Dementia and Cognitive Impairment on Coronary Artery Bypass Grafting Patients in Aging Society

Coronary artery bypass grafting (CABG) is strategy for complex coronary artery disease (CAD) practiced worldwide that has become to be performed in relatively elderly patients in recent years, regarding to the development of off-pump CABG. As the population of elderly patients with cognitive disorders increases, a certain proportion of CABG candidates are likely to have some degree of cognitive impairment, especially dementia. The discussions about the CABG candidates with dementia are still insufficient, although several reports have suggested that 9.6%&ndash20% of CABG candidates may have preoperative dementia. An analysis indicated higher rate of hospital mortality and delirium in dementia patients, but ideal strategies for managing such patients remain controversial. An estimated 20%&ndash35% of CABG patients may have preoperative mild cognitive impairment (MCI), which is associated with an increased risk of morbidity and poor physical recovery after CABG. This preoperative cognitive decline was identified as a predictive factor for post-operative cognitive decline (POCD). Several randomized control trial have compared the cognitive outcomes between elderly high-risk patients after CABG with or without cardiopulmonary bypass, finding no significant cognitive differences between on- and off-pump treatments at 3 to 12 months after CABG. In addition, any late cognitive decline is likely associated with the progression of underlying cerebrovascular disease rather than surgical procedure itself or cardiopulmonary bypass. Preoperative evaluations of the cognitive function may contribute to appropriate postoperative management, reduce the incidence of delirium and improve the overall surgical outcome.