Blood Pressure Management on Cardiovascular AdveRse Events After Major Abdominal Surgery

Inclusion Criteria: 1. Aged ≥ 45 years; 2. Undergoing major abdominal surgery under general anesthesia (expected surgery time \>2h, expected length of postoperative stay \>2d); 3. Fulfill ≥1 of the following criteria (a-f): a. history of coronary artery disease; b. history of stroke; c. history of peripheral arterial disease; d. history of congestive heart failure; e. preoperative NT-proBNP \>200 pg/mL or BNP \>92 mg/L f. preoperative troponin \> upper limit of normal; or fulfill ≥2 of the following criteria (g-l); g. history of chronic kidney disease (preoperative sCr \>133μmol/L or 1.5 mg/dL); h. diabetes requiring medical treatment; i. smoking in the past \>2 years; j.≥ 65 years of age; k. hypertension requiring medical treatment l. history of hypercholesterolemia. Exclusion Criteria: 1. ASA score ≥5; 2. Severe untreated or uncontrolled hypertension (preoperative SBP\>180mmHg and/or DBP\>110mmHg); 3. End-stage renal disease requiring renal-replacement therapy; 4. Acute cardiovascular event within 1 month of surgery, including acute heart failure, acute coronary syndrome and stroke; 5. Preoperative sepsis or septic shock; 6. Preoperative requirement of vasopressor infusion; 7. Current participation in another interventional study; 8. Previous participation in this study; 9. Pregnant or breastfeeding women.