OBJECTIVES: To examine the association between plasma levels of pterins and amino acids and postoperative delirium. DESIGN: Prospective cohort study. SETTING: Cardiothoracic service in an university hospital in Rotterdam, the Netherlands. PARTICIPANTS: One hundred twenty-five individuals aged 70 and older undergoing elective cardiac surgery. MEASUREMENTS: Plasma pterins and amino acids were measured pre- and postoperatively. Using multiple logistic regression analyses, the associations between pterins and amino acid levels and postoperative delirium were examined in relation to age, sex, comorbidity, cognitive functioning (Mini-Mental State Examination (MMSE) score), and cardiac risk factors. RESULTS: Delirium incidence in the main study group was 31.3%. The preoperative measures associated with delirium were neopterin (odds ratio (OR) = 1.05, P = .009); MMSE score less than 28 (OR = 4.39, P = .001); European System for Cardiac Operative Risk Evaluation score greater than 6 (OR = 2.84, P = .03); and combined coronary artery bypass graft (CABG) and aortic, mitral, or tricuspid valve surgery (OR = 4.32, P = .01). Postoperative measures associated with delirium were neopterin (OR = 3.84, P = .02), homovanillic acid (HVA, OR = 1.01, P = .04), and preoperative MMSE score less than 28 (OR = 3.32, P = .008). CONCLUSION: Preoperatively high neopterin levels predicted delirium after cardiac surgery in older adults, in addition to the well-known risk factors of poor cognitive function, high cardio-surgical risk, and combined CABG and valve surgery. Postoperative neopterin and HVA levels were also found to be associated with delirium, together with preoperative cognitive functioning. Plasma neopterin may be a candidate biomarker for delirium after cardiac surgery in these older adults.

Additional Metadata
Keywords Amino acids, Cardiac surgical procedures, Delirium, Immune activation, Neopterin
Persistent URL dx.doi.org/10.1111/j.1532-5415.2011.03885.x, hdl.handle.net/1765/66077
Journal American Geriatrics Society. Journal
Osse, R.J, Fekkes, D, Tulen, J.H.M, Wierdsma, A.I, Bogers, A.J.J.C, van der Mast, R.C, & Hengeveld, M.W. (2012). High preoperative plasma neopterin predicts delirium after cardiac surgery in older adults. American Geriatrics Society. Journal, 60(4), 661–668. doi:10.1111/j.1532-5415.2011.03885.x