Plaque Gray-scale Median Research Articles

Amyloid beta is associated with carotid wall echolucency and atherosclerotic plaque composition

Circulating amyloid-beta 1–40 (Αb40) has pro-atherogenic properties and could serve as a biomarker in atherosclerotic cardiovascular disease (ASCVD). However, the association of Ab40 levels with morphological characteristics reflecting atherosclerotic plaque echolucency and composition is not available. Carotid atherosclerosis was assessed in consecutively recruited individuals without ASCVD (n = 342) by ultrasonography. The primary endpoint was grey scale median (GSM) of intima-media complex (IMC) and plaques, analysed using dedicated software. Vascular markers were assessed at two time-points (median follow-up 35.5 months). In n = 56 patients undergoing carotid endarterectomy, histological plaque features were analysed. Plasma Αb40 levels were measured at baseline. Ab40 was associated with lower IMC GSM and plaque GSM and higher plaque area at baseline after multivariable adjustment. Increased Ab40 levels were also longitudinally associated with decreasing or persistently low IMC and plaque GSM after multivariable adjustment (p < 0.05). In the histological analysis, Ab40 levels were associated with lower incidence of calcified plaques and plaques without high-risk features. Ab40 levels are associated with ultrasonographic and histological markers of carotid wall composition both in the non-stenotic arterial wall and in severely stenotic plaques. These findings support experimental evidence linking Ab40 with plaque vulnerability, possibly mediating its established association with major adverse cardiovascular events.

Plaque characteristics and biomarkers predicting regression and progression of carotid atherosclerosis

SummaryThe factors that influence the atherosclerotic disease process in high-risk individuals remain poorly understood. Here, we used a combination of vascular imaging, risk factor assessment, and biomarkers to identify factors associated with 3-year change in carotid disease severity in a cohort of high-risk subjects treated with preventive therapy (n = 865). The results show that changes in intima-media thickness (IMT) are most pronounced in the carotid bulb. Progression of bulb IMT demonstrates independent associations with baseline bulb IMT, the plaque gray scale median (GSM), and the plasma level of platelet-derived growth factor (PDGF) (standardized β-coefficients and 95% confidence interval [CI] −0.14 [−0.06 to −0.02] p = 0.001, 0.15 [0.02–0.07] p = 0.001, and 0.20 [0.03–0.07] p < 0.001, respectively). Plasma PDGF correlates with the plaque GSM (0.23 [0.15–0.29] p < 0.001). These observations provide insight into the atherosclerotic process in high-risk subjects by showing that progression primarily occurs in fibrotic plaques and is associated with increased levels of PDGF.

Optical coherence tomography and plaque morphology for revascularization of the superficial femoral artery.

The optical coherence tomography (OCT) catheter, Ocelot (Avinger Inc., Redwood City, CA), has been utilized to cross Trans-Atlantic Inter-Society Consensus Document (TASC) D lesions. Studies have assessed the characteristics of high-risk plaques in the carotid artery, but few, if any data exist evaluating OCT and plaque morphology in the superficial femoral artery (SFA). This study assessed SFA plaque morphology using OCT and lesion crossing success in chronic total occlusions (CTOs). We reviewed patients who underwent attempted infrainguinal revascularization with TASC D CTOs using the Ocelot catheter between June 2014 and June 2018, and recorded demographic information, smoking status, and medical comorbidities. A matched cohort of 44 successfully crossed lesions was compared to 44 that failed; images insufficient for analysis were excluded. The morphology of the plaque was studied using OCT at the proximal cap, midpoint of the lesion, and the distal cap. Morphologic data studied included the intima-media thickness ratio, cross-sectional area of the plaque, and gray-scale median of the plaque. A total of 140 patients who underwent lower extremity procedures for TASC D lesions of the SFA with OCT imaging were reviewed with a crossing rate of 69.0%. No significant differences were found between crossed and uncrossed lesions for intima-media thickness or cross-sectional area at the proximal cap, the midpoint, or the distal cap. A lower gray-scale median at the proximal cap was associated with the ability to cross the chronic SFA occlusion (P=0.05). Subgroup analysis stratified by smoking and calcium content also demonstrated that a lower gray-scale median at the proximal cap was associated with the ability to cross the chronic SFA occlusion (P=0.01 and P=0.04, respectively). Lower gray-scale median at the proximal cap of a chronic SFA occlusion calculated using OCT images was associated with the ability to successfully cross the lesion. Higher plaque gray-scale median is correlated with increased calcium, greater fibrous tissue, and signal-rich plaques. Gray-scale median in the proximal cap is useful marker to determine plaque composition and subsequent technical success for crossing chronic SFA occlusions. Further studies are needed to fully determine the utility of OCT images to predict successful endovascular revascularization of chronic SFA occlusions.

Echolucent carotid plaque is associated with restenosis after carotid endarterectomy.

The mechanism of carotid endarterectomy (CEA) restenosis remains unclear. Our research aimed to investigate the relationship between the carotid plaque grayscale median (GSM) value and restenosis after CEA. Between January 2010 and January 2018, 1280 consecutive patients underwent CEA at our institution; 32 patients were diagnosed with restenosis by ultrasound at 1 year after CEA. The correlations between plaque GSM, plaque echogenicity, clinical manifestations, shunting, and restenosis were analyzed. In total, 829 patients were ultimately enrolled; 32 (4%) presented diagnoses of restenosis (mean age 67.3 ± 8.0 years, 81.2% men). The GSM value was lower in the restenosis group (68.1 ± 19.9 vs 59.9 ± 14.7, p = 0.02). After multiple logistic regression analysis, the GSM value was found to be an independent risk factor for restenosis (OR 0.976, 95% CI 0.957-0.995). Shunting was another significant independent risk factor for restenosis (OR 2.39, 95% CI 1.07-5.34). The GSM cutoff value for predicting restenosis was 75 (sensitivity 0.38, specificity 0.84, area under the curve 0.62). We separated the patients into 2 groups by GSM (GSM ≤ 75 and GSM > 75 subgroups). Comparison of the 2 groups indicated that symptomatic manifestation was related to restenosis in the subgroup with GSM ≤ 75, indicating predominantly echolucent plaques, but not in the subgroup with GSM > 75, indicating predominantly echogenic plaques. Predominantly echolucent carotid plaques, as measured by GSM, had a higher restenosis risk at 1 year than echogenic plaques.

Asymptomatic carotid stenosis is associated with cognitive impairment

BackgroundCerebrovascular risk factors (eg, hypertension, coronary artery disease) and stroke can lead to vascular cognitive impairment. The Asymptomatic Carotid Stenosis and Cognitive Function study evaluated the isolated impact of asymptomatic carotid stenosis (no prior ipsilateral or contralateral stroke or transient ischemic attack) on cognitive function. Cerebrovascular hemodynamic and carotid plaque characteristics were analyzed to elucidate potential mechanisms affecting cognition. MethodsThere were 82 patients with ≥50% asymptomatic carotid stenosis and 62 controls without stenosis but matched for vascular comorbidities who underwent neurologic, National Institutes of Health Stroke Scale, and comprehensive neuropsychological examination. Overall cognitive function and five domain-specific scores were computed. Duplex ultrasound with Doppler waveform and B-mode imaging defined the degree of stenosis, least luminal diameter, plaque area, and plaque gray-scale median. Breath-holding index (BHI) and microembolization were measured using transcranial Doppler. We assessed cognitive differences between stenosis patients and control patients and of stenosis patients with low vs high BHI and correlated cognitive function with microembolic counts and plaque characteristics. ResultsStenosis and control patients did not differ in vascular risk factors, education, estimated intelligence, or depressive symptoms. Stenosis patients had worse composite cognitive scores (P = .02; Cohen's d = 0.43) and domain-specific scores for learning/memory (P = .02; d = 0.42) and motor/processing speed (P = .01; d = 0.65), whereas scores for executive function were numerically lower (P = .08). Approximately 49.4% of all stenosis patients were impaired in at least two cognitive domains. Precisely 50% of stenosis patients demonstrated a reduced BHI. Stenosis patients with reduced BHI performed worse on the overall composite cognitive score (t = −2.1; P = .02; d = 0.53) and tests for learning/memory (t = −2.7; P = .01; d = 0.66). Cognitive function did not correlate with measures of plaque burden (degree of stenosis, least luminal diameter, and plaque area) or with plaque gray-scale median. ConclusionsAsymptomatic carotid stenosis is associated with cognitive impairment independent of known vascular risk factors for vascular cognitive impairment. Approximately 49.4% of these patients demonstrate impairment in at least two neuropsychological domains. The deficit is driven primarily by reduced motor/processing speed and learning/memory and is mild to moderate in severity. The mechanism for impairment is likely to be hemodynamic as evidenced by reduced cerebrovascular reserve and the likely result of hypoperfusion from a pressure drop across the stenosis in the presence of inadequate collateralization.

Abstract P043: Higher Levels of CRP and IL-6 are Associated With Femoral Artery Plaque Presence, but Not Plaque Characteristics: The San Diego Population Study (SDPS)

Introduction: The potential involvement of c-reactive protein (CRP), interleukin (IL)-6 and intracellular adhesion molecule (ICAM)-1 in the destabilization, erosion, or rupture of arterial plaque, particularly plaques in the lower extremity arteries is not well-established. Thus, we sought to determine whether circulating levels of CRP, IL-6, and ICAM-1 were associated with the presence, burden, and characteristics of femoral artery plaques. Methods: The San Diego Population Study is a prospective, population-based, multi-ethnic cohort of 1103 men and women averaged age 70 at a follow up exam taking place from 2007-11. At this exam, B-mode ultrasound was used to measure plaque presence, burden, and characteristics, including total plaque area (TPA), mean grey-scale median (GSM), and presence of calcification. Plaques were assessed in the left and right superficial and common femoral arteries. Plaque presence was defined as any plaque in any arterial segment, while plaque burden was total number of plaques summed over all four segments. Circulating CRP, ICAM-1, and IL-6 were also measured at this exam. Associations of CRP, IL-6, and ICAM-1 with plaque presence and burden were assessed using logistic and zero-inflated Poisson regression, respectively. Among those with plaque, linear and logistic regression were used to assess associations of the biomarkers with plaque characteristics. All models adjusted for age, sex, race/ethnicity, BMI, BP, statin use, smoking status, diabetes, peripheral artery disease, and chronic kidney disease. Results: Higher circulating CRP was significantly associated with plaque presence with participants in the highest quartile of CRP having 1.8 times higher odds of having femoral plaque compared to those in the lowest quartile. Participants in the highest quartiles of CRP and IL-6 were significantly more likely to have greater plaque burden compared to those in the lowest quartiles (CRP OR=1.64, 95% CI=1.09-2.44; IL-6 OR=1.65, 95%CI=1.06-2.55). No associations were observed between circulating biomarkers and plaque characteristics, including TPA, GSM, or calcification. Conclusions: Higher levels of circulating CRP and IL-6 are associated with greater plaque burden in the femoral arteries of participants in the SDPS; however, these biomarkers do not appear to be associated with characteristics of femoral artery plaques. These results are consistent with findings in the carotid and coronary arteries.

Признаки нестабильности атеросклеротической бляшки в сонных артериях у больных с острым коронарным синдромом по данным ультразвукового дуплексного сканирования

to study carotid plaques structure in patients with acute coronary syndrome by ultrasound duplex scanning. We included in this study143 patients with acute coronary syndrome (ACS) aged 32-83 years and 28 patients with documented coronary heart disease (CHD) aged 46-83 years. Duplex scanning of carotid arteries was carried out with Philips iU22 ultrasound system and L9-3 linear array transducer. Atherosclerotic plaques in CCA, CCA bifurcation, and ICA from right and left side were investigated. Off-line analysis of B-mode images and plaque gray scale median (GSM) was performed with computer semiautomated workstation MultiVox. 378 plaques of ACS and 59 plaques of CHD patients were studied. We assessed traditional (heterogenous structure, hypoechogenic component, irregular plaque surface) as well as additional (positive remodeling, "layered" structure of plaque, local calcification) criteria of plaque instability. In ACS compared with CHD group there were more plaques with hypoechogenic component (43.4 and 28.8%, p=0.0459), heterogenous structure (77.8 and 64.4%, p=0.0327), irregular surface including irregularities more than 2.0 mm (22.5 and 6.8%, p=0.0048, respectively). There was significant difference in "layered" structure (55.7 and 35.8%, p=0.0011) and insignificant difference in positive remodeling (16.3 and 7.5%, p=0.06, respectively). There were no differences of GSM value (53.1 and 57.2, p=0.24) and local calcification (23.2 and 24.5%, p=0.23, respectively). In our study ultrasound duplex scanning revealed that signs of plaque instability in carotid arteries in patients with ACS were more frequent than in patients with stable CHD. The newly introduced parameter "layered" structure of atherosclerotic plaque was found to be most significant.

Longitudinal Changes in Size and Composition of Carotid Artery Plaques Using Ultrasound: Adaptation and Validation of Methods (Inter- and Intraobserver Variability)

Introduction B-mode ultrasonography of the carotid arteries enables quantitative measurements of atherosclerotic plaque area and composition assessed as grayscale median (GSM). The purpose of this study was to set up a standardized ultrasound protocol to measure longitudinal changes in plaque area and composition and to determine the intra- and interobserver variability of the measurements in a longitudinal population based study, the Age Gene/Environment Susceptibility Reykjavik study. Method A total of 219 participants from the Age Gene/Environment Susceptibility Reykjavik study (76 ± 6 years old, 36% males) underwent 2-dimensional, B-mode ultrasound examination of the carotid arteries approximately 5 years apart for a longitudinal assessment of plaque area and composition. Standardized protocol was used to acquire comparable images from both visits. Ultrasound was performed bilaterally on the common carotid artery, internal carotid artery, and bifurcation. An image analysis program was modified and adapted for a longitudinal assessment of plaque area and plaque composition by GSM. Twenty-five subjects were selected from the group of 219 for intra- and interobserver variability assessment. Results Intraobserver variability for plaque area ranged from 12.10 to 18.63% and 0.89 to 0.96 for coefficient of variation and correlation (r), respectively, for plaque GSM ranged from 7.77 to 8.04% and 0.86 to 0.90. Interobserver variability for plaque area was 23.29% and 0.81 and 8.55% and 0.87 for plaque GSM. Conclusion The results from this study show that ultrasound can be used consistently for assessment of changes in plaque area and GSM over time. This can be achieved by proper training of ultrasound sonographers and by applying and following strict image acquisition and image analysis protocols.

A Novel Ultrasound-Based Carotid Plaque Risk Index Associated with the Presence of Cerebrovascular Symptoms.

The purpose of this study was to determine the efficacy of a novel ultrasound-based carotid plaque risk index (CPRI) in predicting the presence of cerebrovascular symptoms in patients with carotid artery stenosis. This was a cross-sectional, observational study involving 56 patients (mean age 76.6 years, 62.5 % male). Plaque grayscale median (GSM) and surface irregularity indices (SII) were measured in 82 stenosed carotid arteries (range 10 - 95 %) and combined with the degree of stenosis (DOS) in the form of (DOS*SII)/(1 + GSM). A reduced index DOS/(1 + GSM) not incorporating plaque surface irregularities was also investigated. Receiver operating characteristic curves (ROC) were used to study the diagnostic efficacy of CPRI, comparing against DOS and an equivalent risk index constructed using a conventional logistic regression based method with model parameters optimized to the dataset (CPRIlogistic). There were 42 stenosed carotid arteries with cerebrovascular symptoms, and 40 without symptoms. The presence of symptoms significantly correlated with DOS, GSM and SII (p < 0.01). The median CPRI of the symptomatic (asymptomatic) groups were 23.2 (9.2) compared with 0.71 (0.30) for CPRIlogistic (p < 0.01). The diagnostic performance of CPRI exceeded that of CPRIlogistic and DOS, and demonstrated a better separation of the symptomatic and asymptomatic groups. Our novel risk index combines quantitative measures of carotid plaque echogenicity and surface irregularities with the degree of stenosis. It is a better predictor of cerebrovascular symptoms than the degree of stenosis and could be valuable in studies and clinical trials aimed at identifying vulnerable carotid artery stenoses.

Treatment with betablockers is associated with higher grey-scale median in carotid plaques.

BackgroundThe presence of echolucent carotid plaques as defined by low ultrasound grey-scale median (GSM) is associated with a higher risk of stroke and myocardial infarction. Betablockers have shown possible anti-atherosclerotic effects. The aim of the present study was to determine if there is an association between carotid plaque GSM and treatment with betablockers.MethodsThe GSM of the carotid plaques of 350 patients who underwent carotid endarterectomy (CEA) for asymptomatic (n = 113) or symptomatic (n = 237) carotid disease was measured. Patients were divided in two groups based on the absence/presence of an on-going long-term (i.e. at least 6 months) oral treatment with betablockers at the time of CEA.ResultsThe prevalence and type of preoperative neurological symptoms were similar in the two groups. Patients with betablockers had more frequently arterial hypertension (P < .0001), diabetes (P = .035) and a higher BMI (P = .0004), while patients without betablockers were most frequently smokers (P = .017).Patients with betablockers revealed to have higher GSM (37.79 ± 25 vs 32.61 ± 23.50 P = .036). Echogenic plaques (i.e. with GSM > 30) showed to be more frequent in patients with betablockers also after correction for age, gender, the occurrence of preoperative symptoms, diabetes, hypertension, smoking and statins use (P = .024).ConclusionsThese results suggest the use of standardized ultrasound techniques as an important tool in evaluating the effect of anti-atherosclerotic medications and underline the need of.further prospective randomized studies on larger patient cohorts in order to confirm these results.

Ultrasound analysis of gray-scale median value of carotid plaques is a useful reference index for cerebro-cardiovascular events in patients with type 2 diabetes.

Aims/IntroductionMeasurements of plaque echogenicity, the gray-scale median (GSM), were shown to correlate inversely with risk factors for cerebro-cardiovascular disease (CVD). The eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is a potential predictor of CVD risk. In the present study, we assessed the usefulness of carotid plaque GSM values and EPA/AA ratios in atherosclerotic diabetics.Materials and MethodsA total of 84 type 2 diabetics with carotid artery plaques were enrolled. On admission, platelet aggregation and lipid profiles, including EPA and AA, were examined. Using ultrasound, mean intima media thickness and plaque score were measured in carotid arteries. Plaque echogenicity was evaluated using computer-assisted quantification of GSM. The patients were then further observed for approximately 3 years.ResultsGray-scale median was found to be a good marker of CVD events. On multivariate logistic regression analysis, GSM <32 and plaque score ≥5 were significantly associated with past history and onset of CVD during the follow-up period, the odds ratios being 7.730 (P = 0.014) and 4.601 (P = 0.046), respectively. EPA/AA showed a significant correlation with GSM (P = 0.012) and high-density lipoprotein cholesterol (P = 0.039), and an inverse correlation with platelet aggregation (P = 0.046) and triglyceride (P = 0.020). Although most patients with CVD had both low GSM and low EPA/AA values, an association of EPA/AA with CVD events could not be statistically confirmed.ConclusionsThe present results suggest the GSM value to be useful as a reference index for CVD events in high-risk atherosclerotic diabetics. Associations of the EPA/AA ratio with known CVD risk factors warrant a larger and more extensive study to show the usefulness of this parameter.

Wall motion in the stenotic carotid artery: association with greyscale plaque characteristics, the degree of stenosis and cerebrovascular symptoms

BackgroundSystolic dilation of the atherosclerotic carotid artery depends on several factors including arterial compliance and the haemodynamic environment. The purpose of this study was to quantify wall motion in stenotic carotid arteries and investigate any associations with the ultrasound greyscale plaque characteristics, the degree of stenosis, and the presence of cerebrovascular symptoms.MethodsVariations in the lumen diameters of 61 stenotic carotid arteries (stenosis range 10%-95%) from 47 patients were measured before the proximal shoulder of the atherosclerotic plaque using ultrasound image sequences over several cardiac cycles. Absolute and percentage diameter changes from diastole to systole were calculated and their relationship to the degree of stenosis, greyscale plaque characteristics, and the presence of ipsilateral hemispheric symptoms were studied.ResultsThe mean absolute diameter change from diastole to systole was 0.45 mm (s.d. 0.17), and the mean percentage diameter change was 6.9% (s.d. 3.1%). Absolute and percentage diameter changes did not have a statistically significant relationship to the degree of stenosis, greyscale plaque characteristics, or the presence of ipsilateral hemispheric symptoms (p > 0.05). Parameters significantly correlated with the presence of symptoms were the degree of stenosis (p = 0.01), plaque greyscale median (p = 0.02) and the plaque surface irregularity index (p = 0.02).ConclusionsOur study confirmed the degree of stenosis, plaque greyscale median and our surface irregularity index were significant predictors of symptoms, but found no significant correlation between diameter changes of stenosed carotid arteries and the presence of ipsilateral hemispheric symptoms.

Dynamic variations in the ultrasound greyscale median of carotid artery plaques

BackgroundSeveral studies have found that the ultrasound greyscale median (GSM) of carotid artery plaques may be useful for predicting the risk of cerebrovascular events. However, measurements of GSM are typically performed on still ultrasound images ignoring any variations that may be observed on a frame-by-frame basis. The aim of this study was to establish the existence and investigate the nature and extent of these variations.MethodsEmploying a novel method that enabled plaque boundaries to be tracked semi-automatically, variations in the plaque GSM and observed cross-sectional area were measured for 27 carotid artery plaques (19 consecutive patients, stenosis range 10%-80%) over image sequences of up to 10 seconds in length acquired with a mean frame rate of 32 frames per second.ResultsOur results showed a mean inter-frame coefficient of variation (CV) of 5.2% (s.d. 2.5%) for GSM and 4.2% (s.d. 2.9%) for the plaque area. Thirteen of the 27 plaques (48%) exhibited CV in GSM greater than 5% whereas only six plaques (22%) had CV in plaque area of greater than 5%. There was no significant correlation between the CV of GSM and plaque area.ConclusionsInter-frame variations in the plaque GSM such as those found in this study have implications on the reproducibility of GSM measurements and their clinical utility. Studies assessing the GSM of carotid artery plaques should consider these variations.

Abstract WP163: 3D-versus 2D-Ultrasound for Plaque Analysis of Internal Carotid Arteries with Gray-Scale Median

Background: Gray-Scale Median (GSM) analysis of carotid artery stenosis allows quantification of plaque echogenicity, correlates with histology and showed an association with symptoms and cerebral embolic findings. The aim of the study is to demonstrate whether several systematically aquired sections of 3-dimensional Power-Doppler ultrasound (3D-PDUS) datasets comprising whole plaque stenoses provide different GSM than single sections acquired by 2D-PDUS as commonly used for this purpose. Methods: After informed consent, 27 patients were scanned with a 3D-ultrasound (US) probe at 10 Mhz. GSM-analysis was performed offline with a specially designed software (Matlab) in 2D longitudinal scans adjusted to the vessel center line, as well as 3 parasagital - longitudinal sections parallel to each other and 3 views rotated around the center of the plaque, that were aquired off-line from the 3D-datasets by multiplanar rendering. For comparison of the GSM, the median differences between 3D- and the 2D-images as well as standard deviations (SD) were calculated. Mixed model regression analysis was used for further descriptive statistics. Results: The GSM differences between the 3D-parallel and the central longitudinal 2D-reference section showed a markedly higher proportion of the variance due to image-to-image (63%) versus inherent technical-methodological scattering (37%), that was not found for rotated 3D sections (54 versus 46%). The GSM of the longitudinal 3D-sections correlates significantly with the GSM of the 2D-reference section (r = 0.60) as do the rotated 3D views (r = 0.52). Correlation coefficients of the central 3D- with the 2D-longitudinal section differed significantly, when rotation was performed (r = 0.63) instead of sagital rendering (r = 0.85, p &lt; 0.05). Significant over- versus underestimations were noted for high versus low GSM values in the 3D parasagital and rotated views compared to the 2D sections. Conlusions: Variations of the GSM values in between the 3D-sections were largely due to real differences of the echogenicity. The GSM of a single 2D-section may not be representative for the whole 3D plaque structure. Parasagital section rendering should be prefered to analyse whole plaque GSM over rotating sections.

Femoral Plaque Echogenicity and Cardiovascular Risk in Claudicants

The present study was designed to verify whether the evaluation of femoral plaque echogenicity might be a useful tool for cardiovascular risk assessment in patients affected by lower extremity peripheral arterial disease. Lower extremity peripheral arterial disease is a common manifestation of atherosclerosis and is associated with a high risk of developing major cardiovascular events. Vulnerable atherosclerotic plaque plays a central role in the occurrence of acute ischemic events in different vascular territories. Furthermore, atherosclerosis is a systemic disease, and the presence of an unstable atherosclerotic plaque in a certain vascular district, characterized by low echogenicity at B-mode ultrasound, is associated to a greater prevalence of unstable plaques in other vascular beds. Femoral plaque echogenicity of 246 claudicants with ankle/brachial index ≤0.90 was evaluated at B-mode ultrasound by visual analysis and by calculating the grayscale median (GSM) value. In these patients, the occurrence of myocardial infarction and stroke was prospectively assessed. Femoral GSM values and plaque types assessed by visual analysis were highly correlated by Spearman analysis (rho = 0.905, p < 0.001). During a median follow-up of 30 months, 32 patients (13%) had a major cardiovascular event. Compared with patients without events, those who experienced an event during the follow-up had a lower femoral plaque GSM value (42.9 ± 26.2 vs. 58.8 ± 19.3, p = 0.002) and a higher prevalence of hypoechoic femoral plaque at visual analysis (68.8% vs. 19.6%, p < 0.001). At Cox analysis, femoral GSM showed an inverse relationship with cardiovascular risk, even after adjustment for possible confounders (hazard ratio: 0.96, 95% confidence interval [CI]: 0.95 to 0.98, p < 0.001). Furthermore, patients with hypoechoic femoral plaques at visual analysis had a 7.24-fold increased cardiovascular risk compared with patients with hyperechoic plaques after adjustment for possible confounders (95% CI: 3.23 to 16.22, p < 0.001). This study demonstrates that the presence of hypoechoic atherosclerotic femoral plaques is associated with higher cardiovascular risk in lower extremity peripheral arterial disease patients.

Associations of Circulating Adiponectin with Measures of Vascular Function and Morphology

Some previous studies have reported an association between circulating adiponectin and selected measures of vascular function and morphology, but most of these studies have been performed in small samples of patients with preexisting disease. We aimed to evaluate associations between circulating adiponectin and comprehensive measures of vascular function and morphology in a large sample of individuals from the community. We conducted a cross-sectional investigation of 981 70-yr-old participants (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Measures of outcome included vascular function [common carotid artery (CCA) distensibility, flow-mediated dilation, endothelium-dependent and endothelium-independent vasodilation using invasive methods] and vascular morphology [intima-media (IM) thickness, plaque presence, gray scale median (GSM) in the IM and plaques]. In age- and sex-adjusted models, adiponectin was positively associated with IM-GSM, plaque GSM, CCA distensibility, endothelium-dependent and endothelium-independent vasodilation. In multivariable models (with additional adjustment for body mass index; systolic blood pressure; antihypertensive, antidiabetic, and lipid-lowering medication; fasting blood glucose; total cholesterol; high-density lipoprotein cholesterol; creatinine; and smoking), adiponectin remained positively associated with IM-GSM [beta = 2.06; 95% confidence interval (CI), 0.54, 3.58], plaque GSM (beta = 3.11; 95% CI, 0.36, 5.86), and CCA distensibility (beta = 0.04; 95% CI, 0.00, 0.07). Serum levels of adiponectin were positively associated with IM-GSM and plaque GSM (indicating lower fat content in the IM and plaques) and CCA distensibility (indicating higher wall elasticity), independent of potential confounders. Our results imply that adiponectin is associated with less arterial pathology.

Gray-scale median of the atherosclerotic plaque can predict success of lumen re-entry during subintimal femoral-popliteal angioplasty

This study assessed whether the duplex ultrasound (DUS)-derived gray-scale median (GSM) of the most six distal portion of the occluded femoral-popliteal arterial segment can predict success of lumen re-entry for subintimal angioplasty. During the last 3 years, 108 patients (62% men) with a mean age of 73 +/- 10 years underwent 116 primary attempted DUS-guided subintimal angioplasties of the femoral-popliteal segment. Preprocedural B-mode DUS images of the plaque at the most distal occlusion segment were digitalized and normalized using Photoshop (Adobe, San Jose, Calif) software and standard criteria (gray level, 0 to 5 for lumen blood and 185 to 190 for the adventitia on a linear scale of 0 to 255). Overall GSM of the plaque segment about 2 cm long, immediately before the planned re-entry point to the true arterial lumen, was used for retrospective correlation with procedure success and other clinical indicators. Mean plaque GSM for all cases was 22.5 +/- 12.6 (range, 3 to 60). The overall success rate of subintimal angioplasty procedures was 85%. Mean plaque GSM for 99 successful cases (18.4 +/- 7.8) was significantly lower than for 17 cases (46.4 +/- 8.1) where we failed (P < .0001). We failed in 90% of 19 cases with GSM >35, in 71% of 24 cases with GSM >20, and in 50% of 34 cases with GSM >25. There was no statistically significant difference (P = .45) between plaque GSM in 64 patients with diabetes (23.3 +/- 13.5) compared with 52 nondiabetic patients (21.5 +/- 11.4). Similarly, plaque GSM was not statistically different (P = .9) in 52 patients with renal insufficiency (22.7 +/- 13.2) compared with 64 patients with normal creatinine levels (22.4 +/- 12.2). At the 6-month follow-up, no statistically significant difference was found between mean GSM (17.8 +/- 7.8) in 47 stenosis-free cases compared with mean GSM (18 +/- 6.8) in 22 cases where severe restenosis (>70%) or reocclusion was identified by DUS scan (P = .4). Plaque echogenicity represented by DUS-derived GSM can be used to predict the success of primary subintimal femoral-popliteal angioplasties.

B-mode ultrasonographic characterization of carotid atherosclerotic plaques in symptomatic and asymptomatic patients

To identify features on B-mode ultrasonography (US) prevalent in symptomatic plaques and correlate these findings with histopathologic markers of plaque instability. Carotid endarterectomy (CEA) plaques from symptomatic and asymptomatic patients with critical stenoses (>70%) were qualitatively assessed using preoperative B-mode US for echolucency and calcific acoustic shadowing. US echolucency was quantitated ex vivo using computerized techniques for gray-scale median (GSM) analysis. Histopathologic correlates for US plaque echolucency (percentage of necrotic core area) and acoustic shadowing (percentage of calcification area) were determined. Fifty CEA plaques were collected from 48 patients (46 unilateral and two bilateral); 26 of these plaques were from symptomatic patients. Age, degree of stenosis, and atherosclerotic risk factors were similar for the symptomatic and asymptomatic patients. Using preoperative B-mode US, 58%, 35%, and 7% of symptomatic plaques and 18%, 41%, and 41% of asymptomatic plaques were found to be echolucent, echogenic, and calcific, respectively (P < .05). Using ex-vivo B-mode US and GSM analysis, symptomatic plaques were more echolucent (41 +/- 19) than asymptomatic plaques (60 +/- 13), P < .03. A strong inverse correlation was found between the percent plaque necrotic area core and GSM (R = -0.9, P < .001). Percentage of calcification area in plaques with acoustic shadowing was 66% and only 27% in those without acoustic shadowing (P < .05). Using B-mode US, symptomatic plaques are more echolucent and less calcified than asymptomatic plaques and are associated with a greater degree of histopathologic plaque necrosis. Such features are indicative of plaque instability and should be considered in the decision-making algorithm when selecting patients with high-grade asymptomatic carotid stenosis for intervention.

Determinants of carotid plaque instability: echoicity versus heterogeneity.

to identify the echoicity and heterogeneity of carotid plaques associated with ipsilateral symptomatic and asymptomatic neurovascular presentations. cross-sectional study. a total of 113 patients, with 127 symptomatic and asymptomatic plaques, were studied. the duplex images of the plaques were analysed echoically in a computer by means of Grey Scale Median (GSM) [hypoechoic (low GSM), hyperechoic (high GSM)]. The presence or absence of at least two plaque regions within the plaque area being echoically uniform (no variation of echoicity), occupying each at least 10% of the plaque area and having GSM difference greater than the plaque GSM was evaluated to distinguish the heterogeneous (presence of this pattern) from the homogeneous (absence of this pattern) plaques. the symptomatic status was associated with plaques of low median GSM (10.5) and 88% prevalence of the homogeneous pattern as contrasted with the asymptomatic status that was associated with high median GSM (28) and 65% prevalence of the homogeneous pattern [(p=0.001 (GSM), p=0.003 (heterogeneity)]. symptomatic plaques were associated with hypoechoic and predominant homogeneous echo-pattern whereas the asymptomatic ones were associated with hyperechoic and less predominant homogeneous pattern.

Ultrasonic plaque character and outcome after lower limb angioplasty

Purpose: The value of ultrasonic plaque characteristics in identifying patients at “high-risk” of restenosis after percutaneous transluminal angioplasty (PTA) was studied. Methods: Thirty-one arterial stenoses (6 common iliac, 2 external iliac, 1 profunda femoris, 21 superficial femoral, and 1 popliteal) in 17 patients who underwent angioplasty were studied by means of duplex scanning. With a computer-based program, B-mode images were digitized and normalized using 2 reference points, blood and adventitia. A grey level of 0 to 5 was allocated for the lumen (blood) and 180 to 190 for the adventitia on a linear gray scale of 0 to 255 (0 = absolutely black; 255 = absolutely white), and the overall plaque gray-scale median (GSM) of the pixels of the plaque was used as a measure of plaque echodensity. After PTA, follow-up of stenoses was done on day 1, weekly for 8 weeks, at 3 months, 6 months, and 1 year. The total plaque thickness (sum of anterior and posterior components), minimal luminal diameter (MLD), and peak systolic velocity ratio (PSVR) were measured for all stenoses. An increase of more than 2 in the PSVR was the duplex criterion used to signify restenosis. Results: The GSM of the stenoses before angioplasty ranged from 6 to 71 (mean, 31.3 ± 17.9); 17 stenoses had a GSM less than 25 (mean, 18.7 ± 5.3), and 14 had a GSM more than 25 (mean, 46.4 ± 15.8). When the GSM was less than 25, the absolute reduction in plaque thickness on day 1 post-PTA was 3.3 ± 1.8 mm, in contrast to 1.8 ± 1.6 mm when GSM was more than 25 ( P < .03). The restenosis rate (PSVR more than 2) was 41% at 6 months and remained unchanged at 1 year. When the GSM was less than 25, restenosis occurred in 11% of lesions, in comparison with 78% when the GSM was more than 25 ( P < .001). Conclusion: Plaque echodensity can be used to evaluate stenoses before PTA, to predict initial success and identify a subgroup that has a high prevalence of restenosis. The identification of a group at “high-risk” of restenosis can improve the selection of patients for the procedure and also be used in prospective studies on the prevention of restenosis. (J Vasc Surg 1999;29:110-21.)