The study comprised two primary components: a retrospective analysis of clinical big data and a conventional prospective cohort study involving patients undergoing cardiac surgery. The objectives were: 1. To assess the preventive effect of ursodeoxycholic acid on post-cardiac surgery cognitive dysfunction over an eight-year period. 2. To analyze preoperative and postoperative 24-hour plasma samples from prior studies to quantify the levels of glycocalyx and its associated regulatory factors. 3. To evaluate the clinical association between the measured parameters and patient outcomes.

1. Baseline Period Visit 1 (within 24 hours before surgery)

   Sign informed consent Check inclusion/exclusion criteria Demographic data (sex, age, occupation, etc.) Past medical history (stroke, hypertension, diabetes, dyslipidemia, coronary heart disease, diabetes, etc.) and medication history in the past 3 months Vital signs (temperature, pulse, respiration, blood pressure) Preoperative ECG Preoperative echocardiography Laboratory tests (blood routine, blood glucose, blood lipids, liver and kidney function, myocardial enzymes, blood electrolytes, coagulation function) Concomitant therapy Adverse events

2. Intraoperative cardiopulmonary bypass

   Record vital signs and various physiological indicators in the operating room. Routinely perform central venous puncture to establish venous access and monitor central venous pressure, and radial artery puncture to monitor invasive arterial pressure.

   After general anesthesia and endotracheal intubation, routine blood chemistry and arterial blood gas analysis were performed.

   After collecting the above blood samples for testing, the remaining blood was centrifuged, and the plasma was frozen at -80°C for subsequent testing (levels of CRP, IL-6, IL-10, TNF-α, TK/B1R/MMP3, Hyaluronic acid, etc.).

   Operation time Vital signs (temperature, pulse, respiration, blood pressure) Routine blood chemistry and arterial blood gas analysis Document vasoactive drug use

3. 24 hours, 72 hours, 7 days after surgery

   Vital signs (temperature, pulse, respiration, blood pressure) Bedside echocardiography Laboratory tests (blood routine, blood sugar, blood lipids, liver and kidney function, myocardial enzymes, coagulation function, etc.) After collecting the above blood samples for testing, the remaining blood is centrifuged, and the plasma is frozen at -80°C for later testing (levels of glycocalyx) POCD Document treatment regimen (including vasoactive drug use, etc.)

4. Follow-up period

CCU time and total hospital stay 28-day survival status The survival status of the patients was followed up, and the date of death and the cause of death should be recorded in the patients who died.

Research Evaluation Analyze the clinical correlation between glycocalyx and its related indicators and postoperative cognitive dysfunction after cardiac surgery.

Patient Completion/Withdrawal from Study Finish All evaluation data of the patients 28 days after the operation were completely collected and considered as completed cases.

Inclusion criteria:

Voluntary participation in the study; Age ≥ 18 years and ≤ 80 years; Patients undergoing heart surgery: (heart valve replacement surgery with CPB,coronary artery bypass grafting, Morrow procedure, aortic dissection surgery).

Exclusion criteria:

Recipients of solid organ or bone marrow transplants; Patients with autoimmune diseases, tumors, or who have received high-dose steroids or immunosuppressive therapy within the past 2 months; Deemed unsuitable for participation in this study by the researchers. Primary outcome: Postoperative Delirium, postoperative cognitive dysfunction. Objective: Analyze the correlation between polysaccharide coating and cardiac surgery-related indicators.

Inclusion Criteria:

1. Voluntary participation in the study;
2. Age ≥ 18 years and ≤ 80 years;
3. Patients undergoing heart surgery: (coronary artery bypass grafting, heart valve replacement surgery, Morrow procedure, aortic dissection surgery).

Exclusion Criteria:

1. Patients experiencing adverse events during the surgery;
2. Recipients of solid organ or bone marrow transplants;
3. Patients with autoimmune diseases, tumors, or who have received high-dose steroids or immunosuppressive therapy within the past 2 months;
4. Deemed unsuitable for participation in this study by the researchers.

Patients undergoing heart surgery: (coronary artery bypass grafting, heart valve replacement surgery, Morrow procedure, aortic dissection surgery).