Development of a nomogram for predicting clinical outcome in patients with angiogram‐negative subarachnoid hemorrhage

To the best of our knowledge, this is the largest clinical retrospective study in AN‐SAH patients, and is the first time to establish accurate predictive models paired with bleeding pattern. BACKGROUND: Angiogram‐negative subarachnoid hemorrhage (AN‐SAH) has a definite incidence of delayed cerebral ischemia (DCI) and poor clinical outcomes. The purpose is to screen independent factors and establish a nomogram to guide the clinical therapy and assess post‐discharge prognosis. METHODS: We identified 273 consecutive patients referred to our institute from 2013 to 2018 for AN‐SAH. A nomogram to predict poor outcomes was formulated based on the multivariable models of independent risk factors. The accuracy and discrimination of nomograms were determined in training and internal validation cohorts. RESULTS: The overall poor outcome rates of AN‐SAH were 14.3% and 8.7% at 3 months and 12 months, respectively. In addition, perimesencephalic AN‐SAH (PAN‐SAH) presented with a more unfavorable prognosis compared with non‐perimesencephalic AN‐SAH (NPAN‐SAH). The clinical prognosis was associated with the World Federation of Neurosurgical Societies scale (WFNS) (odds ratio, 3.82 [95% CI, 1.15‐12.67] for 3‐month outcome; and odds ratio, 31.69 [95% CI, 3.65‐275.43] for 12‐month outcome), Subarachnoid hemorrhage Early Brain Edema Score (SEBES) (odds ratio, 10.39 [95% CI, 1.98‐54.64] for 3‐month outcome; odds ratio, 10.01 [95% CI, 1.87‐53.73] for 12‐month outcome), and symptomatic vasospasm (odds ratio, 3.16 [95% CI, 1.03‐9.70] for 3‐month outcome; odds ratio, 5.15 [95% CI, 1.34‐19.85] for 12‐month outcome). The nomogram was constructed based on the above features, which represented great predictive value in clinical outcomes. CONCLUSIONS: Symptomatic vasospasm, high WFNS, cerebral edema, and NPAN‐SAH after hemorrhage were associated with poor outcome of AN‐SAH. The nomogram with WFNS (3‐5), SEBES (3‐4), vasospasm, and NPAN‐SAH represented a practical approach to provide individualized risk assessment for AN‐SAH patients.