Analysis of the perioperative change in cognitive function of patients with risk factors for cognitive impairment in cardiovascular surgery.

OBJECTIVE: The purpose of the present study is to assess the perioperative changes in the cognitive function of patients after cardiovascular surgery (CVS) and to find out risk factors for early postoperative cognitive decline.

MATERIALS AND METHODS: From December 2013 to March 2017, 291 patients underwent elective or urgent CVS with cardiopulmonary bypass in our institution. One hundred and fifteen patients, who agreed to an evaluation of their cognitive function, were included in this study. The cognitive function was evaluated by the HDS-R and MMSE at three time points: before surgery, in the early postoperative period and at discharge. The patients' characteristics, perioperative data, HDS-R and MMSE scores were obtained by reviewing their medical records retrospectively.

RESULTS: The patients were stratified into three age groups. In all of the age groups, the early postoperative cognitive functional scores were severely decreased in comparison to the preoperative values. However, by the time of discharge, the function had improved to the same level as before surgery in each of the groups. In addition, the similar tendency was observed in patients with preoperative cognitive dysfunction. Moreover, multiple regression analysis demonstrated that preoperative cognitive function and age were significant risk factors for early cognitive impairment.

CONCLUSION: Although preoperative cognitive decline and patients' age were the risk factors for early postoperative cognitive impairment after CVS, a significant recovery can be expected even in elderly patients or patients with low preoperative cognitive function by the time of discharge.