Delirium, changes in cognitive function, and risk of diagnosed dementia after kidney transplantation

• Published in: American journal of transplantation Vol. 22; no. 12; pp. 2892 - 2902
• Main Authors: Chu, Nadia M., Bae, Sunjae, Chen, Xiaomeng, Ruck, Jessica, Gross, Alden L., Albert, Marilyn, Neufeld, Karin J., Segev, Dorry L., McAdams‐DeMarco, Mara A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Limited 01.12.2022
• Subjects: Aged; Aging; clinical research/practice; Cognition; Cognitive ability; cognitive function; Delirium; Dementia; Dementia - etiology; Dementia disorders; epidemiology; Executive function; health services and outcomes research; Humans; Immunosuppression; kidney disease; Kidney diseases; kidney transplant; Kidney transplantation; Kidney Transplantation - adverse effects; kidney transplantation/nephrology; Kidney transplants; Medical diagnosis; Medicare; mental health; neurology; Neurotoxicity; Prospective Studies; Risk Factors; Transplants & implants; United States; United States; cognitive function; epidemiology; clinical research/practice; kidney transplantation/nephrology; mental health; kidney transplant; kidney disease; delirium; neurology; health services and outcomes research
• ISSN: 1600-6135; 1600-6143
• DOI: 10.1111/ajt.17176

Kidney transplant (KT) recipients with delirium, a preventable surgical complication, are likely to reap cognitive benefits from restored kidney function, but may be more vulnerable to longer‐term neurotoxic stressors post‐KT (i.e., aging, immunosuppression). In this prospective cohort study, we measured delirium (chart‐based), global cognitive function (3MS), and executive function (Trail Making Test Part B minus Part A) in 894 recipients (2009–2021) at KT, 1/3/6‐months, 1‐year, and annually post‐KT. Dementia was ascertained using linked Medicare claims. We described repeated measures of cognitive performance (mixed effects model) and quantified dementia risk (Fine & Gray competing risk) by post‐KT delirium. Of 894 recipients, 43(4.8%) had post‐KT delirium. Delirium was not associated with global cognitive function at KT (difference = −3.2 points, 95%CI: −6.7, 0.4) or trajectories post‐KT (0.03 points/month, 95%CI: −0.27, 0.33). Delirium was associated with worse executive function at KT (55.1 s, 95%CI: 25.6, 84.5), greater improvements in executive function <2 years post‐KT (−2.73 s/month, 95%CI: −4.46,−0.99), and greater decline in executive function >2 years post‐KT (1.72 s/month, 95%CI: 0.22, 3.21). Post‐KT delirium was associated with over 7‐fold greater risk of dementia post‐KT (adjusted subdistribution hazard ratio = 7.84, 95%CI: 1.22, 50.40). Transplant centers should be aware of cognitive risks associated with post‐KT delirium and implement available preventative interventions to reduce delirium risk. Post‐kidney transplant delirium, a preventable surgical complication, is associated with improved executive function in the first two years but worse executive function thereafter, as well as a seven‐fold greater risk of diagnosed dementia.