The predictive value of the CTA Vasospasm Score on delayed cerebral ischaemia and functional outcome after aneurysmal subarachnoid hemorrhage

Abstract

Background and purpose: Delayed cerebral ischaemia (DCI) is a severe complication of aneurysmal subarachnoid hemorrhage that can significantly impact clinical outcome. Cerebral vasospasm is part of the pathophysiology of DCI and therefore a computed tomography angiography (CTA) Vasospasm Score was developed and an exploration was carried out of whether this score predicts DCI and subsequent poor outcome after aneurysmal subarachnoid hemorrhage. Methods: The CTA Vasospasm Score sums the degree of angiographic cerebral vasospasm 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 >2 at 6 months. Receiver operating characteristic analyses were used to assess predictive value and to determine optimal cut-off scores. Inter-rater reliability was evaluated by Cohen's kappa coefficient. Results: This study included 59 patients. CI-DCI occurred in eight 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. Receiver operating characteristic analysis revealed the highest area under the curve on day 5: CI-DCI 0.89 (95% confidence interval [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 the two 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 a high risk of developing (CI-)DCI and unfavorable outcome.