S100B as an additional prognostic marker in subarachnoid aneurysmal hemorrhage*

Abstract
Objectives: Studies of new neuroprotective approaches in patients with subarachnoid aneurysmal hemorrhage and better family information would benefit from the development of laboratory markers of brain ischemia. The goal of this study was to evaluate mean 15-day S100B for predicting outcomes after subarachnoid aneurysmal hemorrhage. Design: Single center prospective cohort with consecutive inclusions. Setting. Anesthesiology and Critical Care Neurosurgical Unit of a university hospital. Patients: One hundred nine patients admitted within 48 hrs after subarachnoid aneurysmal hemorrhage onset and treated by surgical clipping or coiling within 48 hrs following admission. Interventions: We recorded initial World Federation of Neurologic Surgeons and Fisher grades; comorbidities; initial severity; aneurysm location; presence of acute hydrocephalus; presence of intraventricular hemorrhage; initial seizures and neurogenic lung edema; initial troponin values; treatment of aneurysm; and occurrence of vasospasm. Measurements and Main Results: S100B was assayed daily over the first 15 days. Glasgow Outcome Scores were recorded at intensive care unit discharge and after 6 and 12 months. The main outcome criterion was the 12-month Glasgow Outcome Scale score dichotomized as poor (Glasgow Outcome Scale 1-3) or good (Glasgow Outcome Scale 4-5). Seventy percent of patients had good 12-month outcome. Poor outcome was associated with higher initial World Federation of Neurologic Surgeons and Fisher scores, neurogenic lung edema, high mean 15-day S100B but not initial, troponin initial value, intraventricular hemorrhage, angiographically documented vasospasm, all in an univariate manner. After multivariate analysis, only mean 15-day S100B value significantly predicted outcome (p < 0.0005). The best cutoff for the mean 15-day S100B value was 0.23 mu g/L (specificity 0.90, 95% confidence interval [Cl] 0.81-0.95; sensitivity 0.91, 95% Cl 0.75-0.98; area under the curve 0.98, 95% Cl 0.87-0.99). Conclusion: S100B elevation over the first 15 days after subarachnoid aneurysmal hemorrhage is associated with poor outcome after subarachnoid aneurysmal hemorrhage. This result supports the use of S100B as a surrogate marker for brain ischemia in patients with subarachnoid aneurysmal hemorrhage.