Lower blood flow velocity, higher resistance index, and larger diameter of extracranial carotid arteries are associated with ischemic stroke independently of carotid atherosclerosis and cardiovascular risk factors

Insulin resistance in the adipose tissue predicts future vascular resistance: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases

BACKGROUND AND AIMS

Diameter, plaque score, and resistance index (RI) in the common carotid artery (CCA) are indicators of arterial remodeling, atherosclerosis, and vascular resistance, respectively. This study investigated the longitudinal association between adipose tissue insulin resistance or serum free fatty acid (FFA) levels and the CCA parameters.

METHODS

This retrospective cohort analysis included 1089 participants (mean age 57.6 years; 40.0 % women) with data on health checkups from January 1982 to March 2003 and carotid artery ultrasonography from January 2015 to June 2019. Baseline serum FFA and immunoreactive insulin levels were assessed before and 30, 60, and 120 min after glucose ingestion. Adipose insulin resistance index (Adipo-IR) was calculated as the product of fasting serum insulin and FFA levels. An RI value >0.75 was defined as high RI.

RESULTS

A significant association was found between Adipo-IR and RI; however, Adipo-IR showed no association with CCA diameter or plaque score. The incidence of high RI increased with Adipo-IR quartile (Q) groups (47.3 % in Q1, 52.8 % in Q2, 53.3 % in Q3, 62.4 % in Q4; Cochrane-Armitage test for trend, p < 0.001). In multivariate analysis, Adipo-IR levels (Q4 vs. Q1 odds ratio: 1.67, 95 % confidence interval: 1.12-2.51) were positively associated with high RI incidence. Moreover, a significant association was found between RI and serum FFA levels after glucose intake, but not fasting FFA levels.

CONCLUSIONS

Future vascular resistance was predicted by insulin resistance in the adipose tissue. After glucose intake, serum FFA levels may significantly impact vascular resistance development.

A machine learning approach to predict cerebral perfusion status based on internal carotid artery blood flow

BACKGROUND AND OBJECTIVE

Cerebral blood flow (CBF), or perfusion, is a prerequisite for maintaining brain metabolism and normal physiological functions. Diagnosing and evaluating cerebral perfusion status is crucial to managing brain disease. However, cerebral perfusion imaging devices are complicated to operate, should be controlled by specialized technicians, are often large, and are usually installed in fixed places such as hospitals. It is significantly difficult for clinicians to obtain the cerebral perfusion status in time. Considering that CBF is mainly supplied by the internal carotid artery (ICA), this study proposes a cerebral perfusion status prediction model that can automatically quantify the level of cerebral perfusion in patients by modeling the association between ICA blood flow and cerebral perfusion.

MATERIALS AND METHODS

Forty-eight participants were enrolled in the study after screening. We collected participants' ICA ultrasound and brain magnetic resonance imaging (MRI) data before and after dobutamine injection based on a rigorous experimental paradigm and built an ICA-cerebral perfusion datasetdd. Support vector machine (SVM), k-nearest neighbor (KNN), decision tree (DT), random forest (RF), gradient boosting decision tree (GBDT), and extreme gradient boosting (XGBOOST) were used for early prediction of cerebral perfusion status. The SHAP analysis was adopted to reveal the impact of interpretable predictions for each feature.

RESULTS

The XGBOOST model demonstrated the best overall classification performance with an accuracy of 78.01%, sensitivity of 96.67%, specificity of 98.23%, F1 score of 74.57%, Matthews correlation coefficient (MCC) of 62.17%, and area under the receiver operating characteristic curve (AUC) of 87.08%. Accelerated speed, peak systolic flow velocity, and resistance index of ICA blood flow are important factors for cerebral perfusion prediction.

CONCLUSIONS

The proposed method paves a new avenue for the study of predicting cerebral perfusion status automatically and providesv a noninvasive, real-time, and low-cost alternative to brain perfusion imaging. Moreover, this analysis identifies highly predictive features for the cerebral perfusion status and gives clinicians an intuitive understanding of the influence of key features. The prediction models can serve as an early warning tool that offers sufficient time for clinicians to take early intervention measures.

Cardiovascular risk in rare diseases: a prognostic stratification model in a cohort of sarcoidosis patients

Sarcoidosis is a rare granulomatous disease that can affect any organ; as other chronic diseases, it leads to increased risk of atherosclerosis and cardiovascular (CV) disease. The aim of our observational study was to define a prognostic stratification model of sarcoidosis patients based on the evaluation of CV risk through common carotid Doppler ultrasound and cardiovascular risk scores assessment; for this reason, a clinical phenotyping of sarcoidosis patients in four subgroups was done, based on the different organ involvement. A cohort of 53 sarcoidosis patients and a cohort of 48 healthy volunteers were enrolled. Results showed that CV risk was higher in sarcoidosis cohort than in the control group when evaluated through CV risk scores and Doppler parameters: peak-systolic velocity (PSV) and end-diastolic velocity (EDV) were significantly lower in sarcoidosis cohort (p = 0.045 and p = 0.017, respectively), whereas intima media thickness (IMT) showed higher values in sarcoidosis group than in controls (p = 0.016). The analysis of sarcoidosis phenotypes showed no significative differences of CV risk among them when CV risk scores were considered, while partial differences emerged by evaluating subclinical atherosclerosis. Results also highlighted a relationship between CV risk score and carotid Doppler ultrasound parameters: EDV showed an inverse correlation with Framingham score (R = - 0.275, p = 0.004), whereas IMT showed a direct one (R = 0.429; p = 0.001); furthermore, an inverse correlation between PSV and EDV and illness duration (R = - 0.298, p = 0.030 and R = - 0.406, p = 0.002, respectively) was found, so suggesting a higher CV risk in patients with a longer story of disease.

Development and Validation of Machine Learning Models to Classify Artery Stenosis for Automated Generating Ultrasound Report

Duplex ultrasonography (DUS) is a safe, non-invasive, and affordable primary screening tool to identify the vascular risk factors of stroke. The overall process of DUS examination involves a series of complex processes, such as identifying blood vessels, capturing the images of blood vessels, measuring the velocity of blood flow, and then physicians, according to the above information, determining the severity of artery stenosis for generating final ultrasound reports. Generation of transcranial doppler (TCD) and extracranial carotid doppler (ECCD) ultrasound reports involves a lot of manual review processes, which is time-consuming and makes it easy to make errors. Accurate classification of the severity of artery stenosis can provide an early opportunity for decision-making regarding the treatment of artery stenosis. Therefore, machine learning models were developed and validated for classifying artery stenosis severity based on hemodynamic features. This study collected data from all available cases and controlled at one academic teaching hospital in Taiwan between 1 June 2020, and 30 June 2020, from a university teaching hospital and reviewed all patients' medical records. Supervised machine learning models were developed to classify the severity of artery stenosis. The receiver operating characteristic curve, accuracy, sensitivity, specificity, and positive and negative predictive value were used for model performance evaluation. The performance of the random forest model was better compared to the logistic regression model. For ECCD reports, the accuracy of the random forest model to predict stenosis in various sites was between 0.85 and 1. For TCD reports, the overall accuracy of the random forest model to predict stenosis in various sites was between 0.67 and 0.86. The findings of our study suggest that a machine learning-based model accurately classifies artery stenosis, which indicates that the model has enormous potential to facilitate screening for artery stenosis.

Interleukin 37; a possible marker of arterial stiffness in Behçet's disease

BACKGROUND

Interleukin 37 (IL-37) is an anti-inflammatory cytokine previously studied in Behçet's disease (BD) and atherosclerosis. However, little is known about its relation to macro and microcirculations in BD. Previous studies relied mainly on common carotid artery (CCA) intima-media thickness (IMT) and ankle brachial index (ABI) to study atherosclerosis in BD with conflicting results. This study evaluated flow parameters of CCA, ABI and nailfold videocapillaroscopy in relation to serum IL-37 in BD.

METHODS

Forty BD patients and 30 healthy controls were included. IMT, peak-systolic, end-diastolic velocities, resistivity index of CCA and ABI were measured by duplex ultrasound. Capillary loop, length, diameter and morphology were recorded by nailfold videocapillaroscopy. Serum IL-37 levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared to controls, patients had higher mean CCA IMT (p < 0.0001), resistivity index (p < 0.001) and peak-systolic velocity (p=0.09) and lower mean CCA end-diastolic velocity (p=0.002), capillary loop, length, arterial, venous limbs diameter and serum IL-37 (p < 0.001). Patients with ABI ≥ 1.4 "indicating stiff arteries" had higher serum IL-37 (p < 0.05 on left, p>0.05 right sides). Serum IL-37 correlated negatively with left CCA end-diastolic velocity "denoting atherosclerosis" and positively with left posterior tibial artery ABI and CRP (p < 0.03) "denoting inflammation". Multiple regression analysis showed only association with left CCA end-diastolic velocity.

CONCLUSIONS

IL-37 may be related to arterial stiffness in BD and could be used as a possible marker of arteriosclerosis in the disease for further investigations. Changes of CCA peak-systolic, end-diastolic velocities, resistivity index and IMT refer to increased atherosclerosis in larger elastic arteries. In smaller muscular "crural" arteries, vasculitis with possible medial disease may be more evident.

Associations between electrocardiogram and carotid ultrasound parameters: a healthy chinese group study

Background: Electrocardiogram (ECG) and carotid ultrasound (CUS) are important tools for the diagnosis and prediction of cardiovascular disease (CVD). This study aimed to investigate the associations between ECG and CUS parameters and explore the feasibility of assessing carotid health with ECG.

Methods: This cross-sectional cohort study enrolled 319 healthy Chinese subjects. Standard 12-lead ECG parameters (including the ST-segment amplitude [STA]), CUS parameters (intima-media thickness [IMT] and blood flow resistance index [RI]), and CVD risk factors (including sex, age, and systolic blood pressure [SBP]) were collected for analysis. Participants were divided into the high-level RI group (average RI ≥ 0.76, n = 171) and the normal RI group (average RI < 0.76, n = 148). Linear and stepwise multivariable regression models were performed to explore the associations between ECG and CUS parameters.

Results: Statistically significant differences in sex, age, SBP, STA and other ECG parameters were observed in the normal and the high-level RI group. The STA in lead V₃ yielded stronger significant correlations (r = 0.27–0.42, p < 0.001) with RI than STA in other leads, while ECG parameters yielded weak correlations with IMT (|r| ≤ 0.20, p < 0.05). STA in lead V₂ or V₃, sex, age, and SBP had independent contributions (p < 0.01) to predicting RI in the stepwise multivariable models, although the models for IMT had only CVD risk factors (age, body mass index, and triglyceride) as independent variables. The prediction model for RI in the left proximal common carotid artery (CCA) had higher adjusted R² (adjusted R² = 0.31) than the model for RI in the left middle CCA (adjusted R² = 0.29) and the model for RI in the right proximal CCA (adjusted R² = 0.20).

Conclusion: In a cohort of healthy Chinese individuals, the STA was associated with the RI of CCA, which indicated that ECG could be utilized to assess carotid health. The utilization of ECG might contribute to a rapid screening of carotid health with convenient operations.

Acute Hemodynamic Responses to Enhanced External Counterpulsation in Patients With Coronary Artery Disease

Purpose: Enhanced external counterpulsation is a non-invasive treatment that increases coronary flow in patients with coronary artery disease (CAD). However, the acute responses of vascular and blood flow characteristics in the conduit arteries during and immediately after enhanced external counterpulsation (EECP) need to be verified.

Methods: Forty-two patients with CAD and 21 healthy controls were recruited into this study to receive 45 min-EECP. Both common carotid arteries (CCAs), namely, the left carotid (LC) and right carotid (RC), the right brachial (RB), and right femoral (RF) artery were imaged using a Color Doppler ultrasound. The peak systolic velocity (PSV), end-diastolic velocity (EDV), mean inner diameter (ID), resistance index (RI), and mean flow rate (FR) were measured and calculated before, during, and after the 45 min-EECP treatment.

Results: During EECP, in the CCAs, the EDV was significantly decreased, while the RI was markedly increased in the two groups (both P < 0.01). However, immediately after EECP, the RI in the RC was significantly lower than that at the baseline in the patients with CAD (P = 0.039). The FR of the LC was markedly increased during EECP only in the CAD patients (P = 0.004). The PSV of the patients with CAD was also significantly reduced during EECP (P = 0.015) and immediately after EECP (P = 0.005) compared with the baseline. Moreover, the ID of the LC, RB, and RF was significantly higher immediately after EECP than that at the baseline (all P < 0.05) in the patients with CAD. In addition, they were also higher than that in the control groups (all P < 0.05). Furthermore, by the subgroup analysis, there were significant differences in the FR, PSV, and RI between females and males during and immediately after EECP (all P < 0.05).

Conclusions: Enhanced external counterpulsation creates different responses of vascular and blood flow characteristics in carotid and peripheral arteries, with more significant effects in both the carotid arteries. Additionally, the beneficial effects in ID, blood flow velocity, RI, and FR after 45 min-EECP were shown only in the patients with CAD. More importantly, acute improvement of EECP in the FR of the brachial artery was showed in males, while the FR and RI of the carotid arteries changed in females.

Common Carotid Artery Flow Parameters Predict the Incidence of Hypertension

[Figure: see text].

Association between C-reactive protein and carotid plaque in mild-to-moderate idiopathic pulmonary fibrosis

An association between C-reactive protein (CRP) levels and carotid plaque has never been investigated in idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the extent of carotid atherosclerosis in mild-to-moderate IPF and to assess its relationship to serum CRP. This observational retrospective case-control study included 60 consecutive IPF patients (73.8 ± 6.6 years, 45 males) and 60 matched controls, examined between Sep 2017 and Jan 2019. All patients underwent CRP assessment and a carotid Doppler ultrasonography. CRP levels were significantly higher in IPF patients than controls (0.2 ± 0.09 mg/dl vs 0.09 ± 0.04 mg/dl, p < 0.0001). A total of 46 plaques were detected, with higher prevalence in IPF patients than controls (38 vs 8, p < 0.0001). On univariate logistic regression the main variables independently associated with carotid plaque were: age (HR 1.09, 95% CI 1.03-1.16, p = 0.006), hypertension duration (HR 1.05, 95% CI 1.01-1.09, p = 0.01), diabetes duration (HR 1.09, 95% CI 1.01-1.18, p = 0.03), LDL-cholesterol (HR 1.07, 95% CI 1.04-1.10, p < 0.0001) and finally CRP levels (HR 1.73, 95% CI 0.59-5.00, p < 0.0001). Multivariate logistic regression analysis revealed that LDL-cholesterol (HR 1.05, 95% CI 1.01-1.08, p = 0.009) and CRP levels (HR 1.43, 95% CI 0.39-5.19, p < 0.0001) retained statistical significance. Common carotid artery-intima media thickness was significantly correlated with CRP levels in IPF patients (r = 0.86). SerumCRP might represent both an early marker and a potential therapeutic target for carotid atherosclerosis in mild-to-moderate IPF.

Acute Effect of Enhanced External Counterpulsation on the Carotid Hemodynamic Parameters in Patients With High Cardiovascular Risk Factors

Purpose

Enhanced external counterpulsation (EECP) can improve carotid circulation in patients with coronary artery disease. However, the response of carotid hemodynamic parameters induced by EECP in patients with high cardiovascular risk factors remains to be clarified. This study aimed to investigate the acute effect of EECP on the hemodynamic parameters in the carotid arteries before, during, and immediately after EECP in patients with hypertension, hyperlipidemia, and type 2 diabetes.

Methods

Eighty-three subjects were recruited into this study to receive 45-min EECP, including patients with simple hypertension (n = 21), hyperlipidemia (n = 23), type 2 diabetes (n = 18), and healthy subjects (n = 21). Hemodynamic parameters in both common carotid arteries (CCAs) were measured and calculated from Doppler ultrasound images. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean inner diameter (ID), systolic/diastolic flow velocity ratio (VS/VD), flow rate (FR), and resistance index (RI) were monitored before, during, and immediately after 45-min EECP.

Results

EDV and VS/VD were significantly reduced, while RI of CCAs was significantly increased among four groups during EECP (all P < 0.01). Additionally, the ID of CCAs and the FR of left CCA increased in patients with hyperlipidemia during EECP (P < 0.05). PSV of left CCA was reduced in patients with type 2 diabetes (P < 0.05). Moreover, immediately after EECP, ID was significantly higher in patients with hyperlipidemia. The RI of patients with hypertension and PSV and VS/VD of patients with type 2 diabetes were significantly lower compared with baseline (all P < 0.05).

Conclusion

EECP created an acute reduction in EDV, PSV, and VS/VD, and an immediate increase in the RI, FR, and ID of CCAs among the four groups. Additionally, a single 45-min session of EECP produced immediate improvement in the ID of patients with hyperlipidemia, the RI of patients with hypertension, and the PSV and VS/VD of patients with type 2 diabetes. The different hemodynamic responses induced by EECP may provide theoretical guidance for making personalized plans in patients with different cardiovascular risk factors.

Association of Flow Parameters and Diameter in the Common Carotid Artery with Impaired Glucose Metabolism

AIM

Diameter, intima-media thickness (IMT), and flow parameters, including resistance index (RI) and pulsatility index (PI), in the common carotid artery (CCA) are markers of arterial remodeling, atherosclerosis, and vascular resistance, respectively. We investigated the differences among these markers in association with plasma glucose level, serum insulin level, and insulin resistance in participants without cardiovascular disease.

METHODS

CCA parameters (including the CCA interadventitial diameter and mean IMT at the time of 75-g oral glucose tolerance testing) were assessed in 4218 participants. RI and PI were assessed in 3380 of these participants. To assess plasma glucose and serum immunoreactive insulin profiles during oral glucose tolerance testing, we used the total areas under the curves (AUCglu and AUCins, respectively). We used the homeostasis model assessment of insulin resistance (HOMA-IR) and the Matsuda index to assess insulin resistance. Insulin secretion was assessed with the HOMA-β.

RESULTS

AUCglu was significantly associated with CCA interadventitial diameter (β=0.048, P＜0.001), RI (β=0.144, P＜0.001), and PI (β=0.103, P＜0.001) but not with mean IMT. AUCins (β=-0.064, P＜0.001) and HOMA-β (β=-0.054, P＜0.001) were significantly and negatively associated with CCA interadventitial diameter, but not with mean IMT. Both HOMA-IR and Matsuda index were significantly associated with RI and PI.

CONCLUSIONS

These findings indicate that all CCA parameters except IMT are associated with impaired glucose metabolism in patients without cardiovascular disease.

Effectiveness of physical activity interventions in improving objective and patient-reported outcomes in head and neck cancer survivors: A systematic review

OBJECTIVE

To assess the effectiveness of physical activity interventions in improving objective and patient-reported outcomes in HNC survivors.

INTRODUCTION

Multiple guidelines recommend that head and neck cancer (HNC) survivors participate in regular physical activity. Physical activity is associated with improved outcomes and mortality in healthy individuals as well as in certain cancer populations. However, the effectiveness of physical activity interventions in HNC survivors is inadequately understood.

METHODS AND RESULTS

Our literature search through December 2018 identified 2,392 articles. After de-duplication, title and abstract review, full-text review and bibliographic search, 20 studies met all inclusion criteria. Inclusion criteria included any full-body physical activity intervention in HNC survivors that did not target discrete organ sites or functions (e.g. swallowing). Study cohorts included 749 predominantly male participants with a mean age range of 48-63 years. At their conclusion, physical activity interventions were associated with at least one significant improvement in an objective or patient-reported outcome in 75% of studies. Aerobic capacity and fatigue were the most commonly improved outcomes. None of the included studies evaluated associations with survival or recurrence. Although traditional aerobic and resistance interventions were more common, a greater proportion of alternative physical activity (yoga and Tai Chi) interventions demonstrated improved objective and patient-reported outcomes.

CONCLUSION

Physical activity interventions in HNC survivors often conferred some improvement in objective and patient-reported outcomes. Additional highly-powered, randomized controlled studies are needed to establish the optimal type, intensity, and timing of physical activity interventions as well as their impact on oncologic outcomes.

Arterial stiffness as a vascular contribution to cognitive impairment: a fluid dynamics perspective

A model of cerebral pulsatile blood through multiple arterial bifurcations is developed, based on the physics of wave propagation in compliant vessels. The model identifies the conditions for the optimum antegrade flow of blood into the arterioles as a function of the areas and stiffnesses of the arteries. The model predicts and quantifies the reduction in vessel diameter which occurs in progressing from the large central arteries into the arterioles. It also predicts and quantifies the change in vessel compliance which occurs in progressing from the large central arteries, through the small arteries, into the arterioles. Physics predicts that the clinically observed compliance changes are consistent with the efficient delivery of blood to the cerebral capillary bed. The model predicts that increasing arterial stiffening with age, reduces pulsatile cerebral blood flow substantially, potentially resulting in ischemia, hypoperfusion and hypoxia, with attendant neurological and cognition consequences. The model predicts that while central pulse pressure increases with aging, small vessel pulse pressure reduces, contrary to the concept of a pressure wave tsunami in the small vessels. The model also predicts that increased luminal diameters with increasing age, mitigate, somewhat the negative consequences of arterial stiffening, a form of adaptive arterial remodelling.

Correlation of Pre-Hypertension with Carotid Artery Damage in Middle-Aged and Older Adults

The intima–media thickness (IMT), luminal diameters (LDs), flow velocities (FVs), compliance, and β-stiffness of the carotid artery (CA) are considered as independent risk factors for cardiovascular diseases (CVDs). Pre-hypertension (PHT) is also an independent CVD risk factor. This study investigated the association between CA damage (CAD) and PHT. A total of 544 adults participated; their blood pressures (BPs) and CA characteristics were measured using a mercury-free sphygmomanometer and ultrasound. Analysis of covariance (ANCOVA) was performed to assess the differences in the CA characteristics according to the BPs, multinomial logistic regression to evaluate the risk of CAD associated with PHT. In ANCOVA, the CA characteristics of PHT were significantly different from normotensive. The odds ratios (ORs) of IMTmax, LDmax, LDmin, peak-systolic FV (PFV), end-diastolic FV (EFV), PFV/LDmin, EFV/LDmax, compliance, and β-stiffness of PHT were 4.20, 2.70, 3.52, 2.41, 3.06, 3.55, 3.29, 2.02, and 1.84 times higher than those of the normotensive, respectively, in Model 2. In Model 3 adjusted for age, the ORs of LDmax, LDmin, EFV, PFV/LDmin, and EFV/LDmax of PHT were 2.10, 2.55, 1.96, 2.20, and 2.04 times higher than those of the normotensive, respectively. Therefore, the present study revealed that CAD is closely correlated with pre-hypertensive status in adults.

Effects of Cervical Rotation Angle on Atherosclerotic Internal Carotid Artery Blood Flow: A Safety Study Using an Animal Model of Internal Carotid Atherosclerosis

OBJECTIVE

The aim of this study was to investigate the effects of the cervical rotation angle (CRA) on atherosclerotic internal carotid artery blood flow (ICA-BF) in an animal model.

METHODS

Thirty healthy New Zealand white rabbits were included in the study. Twenty of the 30 rabbits were chosen randomly to be the model rabbits, and the remaining 10 were chosen to be the normal rabbits. The model rabbits' left ICAs were treated by atherosclerosis modeling. The left ICAs of the model rabbits with atherosclerotic stenosis were chosen as the experimental group, and the right ICAs of the model rabbits without atherosclerotic stenosis were chosen as the control group. The left ICAs of the normal rabbits were chosen as the blank group. Using color duplex ultrasound, ICA-BF was measured in the artery contralateral to the direction of rotation in the positions of neutral (Pre-0°), 15°, 30°, 45°, 60°, 75°, 90°, and subsequent neutral (Post-0°).

RESULTS

Statistically significant decreases were seen in ICA-BF after cervical spine rotation (from Pre-0° to 90°) in the control group only (P < .05). All the values of end-diastolic velocity in the experimental group were lower than those in the blank group at the same CRAs. The resistance index and pulsatility index of the experimental group were higher than those of the blank group except at 45° rotation.

CONCLUSION

In our animal model, in the rabbits with hyperlipidemia but without atherosclerotic stenosis, CRA had the greatest impact on ICA-BF. Furthermore, at some of the same CRAs (especially neutral, 30°, and 60°), there were statistical differences in ICA-BF among the 3 groups.

The differences of carotid atherosclerosis among non-OSAHS and OSAHS patients of different severities: a cross-sectional study

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a widely prevalent problem with many complications, such as hypertension and cerebral vascular diseases. Atherosclerosis, whose most severe outcome is ischemic stroke, is reported being affected by OSAHS. The objective of this article is to investigate the differences of carotid atherosclerosis patients with or without OSAHS by a cross-sectional research.

MATERIALS AND METHODS

Patients diagnosed with carotid atherosclerosis by ultrasonography were recruited. They were requested to fill the primary screening OSAHS questionnaire. Patients with high tendency of OSAHS underwent polysomnography (PSG) tests into OSAHS group, and patients without OSAHS were into non-OSAHS group. Blood tests and medical history were collected. Carotid atherosclerosis severity was analyzed by carotid artery intima-media thickness (IMT), carotid plaque, blood flow velocity, etc. Differences between the two groups and subgroups were analyzed.

RESULTS

A total of 242 carotid atherosclerosis patients were enrolled including 118 non-OSAHS patients (38 males and 80 females) and 124 OSAHS patients (40 mild, 32 moderate, and 52 severe). Significant differences were found in PSV-ICA and EDV-ICA on both sides (p < 0.05) but no significant differences on IMT and velocity of CCV. CA patients with OSAHS were younger than ones without OSAHS. With the severity of OSAHS increasing, the age of CA patients decreased. The more severity of OSAHS, the younger the patients were. There were no significant differences in comparing cholesterol, triglyceride, HDL, LDL, and glucose.

CONCLUSION

As far as CIMT, carotid plaque, blood flow velocity, and blood lipid are concerned, the severity of CA is not affected by the severity of OSAHS accordantly. The relationship between OSAHS and CA may not be dose dependent.

TRIAL REGISTRATION

This study has been registered on clinical trials (No. NCT03665818).

Common carotid flow velocity is associated with cognitive function after carotid endarterectomy

The relationship between ultrasonographic flow parameters and cognitive function has not been well studied. This study aimed to clarify associations between carotid flow velocity (FV) and cognitive function in patients with a history of carotid endarterectomy (CEA). Ninety-four patients who previously underwent CEA participated in this study. The Neurobehavioral Cognitive Status Examination (Cognistat) and Frontal Assessment Battery (FAB) were adopted to assess cognitive functions at a mean of 6.5 ± 3.2 years after CEA. End-diastolic flow velocity (EDV) of the left and right common carotid artery (CCA) was significantly associated with total Cognistat score (p < 0.001) and total FAB score (p < 0.05). Pulsatility index (PI) of the left CCA was significantly associated with total Cognistat score and total FAB score (p < 0.01). A cut-off right CCA EDV of 14.5 cm/s offered the most reliable predictor of the bottom 25th percentile of total Cognistat score (sensitivity 83.3%, specificity 61.0%, area under the curve (AUC) 0.731, p = 0.0060), while a cut-off left CCA PI of 1.83 was the most reliable predictor of the bottom 25th percentile of total FAB score (sensitivity 73.3%, specificity 60.0%, AUC 0.679, p = 0.0179). Left and right CCA EDV correlated with sub-components of comprehension, construction, judgment, programming (p < 0.01), and conceptualization (p < 0.05). Right CCA EDV correlated with similarity (p < 0.01), repetition, naming, and memory (p < 0.05). Left CCA PI correlated with attention, conceptualization (p < 0.01), repetition, construction, similarity, and mental flexibility (p < 0.05), while right CCA PI correlated with construction (p < 0.05). CCA FV may offer useful markers of cognitive functions in patients with a history of CEA.

Association of Common Carotid Artery Measurements with N-terminal Pro B-type Natriuretic Peptide in Elderly Participants

Objective Numerous studies have reported an association between common carotid artery (CCA) parameters and atherosclerotic cardiovascular disease (CVD). However, the association between CCA parameters and hemodynamic stress on the left ventricle in elderly patients remains unclear. Methods We assessed CCA parameters, including the height-adjusted CCA interadventitial diameter (diameter/height), mean intima-media thickness (IMT), number of plaques, plaque score, resistance index (RI), and pulsatility index (PI) with ultrasonography, using serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels as a marker for hemodynamic stress on the left ventricle in 1,315 participants ≥70 years old without CVD. Of these participants, 706 had hypertension, defined as taking antihypertensive medications, having a systolic blood pressure ≥140 mmHg, and/or having a diastolic blood pressure ≥90 mmHg. Results After adjusting for the confounding factors, the CCA interadventitial diameter/height was significantly associated with the log NT-proBNP in both the normotensive group (β=0.125, p=0.002) and hypertensive group (β=0.080, p=0.029). The RI was significantly associated with the log NT-proBNP in the hypertensive group (β=0.176, p<0.001) but not in the normotensive group. In addition, the PI was significantly associated with the log NT-proBNP in the hypertensive group (β=0.156, p<0.001) but not in the normotensive group. However, no significant association was observed between the mean IMT, number of plaques, and plaque score and log NT-proBNP. Conclusion CCA measurements may be useful markers for hemodynamic stress on the left ventricle in elderly patients.

Autodetect extracranial and intracranial artery stenosis by machine learning using ultrasound

BACKGROUND

and Purpose: This study proposed a machine learning method for identifying ≥50% stenosis of the extracranial and intracranial arteries.

PATIENTS AND METHODS

A total of 8211 patients with both carotid ultrasound and cerebral angiography were enrolled. Support vector machine (SVM) was employed as the machine learning classifier. Carotid Doppler parameters and transcranial Doppler parameters were used as the input features. Feature selection was performed using the Extra-Trees (extremely randomized trees) method.

RESULTS

For the machine learning method, the sensitivities and specificities of identifying stenosis of the extracranial arteries were 88.5%-100% and 96.0%-100%, respectively. The sensitivities and specificities of identifying stenosis of the intracranial arteries were 71.7%-100% and 88.9%-100%, respectively.

CONCLUSIONS

The SVM classifier with feature selection is an efficient method for identifying the stenosis of both intracranial and extracranial arteries. Comparing with traditional Doppler criteria, this machine learning method achieves up to 20% higher in accuracy and 45% in sensitivity, respectively.

Effects of continuous-flow left ventricular assist devices on cerebral hemodynamics

Continuous-flow left ventricular assist devices (LVADs) reduce peak systolic flow, increase diastolic flow, and eliminate pulsatility of circulation. Altered blood flow may lead to a change in end-organ perfusion. Analysis of the flow dynamics of the arteries of end organs, such as the brain, may indicate whether an organ is perfused sufficiently. The aim of this study is to evaluate and identify the flow pattern changes of carotid (CA) and middle cerebral arteries (MCA) in LVAD patients and to compare with heart failure patients and healthy volunteers. Eighty-nine individuals were included in this cross-sectional study. Participants were divided into three groups: LVAD patients (n = 31), heart failure patients (n = 26), and healthy volunteers (n = 27). Carotid and transcranial Doppler ultrasonography were performed for all study groups for peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility (PI), and resistive (RI) indices of CA and MCA. Flow dynamics were compared between the groups. Doppler ultrasonographic data were analyzed at a median 12 (3-47) months after LVAD implantation. CA-PSV was lower in LVAD group compared with the other two groups (P < .001), MCA-PSV of LVAD and heart failure groups were similar and lower than healthy volunteers (P < .05). The highest values for CA-EDV were found in the LVAD group (P < .05). MCA-EDV values were found to be lowest in heart failure group (P < .05). For PI and RI, in all CA and MCA, the LVAD group had lower indices compared with the other two groups (P < .001). In addition, MCA flow analysis in patients with LVADs was identified for the first time with this study.

Common Carotid Artery Diameter and Risk of Cardiovascular Events and Mortality: Pooled Analyses of Four Cohort Studies

Carotid arterial diameter enlargement is a manifestation of arterial remodeling and may be a risk factor for cardiovascular disease (CVD). We evaluated the association between carotid artery diameter and risk of stroke, coronary heart disease, CVD, and all-cause mortality and explored whether the associations could be explained by processes involved in arterial remodeling, that is, blood pressure-related media thickening, arterial stiffness, arterial wall stress, and atherosclerosis. We included 4887 participants (mean age 67±9 years; 54% women) from 4 cohort studies: Rotterdam Study, NEPHROTEST, Hoorn Study, and a study by Blacher et al. Common carotid artery properties were measured using echotracking. Incident cases were recorded based on medical records. We used Cox proportional hazard models adjusting for cardiovascular risk factors and estimates of processes underlying arterial remodeling. During follow-up (mean, 11 years), 379 (8%) individuals had a stroke, 516 had a (11%) coronary heart disease, 807 had a (17%) CVD, and 1486 (30%) had died. After adjustment for cardiovascular risk factors, individuals in the highest tertile of carotid diameter (diameter >8 mm) compared with those in the lowest tertile (diameter <7 mm) had a higher incidence of stroke (hazard ratio, 1.5; 95% confidence interval, 1.1-2.0). From all estimates of processes underlying arterial remodeling, adjustment for carotid intima-media thickness attenuated this association (hazard ratio after adjustment for intima-media thickness, 1.2; 95% confidence interval, 0.9-1.6). Larger carotid diameter was associated with risk of CVD and mortality but not clearly with coronary heart disease risk. We showed that a larger carotid diameter is associated with incident stroke, CVD, and mortality. Carotid intima-media thickness, a measure of blood pressure-related media thickening, partially explained the association with stroke incidence.

Segregating the Distinct Effects of Sedentary Behavior and Physical Activity on Older Adults' Cardiovascular Structure and Function: Part 1-Linear Regression Analysis Approach

BACKGROUND

Physical behavior [PB, physical activity (PA), and sedentary behavior (SB)] can adjust cardiovascular mortality risk in older adults. The aim of this study was to predict cardiovascular parameters (CVPs) using 21 parameters of PB.

METHODS

Participants [n = 93, 73.8 (6.23) y] wore a thigh-mounted accelerometer for 7 days. Phenotype of the carotid, brachial, and popliteal arteries was conducted using ultrasound.

RESULTS

Sedentary behavior was associated with one of the 19 CVPs. Standing and light-intensity PA was associated with 3 and 1 CVP, respectively. Our prediction model suggested that an hourly increase in light-intensity PA would be negatively associated with popliteal intima-media thickness [0.09 mm (95% confidence interval, 0.15 to 0.03)]. sMVPA [moderate-vigorous PA (MVPA), accumulated in bouts <10 min] was associated with 1 CVP. ₁₀MVPA (MVPA accumulated in bouts ≥10 min) had no associations. W50% had associations with 3 CVP. SB%, alpha, true mean PA bout, daily sum of PA bout time, and total week ₁₀MVPA each were associated with 2 CVP.

CONCLUSIONS

Patterns of PB are more robust predictors of CVP than PB (hours per day). The prediction that popliteal intima-media thickness would be negatively associated with increased standing and light-intensity PA engagement suggests that older adults could obtain health benefits without MVPA engagement.

Effects of 24-Week Aerobic and Resistance Training on Carotid Artery Intima-Media Thickness and Flow Velocity in Elderly Women with Sarcopenic Obesity

Aim: Sarcopenic obesity (SO) is closely associated with cardiovascular disease (CVD) in elderly women. Increases in body fat and decreases in muscle mass are closely associated with increased carotid intima-media thickness (CIMT). The aim of this study was to examine the influence of a 24-week aerobic and resistance training program on carotid parameters in SO.

Methods: Fifty elderly women (74.1 ± 6.1 years) with SO were randomly divided into an exercise group and a control group. The exercise group performed combined exercise over 24 weeks, consisting of resistance and aerobic training for 50–80 min, 5 times a week. Carotid variables were measured using B-mode ultrasound. The differences in the carotid variables and the relative changes between baseline and after 24 weeks were evaluated.

Results: In the analysis of variance (ANOVA) results, CIMT (p = 0.013), systolic flow velocity (p = 0.007), diastolic flow velocity (p = 0.006), and wall shear rate (p = 0.010) showed significant interactions. In paired t-test results of the exercise group, CIMT significantly decreased (p < 0.01) and systolic flow velocity (p < 0.01), diastolic flow velocity (p < 0.001), and wall shear rate (p < 0.05) significantly increased after 24 weeks.

Conclusion: The 24-week combined exercise effectively decreased CIMT and increased carotid flow velocity and wall shear ratio. Therefore, combined exercise is thought to contribute to the improvement of the risk of CVD in elderly women with SO.

Temporal and Spatial Variances in Arterial Spin-Labeling Are Inversely Related to Large-Artery Blood Velocity

BACKGROUND AND PURPOSE

The relationship between extracranial large-artery characteristics and arterial spin-labeling MR imaging may influence the quality of arterial spin-labeling-CBF images for older adults with and without vascular pathology. We hypothesized that extracranial arterial blood velocity can explain between-person differences in arterial spin-labeling data systematically across clinical populations.

MATERIALS AND METHODS

We performed consecutive pseudocontinuous arterial spin-labeling and phase-contrast MR imaging on 82 individuals (20-88 years of age, 50% women), including healthy young adults, healthy older adults, and older adults with cerebral small vessel disease or chronic stroke infarcts. We examined associations between extracranial phase-contrast hemodynamics and intracranial arterial spin-labeling characteristics, which were defined by labeling efficiency, temporal signal-to-noise ratio, and spatial coefficient of variation.

RESULTS

Large-artery blood velocity was inversely associated with labeling efficiency (P = .007), temporal SNR (P < .001), and spatial coefficient of variation (P = .05) of arterial spin-labeling, after accounting for age, sex, and group. Correction for labeling efficiency on an individual basis led to additional group differences in GM-CBF compared to correction using a constant labeling efficiency.

CONCLUSIONS

Between-subject arterial spin-labeling variance was partially explained by extracranial velocity but not cross-sectional area. Choosing arterial spin-labeling timing parameters with on-line knowledge of blood velocity may improve CBF quantification.

Effects of 6 months of aerobic and resistance exercise training on carotid artery intima media thickness in overweight and obese older women

AIM

We studied the effects of exercise on carotid intima-media thickness, luminal diameter, and flow velocity in overweight and obese older women, and the associations between carotid parameters changes and other variables.

METHODS

A total of 41 overweight and obese older women (aged 65-77 years, fat mass percent ≥ 32%), who were divided into a control group (n = 20) and a supervised combined exercise group (n = 21). The 24-week combined exercise program (aerobic and resistance exercise) consisted of sessions 40-80 min in length 5 days per week under the supervision of an exercise specialist. Body composition, blood pressure, physical function and carotid variables were assessed. The differences in all variables, and the relative changes between baseline and 24 weeks' follow up were evaluated.

RESULTS

Carotid intima-media thickness, systolic carotid luminal diameter, peak systolic flow velocity and end diastolic flow velocity showed a significant group × time interaction. No interaction was observed for diastolic luminal diameter. In the exercise group, the change of carotid intima-media thickness was significantly associated with systolic blood pressure, maximal walking speed, 1-mile walking time and maximal oxygen uptake. Also, the change of peak systolic flow velocity was significantly associated with skeletal muscle mass, diastolic blood pressure and maximum walking speed.

CONCLUSIONS

Combined exercise can effectively improve carotid intima-media thickness in overweight and obese older women. In addition, exercise training increases the systolic carotid luminal diameter and flow velocity in older women. Therefore, regular combined exercise might help prevent atherosclerotic disease by improving the carotid artery. Geriatr Gerontol Int 2017; 17: 2304-2310.

Is Carotid Artery Ultrasound Still Useful Method for Evaluation of Atherosclerosis?

Carotid ultrasound is an imaging modality that allows non-invasive assessment of vascular anatomy and function. Carotid intima-media thickness (IMT) has been shown to predict cardiovascular (CV) risk in multiple large studies. However, in 2013, American College of Cardiology/American Heart Association guidelines designated that the carotid IMT as class III evidence level was not recommended for use in clinical practice as a routine measurement of risk assessment for a first atherosclerotic CV event. Following the announcement of this guideline, combined common carotid IMT and plaque, including plaque tissue characterization and plaque burden, using 3D ultrasound was reported to be better than either measurement alone in a variety of studies. Moreover, changes in the intima thickness were related to aging and early atherosclerosis, and remodeling of the media thickness was associated with hypertension. Separate measurement is useful for evaluating the effects of different atherosclerotic risk factors on the arterial wall; however, a more detailed and elaborate technique needs to be developed. If so, separate measurement will play an important role in the assessment of atherosclerosis and arterial wall change according to a variety of risk factors, such as metabolic syndrome. In addition, although carotid blood flow velocity is a useful tool for risk classification and prediction in clinical practice, further clinical research is needed. The value of carotid IMT by ultrasound examination for risk stratification remains controversial, and groups developing future guidelines should consider the roles of plaque presence and burden and hemodynamic parameters in additional risk stratification beyond carotid IMT in clinical practice.

Effects of 24-week resistance exercise training on carotid peak systolic and end diastolic flow velocity in healthy older adults

[Purpose] The aim of this study was to examine the effect of resistance exercise on carotid intima-media thickness, luminal diameter, peak systolic flow velocity, end diastolic flow velocity, and wall shear rate in healthy elderly men. [Subjects and Methods] Thirty healthy elderly men (age ≥65 years) were randomly divided into a control (n=15) and resistance exercise (n=15) groups. The 24-week exercise intervention consisted of 3 days of resistance exercise per week using an elastic band per week. Body composition, physical function, blood pressure, and carotid variables were measured at baseline and after 24 weeks. [Results] Body fat percent, skeletal muscle mass, systolic blood pressure, grip strength, arm curl, chair stand up, sit and reach, maximum walking speed, time up and go, and two-minute step test showed significant interaction. Peak systolic flow velocity, end diastolic flow velocity, and wall shear rate also showed significant interaction. [Conclusion] A 24-week resistance exercise program, using elastic bands, effectively improves carotid flow velocity and wall shear rate in healthy elderly men.

Blood Pressure, Carotid Flow Pulsatility, and the Risk of Stroke: A Community-Based Study

BACKGROUND AND PURPOSE

High blood pressure is a major cause of cardiovascular events, and carotid flow pulsatility may be associated with cardiovascular events. However, the combined effect of blood pressure and flow pulsatility on the development of stroke remains unclear. Therefore, we investigated the combined influence of central blood pressure and pulsatility index (PI) on the incidence of stroke.

METHODS

Baseline data from 2033 adults (≥30 years) without stroke history in the Cardiovascular Disease Risk Factor Two-Township Study were linked to incident stroke. Common carotid flow PI was calculated by peak systolic velocity, end-diastolic velocity, and mean vessel velocity, which were measured in the common carotid artery. Hazard ratios for the risk of total stroke resulting from high central systolic blood pressure (CSBP) and high PI were calculated with Cox proportional hazard models.

RESULTS

Over a median follow-up of 9.81 years, 132 people incurred stroke events. The incidence rates of stroke were 1.3, 6.4, and 13.2 per 1000 person-years for tertile groups of CSBP (P for trend<0.05) and 4.3, 7.0, and 9.4 per 1000 person-years for tertile groups of PI (P for trend<0.05). Compared with the first tertile of CSBP, hazard ratios were 4.88 (95% confidence interval, 2.29-10.43) for the second tertile and 10.42 (5.05-21.53) for the third tertile. Hazard ratios of PI were 2.18 (1.39-3.42; third tertile) and 1.64 (1.02-2.63; second tertile) compared with the first tertile. The individuals with a high CSBP and high PI had a 13-fold higher stroke risk compared with those with low CSBP and low PI (13.2; 1.75-99.71) after adjusting for age, sex, and traditional cardiovascular risk.

CONCLUSIONS

CSBP and common carotid PI jointly and independently predicted future stroke. Carotid flow pulsatility may play an important role in the development of stroke.

Carotid flow velocity/diameter ratio is a predictor of cardiovascular events in hypertensive patients

OBJECTIVE

The aim of this study was to evaluate the performance of common carotid artery diameter, flow velocity and flow velocity/artery diameter ratio as predictors of major adverse cardiovascular events (MACEs) in a sample of hypertensive patients.

METHODS

A cohort of 403 hypertensive patients was followed up for a median of 1260 (714) days, and 27 suffered MACEs. At baseline, participants were evaluated by clinical, laboratory, echocardiographic and carotid ultrasound analysis.

RESULTS

Patients with peak-systolic flow velocity (sFV) less than the median value and systolic artery diameter (sAD) greater than the median value presented the worst clinical outcome compared to those with isolated sFV less than the median value or sAD greater than the median value, suggesting an additive effect of these two variables. Further, Kaplan-Meier analysis demonstrated worse outcome for individuals with sFV/sAD ratio less than 85.7/s (optimal cut-off point obtained by receiver-operating characteristic analysis) compared to those with higher sFV/sAD values (log-rank test: P < 0.0001). In stepwise multivariable Cox-regression analyses, sFV/sAD was significantly associated with MACEs (P < 0.001), whereas carotid intima-media thickness and clinically defined high cardiovascular risk did not. Furthermore, area under the receiver-operating characteristic curve for sFV/sAD was higher than that for Framingham risk score (0.77 versus 0.64; P = 0.045), whereas adding sFV/sAD to the Framingham risk factors resulted in increased net reclassification improvement (P = 0.041) and integrated discrimination improvement (P < 0.001).

CONCLUSIONS

Lower carotid sFV/sAD was associated with MACEs in hypertensive patients independent of cardiovascular prediction models and carotid intima-media thickness. These findings suggest that this index may be a promising approach to identify hypertensive subjects at increased risk for future cardiovascular events.

Carotid Artery End-Diastolic Velocity and Future Cerebro-Cardiovascular Events in Asymptomatic High Risk Patients

Background and Objectives

Prognostic value of additional carotid Doppler evaluations to carotid intima-media thickness (IMT) and plaque has not been completely evaluated.

Subjects and Methods

A total of 1119 patients with risk factors for, but without, overt coronary artery disease (CAD), who underwent both carotid ultrasound and Doppler examination were included in the present study. Parameters of interest included peak systolic and end-diastolic velocities, resistive indices of the carotid arteries, IMT, and plaque measurements. The primary end-point was all-cause cerebro-cardiovascular events (CVEs) including acute myocardial infarction, coronary revascularization therapy, heart failure admission, stroke, and cardiovascular death. Model 1 covariates comprised age and sex; Model 2 also included hypertension, diabetes and smoking; Model 3 also had use of aspirin and statin; and Model 4 also included IMT and plaque.

Results

The mean follow-up duration was 1386±461 days and the mean age of the study population was 60±12 years. Amongst 1119 participants, 43% were women, 57% had a history of hypertension, and 23% had diabetes. During follow-up, 6.6% of patients experienced CVEs. Among carotid Doppler parameters, average common carotid artery end-diastolic velocity was the independent predictor for future CVEs after adjustments for all models variables (HR 0.95 per cm/s, 95% confident interval 0.91-0.99, p=0.034 in Model 4) and significantly increased the predictive value of Model 4 (global χ²=59.0 vs. 62.8, p=0.029).

Conclusion

Carotid Doppler measurements in addition to IMT and plaque evaluation are independently associated with future CVEs in asymptomatic patients at risk for CAD.

Light therapy modulates serotonin levels and blood flow in women with headache. A preliminary study

In this study, we looked at the possible effects of low-level laser therapy (LLLT) on blood flow velocity, and serotonin (5-HT) and cholinesterase levels in patients with chronic headache associated with temporomandibular disorders (TMD). LLLT has been clinically applied over the past years with positive results in analgesia and without the report of any side effects. The understanding of biological mechanisms of action may improve clinical results and facilitate its indication. Ten patients presenting headache associated with TMD completed the study. An 830-nm infrared diode laser with power of 100 mW, exposure time of 34 s, and energy of 3.4 J was applied on the tender points of masseter and temporal muscle. Blood flow velocity was determined via ultrasound Doppler velocimetry before and after laser irradiation. The whole blood 5-HT and cholinesterase levels were evaluated three days before, immediately, and three days after laser irradiation. Pain score after treatment decreased to a score of 5.8 corresponding to 64% of pain reduction (P < 0.05). LLLT promoted a decrease in the blood flow velocity (P < 0.05). In addition, the 5-HT levels were significantly increased three days after LLLT (P < 0.05). The cholinesterase levels remained unchanged at the analyzed time points (P > 0.05). Our findings indicated that LLLT regulates blood flow in the temporal artery after irradiation and might control 5-HT levels in patients suffering with tension-type headache associated to TMD contributing to pain relief.

Feasibility of assessment of conjunctival microvascular hemodynamics in unilateral ischemic stroke

Since the internal carotid artery supplies blood to both the eye and the brain, ocular microvascular hemodynamics can be altered due to ischemic stroke. The purpose of the current study was to establish the feasibility of conjunctival microcirculation imaging for detection of inter-ocular differences in microvascular hemodynamics in subjects with unilateral ischemic stroke. Conjunctival microcirculation imaging was performed in both eyes of 15 healthy control subjects and 12 subjects following unilateral ischemic stroke. Diameter and axial blood velocity were measured in multiple conjunctival venules of each eye. A two-way repeated measures analysis of variance was performed to determine the effects of stroke (control vs. stroke) and side of stroke (ipsilateral vs. contralateral) on conjunctival diameter and axial blood velocity. There was no significant main effect of stroke on conjunctival diameter (P=0.7) or conjunctival axial blood velocity (P=0.9). There was no significant main effect of side of stroke on conjunctival diameter (P=0.8), but there was a significant main effect of side of stroke on conjunctival axial blood velocity (P=0.02). There was a significant interaction effect between stroke and side of stroke (P=0.04), indicating that conjunctival axial blood velocity was lower in ipsilateral eyes than in contralateral eyes of stroke subjects. Conjunctival axial blood velocity and internal carotid artery blood velocity were correlated in stroke subjects (r=0.75, P=0.01, N=10). Conjunctival microcirculation imaging is a feasible method to detect inter-ocular differences in microvascular hemodynamics in subjects with unilateral ischemic stroke.

Increased risk of stroke among patients with Crohn's disease: a population-based matched cohort study

BACKGROUND

Crohn's disease (CD) is one type of inflammatory bowel disease (IBD) that has been speculated to share prognostic factors with the development of stroke. There is controversial information in the literature regarding the association between CD and stroke. The present cohort study estimated the risk of subsequent stroke among CD patients compared with matched comparison subjects drawn from a population-based dataset in Taiwan.

METHOD

This study drew data from the Taiwan National Health Insurance Database to conduct a historical cohort study. The study cohort comprised 3309 CD patients, and the comparison cohort comprised 13,236 subjects without an IBD. Cox proportional hazards regressions were performed to estimate the risk of subsequent stroke during the follow-up period. We also conducted additional analyses stratifying by age group and gender.

RESULTS

After adjusting for selected medical co-morbidities and recent prescriptions of selected pharmaceuticals, the hazard ratio (HR) for subsequent stroke among patients with CD was found to be 1.911 (95% confidence interval (CI) = 1.65-2.22) that of comparison subjects. While we did not detect an association between stroke and CD among patients aged 30-40 years, we did detect increased risks for stroke among CD patients aged 40-50 years (HR = 2.29) and those aged over 50 years (HR = 1.88). We also found women (HR = 2.39) to be at a greater risk than men (HR = 1.50).

CONCLUSION

This study reports an increased HR for subsequent stroke among CD patients when compared to matched comparison patients without IBD in an Asian population.

Common carotid artery end-diastolic velocity is independently associated with future cardiovascular events

BACKGROUND

Carotid ultrasound is widely used to measure haemodynamic parameters, such as intima-media thickness and blood flow velocities (i.e. peak-systolic velocity [PSV], end-diastolic velocity [EDV], and resistive index [RI]). However, the association between blood flow velocities and cardiovascular events remains unclear.

DESIGN AND METHODS

Baseline data, including quantitative ultrasonography, were obtained from 3146 adults as part of the Cardiovascular Diseases Risk Factor Two-Township Study. Occurrence of ischaemic heart disease (IHD) and stroke was determined from insurance claims and death certificates. The hazard ratio (HR) of CVD (IHD and stroke combined) was calculated for EDV and PSV of the common carotid artery using Cox models. Net reclassification index and integrated discrimination index were used to evaluate the capacity of EDV to predict IHD, stroke, and CVD.

RESULTS

Median follow-up was 12.8 years. There were 220 cases of IHD and 247 cases of stroke. The HR (95% CI) for CVD from univariate analysis was 4.54 (3.51-5.85) for EDV <15 cm/s relative to EDV ≥ 20 cm/s (p < 0.0001), and 3.23 (2.51-4.15) for PSV < 65 cm/s relative to PSV ≥ 80 cm/s (p < 0.0001). The HR (95% CI) for CVD from multivariate analysis was 1.66 (1.22-2.26) for EDV < 15 cm/s relative to EDV ≥ 20 cm/s, and 1.39 (1.03-1.89) for PSV < 65 cm/s relative to PSV ≥ 80 cm/s. EDV slightly but significantly improved prediction of CVD (integrated discrimination index 0.56%, p = 0.016).

CONCLUSIONS

Low common carotid EDV and PSV were independently associated with future CVD, and EDV improved the prediction of future CVD. More prospective studies are required in different ethnic groups to understand the significance and implication of these findings.

Increased risk of stroke among patients with ulcerative colitis: a population-based matched cohort study

BACKGROUND

The risk of venous thromboembolism (VTE) and the development of atherosclerosis are increased in patients with inflammatory bowel disease (IBD). Ulcerative colitis (UC) is one type of IBD; however, there is controversy in the literature regarding the association between UC and stroke. The present cohort study estimated the risk of subsequent stroke among UC patients compared with that among matched comparison subjects drawn from a population-based data set in Taiwan.

METHODS

This investigation analyzed administrative claims data sourced from the Taiwan National Health Insurance Database. Our study consisted of a study cohort comprising 516 UC patients and a comparison cohort of 2,579 subjects without IBD. Cox proportional hazards regressions were performed to estimate the risk of subsequent stroke during the follow-up period. We also conducted additional analyses investigating the risk of subsequent stroke by age group and gender.

RESULTS

After adjusting for selected medical co-morbidities and recent prescriptions of selected pharmaceuticals, the hazard ratio (HR) for subsequent stroke among patients with UC was 2.045 (95 % confidence interval (CI) = 1.374-3.043) than that among comparison subjects. While we did not detect an association between stroke and UC among patients aged 30-40 or 40-50 years, we did detect increased risks for stroke among UC patients aged over 50 years (HR = 2.045). We also found the association to remain significant for both men (HR = 2.153) and women (HR = 2.750).

CONCLUSIONS

This study detected an increased HR for subsequent stroke among Taiwanese UC patients hen compared to that among matched comparison patients without IBD.

Evaluation of common carotid artery changes in Saudi current smokers using medical ultrasound (B-mode and Doppler)

PURPOSE

This study evaluates using ultrasound the changes that occur in wall thickness, blood flow velocity, and Doppler indices of the common carotid arteries (CCAs) in healthy Saudi adult males who are current smokers.

METHODS

A prospective study was performed between May 2011 and May 2013 with a group consisting of nonsmokers (n = 180; 36 %) and current smokers (n = 320; 64 %) with a mean age of 25 ± 2.6 years. In all cases, the CCA ultrasound scanning protocol met the standards established by the American Institute of Ultrasound in Medicine (AIUM) to measure intima media thickness (IMT), peak systolic velocity (PSV), and end diastolic velocity (EDV). The Statistical Package for the Social Sciences (SPSS) was used to analyze the results.

RESULTS

Significant linear and positive correlations were noted between the level of daily consumption of cigarettes smoked and carotid mean IMT, PSV, and Doppler indices, while a linear and negative correlation was present between cigarette smoking and mean EDV. These findings were significant when compared with the results for nonsmokers.

CONCLUSIONS

Cigarette smoking is associated with CCA morphological changes caused by significant impairment of arterial endothelial function, and an increase in daily cigarette consumption significantly leads to a decrease in the blood flow velocity of CCAs.

Extension of the mitochondria dysfunction hypothesis of metabolic syndrome to atherosclerosis with emphasis on the endocrine-disrupting chemicals and biophysical laws

Metabolic syndrome and its component phenotypes, hyperglycemia, hypertension, (abdominal) obesity and hypertriglyceridemia, are major risk factors for atherosclerosis. Recently, associations between exposure to endocrine‐disrupting chemicals (EDCs), mitochondrial dysfunction, metabolic syndrome and atherosclerosis have been established, suggesting a possible common mechanism underlying these phenomena. Extending a previously proposed mitochondria dysfunction theory of metabolic syndrome and using biophysical laws, such as metabolic scaling, Murray's law and fractal geometry of the vascular branching system, we propose that atherosclerosis could be explained as an ill‐adaptive change occurring in nutrient‐supplying arteries in response to the decreasing tissue energy demand caused by tissue mitochondrial dysfunction. Various aspects of this new hypothesis are discussed.

Exploring carotid sonographic parameters associated with stroke risk among hypertensive stroke patients compared to hypertensive controls

OBJECTIVES

Globally, and particularly in low- and middle-income countries, the prevalence of hypertension is increasing with a consequent rise in the burden of stroke. There is a need to identify biomarkers of stroke, which can be used to design stroke prevention programs in these populations. Sonography is an affordable and widely available imaging modality that is ideal for resource-poor countries. We conducted a case-control study to identify carotid sonographic parameters that may be associated with stroke risk among hypertensive patients.

METHODS

Selected demographic, clinical, and laboratory characteristics were collected from 135 consecutive African hypertensive stroke patients and compared with 117 age and sex-matched hypertensive patients with no clinical evidence of stroke, transient ischemic attacks, or ischemic heart disease (controls). The luminal diameter, intima-media thickness, peak systolic velocity (PSV), and end-diastolic velocity (EDV) of the common and internal carotid arteries were measured in all participants, and other carotid parameters, including pulsatility and resistive indices, were derived. Univariate, bivariate, and multivariate analyses were performed

RESULTS

Among hypertensive patients, carotid parameters significantly (P < .05) associated with stroke included a higher diameter and intima-media thickness as well as a lower PSV and EDV in the common carotid and proximal internal carotid arteries. However, the diameter (>6.3 mm; adjusted odds ratio [OR], 8.91; 95% confidence interval [CI], 2.18-36.34; P = .002) and EDV (>21 cm/s; adjusted OR, 0.15; 95% CI, 0.03-0.71; P = .017) of the common carotid artery were the only parameters associated with stroke in multivariate analysis.

CONCLUSIONS

Among hypertensive patients, the common carotid artery diameter and EDV are significantly associated with stroke risk. These findings have implications for development and evaluation of stroke prevention programs.

The relationship of flow velocities to vessel diameters differs between extracranial carotid and vertebral arteries of stroke patients

BACKGROUND

Chronic changes in flow rate through arteries produce adjustment of arterial diameters. We compared the relationship between flow velocity and diameter in the carotid and in the vertebral arteries of stroke patients.

METHODS

Using triplex ultrasonography, the internal diameter and flow velocities of the common carotid, internal carotid, and vertebral arteries of 176 consecutive stroke patients were measured. Correlations were examined with Pearson's statistics at an alpha level of 0.05.

RESULTS

Mean age of the patients was 59.3 ± 12 years, and 66% had cerebral infarcts. Diameter and blood flow velocities showed significant negative correlations (-0.115 ≥ r ≥ -0.382) in the carotid arteries on both sides, but positive correlations (0.211 ≤ r ≤ 0.320) in the vertebral arteries, even after controlling for age, gender, and blood pressure.

CONCLUSIONS

Our study demonstrated different diameter/flow relationships in the carotid and the vertebral arteries of stroke patients, which may suggest pathologic changes in the adaptive processes governing vessel diameter and growth, especially in the carotid arteries.

Bilateral common carotid artery ultrasound for prediction of incident strokes using intima-media thickness and external diameter: an observational study

Background

External common carotid artery (CCA) diameter and intima-media thickness (IMT) are independently associated with incident stroke and other cardiovascular events. Arterial geometry such as large IMT and large diameter may reflect vulnerable plaques and so impact stroke risk. Finally, arterial changes that exist bilaterally may increase stroke risk.

Method

We studied middle-aged men and women (n=7276) from a prospective observational study who had right (R) and left (L) CCA IMT and external diameters measured via B-mode ultrasound (1987–89) in order to categorize CCA geometry. Using side- and gender-specific IMT and diameter medians, we categorized each measurement as large (≥ median) vs. not large (< median) and defined four geometries: both IMT and diameter were large, only one parameter was large, or neither was large (reference group). Participants were followed for first time stroke through December 31, 1999. We used proportional hazards models to assess associations between right and left CCA geometries with new stroke. We also calculated positive and negative likelihood ratios (+LR and -LR) for CCA bilateral phenotypes as a measure of diagnostic accuracy.

Results

Presence of both large CCA IMT and large diameter on one side was associated with strong stroke risk even after risk factor adjustment (men: RCCA hazard ratio [HR]=3.7 95% confidence interval [CI]=1.9-7.4; LCCA HR=2.4 95% CI=1.4-4.4; women: RCCA HR=4.0 95% CI=1.5-10.5; LCCA HR=5.7 95% CI=1.7-19.0). Presence of both large IMT and large diameter bilaterally was the strongest predictor of stroke identifying 64% of women and 44% of men who developed strokes. This phenotype showed potential for predicting stroke among individuals (women: +LR=3.1, 95% CI=2.6-3.8; men: +LR=2.3, 95% CI=1.8-2.8).

Conclusion

Bilateral carotid artery geometries may be useful for stroke risk prediction.

Common carotid flow velocity is associated with cognition in older adults

AIMS

To assess the relationship between carotid flow velocity and cognitive impairment in patients with mild-moderate (<50%) carotid artery disease.

METHODS

We studied 407 participants with available carotid ultrasound and cognitive measures. We related peak systolic velocity (PSV) and end diastolic velocity (EDV) of internal carotid artery (ICA) and common carotid artery (CCA) and intimal medial thickness (IMT) to Mini Mental State Examination (MMSE), Clock Draw Test (CDT), Activities of Daily Living Scale (ADL)and Montreal Cognitive Assessment (MoCA).

RESULTS

EDV of CCA was significantly different in higher and lower MoCA (MMSE) groups. Multiple regression analysis demonstrated that lower EDV was significantly associated with lower MoCA (+0.459 per standard deviation (SD), p<0. 01 for the left; +0.539 per SD, p<0. 01 for the right) and CDT (odds ratio (OR) 0.093, p< 0.05 for the left; OR) 0.120, p<0. 01 for the right) scores. PSV of left CCA (-0.205 per SD, p<0.05) and IMT (+42.536 per SD, p< 0.001) were associated with ADL. PSV of right CCA was associated with MMSE (+0.081 per SD, p<0.001). No significant relationship between ICA flow velocity and cognitive performance was observed.

CONCLUSIONS

Our preliminary data show that common carotid artery flow velocity was associated with cognitive performance.

Carotid resistive index in treated hypertensive patients: relationship with target organ damage

AIM

The resistive index (RI) is a hemodynamic parameter that reflects local wall extensibility and related vascular resistance. We analyze the relationship between common carotid RI and target organ damage in treated hypertensive patients.

METHODS

We analyzed 265 consecutive hypertensive patients. Risk factors, cardiovascular history and treatments were collected; blood test, urinary albumin excretion (UAE), echocardiography to determine left ventricular mass index (LVMI), ankle-brachial index (ABI) and carotid echo-Doppler ultrasound to calculate the carotid intima-media thickness (IMT) and RI of both common carotids arteries were performed.

RESULTS

A positive correlation was found between carotid RI and age, systolic blood pressure, heart rate, carotid IMT, LVMI, UAE and a negative correlation was found with diastolic blood pressure and ABI. Subjects at the top quartile of carotid RI showed a higher prevalence of left ventricular hypertrophy and peripheral artery disease (increased IMT, carotid plaques and lower ABI) compared with those with low RI (p < 0.05). Multiple regression analysis demonstrated that age, systolic and diastolic blood pressure and LVMI independently influence carotid RI.

CONCLUSION

Carotid RI is related with age, systolic-diastolic blood pressure and LVMI in hypertensive patient. This evaluation could predict the presence of early cardiovascular damage and provide an accurate estimation of overall risk in this population.

Carotid velocities determine cerebral blood flow deficits in elderly men with carotid stenosis <50%

To examine if mild carotid stenosis correlates with silent vascular brain changes, we studied a prospective population-based cohort “Men born in 1914.” Data from followups at ages 68 and 81, have been used. Carotid ultrasound was performed at age 81, and cerebral blood flow (CBF) was measured with SPECT at age 82. Out of 123 stroke-free patients, carotid stenosis <50% was observed in 94% in the right and 89% in the left internal carotid arteries (ICAs). In these subjects, Peak Systolic Velocities in ICA correlated negatively with CBF in a majority of several brain areas, especially in mesial temporal area. Results were limited to normotensive until their seventies, who developed late-onset hypertension with a subsequent blood pressure, pulse pressure, and ankle-brachial index growth. Elderly with asymptomatic carotid stenosis <50% and peak systolic velocities in ICA 0.7–1.3 m/s, should be offered an intensified pharmacotherapy to prevent stroke or silent cerebrovascular events.

Common carotid end-diastolic velocity and intima-media thickness jointly predict ischemic stroke in Taiwan

BACKGROUND AND PURPOSE

In Asian populations, few studies investigated the association between stroke and common carotid artery intima-media thickness (IMT). Our previous case-control studies showed that low end-diastolic velocity (EDV) in common carotid artery, a potential hemodynamic marker of intracranial resistance, was associated with ischemic stroke. Therefore, we investigated the relationship between both EDV and IMT and incident ischemic stroke in an Asian population.

METHODS

Baseline data from 3175 adults (30 years or older) in the Cardiovascular Diseases Risk Factor Two-Township Study were linked to incidental ischemic stroke status derived from insurance claims and death certificate records. Hazard ratios for risk of ischemic stroke for high IMT and low EDV values measured in common carotid artery were calculated using Cox proportional hazard models.

RESULTS

With 9.85 years (median) of follow-up, 184 persons had ischemic stroke develop. Compared with the first tertile of IMT, hazard ratios were 2.03 (95% confidence intervals, 1.27-3.25) for the second tertile and 3.87 (95% confidence intervals, 2.36-5.69) for the third tertile. Hazard ratios of EDV were 5.31 (95% confidence intervals, 3.52-7.99; first tertile) and 1.94 (95% confidence intervals, 1.21-3.09; second tertile) compared with the third tertile. The individuals with high IMT and low EDV had >2-fold ischemic stroke risk compared to those with low IMT and high EDV (2.10; 95% confidence intervals, 1.35-3.26) after adjusting for age, sex, and traditional cardiovascular risk.

CONCLUSIONS

Common carotid IMT and EDV jointly and independently predicted future ischemic stroke in this Taiwanese population. More prospective studies are required in various ethnic groups to understand the significance and implication of the current findings, particularly with respect to EDV.

Genetic variants of connexin37 are associated with carotid intima-medial thickness and future onset of ischemic stroke

BACKGROUND

Carotid intima-medial thickness (IMT) is a surrogate marker of subclinical atherosclerosis. This study aimed to investigate the impacts of genetic variants on IMT and future development of ischemic stroke in a cohort, followed by an independent replication study.

METHODS

B-mode carotid ultrasound was performed among 3330 healthy adults in the CVDFACT cohort study, and the genetic effects of atherosclerosis-related genes including connexin37 (GJA4), C-reactive protein (CRP), paraoxonase (PON1), adiponectin (ACDC), angiotensin-converting enzyme (ACE), beta-adrenergic receptor (ADRB1, ADRB2), antithrombin III (SERPINC1), and kinesin family member 6 (KIF6) were evaluated by a multivariate regression model, adjusting for traditional vascular risk factors. Study subjects were prospectively followed for the development of ischemic stroke to assess the prognostic impacts of these genetic variants. An independent case-control study was performed to replicate the genetic association from the cohort study.

RESULTS

The T allele of connexin37 C1019T polymorphism significantly affected IMT (β=0.014, p=0.013) after adjusting for traditional risk factors. During an average follow-up period of 10.7 years, 80 patients with ischemic stroke (2.4%) were identified. The connexin37 1019T allele was significantly associated with an increased rate of ischemic stroke under an additive model, with hazard ratios (HR) of 2.83 (95% confidence interval, 1.2-6.66) and 1.69 (95% confidence interval, 1.06-2.71), comparing TT and CT genotype with CC, respectively. After Cox analysis, age (HR, 1.78 every 10 years), diabetes mellitus (HR, 2.63), hypertension (HR, 2.08), and the T allele of C1019T polymorphism of GJA4 (HR, 1.69) were identified as independent predictors of ischemic stroke. The relationship between T allele of C1019T polymorphism of GJA4 gene and ischemic stroke was also confirmed by an independent association study.

CONCLUSION

Connexin 37 genetic variants significantly affect carotid IMT and contribute to future development of ischemic stroke.