The occurrence of late cognitive decline in some patients after coronary artery bypass grafting (CABG) is now well documented. The fact that not all studies have found evidence of late decline suggests that it may not be inevitable. The cause of the late cognitive decline after CABG remains controversial, because most studies did not include appropriate control subjects. Some have suggested that the late cognitive decline may be due to a combination of normal aging and progression of underlying cerebrovascular disease. The pattern of the late cognitive changes, with prominent psychomotor slowing and modest or no decline in memory, may be consistent with this hypothesis. One recent epidemiological study concluded that the late cognitive changes might be due to Alzheimer's disease, but another case-control study did not find support for this interpretation. There is evidence from both neuropathological and cognitive studies that candidates for cardiac surgery may have mild AD-type changes preoperatively, thus raising the possibility that for some patients, the surgery is not a direct cause of the late cognitive decline. Rather, the surgery may uncover or accelerate a pre-existing cognitive impairment. In order to determine whether it is the severity of pre-existing cardio- and cerebrovascular disease or the use of cardiopulmonary bypass that confers an increased risk of postoperative dementia, future studies should include controls with a degree of coronary artery disease similar to that of the patients undergoing CABG.
|Number of pages
|Published - 2006
- Cardiac surgery, neuropsychological outcomes
ASJC Scopus subject areas
- Neuropsychology and Physiological Psychology
- Applied Psychology