Carotid arterial stiffness and risk of incident cerebral microbleeds in older people: the Age, Gene/Environment Susceptibility (AGES)-Reykjavik study

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.

The impact of bilateral brachial-ankle pulse wave velocity difference on cardiovascular disease and all-cause mortality

Background

This study aims to investigate the association between an elevated bilateral pulse wave velocity difference (BPWVD) and cardiovascular diseases (CVDs) and all-cause mortality.

Methods

This study included a total of 38,356 participants. A multivariable Cox proportional hazards regression was used to assess the association between high BPWVD and the increased risk of CVDs and all-cause mortality by calculating hazard ratios (HRs) with 95% confidence intervals.

Results

A total of 1,213 cases of CVDs were identified over a mean duration of 6.19 years, including 886 cases of cerebral infarction (CI), 105 cases of intracerebral hemorrhage (ICH), and 222 cases of myocardial infarction (MI), along with 1,182 cases of all-cause mortality. The median BPWVD was 42 cm/s (19-80 cm/s). After adjusting for all confounders and baseline brachial-ankle PWV (baPWV), our analysis revealed a significant correlation between a higher risk of CVDs, MI, and all-cause mortality with an increase in BPWVD per standard deviation. HRs (95% confidence interval) were found to be 1.06 (1.01-1.11), 1.11 (1.02-1.21), and 1.07 (1.04-1.10), respectively. Among the participants with higher baPWV on the left side, the HRs (95% confidence interval) were 1.08 (1.02-1.14) for CVDs, 1.27 (1.10-1.46) for incident ICH, 1.16 (1.00-1.24) for incident MI, and 1.10 (1.07-1.15) for all-cause mortality, for per standard deviation increase in BPWVD.

Conclusions

Our findings reveal a significant correlation between elevated BPWVD and the risks of developing CVDs and all-cause mortality. This highlights the importance of thoroughly evaluating BPWVD as a means of detecting individuals at risk for CVDs and mortality.

Hemorrhagic risk prediction in coronary artery disease patients based on photoplethysmography and machine learning

Hemorrhagic events are the main focus of attention during antithrombosis therapy in patients with coronary artery disease (CAD). This study aims to investigate the potential of using photoplethysmography (PPG) and machine learning techniques to assess hemorrhagic risk in patients with CAD. A total of 1638 patients with CAD were enrolled from January 2018 to October 2019, among which 114 patients were observed to have at least one positive event. Importantly, 102 patients with 9933 records were finally retained for analysis in this study. Participants were required to collect data using the portable PPG acquisition device and the specially designed Android APP. The data was collected and uploaded to a remote server. Based on collected PPG signals, we extracted features in a total of 30 dimensions from time-domain, frequency-domain, and wavelet packet decomposition. Logistic regression, support vector regression, random forest, and XGBoost regression models were established to achieve hemorrhagic risk evaluation, and then, their performances were compared. In total, 10 features extracted from PPG showed statistical significance (p < 0.01) between negative and positive groups. The newly established XGBoost model performed best in the hemorrhagic risk evaluation experiment, wherein the mean area under the curve (AUC) with tenfold cross-validation was 0.762 ± 0.024 and the sensitivity and specificity were 0.679 ± 0.051 and 0.714 ± 0.014, respectively. We established a data acquisition system for PPG signal collection, and demonstrated that a set of features extracted from PPG and the proposed machine learning model are promising in the evaluation of hemorrhagic risk among patients with CAD. In comparison with the traditional HAS-BLED score, the proposed method can obtain the quantitative risk prediction probability from a single PPG record, which has the advantages of dynamics and continuity, and can provide timely feedback for doctors' antithrombotic treatment, which is of great significance for doctors to quickly determine the effectiveness of the treatment and adjust the timely treatment plans accordingly.

5-Year Associations among Cerebral Arterial Pulsatility, Perivascular Space Dilation, and White Matter Lesions

OBJECTIVE

High cerebral arterial pulsatility index (PI), white matter lesions (WMLs), enlarged perivascular spaces (PVSs), and lacunar infarcts are common findings in the elderly population, and considered indicators of small vessel disease (SVD). Here, we investigate the potential temporal ordering among these variables, with emphasis on determining whether high PI is an early or delayed manifestation of SVD.

METHODS

In a population-based cohort, 4D flow MRI data for cerebral arterial pulsatility was collected for 159 participants at baseline (age 64-68), and for 122 participants at follow-up 5 years later. Structural MRI was used for WML and PVS segmentation, and lacune identification. Linear mixed-effects (LME) models were used to model longitudinal changes testing for pairwise associations, and latent change score (LCS) models to model multiple relationships among variables simultaneously.

RESULTS

Longitudinal 5-year increases were found for WML, PVS, and PI. Cerebral arterial PI at baseline did not predict changes in WML or PVS volume. However, WML and PVS volume at baseline predicted 5-year increases in PI. This was shown for PI increases in relation to baseline WML and PVS volumes using LME models (R  ≥  0.24; p < 0.02 and R  ≥  0.23; p < 0.03, respectively) and LCS models ( β  = 0.28; p = 0.015 and β  = 0.28; p = 0.009, respectively). Lacunes at baseline were unrelated to PI.

INTERPRETATION

In healthy older adults, indicators of SVD are related in a lead-lag fashion, in which the expression of WML and PVS precedes increases in cerebral arterial PI. Hence, we propose that elevated PI is a relatively late manifestation, rather than a risk factor, for cerebral SVD. ANN NEUROL 2022;92:871-881.

Aerobic exercise training reduces cerebrovascular impedance in older adults: a 1-year randomized controlled trial

Older adults have higher cerebrovascular impedance than young individuals which may contribute to chronic brain hypoperfusion. Besides, middle-aged athletes exhibit lower cerebrovascular impedance than their sedentary peers. We examined whether aerobic exercise training (AET) reduces cerebrovascular impedance in sedentary older adults. We conducted a proof-of-concept trial that randomized 73 older adults to 1 yr of AET (n = 36) or stretching and toning (SAT, n = 37) interventions. Cerebrovascular impedance was estimated from simultaneous recordings of carotid artery pressure (CAP) via applanation tonometry and cerebral blood flow velocity (CBFV) in the middle cerebral artery via transcranial Doppler using transfer function analysis. Fifty-six participants completed 1-yr interventions, and 41 of those completed cerebrovascular impedance measurements. AET group showed a significant increase in V̇o2peak after the intervention [estimated marginal mean (95% confidence interval); from 22.8 (21.6 to 24.1) to 24.9 (23.6 to 26.2) mL·kg-1·cm-1, P < 0.001], but not SAT [from 21.7 (20.5 to 22.9) to 22.3 (21.1 to 23.7) mL·kg-1·cm-1, P = 0.114]. Coherence between changes in CBFV and CAP was >0.90 in the frequency range of 0.78-3.12 Hz. The averaged cerebrovascular impedance modulus (Z) in this frequency range decreased after 1-yr AET [from 1.05 (0.96 to 1.14) to 0.95 (0.92 to 1.06) mmHg·s·cm-1, P = 0.023], but not SAT [from 0.96 (0.87 to 1.04) to 1.01 (0.92 to 1.10) mmHg·s·cm-1, P = 0.138]. Reductions in Z were correlated positively with reductions in carotid pulse pressure (r = 0.628, P = 0.004) and inversely with mean CBFV (r = -0.563, P = 0.012) in the AET group. One-year AET reduces cerebrovascular impedance in older adults, which may benefit brain perfusion.NEW & NOTEWORTHY Estimation of cerebrovascular impedance is essential for understanding dynamic cerebral blood flow regulation. This randomized controlled trial demonstrated that aerobic exercise training reduced cerebrovascular impedance in older adults, which may benefit brain perfusion.

Short-term effects of electronic cigarettes on cerebrovascular function: A time course study

NEW FINDINGS

What is the central question of this study? Acute exposure to electronic cigarettes (Ecigs) triggers abnormal vascular responses in systemic arteries; however, effects on cerebral vessels are poorly understood and time for recovery is not known. We hypothesized that exposure to cigarettes or Ecigs would trigger rapid (<4 h) impairment of the middle cerebral artery (MCA) but that this would resolve by 24 h. What is the main finding and its importance? Cigarettes and Ecigs caused similar degree and duration of MCA impairment. We find it takes ~72 hours after exposure for MCA function to return to normal. This suggests that Ecig use is likely to produce similar adverse vascular health outcomes to those seen with cigarette smoke.

ABSTRACT

Temporal influences of electronic cigarettes (Ecigs) on blood vessels are poorly understood. In this study, we evaluated a single episode of cigarette versus Ecig exposure on middle cerebral artery (MCA) reactivity and determined how long after the exposure MCA responses took to return to normal. We hypothesized that cigarette and Ecig exposure would induce rapid (<4 h) reduction in MCA endothelial function and would resolve within 24 h. Sprague-Dawley rats (4 months old) were exposed to either air (n = 5), traditional cigarettes (20 puffs, n = 16) or Ecigs (20-puff group, n = 16; or 60-puff group, n = 12). Thereafter, the cigarette and Ecig groups were randomly assigned for postexposure vessel myography testing on day 0 (D0, 1-4 h postexposure), day 1 (D1, 24-28 h postexposure), day 2 (D2, 48-52 h postexposure) and day 3 (72-76 h postexposure). The greatest effect on endothelium-dependent dilatation was observed within 24 h of exposure (∼50% decline between D0 and D1) for both cigarette and Ecig groups, and impairment persisted with all groups for up to 3 days. Changes in endothelium-independent dilatation responses were less severe (∼27%) and shorter lived (recovering by D2) compared with endothelium-dependent dilatation responses. Vasoconstriction in response to serotonin (5-HT) was similar to endothelium-independent dilatation, with greatest impairment (∼45% for all exposure groups) at D0-D1, returning to normal by D2. These data show that exposure to cigarettes and Ecigs triggers a similar level/duration of cerebrovascular dysfunction after a single exposure. The finding that Ecig (without nicotine) and cigarette (with nicotine) exposure produce the same effects suggesting that nicotine is not likely to be triggering MCA dysfunction, and that vaping (with/without nicotine) has potential to produce the same vascular harm and/or disease as smoking.

Reduced cerebral vascular fractal dimension among asymptomatic individuals as a potential biomarker for cerebral small vessel disease

Cerebral small vessel disease is a neurological disease frequently found in the elderly and detected on neuroimaging, often as an incidental finding. White matter hyperintensity is one of the most commonly reported neuroimaging markers of CSVD and is linked with an increased risk of future stroke and vascular dementia. Recent attention has focused on the search of CSVD biomarkers. The objective of this study is to explore the potential of fractal dimension as a vascular neuroimaging marker in asymptomatic CSVD with low WMH burden. D_f is an index that measures the complexity of a self-similar and irregular structure such as circle of Willis and its tributaries. This exploratory cross-sectional study involved 22 neurologically asymptomatic adult subjects (42 ± 12 years old; 68% female) with low to moderate 10-year cardiovascular disease risk prediction score (QRISK2 score) who underwent magnetic resonance imaging/angiography (MRI/MRA) brain scan. Based on the MRI findings, subjects were divided into two groups: subjects with low WMH burden and no WMH burden, (WMH⁺; n = 8) and (WMH⁻; n = 14) respectively. Maximum intensity projection image was constructed from the 3D time-of-flight (TOF) MRA. The complexity of the CoW and its tributaries observed in the MIP image was characterised using D_f. The D_f of the CoW and its tributaries, i.e., D_f (w) was significantly lower in the WMH⁺ group (1.5172 ± 0.0248) as compared to WMH⁻ (1.5653 ± 0.0304, p = 0.001). There was a significant inverse relationship between the QRISK2 risk score and D_f (w), (r_s = − .656, p = 0.001). D_f (w) is a promising, non-invasive vascular neuroimaging marker for asymptomatic CSVD with WMH. Further study with multi-centre and long-term follow-up is warranted to explore its potential as a biomarker in CSVD and correlation with clinical sequalae of CSVD.

Carotid Artery Stiffness: Imaging Techniques and Impact on Cerebrovascular Disease

Arterial stiffness is an important measure of vascular aging and atherosclerosis. Though it is measured in many well-known epidemiologic cohort studies, arterial stiffness is often overlooked in routine clinical practice for a number of reasons including difficulties in measurement, variations in definition, and uncertainties surrounding treatment. Central arterial stiffness, a surrogate for aortic stiffness, is the most commonly measured marker of arterial stiffness. In addition to central stiffness, there are also a number of ultrasound based techniques to measure local vascular stiffness, including carotid stiffness. There is evidence that both local carotid stiffness and central arterial stiffness measures are associated with multiple cerebrovascular processes, including stroke and cognitive dysfunction. Mechanistic explanations supporting this association include increased flow load experienced by the cerebral microvasculature leading to cerebral parenchymal damage. In this article, we review definitions of carotid artery stiffness measures and pathophysiologic mechanisms underpinning its association with plaque development and downstream cerebral pathology. We will review the evidence surrounding the association of carotid stiffness measures with downstream manifestations including stroke, cerebral small vessel disease detected on brain MR such as white matter hyperintensities and covert brain infarctions, brain atrophy, and cognitive dysfunction. With consistent definitions, measurement methods, and further scientific support, carotid stiffness may have potential as an imaging-based risk factor for stroke and cognitive decline.

Impaired Glymphatic Function and Pulsation Alterations in a Mouse Model of Vascular Cognitive Impairment

Large vessel disease and carotid stenosis are key mechanisms contributing to vascular cognitive impairment (VCI) and dementia. Our previous work, and that of others, using rodent models, demonstrated that bilateral common carotid stenosis (BCAS) leads to cognitive impairment via gradual deterioration of the neuro-glial-vascular unit and accumulation of amyloid-β (Aβ) protein. Since brain-wide drainage pathways (glymphatic) for waste clearance, including Aβ removal, have been implicated in the pathophysiology of VCI via glial mechanisms, we hypothesized that glymphatic function would be impaired in a BCAS model and exacerbated in the presence of Aβ. Male wild-type and Tg-SwDI (model of microvascular amyloid) mice were subjected to BCAS or sham surgery which led to a reduction in cerebral perfusion and impaired spatial learning acquisition and cognitive flexibility. After 3 months survival, glymphatic function was evaluated by cerebrospinal fluid (CSF) fluorescent tracer influx. We demonstrated that BCAS caused a marked regional reduction of CSF tracer influx in the dorsolateral cortex and CA1-DG molecular layer. In parallel to these changes increased reactive astrogliosis was observed post-BCAS. To further investigate the mechanisms that may lead to these changes, we measured the pulsation of cortical vessels. BCAS impaired vascular pulsation in pial arteries in WT and Tg-SwDI mice. Our findings show that BCAS influences VCI and that this is paralleled by impaired glymphatic drainage and reduced vascular pulsation. We propose that these additional targets need to be considered when treating VCI.

Asymptomatic Carotid Disease and Cognitive Impairment: What Is the Evidence?

The development of cognitive dysfunction and dementia is a complex, multifactorial process. One of the contributors to various types of cognitive dysfunction is carotid atherosclerosis which can frequently be seen in asymptomatic individuals. There are a number of different manifestations of asymptomatic carotid atherosclerosis including arterial stiffness, carotid intima-media thickening, flow-limiting stenosis, and complex, atherosclerotic plaque. Each of these forms of atherosclerosis may contribute to cerebral parenchymal damage, contributing to cognitive dysfunction. In this review article, we will discuss each of these forms of carotid atherosclerosis, present the potential mechanistic underpinnings behind an association, and then review the scientific evidence supporting potential associations to cognitive dysfunction and dementia.

Magnetic resonance imaging assessment of cerebral small vessel disease intensification in patients with severe aortic valve stenosis

Purpose

To assess the prevalence of the neuroradiological indices of cerebral small vessel disease (CSVD) in patients with severe aortic valve stenosis (AS) in magnetic resonance imaging (MRI).

Material and methods

34 patients (age 60-90 years, 17 women and 17 men) with severe AS and 50 healthy controls (age 61-85 years, 29 women and 21 men) underwent MRI brain examinations, which were analysed for the neuroradiological indices of CSVD: hyperintensities in periventricular white matter (PVWM) and deep white matter (DWM), enlarged perivascular spaces (ePVS), lacunar strokes, and cerebral microbleeds (CMBs).

Results

PVWM hyperintensities were found in 46% of volunteers and was significantly lower (p = 0.027), corresponding to AS patients (80%), the density of lesions was higher in the AS group than in controls (p = 0.019). DWM hyperintensities were found more often in AS patients (76%) than in controls (66%) (p = 0.303), but the densities were similar in both groups. Lacunar strokes were found in 35% of AS patients and 16% of controls (p = 0.042). The average number of lacunar strokes per person was 0.9 in the AS group and 0.3 in the controls (p = 0.035). The AS group showed higher variance in the number of strokes: SD = 1.96 vs. SD = 1.06 in controls. Both prevalence and density of the ePVS and CMBs did not differ significantly between the groups.

Conclusions

Neuroradiological indices of the vascular disease do not provide an unequivocal clue to the pathogenesis of CSVD in patients with severe AS. Most observations imply that CSVD is primarily a consequence of cerebral hypoperfusion caused by AS.

Non-High-Density Lipoprotein Cholesterol and Risk of Cardiovascular disease: the Japan Epidemiology Collaboration on Occupational Health Study

AIMS

We aimed to investigate the association between non-high-density lipoprotein cholesterol (non-HDL-C) levels and the risk of cardiovascular disease (CVD) and its subtypes.

METHODS

In this contemporary cohort study, we analyzed the data of 63,814 Japanese employees aged ≥ 30 years, without known CVD in 2012 and who were followed up for up to 8 years. The non-HDL-C level was divided into 5 groups: ＜110, 110-129, 130-149, 150-169, and ≥ 170 mg/dL. The Cox proportional hazards model was used to calculate the hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) for CVD and its subtypes associated with each non-HDL-C group, considering 130-149 mg/dL as the reference group.

RESULTS

During the study period, 271 participants developed CVD, including 78 myocardial infarctions and 193 strokes (102 ischemic strokes, 89 hemorrhagic strokes, and 2 unknowns). A U-shaped association between non-HDL-C and stroke was observed. In the analysis of stroke subtypes, the multivariable-adjusted HR (95% CI) for hemorrhagic stroke was 2.61 (1.19-5.72), 2.02 (0.95-4.29), 2.10 (1.01-4.36), and 1.98 (0.96-4.08), while that for ischemic stroke was 1.54 (0.77-3.07), 0.91 (0.46-1.80), 0.73 (0.38-1.41), and 1.50 (0.87-2.56) in the ＜110, 110-129, 150-169, and ≥ 170 mg/dL groups, respectively. Individuals with elevated non-HDL-C levels had a higher risk of myocardial infarction.

CONCLUSIONS

High non-HDL-C levels were associated with an increased risk of myocardial infarction. Moreover, high and low non-HDL-C levels were associated with a high risk of stroke and its subtypes among Japanese workers.

The Role of Blood Pressure in Carotid Plaque Incidence: Interactions With Body Mass Index, Age, and Sex-Based on a 7-Years Cohort Study

Background: Although high blood pressure (BP) is a risk factor for carotid plaque, its long-term prognostic value might be underestimated due to its confounding interactions with BMI, age, and gender. Therefore, we conducted a 7-year prospective cohort study to evaluate the prognostic value of BP for the incidence of carotid plaque. Methods: The subjects enrolled in 2011 were free of carotid plaque at baseline and were followed up in 2018. Multivariate Cox proportional-hazards models were used to evaluate the association between BP and carotid plaque incidence. Results: During the follow-up study, the incidence of carotid plaque was 36.5%. The significant positive linear trend showed that subjects with higher BP levels at baseline were more likely to develop carotid plaques at the end. Especially in the female subpopulation, after confounders being adjusted, the carotid plaque was associated with higher BP (adjusted HR 1.52, 95% CI 1.02-2.26), pulse pressure (PP) (adjusted HR 1.15, 95% CI 0.76-1.75), and mean arterial pressure (MAP) (adjusted HR 1.44, 95% CI 1.00-2.08). The adjusted HRs of hypertension, PP, and MAP (HR 27.71, 95% CI 2.27-338.64; HR 14.47, 95% CI 1.53-137.18; HR 9.97, 95% CI 1.29-77.28) were significantly higher after the potential antagonistic interactions between BP categorical indicators and age being adjusted, respectively. Conclusion: High BP indicators might be associated with higher HRs of carotid plaque after adjusting interactions between BP indicators and BMI, age, and gender, which suggests that the incidence of carotid plaque in female adults with high BP indicators might increase significantly with the increase of age.

Exercise, Arterial Stiffness, and Cerebral Vascular Function: Potential Impact on Brain Health

Exercise is associated with higher cognitive function and is a promising intervention to reduce the risk of dementia. With advancing age, there are changes in the vasculature that have important clinical implications for brain health and cognition. Primary aging and vascular risk factors are associated with increases in arterial stiffness and pulse pressure, and reductions in peripheral vascular function.

OBJECTIVE

The purpose is to discuss the epidemiological, observational, and mechanistic evidence regarding the link between age-related changes in vascular health and brain health.

METHODS

We performed a literature review and integrated with our published data.

RESULTS

Epidemiological evidence suggests a link between age-related increases in arterial stiffness and lower cognitive function, which may be mediated by cerebral vascular function, including cerebral vasoreactivity and cerebral pulsatility. Age-associated impairments in central arterial stiffness and peripheral vascular function have been attenuated or reversed through lifestyle behaviors such as exercise. Greater volumes of habitual exercise and higher cardiorespiratory fitness are associated with beneficial effects on both peripheral vascular health and cognition. Yet, the extent to which exercise directly influences cerebral vascular function and brain health, as well as the associated mechanisms remains unclear.

CONCLUSION

Although there is evidence that exercise positively impacts cerebral vascular function, more research is necessary in humans to optimize experimental protocols and address methodological limitations and physiological considerations. Understanding the impact of exercise on cerebral vascular function is important for understanding the association between exercise and brain health and may inform future intervention studies that seek to improve cognition.

Carotid Compliance and Parahippocampal and Hippocampal Volume over a 20-Year Period

INTRODUCTION

We evaluated the association between carotid compliance, a measure of arterial stiffness, to parahippocampal volume (PHV) and hippocampal volume (HV) over 20 years later in the Atherosclerosis Risk in the Community study.

METHODS

We included participants with common carotid compliance measurements at visit 1 (1987-1989) and volumetric brain MRI at visit 5 (2011-2013). The primary outcomes are pooled bilateral PHV and HV. We performed linear regression models adjusting for age, sex, vascular risk factors, and total brain volume.

RESULTS

Of the 614 participants, higher compliance was correlated with higher PHV (R = 0.218[0.144-0.291], p < 0.001) and HV (R = 0.181 [0.105-0.255, p < 0.001]). The association was linear and significant after adjusting for confounders. At follow-up MRI, 30 patients with dementia had lower PHV and HV than patients without dementia (p < 0.001 and p < 0.001, respectively).

CONCLUSION

Carotid compliance is associated with higher PHV and HV when measured 20 years later, further supporting the link between arterial stiffness and cognitive decline.

Long-term cerebrovascular dysfunction in the offspring from maternal electronic cigarette use during pregnancy

Electronic cigarettes (E-cigs) have been promoted as harm-free or less risky than smoking, even for women during pregnancy. These claims are made largely on E-cig aerosol having fewer number of toxic chemicals compared with cigarette smoke. Given that even low levels of smoking are found to produce adverse birth outcomes, we sought to test the hypothesis that vaping during pregnancy (with or without nicotine) would not be harm-free and would result in vascular dysfunction that would be evident in offspring during adolescent and/or adult life. Pregnant female Sprague Dawley rats were exposed to E-cig aerosol (1 h/day, 5 days/wk, starting on gestational day 2 until pups were weaned) using e-liquid with 0 mg/mL (E-cig0) or 18 mg/mL nicotine (E-cig18) and compared with ambient air-exposed controls. Body mass at birth and at weaning were not different between groups. Assessment of middle cerebral artery (MCA) reactivity revealed a 51%-56% reduction in endothelial-dependent dilation response to acetylcholine (ACh) for both E-cig0 and E-cig18 in 1-mo, 3-mo (adolescent), and 7-mo-old (adult) offspring (P < 0.05 compared with air, all time points). MCA responses to sodium nitroprusside (SNP) and myogenic tone were not different across groups, suggesting that endothelial-independent responses were not altered. The MCA vasoconstrictor response (5-hydroxytryptamine, 5-HT) was also not different across treatment and age groups. These data demonstrate that maternal vaping during pregnancy is not harm-free and confers significant cerebrovascular health risk/dysfunction to offspring that persists into adult life. NEW & NOTEWORTHY These data established that vaping electronic cigarettes during pregnancy, with or without nicotine, is not safe and confers significant risk potential to the cerebrovascular health of offspring in early and adult life. A key finding is that vaping without nicotine does not protect offspring from cerebrovascular dysfunction and results in the same level of cerebrovascular dysfunction (compared with maternal vaping with nicotine), indicating that the physical and/or chemical properties from the base solution (other than nicotine) are responsible for the cerebrovascular dysfunction that we observed. Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/maternal-vaping-impairs-vascular-function-in-theoffspring/.

Arterial elasticity, endothelial function and intracranial vascular health: A multimodal MRI study

Vascular dysfunctions, including arterial stiffness and endothelial dysfunction, are prevalent in hypertensive subjects. We aimed to study their relations to subclinical intracranial vascular health in this study. A total of 200 older hypertensive males without overt cardiovascular or cerebrovascular diseases were recruited. Arterial elasticity was measured as carotid-femoral pulse wave velocity (cfPWV) and endothelial function was measured as digital reactive hyperemia index (RHI). Cerebrovascular health was evaluated using MRI in four aspects: intracranial atherosclerosis, brain perfusion as cerebral blood flow (CBF), vascular rarefaction analyzed as visible arterial branches on angiography using a custom-developed analysis technique and small vessel disease measured as white matter hyperintensity (WMH). There was a significant negative association between cfPWV and CBF, suggesting a link between arterial stiffness and CBF decline. Higher cfPWV was also associated with presence of intracranial stenotic plaque and greater WMH volume. RHI was positively related to CBF, indicating that endothelial dysfunction was associated with reduced CBF. All the associations remained significant after adjustment for confounding variables. Arterial stiffness and endothelial dysfunction are associated with reduced brain perfusion in older hypertensive males. Arterial stiffness is also associated with global cerebral vascular injury, affecting both small and medium-to-large arteries.

BCL11B Regulates Arterial Stiffness and Related Target Organ Damage

Supplemental Digital Content is available in the text.

BCL11B (B-cell leukemia 11b) is a transcription factor known as an essential regulator of T lymphocytes and neuronal development during embryogenesis. A genome-wide association study showed that a gene desert region downstream of BCL11B, known to function as a BCL11B enhancer, harbors single nucleotide polymorphisms associated with increased arterial stiffness. However, a role for BCL11B in the adult cardiovascular system is unknown.

Older age and male sex are associated with higher cerebrovascular impedance

Cerebral blood flow (CBF) becomes pulsatile in response to the pulsatile change in perfusion pressure that is regulated by cerebrovascular impedance. In this study, we aimed to characterize age-related differences in cerebrovascular impedance across the adult lifespan. Carotid artery pressure [(CAP), via applanation tonometry] and CBF velocity (CBFV) in the middle cerebral artery (via transcranial Doppler) were measured in 148 healthy adults (21-79 yr, 62% women). Cerebrovascular impedance was quantified using transfer function analysis. Coherence between changes in CBFV and CAP was >0.90 in the frequency range of 0.78-2.73 Hz, suggesting a linear dynamic relationship between these two variables. Impedance modulus at the first harmonics (0.78-1.56 Hz) of CBFV and CAP oscillations (Z₁), reflecting mainly heart rate frequency, was 20% higher in the old (>64 yr, P = 0.002) and 13% higher in the middle-aged (45-64 yr, P = 0.08) than in young individuals (<45 yr). In addition, Z₁ was 24% higher in men than in women (P < 0.001). Multiple linear regression analysis revealed that Z₁ is negatively associated with systolic (β = -0.470), diastolic (β = -0.418), pulsatile (β = -0.374), and mean CBFV (β = -0.473; P < 0.001 for all) after adjustment for age, sex, and body mass index (BMI). These results suggest that older age and male sex are associated with higher cerebrovascular impedance than young individuals, which may contribute to brain hypoperfusion.NEW & NOTEWORTHY Impedance modulus at the first harmonics of cerebral blood flow velocity (CBFV) and carotid artery pressure oscillations (Z₁) was higher in the old (>64 yr) than in the young individuals (<45 yr), and it was higher in men than in women. Z₁ is negatively associated with CBFV after adjustment for age, sex, and body mass index. Increases in cerebrovascular impedance with age may buffer systemic arterial pressure fluctuations at the cost of increased brain hypoperfusion risk.

Association of enlarged perivascular spaces and anticoagulant-related intracranial hemorrhage

OBJECTIVE

To investigate whether enlarged perivascular spaces (PVS) within the basal ganglia or deep cerebral white matter are risk factors for intracranial hemorrhage in patients taking oral anticoagulants (OACs), independent of established clinical and radiologic risk factors, we conducted a post hoc analysis of Clinical Relevance of Microbleeds in Stroke (CROMIS-2) (atrial fibrillation [AF]), a prospective inception cohort study.

METHODS

Patients with atrial fibrillation and recent TIA or ischemic stroke underwent standardized MRI prior to starting OAC. We rated basal ganglia PVS (BGPVS) and centrum semiovale PVS (CSOPVS), cerebral microbleeds (CMBs), white matter hyperintensities, and lacunes. We dichotomized the PVS rating using a threshold of >10 PVS in the relevant region of either cerebral hemisphere. The primary outcome was symptomatic intracranial hemorrhage (sICH). We identified risk factors for sICH using Cox regression.

RESULTS

A total of 1,386 participants with available clinical and imaging variables were followed up for a mean of 2.34 years; 14 sICH occurred (11 intracerebral). In univariable analysis, diabetes, CMB presence, lacune presence, and >10 BGPVS, but not CSOPVS, were associated with sICH. In a multivariable model incorporating all variables with significant associations in univariable analysis, >10 BGPVS (hazard ratio [HR] 8.96, 95% [CI] 2.41-33.4, p = 0.001) and diabetes (HR 3.91, 95% CI 1.34-11.4) remained significant risk factors for sICH.

CONCLUSION

Enlarged BGPVS might be a novel risk factor for OAC-related ICH. The strength of this association and potential use in predicting ICH in clinical practice should be investigated in larger cohorts.

Brain imaging biomarkers of carotid artery disease

Extracranial carotid artery atherosclerotic disease is a major contributor to ischemic stroke. Carotid atherosclerotic disease can present with a spectrum of findings ranging from mild carotid intima-media thickness to high-risk vulnerable carotid plaque features and carotid stenosis. Before leading to clinically overt stroke or transient ischemic attack, there may be other markers of downstream ischemia secondary to carotid atherosclerotic disease. In this review article, we will review some of the imaging findings that may be seen downstream to carotid artery disease on various imaging modalities, including hemodynamic and perfusional abnormalities which may be seen on CT, MR, or using other advanced imaging techniques, white matter hyperintensities on brain imaging, silent or covert brain infarctions, cerebral microbleeds, and regional and generalized cerebral volume loss. Many of these imaging findings are seen routinely on brain magnetic resonance imaging in patients without overt clinical symptoms. Despite frequently being asymptomatic, many of these imaging findings are also strongly associated with increased risk of future stroke, cognitive impairment, and even mortality. We will review the existing evidence underpinning the associations between these frequently encountered imaging findings and carotid artery atherosclerotic disease. Future validation of these imaging findings could lead to them being powerful biomarkers of cerebrovascular health.

Middle-aged endurance athletes exhibit lower cerebrovascular impedance than sedentary peers

Because elevated hemodynamic pulsatility could be mechanical stress against the brain, the dampening function of central and cerebral arteries is crucial. Regular endurance exercise training favorably restores the deteriorated dampening function of the aorta and carotid arteries in older populations, yet its effect on cerebrovascular dampening function remains unknown. To address this question, we compared cerebrovascular impedance, a frequency-domain relationship of the cerebral pressure and flow, in 21 middle-aged masters athletes who have been engaged in endurance training and races for >10 yr (MA, 53 ± 4 yr) with sedentary 21 age-matched (MS, 53 ± 5 yr) and 21 young (YS, 29 ± 6 yr) individuals. Using transfer function analysis, cerebrovascular impedance was computed from the simultaneously recorded carotid artery pressure (CAP, via applanation tonometry) and middle cerebral artery blood flow velocity (CBFV, via transcranial Doppler). In the frequency range of 0.78-3.12 Hz, coherence between pulsatile changes in CAP and CBFV was higher than 0.90 in all groups. All subjects exhibited the highest impedance modulus in the range of the first harmonic oscillations (0.78-1.56 Hz) mainly originating from cardiac ejection. Impedance modulus in this range was significantly lower in the MA than MS groups (0.88 ± 0.24 vs. 1.15 ± 0.29 mmHg·s/cm, P = 0.011) and equivalent to the YS (0.92 ± 0.30 mmHg·s/cm). Among middle-aged subjects, higher impedance modulus was correlated with lower mean CBFV (r = -0.776, P < 0.001) and cerebral cortical perfusion evaluated by MRI (r = -0.371, P = 0.015). These results suggest that middle-aged endurance athletes exhibited the significantly lower modulus of cerebrovascular impedance, which is associated with higher CBFV and cerebral cortical perfusion.NEW & NOTEWORTHY Impedance modulus in the range of first harmonic oscillations (0.78-1.56 Hz), which reflects heart rate at rest, was lower in middle-aged endurance athletes than in age-matched sedentary peers and was similar to young individuals. Prolonged endurance training is associated with the improved cerebrovascular dampening function in middle-aged adults. Lower cerebrovascular impedance modulus may contribute to maintaining brain perfusion in midlife.

Left Common Carotid Artery Biomechanical Properties in Individuals over 80 years: Women Have Stiffer Vessels

BACKGROUND

Considering the longevity of the worldwide population, the cardiovascular diseases deserve particular attention, especially the carotid artery disease in the ≥80-year-old population. The stiffness of the common carotid artery, for example, has been showed in numerous clinical studies as a marker of increased risk of stroke, dementia, and depression. Besides, with the emergence of new surgical techniques such as the transcarotid artery revascularization that uses the common carotid artery as a workstation, the biomechanical and histological features of this vessel, more than ever, must be detailed.

METHODS

Left common carotid artery fragments from 9 cadaver donors (≥80 years old) were evaluated. Biomechanical (failure stress, tension, and strain) and histological (percentage of collagen and elastic fibers) features of these samples were analyzed with special focus on gender differences.

RESULTS

Statistically significant differences in biomechanical and histological features between the genders were observed. The percentage of collagen fiber in intima (P = 0.008) and media (P = 0.041) layers was significantly lower in men than in women. A higher elasticity (failure strain) of the specimens in male gender was also observed (P = 0.025). No significant difference was observed in the layers thickness between the genders regardless which part of the arterial wall was considered.

CONCLUSIONS

These biomechanical and histological findings could be the responsible for the higher left common carotid artery stiffness observed among ≥80-year-old women when compared with men in numerous clinical studies in literature.

Use of anticoagulant therapy and cerebral microbleeds: a systematic review and meta-analysis

BACKGROUND

Anticoagulant therapy increases the risk that cerebral microbleeds (CMBs) progress to intracerebral hemorrhage, but whether the therapy increases risk of CMB occurrence is unclear. We performed a systematic review and meta-analysis to investigate the potential association between anticoagulant use and CMB occurrence in stroke and stroke-free individuals.

METHODS

We searched observational studies in PubMed, Ovid EMBASE, and Cochrane Library from their inception until September 2019. We calculated the pooled odds ratio (OR) and 95% confidence interval (CI) for the prevalence and incidence of CMBs in anticoagulant users relative to non-anticoagulant users.

RESULTS

Forty-seven studies with 25,245 participants were included. The pooled analysis showed that anticoagulant use was associated with CMB prevalence (OR 1.54, 95% CI 1.26-1.88). The association was observed in subgroups stratified by type of participants: stroke-free, OR 1.86, 95% CI 1.25-2.77; ischemic stroke/transient ischemic attack, OR 1.33, 95% CI 1.06-1.67; and intracerebral hemorrhage, OR 2.26, 95% CI 1.06-4.83. Anticoagulant use was associated with increased prevalence of strictly lobar CMBs (OR 1.68, 95% CI 1.22-2.32) but not deep/infratentorial CMBs. Warfarin was associated with increased CMB prevalence (OR 1.64, 95% CI 1.23-2.18), but novel oral anticoagulants were not. Anticoagulant users showed higher incidence of CMBs during long-term follow-up (OR 1.72, 95% CI 1.22-2.44).

CONCLUSION

Anticoagulant use is associated with higher prevalence and incidence of CMBs. This association appears to depend on location of CMBs and type of anticoagulants. More longitudinal investigations with adjustment for confounders are required to establish the causality.

The Hardest Part

Aging has a significant impact not only on every single individual but on society as a whole. Today, people throughout the world exhibit an extended lifespan. Therefore, it becomes increasingly important to develop novel concepts that encourage a modern understanding of the aging process. The concept of healthy aging shifts the perception of aging as a burden towards aging as an opportunity for an extended healthy phase in later life. Morbidity and mortality in the elderly population are greatly defined by a raise in the incidence and prevalence of cardiovascular diseases. Consequently, it is critical to identify risk factors and underlying mechanisms that render the aging (cardio)vascular system prone to disease. In this review, we focus on structural mechanisms of arterial stiffening as a major manifestation of vascular aging and its functional implications for the concept of healthy aging.

Carotid Artery Stiffness and Incident Depressive Symptoms: The Paris Prospective Study III

BACKGROUND

Arterial stiffness may contribute to late-life depression via cerebral microvascular damage, but evidence is scarce. No longitudinal study has evaluated the association between arterial stiffness and risk of depressive symptoms. Therefore, we investigated the association between carotid artery stiffness and incident depressive symptoms in a large community-based cohort study.

METHODS

This longitudinal study included 7013 participants (mean age 59.7 ± 6.3 years; 35.8% women) free of depressive symptoms at baseline. Carotid artery stiffness (high-resolution echo tracking) was determined at baseline. Presence of depressive symptoms was determined at baseline and at 4 and 6 years of follow-up, and was defined as a score ≥7 on the validated Questionnaire of Depression, Second Version, Abridged and/or new use of antidepressant medication. Logistic regression and generalized estimating equations were used.

RESULTS

In total, 6.9% (n = 484) of the participants had incident depressive symptoms. Individuals in the lowest tertile of carotid distensibility coefficient (indicating greater carotid artery stiffness) compared with those in the highest tertile had a higher risk of incident depressive symptoms (odds ratio: 1.43; 95% confidence interval: 1.10-1.87), after adjustment for age, sex, living alone, education, lifestyle, cardiovascular risk factors, and baseline Questionnaire of Depression, Second Version, Abridged scores. Results were qualitatively similar when we used carotid Young's elastic modulus as a measure of carotid stiffness instead of carotid distensibility coefficient, and when we used generalized estimating equations instead of logistic regression.

CONCLUSIONS

Greater carotid stiffness is associated with a higher incidence of depressive symptoms. This supports the hypothesis that carotid stiffness may contribute to the development of late-life depression.

Aortic stiffness, pressure and flow pulsatility, and target organ damage

Measures of aortic stiffness and pressure and flow pulsatility have emerged as correlates of and potential contributors to cardiovascular disease, dementia, and kidney disease. Higher aortic stiffness and greater pressure and flow pulsatility are associated with excessive pulsatile load on the heart, which increases mass and reduces global longitudinal strain of the left ventricle. Excessive stiffness and pulsatility are also associated with microvascular lesions in high-flow organs, such as the brain and kidney, suggesting that small vessels in these organs are damaged by pulsatility. This brief review will summarize evidence relating aortic stiffness to cardiovascular, brain, and kidney disease.

Cerebral small vessel disease: neuroimaging markers and clinical implication

Cerebral small vessel disease (CSVD) is a broad category of cerebrovascular diseases which primarily affect the perforating arterioles, capillaries and venules with multiple distinct etiologies. In spite of distinctive pathogenesis, CSVD shares similar neuroimaging markers, including recent small subcortical infarct, lacune of presumed vascular origin, white matter hyperintensity of presumed vascular origin, perivascular space and cerebral microbleeds. The radiological features of neuroimaging markers are indicative for etiological analysis. Furthermore, in sporadic arteriosclerotic pathogenesis associated CSVD, the total CSVD burden is a significant predictor for stroke events, global cognitive impairment, psychiatric disorders and later life quality. This review aims to summarize the radiological characteristics as well as the clinical implication of CSVD markers and neuroimaging interpretation for CSVD symptomatology.

Relation of serum uric acid to asymptomatic proximal extracranial artery stenosis in a middle-aged Chinese population: a community-based cross-sectional study

OBJECTIVE

Serum uric acid (SUA) has been associated with cardiovascular diseases, including atherosclerosis and carotid artery stenosis. However, data on the relationship between SUA level and proximal extracranial artery stenosis (PEAS) are limited. Therefore, this study investigates the association between SUA levels and the risk of PEAS in asymptomatic Chinese population.

SETTING

This community-based cross-sectional study was conducted in Jidong Community Hospital, Tangshan, Hebei, China between July 2013 and August 2014.

PARTICIPANTS

The study examined 3325 asymptomatic participants (40-60 years) to evaluate the risk of PEAS.

RESULTS

For the participants stratified into quartiles based on gender-specific SUA levels, the prevalence of PEAS increased from Q1 to Q4 from 12.3% to 29.8% in the vertebral artery (VA), and from 2.8% to 5.8% in the common carotid artery. The proportion of PEAS relative to the detected number of arterial stenosis was lower in Q1 than in Q2-Q4. The multivariable ORs and 95% CI of PEAS in the second through fourth compared with the lowest quartiles for arterial stenosis were 1.278 (0.980 to 1.665), 1.117 (0.851 to 1.468) and 1.375 (1.033 to 1.830) (p_trend=0.0399); and for VA stenosis, 1.285 (0.966 to 1.709), 1.085 (0.808 to 1.457) and 1.439 (1.061 to 1.952) (p_trend=0.0235).

CONCLUSION

Elevated SUA concentration is significantly associated with PEAS in an asymptomatic middle-aged Chinese population, and vertebral arteries appeared to be the most vulnerable vessels.

The matrix proteins aggrecan and fibulin-1 play a key role in determining aortic stiffness

Stiffening of the aorta is an important independent risk factor for myocardial infarction and stroke. Yet its genetics is complex and little is known about its molecular drivers. We have identified for the first time, tagSNPs in the genes for extracellular matrix proteins, aggrecan and fibulin-1, that modulate stiffness in young healthy adults. We confirmed SNP associations with ex vivo stiffness measurements and expression studies in human donor aortic tissues. Both aggrecan and fibulin-1 were found in the aortic wall, but with marked differences in the distribution and glycosylation of aggrecan reflecting loss of chondroitin-sulphate binding domains. These differences were age-dependent but the striking finding was the acceleration of this process in stiff versus elastic young aortas. These findings suggest that aggrecan and fibulin-1 have critical roles in determining the biomechanics of the aorta and their modification with age could underpin age-related aortic stiffening.

Associations of carotid arterial compliance and white matter diffusion metrics during midlife: modulation by sex

Sex differences in cerebral white matter (WM) aging have been debated extensively over the past 2 decades without unequivocal resolution. We aimed to determine if the effects of age and arterial stiffness on WM microstructure differ between sexes. Artery elasticity via carotid artery compliance (CAC) and WM diffusion metrics via diffusion tensor image-derived fractional anisotropy (FA) and mean diffusivity (MD) were measured in 155 (87 females) middle-aged (40-62 years) adults. Males demonstrated poorer water diffusion metrics in WM than women in the corpus callosum body, cingulum, and cingulum (hippocampal). Age and CAC had greater effects on WM water diffusion in males than females in midlife independent of education and cardiovascular risk factors. Sex-moderated age (cingulum FA, cingulum [hippocampal] MD, and uncinate MD, all p < 0.05) and CAC (cingulum FA, p < 0.05) related reductions in regional WM diffusion metrics. CAC mediated age-related associations in regional WM diffusion metrics (cingulum FA, cingulum MD, superior corona radiata MD, and uncinate MD, all p < 0.05) in males but not in females. Age and CAC were associated with WM diffusion metrics independent of cardiovascular risk factors. These associations appear to be stronger in males than in females.

Tumor Necrosis Factor Receptor 1 and 2 Are Associated With Risk of Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Raised plasma concentrations of tumor necrosis factor receptors (TNFR) have been linked to arterial stiffness, cerebral microbleeds, and vascular events. The aim of this study was to investigate the association of circulating levels of TNFR1 and TNFR2 with risk for future intracerebral hemorrhage (ICH).

METHODS

The population-based MDCS cohort (Malmö Diet and Cancer Study; n=28 449) was conducted in 1991 to 1996. A nested case-control study was performed in the MDCS, including 220 cases who experienced ICH during the follow-up period (mean age at inclusion 62 years, 48% men) and 244 matched controls. Of the 220 ICH cases, 68 died within 28 days. Conditional logistic regression was used to study the association between plasma levels of TNFR1 and TNFR2 and incident ICH, adjusting for known ICH risk factors.

RESULTS

Concentrations of both TNFR1 and TNFR2 were significantly higher in subjects who developed ICH during the follow-up. The associations remained after adjustment for ICH risk factors (TNFR1: odds ratio [OR], 2.28; 95% confidence interval [CI], 1.26-4.11; P=0.006; TNFR2: OR, 1.77; CI, 1.16-2.70; P=0.008). ORs were somewhat higher for nonlobar ICH (3.04; CI, 1.29-7.14 and 2.39; CI, 1.32-4.32, respectively) than for lobar ICH (2.03; CI, 0.93-4.41 and 1.35; CI, 0.78-2.37, respectively). TNFR1 and TNFR2 were also associated with increased risk of fatal ICH (TNFR1: OR, 4.42; CI, 1.67-11.6; TNFR2: OR, 2.90; CI, 1.50-5.58) and with poor functional outcome according to the modified Rankin Scale.

CONCLUSIONS

High plasma levels of TNFR1 and TNFR2 were associated with incident ICH, most clearly with ICH of nonlobar location. The results suggest that tumor necrosis factor-mediated inflammation could be associated with vascular changes preceding ICH.

Recent Progress in Vascular Aging: Mechanisms and Its Role in Age-related Diseases

As with many age-related diseases including vascular dysfunction, age is considered an independent and crucial risk factor. Complicated alterations of structure and function in the vasculature are linked with aging hence, understanding the underlying mechanisms of age-induced vascular pathophysiological changes holds possibilities for developing clinical diagnostic methods and new therapeutic strategies. Here, we discuss the underlying molecular mediators that could be involved in vascular aging, e.g., the renin-angiotensin system and pro-inflammatory factors, metalloproteinases, calpain-1, monocyte chemoattractant protein-1 (MCP-1) and TGFβ-1 as well as the potential roles of testosterone and estrogen. We then relate all of these to clinical manifestations such as vascular dementia and stroke in addition to reviewing the existing clinical measurements and potential interventions for age-related vascular dysfunction.

Relationship between carotid arterial properties and cerebral white matter hyperintensities

OBJECTIVE

Since arterial stiffness is a functional measure of arterial compliance and may be an important marker of cerebrovascular disease, we examined the association of carotid artery stiffness with white matter hyperintensity volume (WMHV) in a cross-sectional study of 1,166 stroke-free participants.

METHODS

Carotid beta stiffness index (STIFF) was assessed by M-mode ultrasound of the common carotid artery and calculated as the ratio of natural log of the difference between systolic and diastolic blood pressure over STRAIN, a ratio of the difference between carotid systolic and diastolic diameter (DD) divided by DD. WMHV was measured by fluid-attenuated inversion recovery MRI. The associations of STIFF, DD, and STRAIN with WMHV were examined using linear regression after adjusting for sociodemographic, lifestyle, and vascular risk factors.

RESULTS

In a fully adjusted model, larger carotid DD was significantly associated with greater log-WMHV (β = 0.09, p = 0.001). STIFF and STRAIN were not significantly associated with WMHV. In adjusted analyses stratified by race-ethnicity, STRAIN (β = -1.78, p = 0.002) and DD (β = 0.11, p = 0.001) were both associated with greater log-WMHV among Hispanic participants, but not among black or white participants.

CONCLUSIONS

Large carotid artery diameters are associated with greater burden of white matter hyperintensity (WMH) in this multiethnic population. The association between increased diameters, decreased STRAIN, and greater WMH burden is more pronounced among Hispanics. These associations suggest a potential important pathophysiologic role of extracranial large artery remodeling in the burden of WMH.

Association between large artery atherosclerosis and cerebral microbleeds: a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to provide evidence that biomarkers of large artery atherosclerosis, including arterial stenosis and greater carotid intima-media thickness (cIMT), may serve as clinical markers of subclinical haemorrhage-prone cerebral small vessel disease, reflected by cerebral microbleeds (CMBs).

METHODS

We searched PubMed, MEDLINE, Web of Science, EMBASE and the Cochrane Library to identify relevant studies published before 1 July 2016. The association between arterial stenosis and CMBs was estimated by the OR and 95% CI. The association of cIMT and CMBs was calculated using the standardised mean difference (SMD). Heterogeneity and publication bias were explored.

RESULTS

8 studies including a total of 7160 participants were pooled in the meta-analysis. 6 of the included studies were cross-sectional, except that 2 were prospective. We found a significant association between arterial stenosis >50% and the presence of CMBs (OR 1.95, 95% CI 1.13 to 3.36, I²=56.1%). A fixed-effects model suggested that patients with CMBs were more likely to have a greater cIMT (SMD 0.20, 95% CI 0.11 to 0.28, I²=24.7%).

CONCLUSIONS

This systematic review and meta-analysis found that there is a relationship between large artery atherosclerosis and CMBs. Future studies are needed to confirm the impact of atherosclerosis on the CMBs, which may have potential therapeutic implications.

Killing Me Unsoftly: Causes and Mechanisms of Arterial Stiffness

The aorta is a blood vessel that provides a low-resistance path for blood flow directed from the heart to peripheral organs and tissues. However, the aorta has another central hemodynamic function, whereby the elastic nature of the aortic wall provides a significant biomechanical buffering capacity complementing the pulsatile cardiac blood flow, and this is often referred to as Windkessel function. Stiffening of the arterial wall leads to fundamental alterations in central hemodynamics, with widespread detrimental implications for organ function. In this Recent Highlights article, we describe recent contributions in ATVB that have highlighted the novel mechanisms and consequences of arterial stiffness and the clinical conditions in which arterial stiffness occurs, with a focus on advancements in the field.

Intra- and extracranial atherosclerotic disease: casting a new light on emerging trends

Intra- and extracranial atherosclerotic stenosis has been shown to be associated with an increased risk of secondary stroke mortality. Advances in invasive and non-invasive imaging modalities have improved analysis of hemodynamic changes and allowed better delineation of the integrity of intracranial collateralization and plague morphology in patients with artery stenosis. This review focuses on new imaging modalities and clinical applications of currently available techniques, and provides significant insight into future directions in comprehensive analysis of intra- and extracranial atherosclerotic stenosis.

Vascular Smooth Muscle Sirtuin-1 Protects Against Diet-Induced Aortic Stiffness

Arterial stiffness, a major cardiovascular risk factor, develops within 2 months in mice fed a high-fat, high-sucrose (HFHS) diet, serving as a model of human metabolic syndrome, and it is associated with activation of proinflammatory and oxidant pathways in vascular smooth muscle (VSM) cells. Sirtuin-1 (SirT1) is an NAD(+)-dependent deacetylase regulated by the cellular metabolic status. Our goal was to study the effects of VSM SirT1 on arterial stiffness in the context of diet-induced metabolic syndrome. Overnight fasting acutely decreased arterial stiffness, measured in vivo by pulse wave velocity, in mice fed HFHS for 2 or 8 months, but not in mice lacking SirT1 in VSM (SMKO). Similarly, VSM-specific genetic SirT1 overexpression (SMTG) prevented pulse wave velocity increases induced by HFHS feeding, during 8 months. Administration of resveratrol or S17834, 2 polyphenolic compounds known to activate SirT1, prevented HFHS-induced arterial stiffness and were mimicked by global SirT1 overexpression (SirT1 bacterial artificial chromosome overexpressor), without evident metabolic improvements. In addition, HFHS-induced pulse wave velocity increases were reversed by 1-week treatment with a specific, small molecule SirT1 activator (SRT1720). These beneficial effects of pharmacological or genetic SirT1 activation, against HFHS-induced arterial stiffness, were associated with a decrease in nuclear factor kappa light chain enhancer of activated B cells (NFκB) activation and vascular cell adhesion molecule (VCAM-1) and p47phox protein expressions, in aorta and VSM cells. In conclusion, VSM SirT1 activation decreases arterial stiffness in the setting of obesity by stimulating anti-inflammatory and antioxidant pathways in the aorta. SirT1 activators may represent a novel therapeutic approach to prevent arterial stiffness and associated cardiovascular complications in overweight/obese individuals with metabolic syndrome.

FGF21 represses cerebrovascular aging via improving mitochondrial biogenesis and inhibiting p53 signaling pathway in an AMPK-dependent manner

Cerebrovascular aging has a high relationship with stroke and neurodegenerative disease. In the present study, we evaluated the influence of fibroblast growth factor 21 (FGF21) on angiotensin (Ang II)-mediated cerebrovascular aging in human brain vascular smooth muscle cells (hBVSMCs). Ang II induced remarkable aging-phenotypes in hBVSMCs, including enhanced SA-β-gal staining and NBS1 protein expression. First, we used immunoblotting assay to confirm protein expression of FGF21 receptor (FGFR1) and the co-receptor β-Klotho in cultured hBVSMCs. Second, we found that FGF21 treatment partly prevented the aging-related changes induced by Ang II. FGF21 inhibited Ang II-enhanced ROS production/superoxide anion levels, rescued the Ang II-reduced Complex IV and citrate synthase activities, and suppressed the Ang II-induced meprin protein expression. Third, we showed that FGF21 not only inhibited the Ang II-induced p53 activation, but also blocked the action of Ang II on Siah-1-TRF signaling pathway which is upstream factors for p53 activation. At last, either chemical inhibition of AMPK signaling pathway by a specific antagonist Compound C or knockdown of AMPKα1/2 isoform using siRNA, successfully abolished the anti-aging action of FGF21 in hBVSMCs. These results indicate that FGF21 protects against Ang II-induced cerebrovascular aging via improving mitochondrial biogenesis and inhibiting p53 activation in an AMPK-dependent manner, and highlight the therapeutic value of FGF21 in cerebrovascular aging-related diseases such as stroke and neurodegenerative disease.