Adverse neurological and neurocognitive changes continue to occur after coronary artery bypass grafting, despite multiple refinements in surgical and anesthesiological techniques. Previous studies have focused mainly on short-term outcomes, but some recent studies have reported a surprisingly high incidence of cognitive decline up to 5 years after surgery. In one study, decline during the immediate postoperative period was predictive of late cognitive decline, thus establishing a possible link between intraoperative events and late cognitive decline. None of the long-term studies included a control group, making it difficult to rule out normal aging or related causes as the explanation for the late decline. Several lines of evidence now suggest that pre-existing cerebrovascular disease in candidates for coronary artery bypass grafting may play a role in late cognitive decline. A marked increase has been observed in comorbid disease among patients who undergo coronary artery bypass grafting, with more than half having hypertension, diabetes, or other risk factors for cerebrovascular disease. Preoperative magnetic resonance imaging findings in candidates for coronary artery bypass grafting also show a high prevalence of clinically silent white matter ischemic disease. Finally, recent studies in which patients with risk factors for cerebrovascular disease are excluded report little or no cognitive decline after coronary artery bypass grafting, thus raising the possibility that both early and late changes may be partly secondary to pre-existing cerebrovascular disease.
ASJC Scopus subject areas
- Psychiatry and Mental health