Abstract Number: Esoc2026a1295 Associations of Prehospital Blood Pressure Parameters and Key Outcomes in Acute Intracerebral Hemorrhage: Post-Hoc Analysis of the Interact4 Trial

Abstract Background and aims Uncertainty remains about the optimal BP parameters for ICH patients in prehospital settings. We aimed to assess the associations between prehospital BP parameters and clinical outcomes in ICH. Methods A post-hoc analysis of the ICH patients from INTERACT4, which randomized suspected stroke patients in prehospital settings to intensive BP lowering group (targeted 130-140 mmHg) or usual care. The SBP parameters included pre-hospital reduction, pre-hospital minimal, and difference between ambulance and hospital arrival. Major outcomes included mRS 3-6, 90-day mortality, and death or neurological deterioration within 7 days. The associations were determined in logistic or linear regression models adjusting for baseline covariates. Results Among 1029 patients (mean age 64.912.3 y, 32.3% female), median time from randomization to hospital arrival was 13(8-23) min. The prehospital SBP reduction was 17 (5-35) mmHg and prehospital minimal SBP was 163.7(SD 26.6) mmHg. Prehospital SBP reduction was negatively associated with 90-day mortality(aOR 0.91, 95%CI 0.84-0.99, p=0.03), while prehospital minimal SBP was positively associated with death within 90 days (aOR 1.09, 95%CI 1.01-1.19, p=0.03). Elevated SBP difference between ambulance and hospital arrival was associated with increased risk of death within 90 days (aOR 1.07, 95%CI 1.00-1.14, p=0.04). Conclusions Lower achieved SBP and larger reduction were associated with decreased risk of death, but larger SBP rebound was associated with higher risk of worse outcomes, highlighting the importance of ultra-early intensive BP lowering in the ambulance and keep stability during transference for patients with ICH. Conflict of interest nothing to disclose