Impact of Asymptomatic Carotid Artery Disease on Cognitive Functions in Patients Undergoing Off-pump Coronary Artery Bypass Grafting with and without Near-infrared Spectroscopy Monitoring and Intervention Intraoperatively

Background: Postoperative cognitive dysfunction (POCD) is one of the known complications after cardiac surgeries. The incidence of cognitive dysfunction varies considerably but may be as high 50-70% at 1 week after surgery, declining to 30-50% after 2 months. Carotid artery atherosclerosis is a major risk factor for stroke and subsequent cognitive impairment. Near-infrared spectroscopy (NIRS) is a system used for monitoring the activity of the brain. Materials and methods: Forty-three patients with asymptomatic carotid artery lesion (>70%) undergoing elective off-pump coronary artery bypass (OPCAB) underwent preoperative and postoperative neuropsychological evaluations with the Montreal cognitive assessment (MoCA) score. The patients were randomized to receive or not to receive neuromonitoring with NIRS and subsequent management according to an algorithm. Twentyone patients received NIRS monitoring and were managed accordingly and twenty-two patients did not receive NIRS monitoring and management. Results: There was no statistically significant difference in the incidence of POCD between the groups that did or did not receive neuromonitoring and subsequent management based on NIRS at 1 hour, 24 hours, and 1 week post-extubation.