Cohort Study of Postoperative Cognitive Dysfunction After Off-Pump Coronary Artery Bypass Grafting

This is a prospective observational cohort study of patients undergoing off-pump coronary artery bypass grafting. The study aims to investigate postoperative cognitive dysfunction and its association with perioperative clinical factors. Eligible patients will be enrolled before surgery and followed after surgery according to the study protocol.

Baseline information will be collected before surgery, including demographic characteristics, medical history, comorbidities, laboratory test results, and preoperative cognitive assessment. Intraoperative and postoperative data will also be collected, including anesthesia-related variables, surgical information, hemodynamic and monitoring parameters, postoperative clinical status, and relevant complications.

Cognitive function will be assessed before surgery and at predefined postoperative time points using standardized cognitive assessment tools, such as the Montreal Cognitive Assessment. Postoperative cognitive dysfunction will be determined according to the predefined criteria based on changes in cognitive assessment results from baseline to postoperative follow-up.

The study will describe the incidence of postoperative cognitive dysfunction after off-pump coronary artery bypass grafting and evaluate the association between perioperative factors and postoperative cognitive outcomes. The results may help improve understanding of postoperative cognitive dysfunction in this surgical population and provide evidence for perioperative risk assessment and clinical management.

Inclusion criteria

• Age 18 years or older
• Scheduled to undergo elective off-pump coronary artery bypass grafting
• American Society of Anesthesiologists physical status classification I to IV
• Able to complete preoperative cognitive assessments, including the Mini-Mental State Examination and the Montreal Cognitive Assessment
• Written informed consent provided by the patient or family member

Exclusion criteria

• Emergency surgery
• Pre-existing diagnosed cognitive impairment or history of psychiatric disease
• Preoperative cognitive impairment
• Severe neurological disease, such as sequelae of stroke, that may interfere with cognitive assessment
• Severe visual or hearing impairment that prevents completion of cognitive assessment
• Inability to understand Chinese or presence of language communication barriers