Early and delayed blood-brain barrier permeability predicts delayed cerebral ischemia and outcomes following aneurysmal subarachnoid hemorrhage.

Objectives: This study aimed to monitor blood-brain barrier permeability within 24 h and during the delayed cerebral ischemia (DCI) time window (DCITW) spanning 4-14 days after aneurysmal subarachnoid hemorrhage (aSAH) and to investigate its correlation with both DCI occurrence and outcomes at three months.

Methods: A total of 128 patients were stratified based on the DCI occurrence and three-month modified Rankin scale scores. Comparison of K at admission (admission K) and during DCITW (DCITW K) was conducted between DCI and non-DCI groups, as well as between groups with good and poor outcomes. Changes in K were also analyzed. Multivariate logistic regression analysis was performed to identify independent predictors of DCI and poor outcomes.

Results: Admission K (0.58 ± 0.18 vs 0.47 ± 0.12, p = 0.002) and DCITW K (0.54 ± 0.19 vs 0.41 ± 0.14, p < 0.001) were significantly higher in the DCI group compared with the non-DCI group. Although both were higher in the poor outcome group than the good outcome group, the difference was not statistically significant at admission (0.53 ± 0.18 vs 0.49 ± 0.14, p = 0.198). K in the non-DCI group (0.47 ± 0.12 vs 0.41 ± 0.14, p = 0.004) and good outcome group (0.49 ± 0.14 vs 0.41 ± 0.14, p < 0.001) decreased significantly from the admission to DCITW. Multivariate analysis identified DCITW K and admission K as independent predictors of poor outcomes (OR = 1.73, 95%CI: 1.24-2.43, p = 0.001) and DCI (OR = 1.75, 95%CI: 1.25-2.44, p = 0.001), respectively.

Conclusion: Elevated K at admission is associated with the occurrence of DCI. Continuous monitoring of K from admission to DCITW can accurately identify reversible and irreversible changes and can predict outcomes at 3 months.

Clinical Relevance Statement: K measured with CT perfusion is a valuable tool for predicting both delayed cerebral ischemia and three-month outcomes following aneurysmal subarachnoid hemorrhage. Monitoring changes in K from admission to time window of delayed cerebral ischemia can guide treatment and management decisions for aneurysmal subarachnoid hemorrhage patients.

Key Points: • K measured at admission and during the delayed cerebral ischemia time window (4-14 days) holds distinct clinical significance following aneurysmal subarachnoid hemorrhage. • Admission K serves as a predictor for delayed cerebral ischemia, while continuous assessment of K from admission to the delayed cerebral ischemia time window can predict three-month outcomes. • Monitoring K at different stages improves instrumental in enhancing decision-making and treatment planning for patients with aneurysmal subarachnoid hemorrhage.