Abstract Number: Esoc2026a884 Effects of Intensive Blood Pressure Lowering on Perihematomal Edema in Acute Intracerebral Hemorrhage: Pooled Analysis of the Four Interact Trials

Abstract Background and aims Uncertainty persists over the effect of intensive blood pressure (BP) -lowering on perihematomal edema (PHE) growth in acute intracerebral hemorrhage (ICH). We aimed to investigate the effect of intensive BP-lowering on PHE growth in acute ICH. Methods We undertook an individual patient data pooled analysis of the four INTERACT trials, which all had consistent BP-lowering protocols (targeting systolic BP 140 mmHg intensive vs. 180 mmHg guideline within 1 hour). PHE growth was defined as the increase of absolute volume (primary) and edema extension distance (EED, calculated as 4π/3 × hematoma volume + PHE volume) ^ (1/3) − (4π/3 × hematoma volume) ^ (1/3), secondary) from baseline to 24 hours. Linear regression models were conducted, adjusting for related covariates including baseline hematoma volume. Heterogeneity analysis was undertaken to assess the interaction with time from symptom onset to randomization. Results Of 2, 549 ICH patients (mean age 64 y, 35% female) with available 24-hour PHE growth data, early intensive BP-lowering attenuated the absolute PHE growth and EED expansion at 24 hours (mean difference MD -1. 13 mL, 95%CI -1. 94, -0. 33, p=0. 006; -0. 03 -0. 06, -0. 002, p=0. 036, respectively). Moreover, the treatment effect on absolute PHE growth was time-dependent, decreasing as the time from symptom onset to randomization increased, with the greatest benefit observed when treatment was initiated within 2. 2 hours (p for interaction = 0. 009). Conclusions Intensive BP-lowering significantly attenuates PHE growth at 24 hours, with greater benefit when initiated earlier—emphasizing the importance of early initiation of intensive BP-lowering in acute ICH. Conflict of interest Xinwen Ren: nothing to disclose