Calcium at the carotid siphon as an indicator of internal carotid artery stenosis

Impact of Carotid Siphon Calcification on the Course and Outcome of Patients With Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Carotid siphon calcification (CSC) serves as a marker of atherosclerosis and therefore may influence the outcome after subarachnoid hemorrhage (aSAH). We aimed to analyze the impact of CSC on neurological outcomes, ischemia, and vasospasm.

METHODS

A total of 716 patients with aSAH were treated between December 2004 and June 2016 in our central European tertiary neurovascular care center in Essen, Germany. CSC was recorded using the Woodcock scale (grades 0-3) on a computed tomography scan. Study end points included an unfavorable outcome at 6 months post-aSAH (modified Rankin Scale score ≥4), vasospasm, and early cerebral ischemia (72 hours) and delayed cerebral ischemia (delayed cerebral ischemia; >72 hours) in the follow-up computed tomography scans. The associations were adjusted for patients' baseline characteristics and secondary complications. Finally, within a subgroup analysis, patients with and without daily aspirin intake after endovascular aneurysm occlusion were compared.

RESULTS

Increasing grades of CSC were associated with lower rates of vasospasm in the anterior circulation. Severe CSC (grade 3) was independently related to the risk of an unfavorable outcome (adjusted odds ratio [aOR], 4.06 [95% CI, 1.98-8.33]; P<0.001) and early cerebral ischemia (aOR, 1.58 [95% CI, 1.03-2.43]; P=0.035) but not delayed cerebral ischemia (aOR, 1.08 [95% CI, 0.67-1.73]; P=0.763). In the aspirin subgroup analysis, the negative effect of severe CSC on functional outcome remained significant only in aSAH cases without aspirin (aOR, 5.47 [95% CI, 2.38-12.54]; P<0.001). In contrast, there was no association between severe CSC and unfavorable outcomes among individuals with daily aspirin intake (aOR, 0.84 [95% CI, 0.59-4.21]; P=0.603).

CONCLUSIONS

Our data suggest CSC as a cerebrovascular risk factor resulting in higher rates of early cerebral ischemia and unfavorable outcomes after aSAH. However, by increasing arterial stiffness, CSC might lower the probability of vasospasm, which could explain the missing link between CSC and delayed cerebral ischemia. Additionally, aspirin intake seems to potentially mitigate the negative impact of CSC on aSAH outcome. Further investigations are needed to confirm the observations from the present study.

Carotid Siphon Calcification Predicts the Symptomatic Progression in Branch Artery Disease With Intracranial Artery Stenosis

Arterial calcification in the aortic arch, carotid bifurcation, or siphon on computed tomography was associated with cardiovascular disease. The association between arterial calcification prevalence and progression of branch atheromatous disease (BAD) in intracranial artery atherosclerosis was little investigated.

Intracranial Arterial Calcification: Prevalence, Risk Factors, and Consequences: JACC Review Topic of the Week

Intracranial large and small arterial calcifications are a common incidental finding on computed tomography imaging in the general population. Here we provide an overview of the published reports on prevalence of intracranial arterial calcifications on computed tomography imaging and histopathology in relation to risk factors and clinical outcomes. We performed a systematic search in Medline, with a search filter using synonyms for computed tomography scanning, (histo)pathology, different intracranial arterial beds, and calcification. We found that intracranial calcifications are a frequent finding in all arterial beds with the highest prevalence in the intracranial internal carotid artery. In general, prevalence increases with age. Longitudinal studies on calcification progression and intervention studies are warranted to investigate the possible causal role of calcification on clinical outcomes. This might open up new therapeutic directions in stroke and dementia prevention and the maintenance of the healthy brain.

Prevalence and Correlates of Intracranial Atherosclerotic Disease Among Community-Dwelling Older Adults of Amerindian Ancestry. The Three Villages Study

BACKGROUND

Knowledge on the prevalence and correlates of intracranial atherosclerotic disease (ICAD) is limited. We aimed to assess prevalence, clinical and neuroimaging correlates of ICAD in a cohort of older adults of Amerindian ancestry.

METHODS

The study included 581 community-dwellers aged ≥60 years (mean age 71 ± 8.4 years; 57% women) living in rural Ecuadorian villages. ICAD was identified by means of CT determinations of carotid siphon calcifications (CSC) or MRA findings of significant stenosis of intracranial arteries. Fully-adjusted logistic regression models were fitted with biomarkers of ICAD as the dependent variables.

RESULTS

A total of 205 (35%) of 581 participants had ICAD, including 185 with high calcium content in the carotid siphons and 40 with significant stenosis of at least one intracranial artery (20 subjects had both biomarkers). Increasing age, high fasting blood glucose, >10 enlarged basal ganglia-perivascular spaces and non-lacunar strokes were associated with high calcium content in the carotid siphons. In contrast, male gender, moderate-to-severe white matter hyperintensities, lacunar and non-lacunar strokes were associated with significant stenosis of intracranial arteries. Stroke was more common among subjects with any biomarker of ICAD than in those with no biomarkers (29% versus 9%, p < 0.001). Significant stenosis of intracranial arteries was more often associated with stroke than high calcium content in the carotid siphons, suggesting that CSC are more likely an ICAD biomarker than causally related to stroke.

CONCLUSIONS

ICAD prevalence in Amerindians is high, and is significantly associated with stroke. CSC and significant stenosis of intracranial arteries may represent different phenotypes of ICAD.

Lack of Correlation Between Intracranial Carotid Artery Modified Woodcock Calcification Score and Prognosis of Patients With Acute Ischemic Stroke After Intravenous Thrombolysis

There have been few studies about the association between intracranial carotid artery calcification (ICAC) and acute ischemic stroke (AIS) prognosis after intravenous thrombolysis (IVT). We aimed to analyze the association between ICAC and prognosis (including symptomatic intracranial hemorrhage (sICH), functional outcome and death) of AIS patients treated with IVT. In this retrospective study, we consecutively included 232 AIS patients treated with IVT between April 2012 and December 2018. ICAC was evaluated using the modified Woodcock calcification visual score on non-enhanced cranial computed tomography scans. Poor functional outcome was defined as a modified Rankin Scale score > 2 at 3 months. We found that the modified Woodcock calcification score was associated with ICH, poor outcome, and death in univariable analyses on the symptomatic side and/or bilaterally. However, after adjustment for other different covariates, the results showed no significant difference. We documented that the presence and severity of ICAC did not significantly modify the beneficial effects of rtPA treatment in AIS.