Aneurysmal subarachnoid hemorrhage-risk score—impact of pre-existing cardiovascular risk factors on functional patient outcomes

Figure 1. Flowchart. AV, arteriovenous; AVM, arteriovenous malformation; mRS, modified Rankin scale; RIS, radiology information system; SAH, subarachnoid hemorrhage.

Figure 2. Vasosclerosis grading. (A) Grade 0 = no plaques visible. (B) Grade 1 = focal changes without circumferential configuration. (C) Grade 2 = beginning circumferential calcifications without segmental distribution. (D) Grade 3 = continuous circumferential calcifications with segmental distribution.

Figure 3. Impact of independent variables in the dichotomous linear regression model for unfavorable outcome. This figure displays the predicted probabilities of unfavorable outcomes, along with 95% confidence intervals for selected variables that demonstrated significant associations in prior Chi2 Tests (p < 0.05). Up to two variables were chosen to represent different domains: clinical characteristics on admission (WFNS grading scale), radiological characteristics (modified Fisher scale, ICH), and cardiovascular risk factors (arterial hypertension, intracranial vasosclerosis). All variables shown met the criteria for inclusion in the subsequent development of the nomogram. The coefficients (β) represent the change in the log-odds of the outcome for a one-unit increase in a predictor variable, holding other variables constant. Please note, that a grading of 3 on the modified Fisher scale was associated with a lower risk than the gradings 2 and 4, which both include IVH, in contrast to a grading of 3. Therefore, Fisher scale grades 2 and 4 were grouped. ICH, intracerebral hemorrhage; IVH, intraventricular hemorrhage; WFNS, World Federation of Neurosurgical Societies.

Figure 4. Nomogram to predict unfavorable outcome after aSAH, based on a multivariable logistic regression model. The variables identified as significantly predictive in the univariate analysis were included. Each predictor is assigned a score on a single-point scale proportional to its relative contribution in the model. They are arranged in descending order of importance for the model. The sum of all points represents the individual probability for an unfavorable outcome, which can be derived from the bottom scale. Thereby, the nomogram enables a patient-specific risk assessment ranging from 0.4 to 0.8 (Table 4). ICH, intracerebral hemorrhage; WFNS, World Federation of Neurosurgical Societies.