Arterial Stiffness is Associated with Intracranial Arterial Stenosis other than Dolichoectasia in the General Population

Central arterial stiffening and intracranial atherosclerosis: the atherosclerosis risk in communities neurocognitive study (ARIC-NCS): Aortic stiffness & intracranial atherosclerosis

OBJECTIVES

Previous studies suggest an association between central arterial stiffness (CAS) and intracranial atherosclerotic disease (ICAD) among Asian participants with stroke or hypertension; this association has not been evaluated in United States populations. We assessed the cross-sectional association of CAS with ICAD presence and burden in late-life, and differences in association by age, sex, and race.

MATERIALS AND METHODS

We conducted a cross-sectional analysis of 1,285 Atherosclerosis Risk in Communities Study participants [mean age 75 (standard deviation: 5) years, 38 % male, 20  % Black] at Visit 5 (2011-2013). CAS was measured as carotid-femoral pulse wave velocity (cfPWV) using the Omron VP-1000 Plus. ICAD was assessed using high-resolution vessel wall MRI and MR angiography. We evaluated associations of a 1 standard deviation (SD) cfPWV (3.02 m/s) and high vs. non-high cfPWV (≥ 13.57 m/s vs. < 13.57 m/s) with presence of plaques (yes/no) and plaque number (0, 1-2, and >2) using multivariable logistic and ordinal logistic regression models adjusted for covariates.

RESULTS

Each one SD greater cfPWV was associated with higher odds of plaque presence (odds ratio (OR)=1.32, 95 % confidence interval (CI): 1.22, 1.43), and an incrementally higher odds of number of plaques (OR 1-2 vs. 0 plaques = 1.21, 95 % CI: 1.10, 1.33; OR >2 vs. 0 plaques = 1.51, 95 % CI: 1.33,1.71). Results suggested differences by race, with greater magnitude associations among Black participants.

CONCLUSIONS

CAS was positively associated with ICAD presence and burden; cfPWV may be a useful subclinical vascular measure for identification of individuals who are at high risk for cerebrovascular disease.

Associations of Cerebrovascular Regulation and Arterial Stiffness With Cerebral Small Vessel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Cerebral small vessel disease (cSVD) is a major contributing factor to ischemic stroke and dementia. However, the vascular pathologies of cSVD remain inconclusive. The aim of this systematic review and meta-analysis was to characterize the associations between cSVD and cerebrovascular reactivity (CVR), cerebral autoregulation, and arterial stiffness (AS).

METHODS AND RESULTS

MEDLINE, Web of Science, and Embase were searched from inception to September 2023 for studies reporting CVR, cerebral autoregulation, or AS in relation to radiological markers of cSVD. Data were extracted in predefined tables, reviewed, and meta-analyses performed using inverse-variance random effects models to determine pooled odds ratios (ORs). A total of 1611 studies were identified; 142 were included in the systematic review, of which 60 had data available for meta-analyses. Systematic review revealed that CVR, cerebral autoregulation, and AS were consistently associated with cSVD (80.4%, 78.6%, and 85.4% of studies, respectively). Meta-analysis in 7 studies (536 participants, 32.9% women) revealed a borderline association between impaired CVR and cSVD (OR, 2.26 [95% CI, 0.99-5.14]; P=0.05). In 37 studies (27 952 participants, 53.0% women) increased AS, per SD, was associated with cSVD (OR, 1.24 [95% CI, 1.15-1.33]; P<0.01). Meta-regression adjusted for comorbidities accounted for one-third of the AS model variance (R2=29.4%, Pmoderators=0.02). Subgroup analysis of AS studies demonstrated an association with white matter hyperintensities (OR, 1.42 [95% CI, 1.18-1.70]; P<0.01).

CONCLUSIONS

The collective findings of the present systematic review and meta-analyses suggest an association between cSVD and impaired CVR and elevated AS. However, longitudinal investigations into vascular stiffness and regulatory function as possible risk factors for cSVD remain warranted.

CXCR6 Mediates Pressure Overload-Induced Aortic Stiffness by Increasing Macrophage Recruitment and Reducing Exosome-miRNA29b

Aortic stiffness is an independent risk factor for aortic diseases such as aortic dissection which commonly occurred with aging and hypertension. Chemokine receptor CXCR6 is critically involved in vascular inflammation and remodeling. Here, we investigated whether and how CXCR6 plays a role in aortic stiffness caused by pressure overload. CXCR6^-/- and WT mice underwent transverse aortic constriction (TAC) surgery for 8 weeks. CXCR6 deficiency significantly improved TAC-induced aortic remodeling and endothelial dysfunction by decreasing CD11c⁺ macrophage infiltration, suppressing VCAM-1 and ICAM-1, reducing collagen deposition, and downregulating MMP12 and osteopontin in the aorta. Consistently, blocking the CXCL16/CXCR6 axis also reduced aortic accumulation of CD11c⁺ macrophages and vascular stiffness but without affecting the release of TNF-α and IL-6 from the aorta. Furthermore, pressure overload inhibited aortic release of exosomes, which could be reversed by suppressing CXCR6 or CXCL16. Inhibition of exosome release by GW4869 significantly aggravated TAC-induced aortic calcification and stiffness. By exosomal microRNA microarray analysis, we found that microRNA-29b was significantly reduced in aortic endothelial cells (AECs) receiving TAC. Intriguingly, blocking the CXCL16/CXCR6 axis restored the expression of miR-29b in AECs. Finally, overexpression of miR-29b significantly increased eNOS and reduced MMPs and collagen in AECs. By contrast, antagonizing miR-29b in vivo further enhanced TAC-induced expressions of MMP12 and osteopontin, aggravated aortic fibrosis, calcification, and stiffness. Our study demonstrated a key role of the CXCL16/CXCR6 axis in macrophage recruitment and macrophage-mediated aortic stiffness under pressure overload through an exosome-miRNAs-dependent manner.

Arterial stiffness and progression of white matter hyperintensities of presumed vascular origin in community-dwelling older adults of Amerindian ancestry: The Atahualpa Project Cohort

OBJECTIVE

Arterial stiffness - as measured by the aortic pulse wave velocity (aPWV) - has been associated with biomarkers of cerebral small vessel disease (cSVD), in particular with white matter hyperintensities (WMH) of presumed vascular origin. Most studies have been conducted in White and Asian populations, and information on this relationship in other ethnic groups is limited. We designed a longitudinal prospective study to assess the impact of aPWV on WMH progression in individuals of Amerindian ancestry.

PATIENTS AND METHODS

Participants of the Atahualpa Project Cohort were assessed at baseline with aPWV determinations, clinical interviews and brain MRIs. At the end of the study, brain MRIs were repeated in order to ascertain WMH progression. Poisson regression models adjusted for demographics and cardiovascular risk factors were fitted to assess WMH progression incidence rate by baseline levels of aPWV.

RESULTS

The study included 260 individuals aged ≥60 years (mean age: 65.6 ± 6.1 years; 57 % women). The mean aPWV was 9.9 ± 1.5 m/s. Follow-up MRIs revealed WMH progression in 102 (39 %) individuals after a mean follow-up of 6.5 ± 1.4 years. Unadjusted analysis showed a higher baseline aPWV among subjects that developed WMH progression compared with those who did not (p < 0.001). Multivariate Poisson regression models showed an increased WMH progression rate among individuals in the second (IRR: 2.06; 95 % C.I.: 1.09-3.88) and third (IRR: 2.75; 95 % C.I.: 1.29-5.87) tertiles of aPWV compared with those in the first tertile.

CONCLUSIONS

aPWV is associated with WMH progression, suggesting a link between atherosclerosis and cSVD in the study population.

Modified Protocol for Establishment of Intracranial Arterial Dolichoectasia Model by Injection of Elastase Into Cerebellomedullary Cistern in Mice

Background and Purpose

This study aimed to construct an animal model of intracranial arterial dolichoectasia (IADE) applying the modified modeling protocol.

Materials and Methods

Twenty five milliunits elastase and inactivated elastase were, respectively, injected into the cerebellomedullary cistern of 60 C57/BL6 mice which were divided into experimental group (EG, n = 30) and control group (CG, n = 30) by using a computer-based random order generator. The modified modeling protocol clarified these aspects including brain three-dimensional parameters of mouse head fixation, angle of head inclination, fixed position of taper ear, needle holding technique, needle entry depth, prevention of liquid drug back flow, and storage conditions of elastase. And it was observed for the following parts such as mortality, inflammatory factors, craniocerebral arteries scanning, vascular tortuosity index, artery diameter, pathology of the cerebrovascular.

Results

Within differently surveyed stage, the total mortality of mice in EG was 20%. ELISA illustrated that the levels of matrix metalloproteinase-9 (MMP-9) and tumor necrosis factor α (TNF-α) in peripheral blood were increased significantly after modeling. Angiography indicated that 100% of IADE in EG were observed and the diameter and tortuosity index of the basilar artery were significantly increased (P < 0.01). EVG histological processing and staining showed the disrupted internal elastic lamina, the atrophied muscle layer, and the hyalinized connective tissue of the basilar artery with the vascular wall tunica media in EG. Micro-computed tomography reported that the craniocerebral arteries of the mice in EG were outstandingly elongated, tortuous, and dilated.

Conclusion

The modified modeling protocol can reduce the mortality, improve the success rate, and provide a stable animal model for IADE.