Hypotension Prediction Index Software Compared with Standard Advanced Haemodynamic Monitoring in Patients Undergoing Major Aortic Surgery: A Retrospective Study

<b>Background/Objectives:</b> Intraoperative hypotension (IOH) is related to the occurrence of postoperative complications and may be a frequent event during major vascular surgery. The Hypotension Prediction Index (HPI) is a technology applied to predict hypotension and enable preventive interventions. This study aimed to compare intraoperative haemodynamic stability between patients monitored with the HPI algorithm and those monitored with arterial pressure cardiac output (APCO) monitoring. <b>Methods:</b> We performed a retrospective study including 100 adult patients undergoing elective major aortic surgery between January 2023 and June 2025. Fifty patients were managed with APCO monitoring and 50 with the HPI algorithm. The primary endpoint was time-weighted average mean arterial pressure below 65 mmHg (TWA-MAP < 65 mmHg). Secondary endpoints included total hypotension time, number and duration of hypotensive episodes, and time spent with MAP > 90 and > 100 mmHg. Multiple comparison correction (Holm-Bonferroni) was applied separately for hypotension and hypertension outcomes. <b>Results:</b> The primary outcome, TWA-MAP < 65 mmHg, did not differ significantly between groups (0.22 vs. 0.26 mmHg; p=0.27). After correction for multiple comparisons, no hypotension-related outcomes reached statistical significance, although clinically relevant trends were observed: the HPI group showed 50% shorter total hypotension time (5 vs. 10 min; puncorrected=0.03, padjusted=0.18) and 33% shorter episode duration. In contrast, patients in the HPI group spent significantly more time with elevated MAP: 38% vs. 25% of monitored time with MAP > 90 mmHg (padjusted=0.036) and 18% vs. 9% with MAP > 100 mmHg (padjusted=0.036). <b>Conclusions:</b> In patients undergoing major vascular aortic surgery, HPI monitoring did not significantly reduce the burden of hypotension after accounting for multiple comparisons, though clinically meaningful trends were noted. However, HPI use was associated with significantly increased hypertensive exposure, suggesting overly aggressive correction. These findings highlight the need for careful titration of interventions when using predictive algorithms and warrant further prospective randomised studies.