ABSTRACT NUMBER: ESOC2026A853 BLOOD–BRAIN BARRIER DISRUPTION BEFORE ENDOVASCULAR THERAPY IN LARGE CORE PATIENTS PREDICTS PARENCHYMAL HEMATOMA

Abstract Background and aims In acute ischemic stroke due to large vessel occlusion (AIS-LVO) with a large ischemic core, hemorrhagic transformation is a frequent complication after endovascular therapy (EVT). We investigated whether blood–brain barrier (BBB) disruption measured before EVT is associated with 24-hour parenchymal hematoma (PH). Methods We performed a multicenter retrospective study of AIS-LVO patients with a large ischemic core (≥50 mL) on baseline MRI who underwent EVT and had adequate-quality perfusion-weighted imaging. BBB disruption was quantified as the percentage signal increase attributable to gadolinium leakage on perfusion source images. Mean permeability derangement (MPD) was defined as the average permeability of voxels within the ischemic core exceeding a predefined threshold. The primary outcome was PH on 24-hour follow-up imaging. Results Overall, 157 patients were included (median age 72 years; NIHSS 19; onset-to-MRI 2.6 hours; core volume 101 mL). PH occurred in 49 patients (31%). Median MPD was significantly higher among patients with PH compared with those without (7.9% vs 6.1%, P < 0.001). In multivariable analysis, higher MPD remained independently associated with PH after adjusting for core volume, glucose, occlusion site, and onset-to-imaging time (aOR 1.13; 95%CI 1.02–1.25; P = 0.015). Similar associations were observed in a sensitivity analysis restricted to patients with successful reperfusion. PH was independently associated with poor 3-month functional outcome (mRS 4-6: aOR 3.23; 95%CI 1.42–7.34; P = 0.005). Conclusions Pre-EVT BBB disruption quantified on perfusion MRI is associated with 24-hour PH in AIS-LVO patients with a large ischemic core. Strategies targeting BBB stabilization prior to EVT warrant investigation. Conflict of interest Nothing to disclose.