Issues associated with the identification of cognitive change following coronary artery bypass grafting

Objective: Coronary artery bypass grafting (CABG) is a surgical procedure u sed to treat individuals with ischaemic heart disease and to relieve angina . Disruption to the central nervous system (CNS) has frequently been report ed by patients who have undergone CABG. Method: The following paper is a review of the literature that has examined the effects of CABG on the CNS. Results and Conclusions: It becomes apparent that issues about the incidenc e and severity of post-CABG cognitive decline are still unresolved. First, the cause of post-CABG CNS change has not yet been established, although th e presence of changes to brain microvasculature as a result of the presence of microemboli appears to be a likely factor. Second, while some studies h ave reported high rates of poor performance on neuropsychological tests pos toperatively, these reports are often subject to confounds such as variabil ity in postoperative testing intervals, the definition of decline and the n europsychological test batteries used. Finally, improvements in surgical te chniques and changes in patient characteristics may have changed the real n ature and prevalence of post-CABG cognitive decline. The review finishes wi th a series of recommendations for the neuropsychologlical study of CABG.