Prediction and prognosis of delayed cerebral ischemia via continuous monitoring of blood-brain barrier permeability

Background Blood-brain barrier disruption is a prominent pathological characteristic of aneurysmal subarachnoid hemorrhage (aSAH), which can be measured as K trans using CT perfusion. Purpose To monitor K trans within 24 hours of aSAH and during the time window associated with a delayed cerebral ischemia (DCI) event (DCITW), and to explore its association with the trajectory of DCI, including outcome at three months. Methods We retrospectively assessed consecutive aSAH patients from a prospective database between July 2020 and September 2022. Patients were grouped according to the DCI occurrence and three months modified Rankin scale. K trans at admission (admission K trans ) and during DCITW (DCITW K trans ) were compared between DCI and non-DCI groups, and between good outcome and poor outcome groups. The changes in K trans were also analyzed. Multivariate logistic regression analysis was performed to identify independent predictors of DCI and poor outcome. Results One hundred and twenty-eight patients (mean age, 61±12 [SD]; 75 women) were included. Both admission K trans (0.58±0.18 vs 0.47±0.12, P =0.002) and DCITW K trans (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. Both of those were also higher in the poor outcome group compared with the good outcome group, but the difference was not statistically significant at admission (0.53±0.18 vs0.49±0.14, P =0.198). K trans 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 admission to DCITW. Multivariate analysis identified DCITW K trans and admission K trans as independent predictors of poor outcome (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 trans at admission is associated with the occurrence of DCI, but not with outcome at three months. Continuous monitoring of K trans from admission to DCITW can accurately identify reversible and irreversible changes in K trans , and can predict outcome.