The value of white blood cell count and platelet count in predicting delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Introduction: Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) contributes significantly to mortality and morbidity. Neuroinflammation and platelet activation are implicated in its pathophysiology. Research question: This study evaluates the association of admission white blood cell count (WBC) and platelet count (PC), and their combination, with DCI and explores their integration into predictive models. Materials and methods: This single-center cohort study utilized data from a prospective SAH registry (December 2011–December 2019). Patients with confirmed aSAH and recorded WBC and PC within 72 h post-ictus were included. Univariate and multivariate regression models with established predictors, consisting of the modified Fisher scale (mFS) and World Federation of Neurological Surgeons grade (WFNS), were performed. Predictive values were assessed using AUCs (95 % CI) and C-statistics. Results: Of 954 reviewed patients, 660 met inclusion criteria, with 178 (27.0 %) developing DCI. Patients who developed DCI had significantly higher admission WBC levels (mean (SD) 14.3 (5.1) × 10⁹/L vs. 12.7 (4.8) × 10⁹/L, p < 0.001), whereas admission PC did not differ significantly (median (IQR) 255 (201–301) × 10⁹/L vs. 241 (205–289) × 10⁹/L, p = 0.196). WBC was predictive of DCI (OR 1.06, 1.03–1.10), but PC was not (OR 1.00, 1.00–1.02). Of established predictors, mFS was significant (OR 6.42, 1.96–21.02), whereas WFNS was not (OR 0.79, 0.54–1.15). Among all variables, WBC demonstrated highest predictive value (AUC: 0.59, 0.54–0.64), surpassing mFS and WFNS, or their combination. A combined model incorporating WBC, PC, mFS, and WFNS yielded the highest predictive value (AUC: 0.63, 0.58–0.68). Discussion and conclusion: Admission WBC and PC offer modest predictive value for DCI, either alone or combined with neurological status and hemorrhage burden. However, WBC demonstrated highest predictive value of all investigated variables and modestly improves prediction models. Future research should evaluate WBC's utility in models with enhanced predictive performance.