The eSAH score: a simple practical predictive model for SAH mortality and outcomes

Abstract

We developed a simple quantifiable scoring system that predicts aneurysmal subarachnoid hemorrhage (aSAH) mortality, delayed cerebral ischemia (DCI), and modified Rankin scale (mRS) outcomes using readily available SAH admission data with SAH volume (SAHV) measured on computed tomography (CT). We retrospectively analyzed a cohort of 277 patients with aSAH admitted at our Comprehensive Stroke Center at Mayo Clinic in Jacksonville, Florida, between January 5, 2012, and February 24, 2022. We developed a mathematical radiographic model SAHV that measures basal cisternal SAH blood volume using a derivation of the ABC/2 ellipsoid formula (A = width/thickness, B = length, C = vertical extension) on noncontrast CT, which we previously demonstrated is comparable to pixel-based manual segmentation on noncontrast CT. Data were analyzed using t test, χ² test, receiver operator characteristics curve, and area under the curve (AUC) analysis. Multivariate logistic regression analysis with stepwise elimination of variables not contributing to the model (0.05 significance level for entry into the model) was used to develop an enhanced SAH (eSAH) scoring system. Using multivariate logistic regression, we found that age, Glasgow Coma Scale score, and SAHV were significantly associated with mRS outcomes at discharge, in-hospital DCI, and in-hospital mortality. Using these factors, we developed a weighted eSAH score, ranging from 0 to 5, that was strongly predictive of mRS outcomes (AUC = 0.89), DCI (AUC = 0.75), and in-hospital mortality (AUC = 0.88). Our proposed eSAH score, a simple quantitative model based on SAHV, Glasgow Coma Scale score, and age, appears to predict mortality and outcomes in patients with aSAH. A larger cohort validation study is planned.

Keywords: Computed axial tomography; Delayed cerebral ischemia; Mortality; Multivariate analysis; Outcome; Subarachnoid hemorrhage; eSAH score.

Fig. 1

Volumetric analysis Via ABC/2-derived SAHV. (A) Multiple noncontrast CT slices of a patient with aneurysmal subarachnoid hemorrhage. There are visible SAH hyperdensities in multiple cisternal compartments, marked with lines to determine length and width of the respected hemorrhage in mm. Measurement of width, length, and vertical extension (number of noncontrast CT slices with visible SAH) was done in consideration of cisternal anatomy. (B) Illustration of the 5 SAHV compartments measured (created with BioRender.com). (C) These metric variables were then inputted into our Model 1 ABC/2-derived SAHV equation to measure the hemorrhagic volume in each neuroanatomic structure. Each volume was then summed to a cumulative total SAHV. CT indicates computed tomography; SAHV indicates subarachnoid hemorrhage volume.

Fig. 2

ROC curves compared to various outcome measures in patients with aSAH. (A) ROC curve for modified Rankin Scale outcomes based on eSAH score (AUC = 0.8858). (B) ROC curve for outcome based on Hunt and Hess Score (AUC = 0.80). (C) ROC curve for mWFNS scale (AUC = 0.82). (D) ROC curve for mFS (AUC = 0.70). (E) ROC curve for in-hospital mortality based on eSAH score (AUC = 0.8786). (F) ROC curve for DCI based on DCI subscore (AUC = 0.7480). aSAH indicates aneurysmal subarachnoid hemorrhage; AUC, area under the curve; DCI, delayed cerebral ischemia; eSAH, enhanced subarachnoid hemorrhage; ROC, receiver operating characteristic.

Fig. 3

eSAH score with associated MRS outcomes, in-hospital mortality, and DCI - distributions. (A) Proportion of in-hospital mortality by eSAH score. (B) Proportion of mRS outcomes by eSAH score. (C) Proportion of DCI by DCI subscore. (D) Distribution of in-hospital mortality by eSAH score. (E) Distribution of mRS outcomes by eSAH score. (F) Distribution of DCI during admission by DCI subscore. DCI indicates delayed cerebral ischemia; eSAH, enhanced subarachnoid hemorrhage; mRS, modified Rankin Scale.