The Predictive Value of the CTA Vasospasm Score on Delayed Cerebral Ischemia and Functional Outcome after aneurysmal Subarachnoid Hemorrhage

Background and purpose Delayed cerebral ischemia (DCI) is a severe complication of aneurysmal subarachnoid hemorrhage (aSAH) that can significantly impact clinical outcome. Cerebral vasospasm is part of the pathophysiology of DCI and therefore we developed a CTA Vasospasm Score and explored whether this score predicts DCI and subsequent poor outcome after aSAH. Methods The CTA Vasospasm Score summates the degree of angiographic cerebral vasospasm (CVS) of 17 intradural arterial segments. The score ranges from 0 to 34 with a higher score reflecting more severe vasospasm. Outcome measures were cerebral infarction due to DCI (CI-DCI), radiological and clinical DCI, and unfavorable functional outcome defined as a modified Rankin Scale (mRS) > 2 at 6 months. Receiver Operator Characteristic (ROC) analyses were used to assess predictive value and to determine optimal cut-off scores. Interrater reliability was evaluated by Cohen's kappa coefficient. Results This study included 59 patients. CI-DCI occurred in 8 patients (14%), DCI in 14 patients (24%), and unfavorable outcome in 12 patients (20%). Median CTA Vasospasm Scores were higher in patients with (CI-)DCI and poor outcome. ROC analysis revealed the highest Area Under Curve (AUC) on day 5: CI-DCI 0.89 (95% CI 0.79 - 0.99), DCI 0.68 (95% CI 0.50 - 0.87) and functional outcome 0.74 (95% CI 0.57 - 0.91). Cohen's kappa between both raters was moderate to substantial (0.57-0.63). Conclusions This study demonstrates that the CTA Vasospasm Score on day 5 can reliably identify patients with high risk of developing (CI-)DCI and unfavorable outcome.