High-risk populations, particularly elderly individuals and patients with cardiovascular comorbidities, exhibit markedly elevated incidences of postoperative myocardial injury (MINS), acute kidney injury (AKI), and mortality.

Intraoperative hypotension (IOH), a pervasive clinical phenomenon affecting 40%-90% of surgical cases, Substantial observational evidence links IOH severity/duration to ischemic organ injuries (MINS, AKI) and long-term morbidity.Nevertheless, inherent limitations of observational designs-particularly residual confounding-preclude definitive causal inferences. Notably, randomized controlled trials (RCTs) investigating goal-directed hemodynamic interventions demonstrate inconsistent clinical benefits, underscoring the imperative to clarify causal mechanisms between IOH and organ injury. This causal ambiguity arises from two unresolved scientific questions:

(1) Threshold personalization deficit; (2) Therapeutic strategy limitations. In light of current evidence, perioperative hypotension management demands personalized strategies, the investigators propose a multicenter randomized controlled trial (RCT) that aims to clarify the clinical benefits of individualized blood pressure management.

Anesthesia- and surgery-related complications and mortality constitute a critical global public health burden. Annually, over 300 million surgical procedures are performed worldwide, with postoperative complications and mortality standing as predominant contributors to adverse outcomes. High-risk populations, particularly elderly individuals and patients with cardiovascular comorbidities, exhibit markedly elevated incidences of postoperative myocardial injury (MINS), acute kidney injury (AKI), and mortality. Refinement of perioperative management protocols-especially precision-guided hemodynamic control-has emerged as a pivotal strategy for optimizing patient prognosis.

Intraoperative hypotension (IOH), a pervasive clinical phenomenon affecting 40%-90% of surgical cases, is conventionally defined through either absolute thresholds (e.g., systolic blood pressure (SBP) <90 mmHg or mean arterial pressure (MAP) <65 mmHg) or relative reductions from baseline values (>20% decline). Its high prevalence and association with end-organ hypoperfusion have positioned IOH as a central concern in perioperative care. Substantial observational evidence links IOH severity/duration to ischemic organ injuries (MINS, AKI) and long-term morbidity. Nevertheless, inherent limitations of observational designs-particularly residual confounding-preclude definitive causal inferences. Notably, randomized controlled trials (RCTs) investigating goal-directed hemodynamic interventions demonstrate inconsistent clinical benefits, underscoring the imperative to clarify causal mechanisms between IOH and organ injury.

This causal ambiguity arises from two unresolved scientific questions:

1. Threshold personalization deficit: Current paradigms predominantly apply population-based fixed thresholds (e.g., MAP ≥75-80 mmHg vs. ≥60 mmHg), disregarding interindividual hemodynamic variability. Although The Intraoperative Norepinephrine to Control Arterial Pressure (INPRESS) study used personalized blood pressure targets, its approach of measuring baseline blood pressure during a single clinic visit conflicts with current evidence. Research shows that 24-hour ambulatory monitoring is the most reliable method to capture an individual's true baseline blood pressure and daily fluctuations.
2. Therapeutic strategy limitations: Conventional protocols emphasizing aggressive vasopressor use to achieve arbitrary pressure targets may inadvertently increase complications like anastomotic leakage and AKI. Furthermore, the multifactorial etiology of IOH-encompassing hypovolemia, vasoplegia, and impaired cardiac contractility-demands etiology-specific management algorithms rather than universal interventions.

In light of current evidence, perioperative hypotension management demands personalized strategies. To address this need, the investigators propose a multicenter randomized controlled trial (RCT) that pioneers the integration of ambulatory blood pressure monitoring (ABPM) with etiology-specific intervention protocols. This study aims to clarify the clinical benefits of individualized blood pressure management and establish high-quality evidence to advance precision anesthesia practices in perioperative care.

Inclusion Criteria:

• Aged 65-90 yr;

• Scheduled to undergo elective non-cardiac major surgery under general anesthesia (with an estimated surgery duration of ≥ 2 hours and an anticipated postoperative hospital stay of ≥ 2 days);

• Patients with high cardiovascular risk, meeting at least one of the following conditions:

  1. History of stroke;
  2. History of coronary artery disease;
  3. History of congestive heart failure;
  4. History of peripheral arterial disease;
  5. Preoperative brain natriuretic peptide (BNP) ≥ 92 mg/L or N-terminal pro-brain natriuretic peptide (NT-proBNP) ≥ 300 ng/L;
  6. Preoperative cardiac troponin (cTn) or high-sensitivity cardiac troponin (hs-cTn) > upper reference limit;
  7. Hypertension requiring medication treatment;
  8. Diabetes requiring medication treatment;
  9. History of chronic kidney disease;
  10. Continuous smoking for 2 years or more, with interruptions of less than one month before the current hospital admission;
  11. Hypercholesterolemia;
  12. History of transient ischemic attack.

Exclusion Criteria:

• Refuse to participate this trial;
• Inability to communicate in the preoperative period because of coma, profound dementia, or language barrier;
• Severe uncontrolled hypertension before surgery (systolic blood pressure ≥ 180 mmHg, diastolic blood pressure ≥ 110 mmHg);
• Severe hepatic dysfunction (Child-Pugh Class C); or severe renal dysfunction required preoperative dialysis; or American Society of Anesthesiologists (ASA) physical status ≥ V; or expectation lifespan ≤ 24h;
• Unstable cardiovascular conditions: acute coronary syndrome, decompensated heart failure, severe arrhythmias, severe valvular heart disease;
• Scheduled to undergo neurosurgical procedures, transplantation, vascular surgery;
• Urgent surgery;
• Diagnosed with sepsis or sepsis shock before surgery.
• Requiring vasopressor treatment before surgery.
• Unable to finish 24-hour automated blood pressure monitor;
• Current participation in another interventional study.
• Any condition deemed ineligible for participation by clinicians.