Homocysteine and C-reactive protein are not markers of cognitive impairment in patients with major cardiovascular disease.

Abstract

Raised concentrations of plasma homocysteine and C-reactive protein (CRP) are associated with vascular disease and have also been implicated as independent risk factors for cognitive impairment in population studies. To investigate the association of plasma homocysteine and CRP with cognition in patients scheduled for coronary artery bypass graft (CABG) surgery. Cognition was assessed in 264 patients using a standard battery of neuropsychological tests. Patients were classified as having preexisting cognitive impairment (PreCI) by reference to a healthy control group or postoperative cognitive dysfunction (POCD) by reference to baseline test scores. PreCI was present in 37.3% of patients, and POCD was present in 18.3, 12.1 and 13.6% of patients at 1 week, 3 months and 12 months postoperatively. On multivariate analysis neither homocysteine nor CRP were independently associated with cognition at any testing time but were strongly associated with age and left ventricular function. PreCI and POCD are present in a substantial proportion of patients undergoing CABG surgery but there is no independent association with either baseline homocysteine or CRP levels. It is possible that cognitive impairment may result from the vascular disease rather than a direct association with either homocysteine or CRP.