The Seoul PeRioperative OUTcome research-4 (SPROUT-4) trial is set to investigate whether individualized blood pressure management during major noncardiac surgery can improve patient outcomes. This multicenter, parallel-group, randomized controlled superiority trial will enroll high-risk patients from five tertiary university hospitals in South Korea, comparing individualized blood pressure targets with conventional management. The study aims to address the critical need for optimized perioperative blood pressure control to reduce postoperative complications.
Study Design and Patient Population
The SPROUT-4 trial will include patients undergoing elective major noncardiac surgery under general anesthesia with an expected duration of more than 2 hours. High-risk patients are defined as those aged ≥65 years or those aged ≥45 years with more than one of the following: coronary artery disease, peripheral vascular disease, transient ischemic attack or stroke, or congestive heart failure. Exclusion criteria include emergency surgery, organ transplantation, uncontrolled hypertension (SBP ≥180 mmHg or diastolic blood pressure ≥110 mmHg), severe renal dysfunction (estimated glomerular filtration rate <30 ml/min/1.73 m2), acute decompensated heart failure, sepsis, or shock.
Intervention and Control
Patients will be randomized to either the individualized (intervention group) or conventional blood pressure management group (control group). In the control group, the protocol dictates maintaining a mean arterial pressure (MAP) of at least 65 mmHg and a systolic blood pressure (SBP) of at least 90 mmHg throughout surgery. In the intervention group, MAP and SBP will be maintained at no less than 20% below baseline values, calculated as the average of all MAP and SBP measurements obtained from the day before surgery until the morning of the surgery. A minimum MAP of 50–55 mmHg will be maintained regardless of the calculated target values in the intervention group for safety reasons.
Primary and Secondary Outcomes
The primary outcome is a composite of all-cause death, stroke, myocardial infarction (MI), new or worsening congestive heart failure, unplanned coronary revascularization, and acute kidney injury (AKI). These outcomes will be assessed within 7 days after surgery or until discharge, whichever occurs first. Secondary outcomes include individual components of the primary composite outcome, postoperative hospital length of stay, unplanned intensive care unit admission during index hospitalization, and new-onset atrial fibrillation.
Statistical Analysis and Sample Size
The trial aims to enroll a total of 1896 participants, with 948 in each group. This sample size is calculated to detect a 5% reduction in the incidence rate of the primary outcome in the intervention group compared to an estimated 9% incidence in the control group, with an α of <0.05 and a β of <0.1, assuming a dropout rate of 10%. All analyses will be conducted in an intention-to-treat manner, using the chi-squared test to compare the primary outcome between the groups. Statistical significance will be set at P<0.05.
Data Monitoring and Safety
A Data and Safety Monitoring Board, consisting of two cardiovascular anesthesiology and perioperative care specialists, will convene every 6 months to rigorously review the trial data, evaluate patient safety, monitor trial progress, and ensure data integrity. The trial is registered at ClinicalTrials.gov (NCT06225453).
