Associations of brachial-ankle pulse wave velocity and carotid atherosclerotic lesions with silent cerebral lesions

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.

Novel Biomarkers and Imaging Indices for the "Vulnerable Patient" with Carotid Stenosis: A Single-Center Study

BACKGROUND

We investigated the relationship of matrix metalloproteinases (MMPs), cardio-ankle vascular index (CAVI), and Gray-Scale Median (GSM) score with the severity and vulnerability of carotid atherosclerosis and major adverse cardiovascular events (MACE) during follow-up of carotid artery revascularization.

METHODS

We enrolled 262 patients undergoing carotid revascularization therapy (GRT), 109 asymptomatic patients with low-grade carotid stenosis (40-70%) receiving conservative treatment (GCT), and 92 age- and sex-matched control subjects without carotid atherosclerosis (GCO). All participants underwent carotid ultrasound and we assessed at baseline clinical parameters, metabolic profile, CAVI, GSM, and circulating levels of hsCRP, MMP-3,-7,-9, and TIMP-1.

RESULTS

Both GRT and GCT presented with elevated CAVI, MMPs, and TIMP-1 levels compared to GCO (p < 0.001). The escalation highly correlated to the presence of symptoms or paralleled the degree of carotid stenosis (p < 0.001). During follow-up (mean duration: 55 months), 51 GRT patients experienced MACE unrelated to the revascularization procedure. Within GRT, diabetes (HR: 2.07; CI: 1.55-2.78, p < 0.001), smoking (HR: 1.67; CI: 1.35-1.95, p < 0.001), high CAVI (HR: 1.22; CI: 1.09-1.43, p = 0.023) and MMP-9 (HR: 1.44; CI: 1.29-2.15, p = 0.005), and low GSM (HR: 1.40; CI: 1.16-2.12, p = 0.002) independently predicted MACE occurrences, despite the optimum medical therapy.

CONCLUSIONS

Novel imaging and biochemical biomarkers were positively associated with atherosclerosis severity, while CAVI, MMP-9, and low GSM showed a positive, independent relationship with MACE after carotid revascularization, describing "vulnerable patients".

The Association between Ankle-Brachial Index/Pulse Wave Velocity and Cerebral Large and Small Vessel Diseases in Stroke Patients

(1) Background: The study investigated whether the ankle-brachial index (ABI) and pulse wave velocity (baPWV) could reflect the severity of small vessel disease (SVD) and large artery atherosclerosis (LAA). (2) Methods: A total of 956 consecutive patients diagnosed with ischemic stroke were prospectively enrolled from July 2016 to December 2017. SVD severity and LAA stenosis grades were evaluated via magnetic resonance imaging and carotid duplex ultrasonography. Correlation coefficients were calculated between the ABI/baPWV and measurement values. Multinomial logistic regression analysis was performed to determine predictive potential. (3) Results: Among the 820 patients included in the final analysis, the stenosis grade of extracranial and intracranial vessels was inversely correlated with the ABI (p < 0.001, respectively) and positively correlated with the baPWV (p < 0.001 and p = 0.004, respectively). Abnormal ABI, not baPWV, independently predicted the presence of moderate (adjusted odds ratio, aOR: 2.18, 95% CI: 1.31-3.63) to severe (aOR: 5.59, 95% CI: 2.21-14.13) extracranial vessel stenosis and intracranial vessel stenosis (aOR: 1.89, 95% CI: 1.15-3.11). Neither the ABI nor baPWV was independently associated with SVD severity. (4) Conclusions: ABI is better than baPWV in screening for and identifying the existence of cerebral large vessel disease, but neither test is a good predictor of cerebral SVD severity.

Role of Preoperative Ultrasound Shear-Wave Elastography and Radiofrequency-Based Arterial Wall Tracking in Assessing the Vulnerability of Carotid Plaques: Preliminary Results

We aimed at evaluating the ability of point shear-wave elastography (pSWE) and of a radiofrequency (RF) echo-tracking-based method in preoperatively assessing the vulnerability of the carotid plaque in patients undergoing carotid endarterectomy (CEA) for significant asymptomatic stenosis. All patients who underwent CEA from 03/2021 to 03/2022 performed a preoperative pSWE and an RF echo-based wall evaluation of arterial stiffness using an Esaote MyLab ultrasound system (EsaoteTM, Genova, Italy) with dedicated software. The data derived from these evaluations (Young's modulus (YM), augmentation index (AIx), pulse-wave velocity (PWV)) were correlated with the outcome of the analysis of the plaque removed during the surgery. Data were analyzed on 63 patients (33 vulnerable and 30 stable plaques). In stable plaques, YM was significantly higher than in vulnerable plaques (49.6 + 8.1 kPa vs. 24.6 + 4.3 kPa, p = 0.009). AIx also tended to be slightly higher in stable plaques, even if it was not statistically significant (10.4 + 0.9% vs. 7.7 + 0.9%, p = 0.16). The PWV was similar (12.2 + 0.9 m/s for stable plaques vs. 10.6 + 0.5 m/s for vulnerable plaques, p = 0.16). For YM, values >34 kPa had a sensitivity of 50% and a specificity of 73.3% in predicting plaque nonvulnerability (area under the curve = 0.66). Preoperative measurement of YM by means of pSWE could be a noninvasive and easily applicable tool for assessing the preoperative risk of plaque vulnerability in asymptomatic patients who are candidates for CEA.

Association between estimated pulse wave velocity and silent lacunar infarct in a Korean population

Aims

Previous studies have proposed the estimated pulse wave velocity (ePWV) as a simple and cost-effective measure of arterial stiffness. Since arterial stiffness plays a role in the progression of silent lacunar infarct (SLI), our present work aims to evaluate the association between ePWV and the presence of SLI.

Methods

The present work was based on a cross-section study. Our study included 1,011 neurologically healthy Korean participants. The SLI was evaluated using brain magnetic resonance images (MRI). The ePWV was derived from a published equation using age and mean blood pressure (MBP). Logistic regression analyses were performed to investigate the association between ePWV and SLI. The linear relationship and robustness were evaluated using smooth curve fitting and subgroup analyses, respectively.

Results

The prevalence of SLI was 11.87%. After fully adjusting for covariates, per 1 m/s increase of ePWV casted 31% additional risk for SLI (P = 0.009). When dividing the ePWV into quartiles, the top quartile had 4.01 times risk compared with the bottom quartile. The increasing trend across the quartiles was statistically significant (P for trend < 0.001). Consistently, smooth curve fitting revealed that the risk of SLI elevated linearly with the increase of ePWV. Finally, subgroup analysis suggested that the association was robust in several sub-populations divided by age, sex, smoking, hypertension, diabetes mellitus (DM), coronary artery occlusive disease (CAOD), hyperlipidemia, and statin medication (all P for interaction > 0.05).

Conclusion

The current study revealed an independent and positive association between ePWV and the presence of SLI in a neurologically healthy Korean population.

Intima Media Thickness and Cognitive Function Among Adults: Meta-Analysis of Observational and Longitudinal Studies

Background

Carotid structural changes measured by intima media thickness (IMT) have been related to cognitive complaints during aging. Therefore, the aims of this meta‐analysis were (1) to elucidate the relationship between vascular status, measured as IMT, and cognitive domains distinguishing between global cognition, executive functions, memory and attention; and (2) to explore whether demographic (ie, age and sex), clinical (ie, body mass index and IMT baseline values), and procedure characteristics influence this association.

Methods and Results

We performed a systematic review of MEDLINE (via PubMed), Scopus, and Web of Science databases from their inception to June 2021. Studies meeting the following inclusion criteria were included: (1) the participants were adults; (2) the exposure was carotid IMT; (3) the outcome was cognitive function, including global cognition, executive function, memory, and attention measured using standardized tests; and (4) the study design was cross‐sectional or longitudinal including unadjusted and adjusted analyses. A total of 19 cross‐sectional and 15 longitudinal studies were included and demographic (age and sex), clinical (body mass index and baseline IMT values), and procedure characteristics were analyzed as potential mediator or moderators of the association.

Conclusions

Our data support negative associations between IMT and cognitive function in cross‐sectional studies. The association between IMT and cognition lost significance in longitudinal studies and when controlling for covariates in cross‐sectional studies. Finally, the strength of these associations seems not to be modified by age, sex, body mass index, and baseline IMT values. This systematic review and meta‐analysis adds to the evidence supporting the use of IMT as a measure for identifying patients at risk of cognitive decline.

The Association of Arterial Stiffness With Significant Carotid Atherosclerosis and Carotid Plaque Vulnerability

Arterial stiffness and its valid index, the cardio-ankle vascular index (CAVI), have emerged as predictors of adverse cardiovascular outcomes. We investigated the relationship of the CAVI with significant carotid stenosis (> 50%) and the related cerebrovascular symptoms or carotid plaque echogenicity, assessed by ultrasound gray-scale median (GSM) score, at baseline and after carotid artery stenting (CAS). We prospectively enrolled 113 patients with carotid stenosis (70-99% for asymptomatic and > 50% for symptomatic participants) eligible for CAS. Age- and sex-matched individuals (n = 38) served as controls (CON). Clinical data, CAVI, and biochemical profile were obtained at baseline. Clinical assessment and CAVI measurement were performed 6 months after CAS. Compared with the CON group, the CAS group had a higher incidence of co-morbidities (diabetes, hypertension, and hyperlipidemia), higher CAVI values (9.94 ± 2.14 vs 7.85 ± .97 m/sec, P < .001), but a better lipid profile due to increased prescription of statins. The symptomatic CAS subgroup showed higher CAVI ( P < .001), high-sensitivity C-reactive protein ( P = .048), and osteoprotegerin ( P = .002) levels than the asymptomatic one. In multivariate analysis, CAVI at baseline was independently associated with the presence of significant carotid atherosclerosis (β = .695, P < .001), cerebrovascular events (β = .474, P < .001), and GSM score (β = −.275, P = .042). Raised CAVI values were independently associated with significant carotid stenosis and plaque vulnerability.

Does the Internal Carotid Artery Attenuate Blood-Flow Pulsatility in Small Vessel Disease? A 7 T 4D-Flow MRI Study

Background

Increased cerebral blood‐flow pulsatility is associated with cerebral small vessel disease (cSVD). Reduced pulsatility attenuation over the internal carotid artery (ICA) could be a contributing factor to the development of cSVD and could be associated with intracranial ICA calcification (iICAC).

Purpose

To compare pulsatility, pulsatility attenuation, and distensibility along the ICA between patients with cSVD and controls and to assess the association between iICAC and pulsatility and distensibility.

Study Type

Retrospective, explorative cross‐sectional study.

Subjects

A total of 17 patients with cSVD, manifested as lacunar infarcts or deep intracerebral hemorrhage, and 17 age‐ and sex‐matched controls.

Field Strength/Sequence

Three‐dimensional (3D) T1‐weighted gradient echo imaging and 4D phase‐contrast (PC) MRI with a 3D time‐resolved velocity encoded gradient echo sequence at 7 T.

Assessment

Blood‐flow velocity pulsatility index (vPI) and arterial distensibility were calculated for seven ICA segments (C1–C7). iICAC presence and volume were determined from available brain CT scans (acquired as part of standard clinical care) in patients with cSVD.

Statistical Tests

Independent t‐tests and linear mixed models. The threshold for statistically significance was P < 0.05 (two tailed).

Results

The cSVD group showed significantly higher ICA vPI and significantly lower distensibility compared to controls. Controls showed significant attenuation of vPI over the carotid siphon (−4.9% ± 3.6%). In contrast, patients with cSVD showed no attenuation, but a significant increase of vPI (+6.5% ± 3.1%). iICAC presence and volume correlated positively with vPI (r = 0.578) in patients with cSVD and negatively with distensibility (r = −0.386).

Conclusion

Decreased distensibility and reduced pulsatility attenuation are associated with increased iICAC and may contribute to cSVD. Confirmation in a larger prospective study is required.

Evidence Level

2

Technical Efficacy

Stage 2

Inflammation, Nitro-Oxidative Stress, Impaired Autophagy, and Insulin Resistance as a Mechanistic Convergence Between Arterial Stiffness and Alzheimer's Disease

The average age of the world's elderly population is steadily increasing. This unprecedented rise in the aged world population will increase the prevalence of age-related disorders such as cardiovascular disease (CVD) and neurodegeneration. In recent years, there has been an increased interest in the potential interplay between CVDs and neurodegenerative syndromes, as several vascular risk factors have been associated with Alzheimer's disease (AD). Along these lines, arterial stiffness is an independent risk factor for both CVD and AD. In this review, we discuss several inflammaging-related disease mechanisms including acute tissue-specific inflammation, nitro-oxidative stress, impaired autophagy, and insulin resistance which may contribute to the proposed synergism between arterial stiffness and AD.

Carotid plague formation is associated with ankle-brachial index in elderly people

AIMS

This study aimed at examining whether ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) were independently associated with carotid Intima-media thickness (CIMT) or carotid artery plaque (CAP) in elderly people.

METHODS

A cross-sectional analysis was performed in 155 individuals aged over 75 years who underwent the measurements of ABI and baPWV. Low ABI was defined as ABI ≤ 1.0. High baPWV was defined as baPWV > 2000 cm/s. The CIMT and CAP were measured with a B-mode tomographic ultrasound system.

RESULTS

Neither ABI nor baPWV was associated with CIMT in this elderly population. The group with low ABI (≤ 1.0) was significantly associated with a higher prevalence of carotid plaque (P = 0.001), while the relationship between baPWV and prevalence of carotid plaque was not found. Linear regression analysis showed that the value of ABI was significantly associated with the thickness of carotid plaque. Even in the full adjusted model, each 0.01unit ABI decreasing still increased 0.1663 mm of carotid plaque thickness (P = 0.004). Logistic Regression Analysis demonstrated that ABI lower than 1.0 had predictive value in the formation of carotid plaque with top quartile thickness (OR 2.834, 95% CI 1.131-7.099, P = 0.026). Furthermore, individuals with low ABI (≤ 1.0) were more likely to form hypoechoic carotid plaques according to ultrasonography.

CONCLUSION

Low ABI but not high baPWV was associated with the formation of carotid plaque. Furthermore, ABI was significantly associated with the thickness and morphology of carotid plaque in elderly people.

Brachial-Ankle Pulse Wave Velocity is Related to the Total Cerebral Small-Vessel Disease Score in an Apparently Healthy Asymptomatic Population

INTRODUCTION

Cerebral small-vessel disease (CSVD) is an extensive cerebrovascular disease associated with many poor outcomes. Previous studies have shown that brachial-ankle pulse wave velocity (baPWV) is related to various neuroimaging signatures, but its association with the total CSVD burden remains unknown. We aimed to explore whether baPWV is related to the total CSVD score and to establish a cutoff for detecting the presence and severity of CSVD, which may guide clinical preventive measures.

METHODS

We retrospectively selected 684 neurologically healthy participants to explore correlations between baPWV and the total CSVD score and each of its components (lacunes, white matter hyperintensity (WMH), perivascular space (PVS), and cerebral microbleeds (CMBs)). Subsequently, we established two receiver operating characteristic (ROC) curves to study the effectiveness of baPWV in predicting CSVD (scores 1-4) and severe CSVD (scores 3-4).

RESULTS

The median baPWV was 13.16 m/s, which increased significantly with increasing scores (0-4). BaPWV was significantly higher among persons with each component of the total CSVD score than among those without any components. Multivariable ordinal logistic regression analyses showed that a one-unit (m/s) change in baPWV significantly increased the total CSVD score by 0.012. The optimal baPWV cutoffs for detecting CSVD and severe CSVD were 13.12 m/s and 15.63 m/s, respectively.

CONCLUSIONS

BaPWV was positively correlated with the total CSVD score, suggesting that baPWV measurement is a useful method for early diagnosis of CSVD, which may contribute to preventing and controlling CSVD progression in the general population of China.

Asymptomatic carotid stenosis and concomitant silent brain infarctions

Objectives

This review aims to clarify (1) the definition of silent brain infarct (SBI), (2) the diagnostic criteria of SBI using magnetic resonance imaging (MRI), (3) the prevalence of patients with asymptomatic carotid stenosis and SBI based on MRI assessment, (4) the association of SBI and asymptomatic carotid stenosis and the risk of stroke compared to patients without SBI, (5) the association between development of dementia/cognitive impairment in people with asymptomatic carotid stenosis and SBI, and (6) the evidence for treating patients with carotid stenosis and SBI.

Methods

A systematic search of PubMed and Scopus including all studies published from 2000 to 2018 and written in English.

Results

No consensus of the definition and diagnostic criteria for SBI was found. The prevalence of SBI in asymptomatic carotid patients is 17–33.3%. SBI is a significant risk factor for future stroke, OR 4.6 (95% CI: 3.0–7.2; p < 0.0001). One substudy showed that immediate CEA is beneficial compared to delayed CEA in these patients, showing a 45% reduction in annual stroke rate from 1.5%/year to 0.7%/year.

Conclusion

This review emphasizes the need to standardize the definition and diagnostic criteria of SBI on MRI. Current evidence suggests an increased risk and a small potential benefit of offering carotid endarterectomy to patient with silent brain infarct. Prospective studies are warranted to elucidate these issues further.

Association between Cerebral Arterial Stiffness and Large Artery Atherosclerosis in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Carotid-cerebral pulse wave velocity (ccPWV) reflects the segment (C-M segment) stiffness between common carotid artery and ipsilateral middle cerebral artery. The C-M segment atherosclerosis (CMSA) is regarded as a most frequent cause of anterior circulation ischemic stroke. We therefore, attempted to investigate the relationship between cerebral arterial stiffness and CMSA, and provide reliable data for the early diagnosis of CMSA.

METHODS

Between June 2012 and August 2016, 81 acute ischemic stroke (AIS) patients with 154 C-M segments successfully evaluated with digital subtraction angiography and ccPWV were enrolled into this study. Patient demographics and clinical data were retrieved from our AIS databases.

RESULTS

Multivariate analyses showed that ccPWV was independently associated with CMSA (β = 39.6, P = .009) and Systolic blood pressure (β = 7.1, P < .001) in AIS patients. The values of ccPWV had a trend to be higher in the groups with more lesions (F = 45.9, P < .01) and severer stenosis (F = 102.6, P = .000), and was positively correlated with the number of lesions (r = .662, P = .000), and degree of stenosis (r = .858, P = .000) of CMSA. The fractional polynomial plots with 95% CIs also describe the close relationship between ccPWV and the number of lesions and degree of stenosis in CMSA.

CONCLUSIONS

Cerebral arterial stiffness is independently associated with the presence of CMSA, closely related to the vascular damage of C-M segment and reflects the vascular structure change of C-M segment in AIS patients. It may have the potential for assessment of CMSA in its initial stage.

Beta-blocker therapy is associated with a lower incidence of syncope due to fast ventricular tachycardias among implantable cardioverter-defibrillator patients with left ventricular dysfunction: results from a multicenter study

INTRODUCTION

Among implantable cardioverter-defibrillator (ICD) patients, a substantial proportion of syncopes are due to fast ventricular tachycardias (FVTs). In the experimental models of ventricular tachycardias, the arterial vasoconstriction plays an important role in recovering the arterial pressure. Since beta-blockers increase vascular resistance, we hypothesized that beta-blockers could reduce the occurrence of syncope due to FVTs. Our objective was to determine the relationship between the beta-blocker therapy and the incidence of syncope in FVT (cycle length [CL] 250-320 ms) occurring in ICD patients. Slow VTs were excluded because of the lack of symptoms and VF episodes because of the small number.

METHODS AND RESULTS

In this multicenter study, 226 patients (LVEF 31 ± 10%) with single-chamber ICDs were followed. FVT programming was standardized, including antitachycardia pacing (ATP) as initial therapy. Symptoms were correlated with ICD-stored episode data of FVTs. The beta-blocker therapy was determined at each FVT presentation. We analyzed 289 FVTs (CL 291 ± 21 ms; 77% under beta-blockers; median of the duration:8 s) occurring consecutively in 52 ICD patients. The frequency of FVT-related syncope was 22 (7.6%). Beta-blockers were associated with a lower heart rate preceding FVT (85 ± 22 vs. 94 ± 23 bpm; p = 0.009), a higher ATP effectiveness (86 vs. 57%; p < 0.001), a lower duration of episodes (8 [2] vs. 10 [14] s; p < 0.001), and a lower incidence of FVT-related syncope (4.5 vs. 18%; p < 0.001). By logistic regression, a FVT > 8 s (OR = 21; p = 0.003) and the beta-blocker therapy (OR = 0.3; p = 0.012) were found as independent predictors of syncope.

CONCLUSION

Among ICD patients with left ventricular dysfunction, beta-blockers are associated with a lower incidence of FVT-related syncope.

Carotid Stenosis and Impaired Cognition: The Effect of Intervention

There is a clear association between carotid artery stenosis and cognitive impairment. However, there is no consensus as to how to interpret this association, and what, if any, impact this connection should have on the management of carotid stenosis. A review of the relevant literature suggests that although an intervention to relieve carotid stenosis in patients without clinically significant cognitive impairment does not improve cognition, there may be a cognitive benefit with intervention for carotid stenosis in those patients with clinically significant cognitive disorders.

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.

Brachial-Ankle Pulse Wave Velocity as a Predictor of Silent Cerebral Embolism after Carotid Artery Stenting

BACKGROUND

In neuroendovascular therapy, the effect of arterial stiffness on postprocedural cerebral thromboembolism is unknown. In this observational study, we examined the relationship between cerebral thromboembolism after carotid artery stenting and arterial stiffness.

METHODS

From April 2015 to February 2017, we enrolled consecutive patients undergoing scheduled carotid artery stenting in our institution. In all patients, preprocedural brachial-ankle pulse wave velocity was used to assess arterial stiffness, whereas the number of new cerebral ischemic lesions on diffusion-weighted magnetic resonance imaging was assessed after treatment. We also analyzed patient data and details of procedures in patients with carotid artery stenting.

RESULTS

Twenty-one patients completed the study. The mean brachial-ankle pulse wave velocity was 1879 cm/s. There was no association of cerebral thromboembolisms with age, unstable plaque, protection device, or type of stent. However, the brachial-ankle pulse wave velocity was an independent predictor of cerebral thromboembolisms (P = .0017).

CONCLUSIONS

Brachial-ankle pulse wave velocity is predictive of silent cerebral embolisms on diffusion-weighted magnetic resonance imaging after carotid artery stenting.

Clinical usefulness of ankle brachial index and brachial-ankle pulse wave velocity in patients with ischemic stroke

Ankle brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) are widely used noninvasive modalities to evaluate atherosclerosis. Recently, evidence has increased supporting the use of ABI and baPWV as markers of cerebrovascular disease. This study sought to examine the relationship between ABI and baPWV with ischemic stroke. This study also aimed to determine which pathogenic mechanism, large artery disease (LAD) or small vessel disease (SVD), is related to ABI or baPWV. Retrospectively, 121 patients with ischemic stroke and 38 subjects with no obvious ischemic stroke history were recruited. First, ABI and baPWV were compared between the groups. Then, within the stroke group, the relevance of ABI and baPWV with regard to SVD and LAD, which were classified by brain magnetic resonance image (MRI) and magnetic resonance angiography (MRA) or computed tomography angiography (CTA) findings, was assessed. The baPWV was higher in the stroke group than non-stroke group (1,944.18±416.6 cm/s vs. 1,749.76±669.6 cm/s, P<0.01). Regarding LAD, we found that mean ABI value was lower in the group with extracranial large artery stenosis (P<0.01), and there was an inverse linear correlation between ABI and the grade of extracranial large artery stenosis (P<0.01). For SVD, there was a significant correlation between SVD and baPWV (2,057.6±456.57 cm/s in the SVD (+) group vs. 1,491±271.62 cm/s in the SVD (-) group; P<0.01). However, the grade of abnormalities detected in SVD did not correlate linearly with baPWV. These findings show that baPWV is a reliable surrogate marker of ischemic stroke. Furthermore, baPWV and ABI can be used to indicate the presence of small vessel disease and large arterial disease, respectively.

Brachial-Ankle Pulse Wave Velocity is Associated with Composite Carotid and Coronary Atherosclerosis in a Middle-Aged Asymptomatic Population

Aim: Although arterial stiffness has been associated with the development of atherosclerosis, the role of brachial-ankle pulse wave velocity (baPWV) for diagnosing composite coronary and carotid atherosclerosis has not been completely elucidated.

Method: We enrolled 773 asymptomatic individuals who were referred from 25 public health centers in Seoul and who underwent carotid ultrasonography and coronary computed tomography. Noninvasive hemodynamic parameters, including baPWV, were also measured. Composite coronary and carotid atherosclerosis was defined as follows: 1) coronary artery calcium (CAC) score ≥ 100, 2) coronary artery stenosis (CAS) ≥ 50% of diameter stenosis, 3) carotid intima medial thickness (CIMT) ≥ 0.9 mm, or 4) presence of carotid artery plaque (CAP).

Results: The incidence of composite coronary and carotid atherosclerosis was 28.2%. Coronary atherosclerosis (CAC and CAS) was significantly associated with carotid atherosclerosis (CIMT and CAP). Subjects with higher baPWV (highest quartile) had a higher prevalence of composite coronary and carotid atherosclerosis (p < .001). Although multivariate analysis failed to show baPWV as an independent predictor for composite atherosclerosis, baPWV had moderate diagnostic power to detect a subject with more than two positive subclinical atherosclerosis exams [area under the curve (AUC), 0.692].

Conclusion: baPWV was associated with the composite coronary and carotid atherosclerotic burden in a community-based asymptomatic population.

Association of Brachial-Ankle Pulse Wave Velocity with Asymptomatic Intracranial Arterial Stenosis in Hypertension Patients

BACKGROUND

Intracranial arterial stenosis is a common cause of ischemic stroke in Asians. We therefore sought to explore the relationship of brachial-ankle pulse wave velocity and intracranial arterial stenosis in 834 stroke-free hypertensive patients.

METHODS

Intracranial arterial stenosis was evaluated through computerized tomographic angiography. Brachial-ankle pulse wave velocity was measured by an automated cuff device.

RESULTS

The top decile of brachial-ankle pulse wave velocity was significantly associated with intracranial arterial stenosis (P = .027, odds ratio = 1.82; 95% confidence interval: 1.07-3.10). The patients with the top decile of brachial-ankle pulse wave velocity showed 56% higher risk for the presence of intracranial arterial stenosis to the whole population, which was more significant in patients younger than 65 years old. We also found that brachial-ankle pulse wave velocity related to both intracranial arterial stenosis and homocysteine.

CONCLUSION

Our study showed the association of brachial-ankle pulse wave velocity with asymptomatic intracranial arterial stenosis in hypertension patients, especially in relative younger subjects. Brachial-ankle pulse wave velocity might be a relatively simple and repeatable measurement to detect hypertension patients in high risk of intracranial arterial stenosis.

Association of arterial stiffness with progression of subclinical brain and cognitive disease

OBJECTIVE

We tested whether abnormal arterial stiffness and blood pressure would be associated with progression of brain aging measured by brain MRI and neurocognitive testing.

METHODS

Framingham Offspring Cohort participants (n = 1,223, 61 ± 9 years, 56% women) without previous stroke or dementia underwent applanation tonometry, brain MRI, and neurocognitive testing at examination 7 (1998-2001). Follow-up brain MRI and neurocognitive testing was performed at examination 8 (2005-2008, mean interval 6.4 ± 1.3 years). We related examination 7 inverse-transformed carotid-femoral pulse wave velocity (iCFPWV), central pulse pressure (CPP), and mean arterial pressure to changes in the following variables between examinations 7 and 8: total cerebral brain volume, white matter hyperintensity volume, and performance on executive function and abstraction tasks, the Trail Making Test, Parts B and A (ΔTrails B-A), and Similarities tests.

RESULTS

Higher baseline iCFPWV and CPP were associated with greater progression of neurocognitive decline (iCFPWV and ΔTrails B-A association: SD unit change in outcome variable per SD change in tonometry variable [β] ± SE = 0.10 ± 0.04, p = 0.019; CPP and ΔSimilarities association: -0.08 ± 0.03, p = 0.013). Higher mean arterial pressure, but not iCFPWV or CPP, was associated with increase in white matter hyperintensity volume ([β ± SE] 0.07 ± 0.03, p = 0.017). No tonometry measures were associated with change in cerebral brain volume.

CONCLUSIONS

In middle-aged and older adults without evidence of clinical stroke or dementia, elevated arterial stiffness and pressure pulsatility are associated with longitudinal progression of subclinical vascular brain injury and greater neurocognitive decline. Treatments to reduce arterial stiffness may potentially reduce the progression of neurovascular disease and cognitive decline.

Intima-Media Thickness and Cognitive Function in Stroke-Free Middle-Aged Adults: Findings From the Coronary Artery Risk Development in Young Adults Study

BACKGROUND AND PURPOSE

The relationship between carotid artery intima-media thickness (IMT) and cognitive function in midlife remains relatively unexplored. We examined the association between IMT and cognitive function in a middle-aged epidemiological cohort of 2618 stroke-free participants.

METHODS

At the year 20 visit (our study baseline), participants from the Coronary Artery Risk Development in Young Adults study had IMT measured by ultrasound at the common carotid artery. Five years later, participants completed a cognitive battery consisting of the Rey Auditory-Verbal Learning Test of verbal memory, the Digit Symbol Substitution Test of processing speed, and the Stroop test of executive function. We transformed cognitive scores into standardized z scores, with negative values indicating worse performance.

RESULTS

Mean age at baseline was 45.3 years (SD, 3.6). Greater IMT (per 1 SD difference of 0.12 mm) was significantly associated with worse performance on all cognitive tests (z scores) in unadjusted linear regression models (verbal memory, -0.16; 95% confidence interval [CI], -0.20 to -0.13; processing speed, -0.23; 95% CI, -0.27 to -0.19; and executive function, -0.17; 95% CI, -0.20 to -0.13). In models adjusted for sociodemographics and vascular risk factors that lie earlier in the causal pathway, greater IMT remained negatively associated with processing speed (-0.06; 95% CI, -0.09 to -0.02; P, 0.003) and borderline associated with executive function (-0.03; 95% CI, -0.07 to 0.00; P, 0.07) but not with verbal memory.

CONCLUSIONS

We observed an association between greater IMT and worse processing speed-a key component of cognitive functioning-at middle age above and beyond traditional vascular risk factors. Efforts targeted at preventing early stages of atherosclerosis may modify the course of cognitive aging.

Association between arterial stiffness, cerebral small vessel disease and cognitive impairment: A systematic review and meta-analysis

Arterial stiffness may be a cause of cerebral small vessel disease and cognitive impairment. We therefore performed a systematic review and meta-analysis of studies on the association between stiffness, cerebral small vessel disease and cognitive impairment. For the associations between stiffness (i.e. carotid-femoral pulse wave velocity (cfPWV), brachial-ankle PWV (baPWV), carotid stiffness and pulse pressure) on the one hand and cerebral small vessel disease and cognitive impairment on the other, we identified 23 (n=15,666/20 cross-sectional; 1 longitudinal; 2 combined cross-sectional/longitudinal) and 41 studies (n=57,671/26 cross-sectional; 11 longitudinal; 4 combined cross-sectional/longitudinal), respectively. Pooled analyses of cross-sectional studies showed that greater stiffness was associated with markers of cerebral small vessel disease with odds ratios, per +1 SD, of 1.29-1.32 (P<.001). Studies on cognitive impairment could not be pooled due to large heterogeneity. Some (but not all) studies showed an association between greater stiffness and cognitive impairment, and the strength of this association was relatively weak. The present study supports the hypothesis that greater arterial stiffness is a contributor to microvascular brain disease.

The epidemiology of silent brain infarction: a systematic review of population-based cohorts

BACKGROUND

Cerebral infarction is a commonly observed radiological finding in the absence of corresponding, clinical symptomatology, the so-called silent brain infarction (SBI). SBIs are a relatively new consideration as improved imaging has facilitated recognition of their occurrence. However, the true incidence, prevalence and risk factors associated with SBI remain controversial.

METHODS

Systematic searches of the Medline and EMBASE databases from 1946 to December 2013 were performed to identify original studies of population-based adult cohorts derived from community surveys and routine health screening that reported the incidence and prevalence of magnetic resonance imaging (MRI)-determined SBI.

RESULTS

The prevalence of SBI ranges from 5% to 62% with most studies reported in the 10% to 20% range. Longitudinal studies suggest an annual incidence of between 2% and 4%. A strong association was seen to exist between epidemiological estimates of SBI and age of the population assessed. Hypertension, carotid stenosis, chronic kidney disease and metabolic syndrome all showed a strong association with SBI. Heart failure, coronary artery disease, hyperhomocysteinemia and obstructive sleep apnea are also likely of significance. However, any association between SBI and gender, ethnicity, tobacco or alcohol consumption, obesity, dyslipidemia, atrial fibrillation and diabetes mellitus remains unclear.

CONCLUSIONS

SBI is a remarkably common phenomenon and endemic among older people. This systematic review supports the association of a number of traditional vascular risk factors, but also highlights disparities between clinically apparent and silent strokes, potentially suggesting important differences in pathophysiology and warranting further investigation.

Arterial stiffness, the brain and cognition: a systematic review

BACKGROUND

Arterial stiffness is a known predictor of cardiovascular disease, and has also been associated with markers of cerebral small vessel disease as well as poor cognitive function and cognitive decline. The consistency of these associations and their relationship to each other are unclear.

METHOD

We conducted a systematic review of the evidence associating arterial stiffness with cognitive function and cognitive decline, and with makers of cerebral small vessel disease, specifically lacunar infarcts and white matter hyperintensities.

RESULTS

Thirteen cross-sectional studies examining arterial stiffness and white matter hyperintensities or lacunar infarctions reported a positive association between increased arterial stiffness and radiological findings of cerebral small vessel disease. Two longitudinal studies examining the relationship between arterial stiffness and white matter hyperintensities found increased pulse wave velocity to be an independent predictor of white matter hyperintensity volume. Fifteen cross-sectional and seven longitudinal studies examining arterial stiffness and cognition were identified. Fourteen of the fifteen cross-sectional studies associated increased arterial stiffness with lower cognitive function, and six of the seven longitudinal studies found arterial stiffness to be predictive of cognitive decline.

CONCLUSION

Arterial stiffness is associated with cerebral small vessel disease and decreased cognitive function. However methodological limitations such as differing covariates between studies and an over-reliance on the MMSE to measure cognition are a concern across much of the literature.

Arterial stiffness and functional outcome in acute ischemic stroke

OBJECTIVE

Arterial stiffness is a common change associated with aging and can be evaluated by measuring pulse wave velocity (PWV) between sites in the arterial tree, with the stiffer artery having the higher PWV. Arterial stiffness is associated with the risk of stroke in the general population and of fatal stroke in hypertensive patients. This study is to clarify whether PWV value predicts functional outcome of acute ischemic stroke.

METHODS

ONE HUNDRED PATIENTS WERE ENROLLED WITH A DIAGNOSIS OF ACUTE ISCHEMIC STROKE AND CATEGORIZED INTO TWO GROUPS: large-artery atherosclerosis (LAAS) or small vessel disease (SVD) subtype of Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Each group was divided into two sub-groups based on the functional outcome of acute ischemic stroke, indicated by modified Rankin Scale (mRS) at discharge. Poor functional outcome group was defined as a mRS ≥ 3 at discharge. Student's t-test or Mann-Whitney U-test were used to compare maximal brachial-ankle PWV (baPWV) values.

RESULTS

Twenty-four patients whose state was inadequate to assess baPWV or mRS were excluded. There were 38 patients with good functional outcome (mRS < 3) and 38 patients with poor functional outcome (mRS ≥ 3). The baPWV values were significantly higher in patients with poor outcome (2,070.05 ± 518.37 cm/s) compared with those with good outcome (1,838.63 ± 436.65) (p = 0.039). In patients with SVD subtype, there was a significant difference of baPWV values between groups (2,163.18 ± 412.71 vs. 1,789.80 ± 421.91, p = 0.022), while there was no significant difference of baPWV among patients with LAAS subtype (2,071.76 ± 618.42 vs. 1,878.00 ± 365.35, p = 0.579).

CONCLUSIONS

Arterial stiffness indicated by baPWV is associated with the functional outcome of acute ischemic stroke. This finding suggests that measurement of baPWV predicts functional outcome in patients with stroke especially those whose TOAST classification was confirmed as SVD subtype.

Renal and vascular protective effects of ezetimibe in chronic kidney disease

OBJECTIVE

Dyslipidemia is a risk factor for not only cardiovascular diseases (CVD), but also chronic kidney disease (CKD). Ezetimibe, a cholesterol absorption inhibitor, lowers cholesterol levels by inhibiting both extrinsic and intrinsic cholesterol absorption via the gastrointestinal duct. However, very few studies have examined its efficacy and safety for patients with dyslipidemia complicated with CKD.

METHODS

Thirty-seven dyslipidemic patients (low density lipoprotein cholesterol (LDL-C) levels ≥120 mg/dL) complicated with CKD were given ezetimibe (10 mg/day) for twenty-four weeks. The efficacy and safety of the therapy, including the anti-atherosclerotic and renal protective effects, were then examined.

RESULTS

Significant decreases were observed in the levels of LDL-C (158.9 ± 26.9 mg/dL→123.0 ± 31.8 mg/dL; p<0.0001), remnant-like lipoprotein cholesterol (9.3 ± 5.3 mg/dL→7.3 ± 3.8 mg/dL; p<0.05) and lipoprotein (a) (22.0 ± 16.1 mg/dL→16.4 ± 11.0 mg/dL; p<0.01). The estimated glomerular filtration rate did not change, but the urine protein to creatinine ratio decreased significantly (1,107.3 ± 1,454.2 mg/gCre→732.1 ± 1,237.8 mg/gCre; p<0.05). No changes were observed in the carotid intima media thickness, but the brachial-ankle pulse wave velocity decreased significantly (1,770.4 ± 590.3 cm/sec→1,702.5 ± 519.9 cm/sec; p<0.05). No adverse events were observed.

CONCLUSION

Ezetimibe can be safely administered even to patients with CKD. The results of this study indicate that ezetimibe may provide some renal protection and suppress the complications of CVD in CKD patients.

Pulse wave velocity is associated with β-amyloid deposition in the brains of very elderly adults

OBJECTIVE

To determine arterial stiffness and β-amyloid (Aβ) deposition in the brain of dementia-free older adults.

METHODS

We studied a cohort of 91 dementia-free participants aged 83-96 years. In 2009, participants completed brain MRI and PET imaging using Pittsburgh compound B (PiB; a marker of amyloid plaques in human brain). In 2011, we measured resting blood pressure (BP), mean arterial pressure (MAP), and arterial stiffness by pulse wave velocity (PWV) in the central, peripheral, and mixed (e.g., brachial ankle PWV [baPWV]) vascular beds, using a noninvasive and automated waveform analyzer.

RESULTS

A total of 44/91 subjects were Aβ-positive on PET scan. Aβ deposition was associated with mixed PWV, systolic BP, and MAP. One SD increase in baPWV resulted in a 2-fold increase in the odds of being Aβ-positive (p = 0.007). High white matter hyperintensity (WMH) burden was associated with increased central PWV, systolic BP, and MAP. Compared to Aβ-negative individuals with low WMH burden, each SD increase in PWV was associated with a 2-fold to 4-fold increase in the odds of being Aβ-positive and having high WMH.

CONCLUSIONS

Arterial stiffness was associated with Aβ plaque deposition in the brain, independent of BP and APOE ε4 allele. The associations differed by type of brain abnormality and vascular bed measured (e.g., WMH with central stiffness and Aβ deposition and mixed stiffness). Arterial stiffness was highest in individuals with both high Aβ deposition and WMH, which has been suggested to be a "double hit" contributing to the development of symptomatic dementia.

Large-vessel correlates of cerebral small-vessel disease

OBJECTIVE

Our aim was to investigate the relationship of carotid structure and function with MRI markers of cerebral ischemic small-vessel disease.

METHODS

The study comprised 1,800 participants (aged 72.5 ± 4.1 years, 59.4% women) from the 3C-Dijon Study, a population-based, prospective cohort study, who had undergone quantitative brain MRI and carotid ultrasound. We used multivariable logistic and linear regression adjusted for age, sex, and vascular risk factors.

RESULTS

Presence of carotid plaque and increasing carotid lumen diameter (but not common carotid artery intima-media thickness) were associated with higher prevalence of lacunar infarcts: odds ratio (OR) = 1.60 (95% confidence interval [CI]: 1.09-2.35), p = 0.02 and OR = 1.24 (95% CI: 1.02-1.50), p = 0.03 (by SD increase). Carotid plaque was also associated with large white matter hyperintensity volume (WMHV) (age-specific top quartile of WMHV distribution): OR = 1.32 (95% CI: 1.04-1.67), p = 0.02, independently of vascular risk factors. Increasing Young elastic modulus and higher circumferential wall stress, reflecting augmented carotid stiffness, were associated with increasing WMHV (effect estimate [β] ± standard error: 0.0003 ± 0.0001, p = 0.024; β ± standard error: 0.005 ± 0.002, p = 0.008). Large WMHV was also associated with increasing Young elastic modulus (OR = 1.22 [95% CI: 1.04-1.42], p = 0.01) and with decreasing distensibility coefficient (OR = 0.83 [95% CI: 0.69-0.99], p = 0.04), independently of vascular risk factors. Associations of carotid lumen diameter with lacunar infarcts and of carotid stiffness markers with WMHV were independent of carotid plaque.

CONCLUSIONS

In addition to and independently of carotid plaque, increasing carotid lumen diameter and markers of carotid stiffness were associated with increasing prevalence of lacunar infarcts and increasing WMHV, respectively.

Carotid atherosclerosis and prospective risk of dementia

BACKGROUND AND PURPOSE

Although vascular risk factors have been implicated in the development of all-cause dementia and Alzheimer disease (AD), few studies have examined the association between subclinical atherosclerosis and prospective risk of dementia.

METHODS

Participants from the Baltimore Longitudinal Study of Aging (n=364; age, 60-95 years; median age, 73; 60% male; 82% white) underwent initial carotid atherosclerosis assessment and subsequently were assessed for dementia and AD annually for up to 14 years (median, 7.0). Cox proportional hazards models predicting all-cause dementia and AD were adjusted for age, sex, race, education, blood pressure, cholesterol, cardiovascular disease, diabetes mellitus, and smoking.

RESULTS

Sixty participants developed dementia, with 53 diagnosed as AD. Raw rates of future dementia and AD among individuals initially in the upper quintile of carotid intimal medial thickness or with bilateral carotid plaque were generally double the rates of individuals with intimal medial thickness in the lower quintiles or no plaque at baseline. Adjusted proportional hazards models revealed >2.5-fold increased risk of dementia and AD among individuals in the upper quintile of carotid intimal medial thickness, and approximately 2.0-fold increased risk of dementia among individuals with bilateral plaque.

CONCLUSIONS

Multiple measures of carotid atherosclerosis are associated with prospective risk of dementia. Individuals in the upper quintile of carotid intimal medial thickness or bilateral carotid plaque were at greatest risk. These findings underscore the possibility that early intervention to reduce atherosclerosis may help delay or prevent onset of dementia and AD.

Aortic pulse wave velocity predicts focal white matter hyperintensities in a biracial cohort of older adults

Although the cross-sectional relationship of arterial stiffness with cerebral small vessel disease is consistently shown in middle-aged and young-old adults, it is less clear whether these associations remain significant over time in very old adults. We hypothesize that arterial stiffness is longitudinally associated with white matter characteristics, and associations are stronger within watershed areas. Neuroimaging was obtained in 2006-2008 from 303 elderly (mean age 82.9 years, 59% women, 41% black) with pulse wave velocity (PWV) measures in 1997-1998. Multivariable regression models estimated the coefficients for PWV (cm/sec) in relationship to presence, severity, and spatial distribution of white matter hyperintensities (WMH), gray matter volume, and fractional anisotropy from diffusion tensor, adjusting for demographic, cardiovascular risk factors, and diseases from 1997-1998 to 2006-2008. Higher PWV in 1997-1998 was associated with greater WMH volume in 2006-2008 within the left superior longitudinal fasciculus (age and total brain WMH adjusted, P=0.023), but not with WMH in other tracts or with fractional anisotropy or gray matter volume from total brain (P>0.2). Associations were stronger in blacks than in whites, remaining significant in fully adjusted models. Elderly with WMH in tracts related to processing speed and memory are more likely to have had higher PWV values 10 years prior, before neuroimaging data being available. Future studies should address whether arterial stiffness can serve as an early biomarker of covert brain structural abnormalities and whether early arterial stiffness control can promote successful brain aging, especially in black elderly.

Arterial Stiffness and Cerebral Small Vessel Disease

Background and Purpose—

Aging and vascular risk factors contribute to arterial stiffening. Increased arterial stiffness exposes the small vessels in the brain to abnormal flow pulsations and, as such, may contribute to the pathogenesis of cerebral small vessel disease. In a population-based study, we investigated the association between arterial stiffness, as measured by aortic pulse wave velocity (aPWV), and small vessel disease.

Methods—

Overall, 1460 participants (mean age, 58.2 years) underwent aPWV measurement and brain MRI scanning. We calculated aPWV by measuring time differences and distances between pulse waves in the carotid and femoral arteries. Using automated MRI analysis, we obtained white matter lesion volumes. Infarcts and microbleeds were rated visually. We used linear and logistic regression models to associate aPWV with small vessel disease, adjusting for age, sex, mean arterial pressure, and heart rate and additionally for cardiovascular risk factors. Subsequently, we explored associations in strata of hypertension.

Results—

In the study group, higher aPWV was associated with larger white matter lesion volume (difference in volume per SD increase in aPWV 0.07; 95% CI, 0.02–0.12) but not with lacunar infarcts or microbleeds. In persons with uncontrolled hypertension, higher aPWV was significantly associated with larger white matter lesion volume (difference in volume per SD increase in aPWV 0.09; 95% CI, 0.00–0.18), deep or infratentorial microbleeds (OR, 2.13; 95% CI, 1.16–3.91), and to a lesser extent also with lacunar infarcts (OR, 1.63; 95% CI, 0.98–2.70). No such associations were present in persons with controlled hypertension or without hypertension.

Conclusions—

In our study, increased arterial stiffness is associated with a larger volume of white matter lesions.

Silent Brain Infarction – A Review of Recent Observations

Silent brain infarction is a cerebral ischaemic event evident on brain imaging without any clinical symptom. Silent brain infarction is often detected in apparently healthy, elderly people and in different selected patient groups as well. Lately, several studies were carried out in order to identify the clinical conditions leading to silent brain infarction. A large number of clinical and paraclinical parameters were found to increase silent brain infarction prevalence, and the continuously growing list of risk factors revealed that the majority of them are similar to those related to stroke. Accordingly, some consider silent brain infarction the preclinical stage of clinically overt stroke. This point of view emphasizes the early recognition and management of silent brain infarction-related risk factors, and a great need for comparative studies, which could elicit the most sensitive indicators of the increased silent brain infarction risk, especially the ones that could be cost-effectively screened in the large populations as well.

Silent brain infarct is independently associated with arterial stiffness indicated by cardio-ankle vascular index (CAVI)

It is still unclear whether silent brain infarct (SBI) and white-matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) scans are associated with cardio-ankle vascular index (CAVI), a novel parameter of arterial stiffness. We studied 220 consecutive patients (mean age, 69 years) without a history of stroke or transient ischemic attack. Patients were assessed for the presence of SBI, WMHs and risk factors. Arterial stiffness was evaluated using CAVI. Patients were categorized into one of two groups according to the presence or absence of SBI and WMHs, and clinical characteristics were compared between the two groups. CAVI was significantly higher in patients with SBI or in patients with WMHs than in those without those respective findings. The CAVI cutoff values for detection of SBI and WMHs were 9.2 and 8.9, respectively. On multivariable analyses, CAVI, a one point increase in CAVI: odds ratio (OR), 1.25; 95% confidence interval (CI), 1.01-1.56; CAVI ≥9.2: OR, 2.34; 95% CI, 1.16-5.02, was independently associated with SBI, however, CAVI was not independently associated with WMHs. Patients with CAVI ≥9.2 had higher OR for the presence of both SBI and WMHs (OR, 2.57; 95% CI, 1.15-5.98) when compared with patients with CAVI <9.2 after adjustment for age and sex. SBI is independently associated with arterial stiffness indicated by CAVI.

Aortic pulse wave velocity is associated with measures of subclinical target organ damage

OBJECTIVES

Our goal was to evaluate the associations of central arterial stiffness, measured by aortic pulse wave velocity (aPWV), with subclinical target organ damage in the coronary, peripheral arterial, cerebral, and renal arterial beds.

BACKGROUND

Arterial stiffness is associated with adverse cardiovascular outcomes. We hypothesized that aPWV is associated with subclinical measures of atherosclerosis-coronary artery calcification (CAC) and ankle-brachial index (ABI) and arteriolosclerosis-brain white matter hyperintensity (WMH) and urine albumin-creatinine ratio (UACR).

METHODS

Participants (n = 812; mean age 58 years; 58% women, 71% hypertensive) belonged to hypertensive sibships and had no history of myocardial infarction or stroke. aPWV was measured by applanation tonometry, CAC by electron beam computed tomography, ABI using a standard protocol, WMH volume by brain magnetic resonance, and UACR by standard methods. WMH was log-transformed, whereas CAC and UACR were log-transformed after adding 1 to reduce skewness. The associations of aPWV with CAC, ABI, WMH, and UACR were assessed by multivariable linear regression using generalized estimating equations to account for the presence of sibships. Covariates included in the models were age, sex, body mass index, history of smoking, hypertension and diabetes, total and high-density lipoprotein cholesterol, estimated glomerular filtration rate, use of aspirin and statins, and pulse pressure.

RESULTS

The mean ± SD aPWV was 9.8 ± 2.8 m/s. After adjustment for age, sex, conventional cardiovascular risk factors, and pulse pressure, higher aPWV (1 m/s increase) was significantly associated with higher log (CAC + 1) (β ± SE = 0.14 ± 0.04; p = 0.0003), lower ABI (β ± SE = -0.005 ± 0.002; p = 0.02), and greater log (WMH) (β ± SE = 0.03 ± 0.009; p = 0.002), but not with log (UACR + 1) (p = 0.66).

CONCLUSIONS

Higher aPWV was independently associated with greater burden of subclinical disease in coronary, lower extremity, and cerebral arterial beds, highlighting target organ damage as a potential mechanism underlying the association of arterial stiffness with adverse cardiovascular outcomes.

Silent cerebral events in asymptomatic carotid stenosis

BACKGROUND

Approximately 20% of strokes are attributable to carotid stenosis. However, the number of asymptomatic patients needed to prevent one stroke or death with endarterectomy is high at 17 to 32. There is a clear need to identify asymptomatic individuals at high risk of developing future ischemic events to improve the cost-effectiveness of surgery. Our aim was to examine the evidence for subclinical microembolization and silent brain infarction in the prediction of stroke in asymptomatic carotid stenosis using transcranial Doppler (TCD), computed tomography (CT), and magnetic resonance imaging (MRI).

METHODS

The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Articles regarding humans between 1966 and 2010 were identified through systematic searches of Pubmed, MEDLINE, and EMBASE electronic databases using a predetermined search algorithm.

RESULTS

Fifty-eight full text articles met the inclusion criteria. A median of 28% of microemboli positive patients experienced a stroke or transient ischemic attack during follow-up compared with 2% of microemboli negative patients (P = .001). The same was true for the end point of stroke alone with a median of 10% of microemboli positive patients experiencing a stroke vs 1% of microemboli negative patients (P = .004). A specific pattern of silent CT infarctions was related to future stroke risk (odds ratio [OR] = 4.6; confidence interval [CI] = 3.0-7.2; P < .0001). There are no prospective MRI studies linking silent infarction and stroke risk.

CONCLUSIONS

There is level 1 evidence for the use of TCD to detect microembolization as a risk stratification tool. However, this technique requires further investigation as a stroke prevention tool and would be complemented by improvements in carotid plaque imaging.

Silent Brain Infarcts

Background and Purpose—

Silent brain infarcts (SBIs) have been recognized as common lesions in elderly subjects and their diagnosis relies on brain imaging. In this study, we aimed to evaluate the different MRI parameters and criteria used for their evaluation in the literature to better understand the variation across studies and related limitations.

Method—

Original MRI studies of SBI performed in human populations and reported in the English literature were reviewed. Analyses were restricted to population-based studies or studies in which at least 50 subjects with SBI were detected. The MRI parameters as well as the MRI criteria of SBI (size, signal characteristics, and criteria for differentiation of dilated Virchow-Robin spaces) were described and analyzed.

Result—

Magnetic field strength, slice thickness, and gap between slices greatly varied among the 45 articles included in this review. The MRI definition of SBI was inconsistent across studies. In half of them, SBI was defined as hypointense on T1 and hyperintense on T2-weighted images. Exclusion criteria for dilated Virchow-Robin spaces were used only in 7 studies.

Conclusions—

The variation in MRI characteristics and diagnostic criteria for SBI represent a major limitation for interpretation and comparison of data between studies. Efforts are needed to reach unified imaging criteria for SBI.

Impact of impaired fasting glucose and impaired glucose tolerance on arterial stiffness in an older Chinese population: the Guangzhou Biobank Cohort Study-CVD

The aim of the study was to compare the impact of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) on vascular function among older Chinese people. A random sample of 671 men and 603 women aged 50 to 85 years without known diabetes from the Guangzhou Biobank Study-CVD was examined in a cross-sectional study. Subjects with no previously confirmed or treated diabetes but with both fasting plasma glucose less than 5.6 mmol/L and 2-hour glucose from 7.8 to less than 11.0 mmol/L were classified as having isolated IGT, and those with no previously confirmed and treated diabetes but with both fasting plasma glucose from 5.6 to less than 7.0 mmol/L and 2-hour glucose less than 7.8 mmol/L were classified as having isolated IFG. A total of 11.0% of the men and 8.6% of the women had isolated IFG, and 17.7% of the men and 18.6% of the women had isolated IGT. The brachial-ankle pulse wave velocity and pulse pressure were increased in both the isolated IFG and isolated IGT subjects compared with the normoglycemia group (both Ps < .001). Compared with subjects with isolated IFG, those with isolated IGT appeared to have a higher age- and sex-adjusted brachial-ankle pulse wave velocity (1543 +/- 22 vs 1566 +/- 17, P = .07) and to be more insulin resistant (2-hour postload insulin: 54.2 +/- 2.13 vs 26.8 +/- 2.99 muU/mL, P < .001), had a worse lipid profile (apolipoprotein [apo] B: 1.07 +/- 0.02 vs 0.97 +/- 0.02 g/L, P < .001; apo B/apo A-1 ratio: 0.80 +/- 0.02 vs 0.69 +/- 0.02, P < .001), but had lower glycosylated hemoglobin levels (6.03% +/- 0.06% vs 5.86% +/- 0.04%, P < .001) (values are mean +/- SE). Subjects with isolated IGT had greater arterial stiffness, probably as a result of being more insulin resistant, with a worse lipid profile than those with isolated IFG. The sole use of fasting glucose level to identify prediabetic people would fail to identify a significant proportion of the at-risk population.

Relationship between carotid intima-media thickness and silent cerebral infarction in Japanese subjects with type 2 diabetes

OBJECTIVE

We examined the relationship between intima-media thickness of common carotid artery (CCA-IMT) and silent cerebral infarction (SCI) with the magnetic resonance imaging (MRI) study in Japanese subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

The brain MRI study and the carotid ultrasonography were performed in a total of 217 consecutive Japanese subjects with type 2 diabetes. Various risk factors for SCI were examined using multiple logistic analyses.

RESULTS

The SCI was found in 60.4% of the diabetic subjects. In the diabetic subjects, age, systolic blood pressure (SBP), pulse wave velocity, and CCA-IMT were significantly higher in the subjects with SCI than in those without it. Multiple logistic analyses indicated that age, SBP, and CCA-IMT were significant and independent risk factors of SCI in the diabetic subjects.

CONCLUSIONS

CCA-IMT, but not pulse wave velocity, was independently associated with SCI in Japanese subjects with type 2 diabetes.

Extracellular matrix alterations in hypertensive vascular remodeling

Vascular cells are very sensitive to their hemodynamic environment. Any change in blood pressure or blood flow can be sensed by endothelial and vascular smooth muscle cells and ultimately results in structural modifications within the vascular wall that accommodate the new conditions. In the case of hypertension, the increase in arterial stretch stimulates vessel thickening to normalize the tensile forces. This process requires modification of the extracellular matrix and of cell-matrix interactions, which mainly involves extracellular proteases. In hypertension, chronic exposure of the arterial wall to stretch leads to vascular remodeling, arterial stiffness and calcification, which finally affect target organ function. This review surveys how mechanical stretch regulates extracellular proteases, considering the signaling pathways involved and the consequences on the cardiovascular system.

Carotid intimal medial thickness predicts cognitive decline among adults without clinical vascular disease

BACKGROUND AND PURPOSE

Though clinical cardiovascular and cerebrovascular diseases are established risk factors for cognitive decline and dementia, less is known about the relations between vascular health and cognition among individuals without these diseases. Carotid intimal medial thickness (IMT), a measure of subclinical vascular disease, is associated with concurrent decrements in cognitive function, but relatively little research has examined longitudinal relations between carotid IMT and prospective cognitive decline.

METHODS

We examined relations of carotid IMT to prospective trajectories of cognitive function among 538 (aged 20 to 93, 39% male, 66% white) participants in the Baltimore Longitudinal Study of Aging (BLSA) free of known cardiovascular, cerebrovascular, and neurological disease. Participants underwent initial carotid ultrasonography and repeat neuropsychological testing on up to 8 occasions over up to 11 years of follow-up. Mixed-effects regression analyses were adjusted for age, gender, race, education, mean arterial pressure, body mass index, total cholesterol, smoking, depressive symptoms, and cardiovascular medication use.

RESULTS

Individuals with greater carotid IMT displayed accelerated decline in performance over time on multiple tests of verbal and nonverbal memory, as well as a test of semantic association fluency and executive function.

CONCLUSIONS

Carotid IMT predicts accelerated cognitive decline, particularly in the domain of memory, among community-dwelling individuals free of vascular and neurological disease.

Carotid atherosclerosis in ischemic cerebrovascular patients

Background

Cerebral emboli resulting from atherosclerosis at the carotid bifurcation is a major cause of ischemic stroke. A convenient and prompt evaluation is necessary for secondary prevention and treatment.

Methods

In this study, one hundred and thirty eight patients with cerebral ischemic events were enrolled; 100 patients with nonischemic cerebral diseases were enrolled as controls. Noninvasive ultrasound was used to measure the atherosclerotic plaques and intima-media thickness (IMT) of carotid and femoral artery.

Results

Our results showed that patients in study group had higher incidence and severity of carotid and femoral plaques, and higher mean intima-media thickness (IMT) at both the carotid and femoral sites compared with that of controls (p < 0.01). Carotid atherosclerosis were highly prone to have instability plaques in study group(p < 0.001).

Conclusions

This cross-sectional study showed that, the prevalence of carotid atherosclerosis and the unstable plaques were higher in cerebral ischemic patients.

Keywords

Carotid artery; Atherosclerosis; Intima-media thickness; Cerebral ischemic stroke

Increased aortic pulse wave velocity is associated with silent cerebral small-vessel disease in hypertensive patients

Aortic stiffness predicts an excess risk of stroke, supposedly via cerebral small-vessel disease. White matter hyperintensities, silent lacunar infarcts, and brain microbleeds, manifestations of cerebral small-vessel disease on neuroimaging, may precede overt cerebrovascular disease. Therefore, we assessed whether aortic stiffness is also related to such lesions. In 167 hypertensive patients (85 men) without a history of cardiovascular or cerebrovascular disease, a mean age of 51.8+/-13.1 years, and untreated office blood pressure levels of 169+/-25/104+/-12 mm Hg, we determined aortic pulse wave velocity and office and ambulatory 24-hour pulse pressure (off medication), as well as the volume of white matter hyperintensities and the presence of lacunar infarcts and microbleeds using brain MRI. Linear and logistic regression analyses were performed to assess the relationships between the arterial stiffness measures and brain lesions. Aortic stiffness and pulse pressure were significantly related to each of the brain lesions in univariate analyses (P<0.05). Multivariate analyses, adjusted for age, sex, brain volume, mean arterial pressure, and heart rate, showed that a higher pulse wave velocity was significantly associated with a greater volume of white matter hyperintensities (unstandardized regression coefficient: 0.041; 95% CI: 0.005 to 0.078; P<0.05) and the presence of lacunar infarcts (odds ratio [per SD increase in pulse wave velocity]: 1.78; 95% CI: 1.06 to 2.99; P<0.05) but not with microbleeds. The models for pulse pressure failed to reach statistical significance in multivariate analyses. In conclusion, aortic stiffness is independently associated with manifestations of cerebral small-vessel disease in hypertensive patients, linking systemic large- to cerebral small-artery disease.