Non-contrast computed tomography at the end of the acute care phase as an additional prognostic tool after aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition with high morbidity and mortality. Long-term outcomes remain difficult to predict. Computed tomography (CT) is central to diagnosis and early risk stratification, yet the prognostic value of non-contrast CT at the end of the acute care phase is not fully established. We conducted a retrospective single-center study of adult patients with confirmed aSAH admitted to the Neurocritical Care Unit (NCCU) of the University Hospital Zurich (January 2016-June 2024). Survivors with CT at discharge from the NCCU and 12-month follow-up were included. Functional outcome was assessed using the Glasgow Outcome Scale Extended (GOSE) and dichotomized as favorable (5-8) or unfavorable (1-4). CT scans were evaluated for infarcts, hemorrhage distribution, hydrocephalus requiring shunt, midline shift, and decompressive surgery. Multivariable logistic regression with multiple imputation by chained equations (MICE) addressed missing data, with days from admission to discharge CT included as a covariate in the clinical-severity model to control for differential timing. Discriminative performance was assessed using receiver operating characteristic (ROC) curve analysis. Of 500 admitted patients, 325 met inclusion criteria. At 12 months, 234 had favorable and 91 unfavorable outcomes. In a radiological model, increasing age and infarcts involving the thalamus, basal ganglia, corpus callosum, and cerebellum, together with cortical infarction and intraventricular hemorrhage, were independently associated with unfavorable outcome; sulcal subarachnoid hemorrhage showed only a non-significant trend toward a protective association. In a separate clinical-severity model, increasing age, ventriculoperitoneal shunt placement, decompressive craniectomy, and days-to-CT scan were independently associated with unfavorable outcome. ROC analysis showed low-to-moderate discriminative ability (AUC range 0.529-0.688), with intraventricular hemorrhage performing best. Discharge non-contrast CT provides incremental prognostic information in aSAH survivors. Deep or midline infarctions are particularly decisive for early prognostication and rehabilitation using routinely available imaging.