Core Blood-Brain Barrier Disruption in Patients With Large Vessel Occlusion

Multimodal imaging has expanded treatment for patients with acute ischemic stroke with large vessel occlusion. Blood-brain barrier (BBB) disruption measured in the ischemic core is associated with hemorrhagic transformation. However, the associations between core BBB disruption (cBBBD) and baseline clinical/imaging variables, as well as 3-month outcome, have not been explored.

This is a retrospective multicenter analysis of consecutive anterior circulation patients with acute ischemic stroke with large vessel occlusion, presenting over a 4-year time period, who were transferred from a primary to a comprehensive stroke center for possible endovascular therapy, with magnetic resonance imaging that included perfusion-weighted imaging before transfer. Magnetic resonance imaging scans were processed using RAPID software to generate penumbral imaging variables. Perfusion-weighted images were processed to detect and quantify contrast leakage; cBBBD was calculated as the average of all leaky voxels in the ischemic core. Poor functional outcome was defined as a modified Rankin Scale score of >2 at 3 months. Linear regression was used except for the outcome, which used logistic regression, controlling for age, stroke severity, and baseline functional status.

Out of 411 patients transferred for endovascular therapy, 291 were included in this analysis with a median age of 74 years; 49% were female patients. The median National Institutes of Health Stroke Scale score was 13, the mean core volume was 32.3 mL, and the mean cBBBD was 2.1%. 71% of patients underwent endovascular therapy. Admission National Institutes of Health Stroke Scale score (P<0.001) and glucose level (P=0.033) were independently correlated with cBBBD. All imaging variables correlated strongly with cBBBD (P<0.001). The strongest correlation was 0.50, observed between cBBBD and mismatch ratio (r²=0.254). Increasing cBBBD was independently associated with poor functional outcome (adjusted odds ratio, 1.16 [CI, 1.03-1.32]; P=0.019; n=279), indicating that for every 1% increase in cBBBD, the odds of having a poor functional outcome increase by 16%.

In acute ischemic stroke with large vessel occlusion, disruption of the BBB in the core lesion is independently associated with clinical outcome. cBBBD represents a new imaging profile for acute stroke that may help guide treatments.