The association of renal impairment with different patterns of intracranial arterial calcification: Intimal and medial calcification

Intracranial arterial calcification in patients with unruptured and ruptured intracranial aneurysms

OBJECTIVES

Arterial calcification is thought to protect against rupture of intracranial aneurysms, but studies in a representative population of intracranial aneurysm patients have not yet been performed. The aim was to compare the prevalence of aneurysm wall calcification and intracranial carotid artery calcification (ICAC) between patients with an unruptured intracranial aneurysm (UIA) and a ruptured intracranial aneurysm (RIA).

MATERIALS AND METHODS

We matched 150 consecutive UIA patients to 150 RIA patients on age and sex. Aneurysm wall calcification and ICAC were quantified on non-contrast enhanced computed tomography images with the modified Agatston score. We compared the prevalence of aneurysm wall calcification, ICAC, and severe ICAC (defined as a modified Agatston score in the fourth quartile) between UIA and RIA patients using univariate and multivariate conditional logistic regression models adjusted for aneurysm characteristics and cardiovascular risk factors.

RESULTS

Aneurysm wall calcification was more prevalent in UIA compared to RIA patients (OR 5.2, 95% CI: 2.0-13.8), which persisted after adjustment (OR 5.9, 95% CI: 1.7-20.2). ICAC prevalence did not differ between the two groups (crude OR 0.9, 95% CI: 0.5-1.8). Severe ICAC was more prevalent in UIA patients (OR 2.0, 95% CI: 1.1-3.6), but not after adjustment (OR 1.0, 95% CI: 0.5-2.3).

CONCLUSIONS

Aneurysm wall calcification but not ICAC was more prevalent in UIAs than in RIAs, which corresponds to the hypothesis that calcification may protect against aneurysmal rupture. Aneurysm wall calcification should be further assessed as a predictor of aneurysm stability in prospective cohort studies.

CLINICAL RELEVANCE STATEMENT

Calcification of the intracranial aneurysm wall was more prevalent in unruptured than ruptured intracranial aneurysms after adjustment for cardiovascular risk factors. Calcification may therefore protect the aneurysm against rupture, and aneurysm wall calcification is a candidate predictor of aneurysm stability.

KEY POINTS

Aneurysm wall calcification was more prevalent in patients with unruptured than ruptured aneurysms, while internal carotid artery calcification was similar. Aneurysm wall calcification but not internal carotid artery calcification is a candidate predictor of aneurysm stability. Cohort studies are needed to assess the predictive value of aneurysm wall calcification for aneurysm stability.

Association between Obstructive Sleep Apnea and Intracranial Artery Calcification Stratified by Gender and Body Mass Index: A Hospital-Based Observational Study

BACKGROUND AND OBJECTIVES

Obstructive sleep apnea (OSA) is an independent risk factor for stroke. Furthermore, intracranial arterial calcification (IAC) has been validated as a marker for subclinical cerebrovascular disease. However, the relationship between OSA with IAC was less studied compared with its established association with coronary artery calcification. In this study, we aimed to investigate the association between the severity of OSA and the degree of IAC in hospitalized patients without preexisting cardiovascular disease.

METHODS

This hospital-based observational study was conducted from June 1, 2017, to May 1, 2019. In total, 901 consecutive patients who underwent head computed tomography scans and portable sleep monitoring were included. On the basis of the apnea-hypopnea index (AHI), patients were divided into four OSA severity groups (normal: AHI <5/h; mild: 5≤ AHI <15/h; moderate: 15≤ AHI <30/h; severe: AHI ≥30/h). Associations of OSA with IAC scores were assessed by using multivariate logistic regression analysis.

RESULTS

Of the 901 patients, 484 (53.7%) were men; the mean (SD) age was 66.1 (10.0) years. The non-OSA group included 207 (23.0%) patients; mild OSA, 209 (23.2%); moderate OSA, 235 (26.1%); and severe OSA, 169 (18.8%). Mean IAC scores were higher in the severe OSA group compared with non-, mild, and moderate OSA groups (4.79 vs. 2.58; 4.79 vs. 2.94; 4.79 vs. 3.39; p < 0.001). Multivariate analysis adjusted for confounding factors revealed that only severe OSA was associated with a higher IAC score (odds ratio [OR]: 1.65; 95% confidence interval [CI]: 1.43-1.91; p < 0.001). In stratified analyses by BMI, among participants with a BMI <25 kg/m2, the positive association between AHI values and IAC scores was found in the moderate OSA group (OR: 1.23; 95% CI: 1.05, 1.43; p = 0.01) and the severe OSA group (OR: 1.96; 95% CI: 1.55, 2.48; p < 0.001). When stratified by gender, in women, the positive association was found in the moderate OSA group (adjusted OR: 1.21; 95% CI: 1.02-1.51; p = 0.016) and the severe OSA group (adjusted OR: 1.76; 95% CI: 1.36-2.25; p < 0.001). For the men group, a positive association between IAC scores and AHI was only observed in the severe OSA group.

DISCUSSION

These findings suggest that OSA, in particular severe OSA (AHI ≥30), is independently associated with higher IAC scores. Women and no-obesity individuals appeared more susceptible to adverse OSA-related subclinical cerebrovascular disease as measured by IAC scores.

The correlation between medial pattern of intracranial arterial calcification and white matter hyperintensities

BACKGROUND AND AIMS

Despite reported correlations between intracranial arterial calcification (IAC) and white matter hyperintensities (WMH), little is known about the relationship between IAC pattern and WMH. By differentiating intimal and medial IAC, we aimed to investigate the relationship between IAC pattern and WMH.

METHODS

Consecutive acute stroke patients were included. IAC pattern was categorized as intimal or medial on plain brain CT. The number of cerebral arteries involved by IAC for each patient was recorded. IAC severity was defined as focal or diffuse. On brain MRI, the burden of WMH was visually graded and classified as absent mild, moderate and severe. Multiple logistic regression was performed to examine the relationship between IAC and WMH.

RESULTS

Among 265 patients, intimal IAC was detected in 54.7% patients and medial IAC in 48.5% patients. Diffuse IAC was present in 27.9% patients, all of which were medial. WMH was found in 75.5% patients, including 39.6% patients with mild WMH, 26.0% with moderate WMH, and 9.8% with severe WMH. The severity of medial IAC was correlated with WMH occurrence (p < 0.001). Chi-square linear trend suggested the number of arteries involved by medial IAC (p < 0.001) and the severity of medial IAC (p < 0.001) were correlated with WMH burden. Multiple ordinal logistic regression demonstrated a positive correlation of WMH burden with the number of arteries involved by medial IAC (p < 0.001) and the severity of medial IAC (p < 0.001).

CONCLUSIONS

Medial IAC was correlated with WMH. The dose-effect relationship between medial IAC and WMH suggests underlying shared mechanisms of intracranial large artery disease and small vessel disease.