Blood-Brain Barrier Disruption Before Interhospital Transfer for Thrombectomy and Clinical Outcome

BACKGROUND AND OBJECTIVES: In acute ischemic stroke with large vessel occlusion (AIS-LVO), interhospital transfer for endovascular therapy (EVT) provides an ideal therapeutic window during which neuroprotective strategies could be evaluated, allowing sufficient exposure before reperfusion. We aimed to determine whether blood-brain barrier (BBB) disruption assessed before interhospital transfer for EVT is associated with 24-hour hemorrhagic transformation (HT) and 3-month functional outcome. METHODS: In this multicenter retrospective study, we included patients with anterior circulation AIS-LVO transferred from 4 French primary stroke centers (PSCs) to comprehensive stroke centers for EVT assessment, with baseline MR perfusion imaging performed at the PSC before transfer. BBB disruption was quantified as the percentage signal change due to gadolinium leakage on perfusion source images. Mean permeability derangement (MPD) was defined as the average of all voxels within the ischemic core exhibiting permeability values greater than a prespecified threshold. The primary outcome was any intraparenchymal HT on 24-hour follow-up imaging. The association between MPD and HT was studied in multivariable mixed binary logistic regression analyses. RESULTS: = 0.006). DISCUSSION: BBB disruption on pretransfer perfusion MRI is associated with 24-hour HT and poor 3-month functional outcome in patients with AIS-LVO. These findings highlight its potential value for early risk stratification and justify prospective evaluation of BBB-targeted strategies during interhospital transfer for EVT.