Individualized Perioperative Blood Pressure Management in Patients Undergoing Major Abdominal Surgery: The IMPROVE-multi Randomized Clinical Trial.

Importance: Intraoperative hypotension is associated with organ injury. However, it remains unknown if targeted blood pressure management during surgery can improve clinical outcomes. Objective: To evaluate whether individualized vs routine perioperative blood pressure management during major abdominal surgery improves clinical outcomes in patients considered at high risk of postoperative complications. Design, Setting, and Participants: This randomized single-blind clinical trial enrolled patients 45 years or older undergoing elective major abdominal surgery with general anesthesia expected to last 90 minutes or longer who had at least 1 additional high-risk criterion between February 26, 2023, and April 25, 2024, at 15 German university hospitals. The date of last follow-up was July 25, 2024. Intervention: Patients were randomized in a 1:1 ratio to individualized perioperative blood pressure management (with mean arterial pressure [MAP] targets based on preoperative mean nighttime MAP assessed using automated blood pressure monitoring) or routine blood pressure management with a MAP target of 65 mm Hg or higher. Main Outcomes and Measures: The primary outcome was the incidence of a composite outcome of acute kidney injury, acute myocardial injury, nonfatal cardiac arrest, or death within the first 7 postoperative days. There were 22 secondary outcomes, including infectious complications within the first 7 postoperative days and a composite outcome of need for kidney replacement therapy, myocardial infarction, nonfatal cardiac arrest, or death within 90 days after surgery. Results: Of the 1272 patients enrolled, 1142 were randomized (571 patients to each group), and 1134 were included in the primary analysis (median age, 66 years [IQR, 59-73 years]; 34.1% female). The primary outcome occurred in 190 of 567 patients (33.5%) assigned to individualized blood pressure management and 173 of 567 patients (30.5%) assigned to routine blood pressure management (relative risk, 1.10 [95% CI, 0.93-1.30]; P = .31). None of the 22 secondary outcomes were significantly different, including infectious complications within the first 7 postoperative days (90/567 [15.9%] vs 97/567 [17.1%]; P = .63) and a composite outcome of need for kidney replacement therapy, myocardial infarction, nonfatal cardiac arrest, or death within 90 days after surgery (32/566 [5.7%] vs 20/567 [3.5%]; P = .12). Conclusions and Relevance: Among patients at high risk of postoperative complications undergoing major abdominal surgery, individualized perioperative blood pressure management with MAP targets based on preoperative mean nighttime MAP did not decrease the composite outcome of acute kidney injury, acute myocardial injury, nonfatal cardiac arrest, or death within the first 7 postoperative days compared with routine blood pressure management with a MAP target of 65 mm Hg or higher. Trial Registration: ClinicalTrials.gov Identifier: NCT05416944.