Plasma concentrations of nitric oxide products and cognitive dysfunction following coronary artery bypass surgery.
OBJECTIVE
Prospective longitudinal studies now indicate that cognitive dysfunction following coronary artery bypass surgery (CABG) is both common and persistent. This dysfunction is due in part to the inflammatory response and cerebral ischaemia-reperfusion, with nitric oxide (NO) as an important mediator of both. We hypothesized that a clinically significant association exists between plasma concentrations of nitrate/nitrite (NO3-/NO2-) and cognitive dysfunction after CABG.


METHODS
Cognitive assessment was performed on 36 adult patients the day before CABG, on the fourth postoperative day and 3 months postoperatively. Patient spouses (n = 10) were also studied.


RESULTS
A new cognitive deficit was present in 22/36 (62%) 4 days postoperatively and in 16/35 (49%) of patients, 3 months postoperatively. Patients who had cognitive dysfunction 3 months postoperatively were more likely to have cognitive dysfunction and increased plasma NO3-/NO2- concentrations compared to the non-deficit group preoperatively (22.6 (9.2) vs. 27.6 (8.4)) (P = 0.002). Plasma NOx (NO3- plus NO2-) concentrations were greater in patients with cognitive dysfunction 3 months postoperatively, 2 h (24.2 (6.3) vs. 19.1 (5.2)) (P = 0.002), and 12 h postoperatively (24.8 (7.6) vs. 18.8 (5.6)) (P = 0.001). There was, however, a time course similarity in NOx elevations for both deficit and non-deficit groups.


CONCLUSIONS
Perioperative plasma NOx concentrations do not serve as an effective biomarker of cognitive deficit after CABG.
Harmon
D
D
Walton Centre for Neurology and Neurosurgery, Liverpool, UK. dominicharmon@hotmail.com
Eustace
N
N
Ghori
K
K
Butler
M
M
O'Callaghan
S
S
O'Donnell
A
A
Moore-Groarke
G M
GM
Shorten
G
G
D000328:Adult; D000339:Affect / Q000502:physiology; D000368:Aged; D015415:Biomarkers; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003072:Cognition Disorders / Q000097:blood* / Q000209:etiology* / Q000523:psychology; D003693:Delirium / Q000139:chemically induced / Q000523:psychology; D003863:Depression / Q000175:diagnosis / Q000523:psychology; D005112:Extracorporeal Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D009483:Neuropsychological Tests; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000097:blood*; D020030:Nitric Oxide Donors / Q000627:therapeutic use; D009573:Nitrites / Q000097:blood; D011183:Postoperative Complications / Q000097:blood* / Q000523:psychology; D011446:Prospective Studies; D015203:Reproducibility of Results
D015415:Biomarkers; D009566:Nitrates; D020030:Nitric Oxide Donors; D009573:Nitrites; D009569:Nitric Oxide