The Primary Objective of This Study Was to Investigate the Effect of Insulin on Myocardial Perfusion and Cardiac Function in Patients Undergoing Cardiac Surgery for CPB Using Transesophageal Echocardiography (TEE) to Detect CSBF

Inclusion criteria included 1. age 55-80 years, ASA grade II-III, regardless of gender, 2. BMI 18.5-28.0 kg/m2, 3. scheduled for elective coronary artery bypass grafting (CABG), valve repair or replacement, or a combination of these procedures with cardiopulmonary bypass. Exclusion criteria 1. non-first cardiac surgery; 2. emergency cardiac surgery; 3. severe heart failure with preoperative left ventricular ejection fraction \<30%; 4. contraindication to TEE; 5. kidney disease requiring replacement therapy; 6. combined with multi-organ insufficiency; 7. Severe infection requiring continuous antibiotic treatment; 8. use of large doses of hormone or nonsteroidal anti-inflammatory drugs within the last 2 weeks. 9. after the patient entered the operating room, if the first blood glucose exceeded 180 mg/dl, a second test was performed 15 minutes later, and if the average of the two blood glucoses exceeded 180 mg/dl, the patient was excluded as well. Elimination criteria included 1. unplanned secondary CPB; 2. need for intra-aortic balloon pump technical support during the study period; 3. TEE image acquired with poor quality.