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Background: Studies have indicated that the presence and size of subclinical atherosclerotic plaques improve the prediction of atherosclerotic cardiovascular events (ASCVE) over and above that provided by conventional risk factors alone. However, the relative contribution of different ultrasonographic measurements and sites of measurements on the 10-year ASCVD risk is largely unknown.Objectives: Our aims were to determine the relative performance of carotid intima-media thickness, plaque thickness, and plaque area in 10-year ASCVD prediction when added to conventional risk factors as well as whether the vascular territory of these measurements, carotid or common femoral bifurcation, and the number of bifurcations with plaque (NBP) influence prediction.Methods: We enrolled 985 adults (mean age: 58.1 ± 10.2 years) free of atherosclerotic cardiovascular disease. Conventional risk factors were recorded, and both carotid and common femoral bifurcations were scanned with ultrasonography. The primary endpoint was a composite of first-time fatal or nonfatal ASCVE.Results: Over a mean ± SD follow-up of 13.2 ± 3.7 years, ASCVE occurred in 154 (15.6%) participants. By adding different plaque measurements to conventional risk factors in a Cox model, net reclassification improvement was 10.4% with maximum intima-media thickness, 9.5% with carotid plaque thickness, and 14.2% with carotid plaque area. It increased to 16.1%, 16.6%, and 16.6% (P < 0.0001) by adding measurements from 4 bifurcations: NBP, total plaque thickness, and total plaque area, respectively.Conclusions: NBP, total plaque thickness, or total plaque area from both the carotid and common femoral bifurcations provides a better prediction of future ASCVE than measurements from a single site. The results need to be validated in an independent cohort. [ABSTRACT FROM AUTHOR]

The Cyprus Study is a prospective cohort study of cardiovascular disease (CVD). Its aim is to determine the relationship of intima-media thickness (IMT) of the common carotid (IMTcc), maximum thickness of IMT in the carotid bifurcation (IMTmax), number of carotid and femoral bifurcations with plaque and total plaque thickness (TPT) (sum of the maximum plaque measurements taken from the four bifurcations scanned) with the prevalence of clinical CVD. A total of 767 individuals (46% male) over the age of 40 years were recruited from a mountain village and a town outside the capital Nicosia. In addition to clinical examination, carotid and common femoral bifurcations were scanned with ultrasound. After controlling for conventional risk factors, there was little evidence of an association of IMTcc with CVD prevalence. However, IMTmax and TPT were associated with 2.9-fold (1.22 to 7.07) and 6.87-fold (2.42 to 19.43) increased odds of CVD prevalence, respectively. In conclusion, the TPT and number of bifurcations with plaque are more strongly associated with the prevalence of CVD. These findings warrant investigation in prospective studies to document associations with incident CVD events. [ABSTRACT FROM AUTHOR]

Objective Patients with SLE have increased prevalence of clinical cardiovascular disease (CVD) and subclinical atherosclerosis. Although 30–40% of patients with SLE have vascular plaque on ultrasound scanning, this study is the first to consider the relationship between total burden of plaque and subsequent CVD risk. Methods One hundred patients with SLE and without any previous clinical CVD underwent vascular ultrasound scans of both carotid and both common femoral bifurcations between 2011 and 2013. Clinical, serological, demographic and treatment data were collected at baseline. Patients were followed till 2020 to identify those who developed new onset coronary disease or stroke. Statistical analysis to identify factors associated with increased risk of developing CVD events was carried out. Results Thirty-six patients had plaque at baseline. During follow-up five patients (all had baseline plaque) developed coronary disease and two, without baseline plaque, developed lacunar strokes. Mean (s. d.) age of these patients was 46.5 (4.5) years. Patients with three or more baseline bifurcations with plaque were 10 times more likely to develop CVD than those with 0–2 bifurcations with plaques (OR 9.9, P  = 0.009). TPA > 16mm2 was associated with six-fold increased risk of CVD (OR = 6.44, P  = 0.028). Patients with disease duration > 14 years were more likely than those with disease duration < 14 years to develop CVD (OR 8.3 P  = 0.043) Conclusions The number of bifurcations with plaque and TPA in patients with SLE may be valuable in assessing risk of CVD and deciding on clinical measures to reduce this risk. [ABSTRACT FROM AUTHOR]

Objectives Patients with SLE have an increased risk of developing cardiovascular disease (CVD). Multiple studies have shown that these patients have increased numbers of carotid plaques and greater intima-media thickness (IMT) than healthy controls. Measures such as total plaque area (TPA) and plaque echogenicity may be more sensitive and more relevant to cardiovascular risk than presence of plaque and IMT alone. Our objective was to produce the first report of TPA and echogenicity in a population of patients with SLE. Methods One hundred patients with SLE and no history of clinical CVD were recruited. Clinical, serological and treatment variables were recorded and serum was tested for antibodies to apolipoprotein A-1 and high-density lipoprotein. Both carotid and both femoral artery bifurcations of each patient were scanned to determine IMT, TPA and echogenicity of plaques. Univariable and multivariable statistical analyses were carried out to define factors associated with each of these outcomes. Results Thirty-six patients had carotid and/or femoral plaque. Increasing age was associated with presence of plaque and increased IMT. Triglyceride levels were associated with presence of plaque. Mean (s. d.) TPA was 60.8 (41.6) mm2. Patients taking prednisolone had higher TPA. Most plaques were echolucent, but increased echogenicity was associated with prednisolone therapy and persistent disease activity. Conclusion TPA and plaque echogenicity in patients with SLE are associated with different factors than those associated with presence of plaque and IMT. Longitudinal studies may show whether these outcome measures add value in the management of cardiovascular risk in SLE. [ABSTRACT FROM AUTHOR]

The robust border identification of atherosclerotic carotid plaque, the corresponding degree of stenosis of the common carotid artery (CCA), and also the characteristics of the arterial wall, including plaque size, composition, and elasticity, have significant clinical relevance for the assessment of future cardiovascular events. To facilitate the follow-up and analysis of the carotid stenosis in serial clinical investigations, we propose and evaluate an integrated system for the segmentation of atherosclerotic carotid plaque in ultrasound videos of the CCA based on video frame normalization, speckle reduction filtering, M-mode state-based identification, parametric active contours, and snake segmentation. Initially, the cardiac cycle in each video is identified and the video M???mode is generated, thus identifying systolic and diastolic states. The video is then segmented for a time period of at least one full cardiac cycle. The algorithm is initialized in the first video frame of the cardiac cycle, with human assistance if needed, and the moving atherosclerotic plaque borders are tracked and segmented in the subsequent frames. Two different initialization methods are investigated in which initial contours are estimated every 20 video frames. In the first initialization method, the initial snake contour is estimated using morphology operators; in the second initialization method, the Chan???Vese active contour model is used. The performance of the algorithm is evaluated on 43 real CCA digitized videos from B-mode longitudinal ultrasound segments and is compared with the manual segmentations of an expert, available every 20 frames in a time span of 3 to 5 s, covering, in general, 2 cardiac cycles. The segmentation results were very satisfactory, according to the expert objective evaluation, for the two different methods investigated, with true-negative fractions (TNF-specificity) of 83.7 ?? 7.6% and 84.3 ?? 7.5%; true-positive fractions (TPF-sensitivity) of 85.42 ?? 8.1% and 86.1 ?? 8.0%; and between the ground truth and the proposed segmentation method, kappa indices (KI) of 84.6% and 85.3% and overlap indices of 74.7% and 75.4%. The segmentation contours were also used to compute the cardiac state identification and radial, longitudinal, and shear strain indices for the CCA wall and plaque between the asymptomatic and symptomatic groups were investigated. The results of this study show that the integrated system investigated in this study can be successfully used for the automated video segmentation of the CCA plaque in ultrasound videos. [ABSTRACT FROM AUTHOR]

We aimed to test the association between matrix metalloproteinase (MMP) genetic polymorphisms and (a) intima–media thickness in the common carotid (IMTcc) and (b) the presence of plaques in the carotid and femoral bifurcations. Carotid and femoral bifurcations were scanned with ultrasound in 762 Cypriot community dwellers (46% men) over the age of 40 years. IMTcc and the presence of plaques were recorded. The MMP1 1G/2G, MMP3 5A/6A, MMP7 -181A>G, MMP9 R279Q, and MMP12 -82A>G polymorphisms were determined with the TaqMan method. In men, the presence of plaques in any bifurcation was associated with the MMP9 279Q allele (ORadjusted=4.50; 95% CI=2.0 to 10.1; p<0.001) and the MMP7 -181A allele was associated with the presence of femoral plaques (ORadjusted=2.61; 95% CI=1.36 to 4.99; p=0.004). In women, the presence of femoral plaques was associated with the MMP12 -82G allele (ORadjusted=1.9; 95% CI=1.14 to 3.16; p=0.014). Our results suggest that the effect of common MMP genotypes on plaque presence may be site- and sex-dependent. [ABSTRACT FROM AUTHOR]

Background: We aimed to explore the association between presence and number of components of the Metabolic Syndrome (MetS) and subclinical atherosclerosis outcomes (common carotid intima media thickness, plaque presence and sum of plaque area) in both the carotid and femoral bifurcations. Methods: Cross-sectional analysis of 771 volunteers from the ongoing epidemiological Cyprus Study (46% male; mean age = 60.1 ± 9.8). (a) Carotid intima-media thickness (IMTcc), (b) sum of plaque area in the carotid bifurcations (sum of the largest plaques in each carotid bifurcation-SPAcar), (c) sum of plaque area in the femoral bifurcations (sum of the largest plaques in each femoral bifurcation-SPAfem) and (d) sum of plaque area in both carotid and femoral bifurcations (sum of the areas of the largest plaques present in each of the four bifurcations-SPA) were measured at baseline using ultrasound. Presence and number of components of the MetS was ascertained using the National Cholesterol Education Program ATPIII definition and their association tested using multivariable regression models. Results: MetS was present in 259 (33.6%) individuals and was associated with a 0.02 mm increase in IMTcc (95% CI: 0.00 to 0.04, p = 0.047) after adjustment for age, sex, family history of CVD, alcohol consumption (BU/week) and smoking (pack-years). Each additional component of the MetS was associated with a 16% higher SPA (95% CI: 6.8% to 25.2%, pfor trend = 0.001), a 10% higher SPAcar (95% CI: 5% to 24%, pfor trend = 0.003) and a 14% higher SPAfem in the adjusted model. Conclusions: We confirm an association between the MetS and IMTcc as well as report for the first time an association between the MetS and its components and femoral plaque area, in a general population over 40 years of age. Having any risk factors for the MetS increases the risk for subclinical atherosclerosis, with the risk increasing with each additional component. Using the dichotomous definition of the MetS may be overlooking the risk for subclinical atherosclerosis -and by inference future cardiovascular events- associated with having less than 3 risk factors. [ABSTRACT FROM AUTHOR]

The selection of carotid atherosclerosis patients for surgery or stenting is a crucial task in atherosclerosis disease management. In order to select only those symptomatic cases who need surgery, we have, in this work, presented a computer-aided diagnostic technique to effectively classify symptomatic and asymptomatic plaques from B-mode ultrasound carotid images. We extracted several grayscale features that quantify the textural differences inherent in the manually delineated plaque regions and selected the most significant among these extracted features. These features, along with the degree of stenosis (DoS), were used to train and test a support vector machine (SVM) classifier using threefold stratified cross-validation using a data set consisting of 160 (50 symptomatic and 110 asymptomatic) images. Using 32 features in an SVM classifier with a polynomial kernel of order 1, we obtained the best accuracy of 90.66%, sensitivity of 83.33%, and specificity of 95.39%. The DoS was found to be a valuable feature in addition to other texture-based features. We have also proposed the plaque risk index ( PRI) made up of a combination of significant features such that the PRI has unique ranges for both plaque classes. PRI can be used in monitoring the variations in features over a period of time which will provide evidence on how and which features change as asymptomatic plaques become symptomatic. [ABSTRACT FROM PUBLISHER]

Computer-aided diagnosis (CAD) of carotid atherosclerosis into symptomatic or asymptomatic is useful in the analysis of cardiac health. This paper describes a patented CAD system called Atheromatic™ for symptomatic versus asymptomatic plaque classification in carotid ultrasound images. The system involves two steps: 1) feature extraction using a combination of discrete wavelet transform and averaging algorithms and 2) classification using a support vector machine (SVM) classifier for automated decision making. The CAD system was evaluated using a database consisting of 150 asymptomatic and 196 symptomatic plaque regions which were labeled using the ground truth based on the presence or absence of symptoms. Threefold cross-validation protocol was adapted for developing and testing the classifiers. We observed that the SVM classifier with a polynomial kernel of order 2 was to achieve a classification accuracy of 83.7%. [ABSTRACT FROM PUBLISHER]

Intima-media thickness (IMT) is now being considered as an indicator of atherosclerosis. Our group has developed several feature-based IMT measurement algorithms such as the Completely Automated Layer EXtraction (CALEX) (which is a class of patented AtheroEdge Systems from Global Biomedical Technologies, Inc., CA, USA). These methods are based on the hypothesis that the highest pixel intensities are in the far wall of the common carotid artery (CCA) or the internal carotid artery (ICA). In this paper, we verify that this hypothesis holds true for B-mode longitudinal ultrasound (US) images of the carotid wall. This patented methodology consists of generating the composite image (the arithmetic sum of images) from the database by first registering the carotid image frames with respect to a nearly straight carotid-artery frame from the same database using: 1) B-spline-based nonrigid registration and 2) affine registration. Prior to registration, we segment the carotid-artery lumen using a level-set-based algorithm followed by morphological image processing. The binary lumen images are registered, and the transformations are applied to the original grayscale CCA images. We evaluated our technique using a database of 200 common carotid images of normal and pathologic carotids. The composite image presented the highest intensity distribution in the far wall of the CCA/ICA, validating our hypothesis. We have also demonstrated the accuracy and improvement in the IMT segmentation result with our CALEX 3.0 system. The CALEX system, when run on newly acquired US images, shows the IMT error of about 30 \mu\m. Thus, we have shown that the CALEX algorithm is able to exploit the far-wall brightness for accurate IMT measurements. [ABSTRACT FROM PUBLISHER]

The aim of this paper is to describe a novel and completely automated technique for carotid artery (CA) recognition, far (distal) wall segmentation, and intima–media thickness (IMT) measurement, which is a strong clinical tool for risk assessment for cardiovascular diseases. The architecture of completely automated multiresolution edge snapper (CAMES) consists of the following two stages: 1) automated CA recognition based on a combination of scale–space and statistical classification in a multiresolution framework and 2) automated segmentation of lumen–intima (LI) and media–adventitia (MA) interfaces for the far (distal) wall and IMT measurement. Our database of 365 B-mode longitudinal carotid images is taken from four different institutions covering different ethnic backgrounds. The ground-truth (GT) database was the average manual segmentation from three clinical experts. The mean distance \pm standard deviation of CAMES with respect to GT profiles for LI and MA interfaces were 0.081 \pm 0.099 and 0.082 \pm 0.197 mm, respectively. The IMT measurement error between CAMES and GT was 0.078 \pm 0.112 mm. CAMES was benchmarked against a previously developed automated technique based on an integrated approach using feature-based extraction and classifier (CALEX). Although CAMES underestimated the IMT value, it had shown a strong improvement in segmentation errors against CALEX for LI and MA interfaces by 8% and 42%, respectively. The overall IMT measurement bias for CAMES improved by 36% against CALEX. Finally, this paper demonstrated that the figure-of-merit of CAMES was 95.8% compared with 87.4% for CALEX. The combination of multiresolution CA recognition and far-wall segmentation led to an automated, low-complexity, real-time, and accurate technique for carotid IMT measurement. Validation on a multiethnic/multi-institutional data set demonstrated the robustness of the technique, which can constitute a clinically valid IMT measurement for assistance in atherosclerosis disease management. [ABSTRACT FROM AUTHOR]