Assessment and Patient Health Questionnaire 9, respectively. During hospitalization, delirium was diagnosed using the Confusion Assessment Method (Confusion Assessment Method/Confusion Assessment Method Intensive Care Unit). Follow-up assessments were carried out via telephone interview at 6 to 9 months after cardiac surgery using the EuroQoL-5D, Patient Health Questionnaire 9, Alcohol Use Disorders Identification Test Consumption, Memory Impairment Screen, and Category Fluency Test assessments. We examined resultant scores in the domains of cognition and mood among delirious and nondelirious cohorts, controlling for confounders deemed clinically relevant.

A total of 197 patients were enrolled in the study, of whom 44 (22%) developed postoperative delirium. After adjustment, no differences were observed in cognitive functioning between the delirious and nondelirious subjects after 6 to 9 months. However, delirious patients were more likely to experience self-reported problems in affective (depression and anxiety) functioning as measured by the EuroQoL-5D (odds ratio, 4.41; 95% confidence interval, 1.51-12.92; P < .01).

Postoperative delirium is associated with increased anxiety and depression at 6 to 9 months postcardiac surgery. Future investigation should seek to evaluate the utility of screening programs for affective disorders in those individuals who develop delirium in the postoperative period.