Computed tomography angiography findings predictive of post-intervention vasospasm in patients with aneurysmal subarachnoid hemorrhage

Objective: To evaluate the association of CT/CT angiography (CTA) findings and clinical characteristics with subsequent vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods-: Consecutive presentation CTA head exams in patients with aSAH between January 2005 and June 2015 were retrospectively evaluated for intracranial arterial calcification, undulation and non-calcified stenosis. Additional variables including modified Fisher Scale (mFS), Glasgow Coma Scale (GCS) and neurological exam status were reviewed. Associations of CTA findings with the incidence of angiographic vasospasm were assessed with multivariate logistic regression models using the least absolute shrinkage and selection operator machine-learning algorithm. Model performance was summarized using c-index with bootstrap optimism-adjustment. Results Intracranial arterial calcification, seen in 51.7% of 195 total patients, was protective against vasospasm (OR-0.6; 95% CI-0.52-0.67; p = 0.009), while arterial undulation (24%) was associated with subsequent vasospasm (OR-2.6; 95% CI-1.3-5.1; p = 0.007). Non-calcified intracranial arterial stenosis (5%) was associated with subsequent vasospasm, (OR-4.7; 95% CI-1.0-22.8; p = 0.054). Least absolute shrinkage and selection operator selected all three CTA findings as predictors in a multivariate model for vasospasm in addition to clinical factors, which demonstrated superior predictive performance (c-index-0.74; 95% CI-0.69-0.82) compared to a model based on mFS and clinical factors only (c-index0.66; 95% CI-0.57-0.75; p = 0.010 for the difference). Conclusion: Presentation CTA findings combined with clinical factors may better predict the development of vasospasm in patients with aSAH compared to current prognostic models alone. Advances in knowledge: The combination of initial CT/ CTA and clinical findings better predict development of vasospasm after aSAH. This can lead to better markers for use in future clinical trials to develop vasospasm preventative treatments and potentially provide better targets for early aggressive treatment.