HIgh versus STAndard blood Pressure target in hypertensive high-risk patients undergoing elective major abdominal surgery: the HISTAP multicenter randomized clinical trial

Purpose: The optimal mean arterial pressure (MAP) target in high-risk hypertensive patients undergoing major abdominal surgery remains unclear. The HISTAP trial evaluated whether targeting an intraoperative MAP ≥ 80 compared with ≥ 65 mmHg reduces postoperative organ dysfunction and 30-day mortality, in this population. Methods: HISTAP was a multicenter, randomized trial conducted at 18 Italian centers between March 2023 and April 2025. The study included patients aged ≥ 60 years with chronic hypertension requiring home therapy, undergoing elective major abdominal surgery and having at least one additional high-risk criterion. The intraoperative MAP was targeted to ≥ 80 mmHg (Treatment group) or ≥ 65 mmHg (Control group). The primary outcome was a composite endpoint including postoperative mortality and at least one major organ dysfunction. Findings: Of 636 randomized patients, 6 were excluded since surgery was canceled after randomization, 630 completed the trial and were included in the intention-to-treat analysis (median age, 74 years [IQR, 69-79]). Mean intraoperative MAP was 77 ± 7 mmHg in the Control group and 88 ± 9 mmHg in the Treatment group. The primary composite outcome occurred in 48.9% of patients in the Control group versus 38.1% of patients in the Treatment group (relative risk, 0.78; 95% CI 0.65-0.93; P = 0.006). Acute kidney injury was significantly less frequent in the Treatment group (23.5 vs. 33.7%; P = 0.005). Interpretation: Among hypertensive patients receiving continuous hemodynamic monitoring and protocolized fluid therapy at increased postoperative risk undergoing major abdominal surgery, targeting an intraoperative MAP ≥ 80 mmHg, compared with ≥ 65 mmHg, reduced major organ dysfunction, primarily due to fewer mild-to-moderate acute kidney injuries. Trial registration: The HISTAP trial has been registered at ClinicalTrials.gov, NCT05637606 (Date of registration: 24 November 2022).