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-index-0.66; 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.

The Association of Intracranial Vascular Calcification and Stenosis With Acute Ischemic Cerebrovascular Events.

OBJECTIVE: The aim of this article was to evaluate the association of intracranial artery calcification (IAC) with acute downstream ischemic stroke (dAIS)/transient ischemic attack while considering stenosis. METHODS: Consecutive stroke computed tomography angiography head/neck examinations from January 2010 to April 2010 were reviewed. Per-vessel IAC and stenosis of greater than or equal to 30% were documented by 2 neuroradiologists. Associations between calcification and dAIS were assessed using multivariate logistic regression, controlling for traditional risk factors and stenosis. RESULTS: A total of 1287 arterial segments from 99 patients were reviewed. Intracranial artery calcification was significantly associated with dAIS (odds ratio [OR], 2.2; P = 0.009). This association persisted among nonstenotic arteries, with significantly higher likelihood of dAIS for arteries with IAC than those without (OR, 2.5; P = 0.009). However, among stenotic arteries, calcified stenoses had a lower association of dAIS than noncalcified stenoses (OR, 0.55; 95% confidence interval, 0.17-1.8; P = 0.33). CONCLUSIONS: Without concurrent stenosis, IAC is a significant risk factor for dAIS. When stenosis is present, IAC does not increase the association with dAIS. Stenotic and nonstenotic calcifications may represent different disease processes, as represented in the histology literature.