Highlight
- Targeting a higher intraoperative mean arterial pressure (MAP ≥80 mmHg) in hypertensive high-risk patients significantly reduces postoperative major organ dysfunction compared to the standard target (MAP ≥65 mmHg).
- Reduction in acute kidney injury incidence accounts for much of the observed benefit in postoperative outcomes with higher MAP targeting.
- The HISTAP multicenter randomized trial provides high-level evidence to refine blood pressure management strategies during major abdominal surgery in older hypertensive patients.
Study Background
Major abdominal surgery in older patients with chronic hypertension presents unique challenges, including an increased risk of postoperative organ dysfunction and mortality. Intraoperative hemodynamic management, particularly blood pressure control, is critical to ensure adequate organ perfusion. While guidelines often recommend maintaining mean arterial pressure (MAP) at or above 65 mmHg during surgery, the optimal MAP target for hypertensive patients at high risk has been unclear. This uncertainty arises because chronic hypertension shifts the autoregulatory range of organ perfusion to higher pressures, potentially necessitating higher intraoperative blood pressure targets to avoid ischemic complications. The HISTAP trial aimed to address this clinical gap by evaluating the effects of two MAP targets on postoperative outcomes in this vulnerable population.
Study Design
The HISTAP trial was a multicenter, randomized controlled study conducted across 18 Italian centers between March 2023 and April 2025. The trial enrolled patients aged 60 years or older with diagnosed chronic hypertension requiring home antihypertensive therapy, who were scheduled for elective major abdominal surgery and exhibited at least one additional high-risk feature (such as cardiovascular comorbidities or frailty). Participants were randomized to receive protocolized intraoperative blood pressure management targeting either a MAP ≥80 mmHg (Treatment group) or the standard MAP ≥65 mmHg (Control group). Continuous hemodynamic monitoring and protocolized fluid therapy were employed to ensure goal-directed management. The primary endpoint was a composite of postoperative mortality and occurrence of at least one major organ dysfunction within 30 days. Secondary outcomes included incidence of acute kidney injury and other organ-specific complications.
Key Findings
A total of 636 patients were randomized, with 630 patients completing the trial and analyzed on an intention-to-treat basis. The median age was 74 years (interquartile range 69–79). The mean intraoperative MAP achieved was 88 ± 9 mmHg in the higher-target group and 77 ± 7 mmHg in the standard-target group, confirming effective separation of blood pressure targets.
The composite primary outcome occurred in 38.1% of patients in the Treatment group compared with 48.9% in the Control group, corresponding to a relative risk reduction of 22% (relative risk 0.78; 95% confidence interval 0.65–0.93; P=0.006). This statistically significant reduction was primarily driven by fewer cases of postoperative acute kidney injury (23.5% vs. 33.7% in the Treatment and Control groups, respectively; P=0.005).
Other major organ dysfunction components and 30-day mortality showed trends favoring the higher MAP target but did not reach statistical significance individually. The safety profile was comparable between groups, with no increase in adverse events such as myocardial ischemia or stroke observed in the higher MAP target group.
Expert Commentary
The HISTAP trial provides robust evidence supporting a paradigm shift for intraoperative blood pressure targets in hypertensive high-risk patients undergoing major abdominal surgery. From a physiological perspective, chronic hypertension causes an adaptive rightward shift of cerebral and renal autoregulation curves, making traditional MAP thresholds potentially insufficient to maintain organ perfusion. The reduction in acute kidney injury is clinically important, given its association with long-term morbidity and increased healthcare costs.
These results align with previous observational and experimental studies suggesting tailored blood pressure management based on individual patient risk factors and comorbidities. However, some limitations merit consideration. The study focused on elective abdominal surgery and older hypertensive adults, limiting generalizability to emergency surgery or younger populations. Additionally, while acute kidney injury reduced significantly, other organ dysfunction endpoints require further research to clarify broader impacts.
Future guidelines may consider endorsing higher intraoperative MAP targets in this subgroup, incorporating continuous hemodynamic monitoring and goal-directed fluid optimization as standard practice components.
Conclusion
The HISTAP multicenter randomized clinical trial demonstrates that targeting an intraoperative MAP of at least 80 mmHg in high-risk hypertensive patients undergoing elective major abdominal surgery significantly reduces postoperative major organ dysfunction, particularly acute kidney injury. Personalized blood pressure management in the operating room, guided by patients’ chronic hypertension status and surgical risk, optimizes outcomes and represents a critical evolution in perioperative care standards.
Funding and Trial Registration
The HISTAP trial was supported by the SIAARTI Study Group and other collaborating institutions across Italy. The study is registered on ClinicalTrials.gov under identifier NCT05637606, with registration dated November 24, 2022.
References
- Cecconi M, Cortegiani A, Noto A, et al. HIgh versus STAndard blood Pressure target in hypertensive high-risk patients undergoing elective major abdominal surgery: the HISTAP multicenter randomized clinical trial. Intensive Care Med. 2026 Jun 29. PMID: 42370999.
- Fisher DJ, Hall JE. Renal autoregulation and hypertension: physiological basis for clinical practice. Hypertension. 2023;81(2):253-262.
- Flick RP, Warner ME. Perioperative Management of the Hypertensive Patient. Anesthesiol Clin. 2022;40(1):67-82.
