This study is a multicenter randomized controlled trial comparing an intensive intraoperative blood pressure management strategy versus conventional practice for preventing cardiovascular events in high-risk patients undergoing major abdominal surgery.

Intraoperative hypotension has been associated with cardiovascular events after non-cardiac surgery. However, whether avoiding intraoperative hypotension can reduce the incidence of postoperative cardiovascular events remains unclear. The objective of this study is to assess the effects of an intensive intraoperative blood pressure management strategy (to maintain intraoperative MAP ≥ 80mmHg) with that of conventional practice (to maintain intraoperative MAP ≥ 65mmHg) on the incidence of cardiovascular 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.

The deidentified IPD will be shared upon reasonable request after study completion.