Admission EASIX is associated with delayed cerebral ischemia and functional outcome after subarachnoid hemorrhage: a retrospective cohort study

Background Endothelial dysfunction plays a central role in secondary brain injury after subarachnoid hemorrhage (SAH). The Endothelial Activation and Stress Index (EASIX), derived from routine laboratory parameters, has emerged as a surrogate marker of endothelial stress. We aimed to investigate the association between admission EASIX values and delayed cerebral ischemia (DCI) as well as 3-month functional outcome in patients with SAH.Methods In this retrospective single-center study, 90 patients with aneurysmal and non-aneurysmal SAH admitted between January 2020 and June 2025 were analyzed. EASIX was calculated within the first 2 hours of admission as: (LDH × creatinine)/platelet count. Multivariable logistic regression models were used to identify independent associations with DCI and poor functional outcome (mRS ≥ 3). Discriminatory performance was assessed using receiver operating characteristic (ROC) curve analysis.Results DCI occurred in 37.7% of patients, and 35.6% had poor 3-month functional outcomes. Higher admission EASIX values were independently associated with DCI (OR 4.91, 95% CI 1.05–22.8, p = 0.042) and poor functional outcome (OR 3.00, 95% CI 1.06–8.51, p = 0.039). The area under the curve (AUC) was 0.69 for DCI and 0.65 for functional outcome, indicating modest discriminatory performance.Conclusions Admission EASIX was independently associated with DCI and unfavorable 3-month outcomes in SAH. While its predictive performance was modest, EASIX may serve as a practical complementary biomarker for early risk stratification in neurocritical care settings.