Adding carotid total plaque area to the Framingham risk score improves cardiovascular risk classification

Adherence to Dietary Patterns and Cardiovascular Disease Risk: A Cross-Sectional Study of Total Carotid Plaque Area in Argentina

Objective

Assessing subclinical atherosclerosis (sAT) is crucial for preventing cardiovascular disease. The Mediterranean diet is considered the gold standard for cardiovascular protection, but cultural and economic barriers can hinder adherence to it. The prudent dietary pattern (DP) has been associated with protective effects against chronic diseases. However, its impact on primary cardiovascular prevention remains uncertain. This study examined adherence to various DPs and their effect on sAT, measured by total carotid plaque area (TPA).

Methods

This cross-sectional study included 116 adults enrolled in a cardiovascular prevention program. Demographic, clinical, laboratory, and TPA data were collected. Adherence to DPs was assessed using a food frequency questionnaire. Participants were categorized according to their adherence to 4 mutually exclusive DPs: prudent, traditional, sweet, and mixed. Generalized linear models were used to assess the effect of DPs on TPA, adjusting for relevant cardiovascular variables.

Results

The traditional, sweet, and mixed DPs were associated with higher TPA values than the prudent DP, with medians (interquartile range) of 27 (99), 39 (49), 27.5 (58), and 0 (36) mm2, respectively. Gamma regression analysis found that the beta exponents for the traditional, sweet, and mixed DPs versus the prudent DP were 3.78 (p=0.046); 3.73 (p=0.013), and 2.20 (p=0.072), respectively. Systolic blood pressure values were higher for the sweet and mixed DPs than for the prudent DP (133.9±11.7; 132.5±13.9 and 122.7±8.8 mmHg, respectively; p<0.05).

Conclusion

These findings underscore the importance of additional research and targeted interventions to promote healthier DPs to promote improvements in cardiovascular health.

An image registration-based self-supervised Su-Net for carotid plaque ultrasound image segmentation

BACKGROUND AND OBJECTIVES

Total Plaque Area (TPA) measurement is critical for early diagnosis and intervention of carotid atherosclerosis in individuals with high risk for stroke. The delineation of the carotid plaques is necessary for TPA measurement, and deep learning methods can automatically segment the plaque and measure TPA from carotid ultrasound images. A large number of labeled images is essential for training a good deep learning model, but it is very difficult to collect such large labeled datasets for carotid image segmentation in clinical practice. Self-supervised learning can provide a possible solution to improve the deep-learning models on small labeled training datasets by designing a pretext task to pre-train the models without using the segmentation masks. However, the existing self-supervised learning methods do not consider the feature presentations of object contours.

METHODS

In this paper, we propose an image registration-based self-supervised learning method and a stacked U-Net (SSL-SU-Net) for carotid plaque ultrasound image segmentation, which can better exploit the semantic features of carotid plaque contours in self-supervised task training.

RESULTS

Our network was trained on different numbers of labeled images (n = 10, 33, 50 and 100 subjects) and tested on 44 subjects from the SPARC dataset (n = 144, London, Canada). The network trained on the entire SPARC dataset was then directly applied to an independent dataset collected in Zhongnan hospital (n = 497, Wuhan, China). For the 44 subjects tested on the SPARC dataset, our method yielded a DSC of 80.25-89.18% and the produced TPA measurements, which were strongly correlated with manual segmentation (r = 0.965-0.995, ρ< 0.0001). For the Zhongnan dataset, the DSC was 90.3% and algorithm TPAs were strongly correlated with manual TPAs (r = 0.985, ρ< 0.0001).

CONCLUSIONS

The results demonstrate that our proposed method yielded excellent performance and good generalization ability when trained on a small labeled dataset, facilitating the use of deep learning in carotid ultrasound image analysis and clinical practice. The code of our algorithm is available https://github.com/a610lab/Registration-SSL.

Value of carotid intima thickness in assessing advanced carotid plaque vulnerability: a study based on carotid artery ultrasonography and carotid plaque histology

Background

Research has shown that carotid intima-media thickness (CIMT) could help to predict carotid plaque (CP) progression in patients with mild carotid stenosis. However, the debate continues as to the value of carotid intima thickness (CIT) in monitoring the development of CP in patients with severe carotid stenosis. This study sought to evaluate the relationships between CIT and the ultrasonic characteristics of CP and to analyze the value of CIT and the ultrasonic parameters of CP in assessing plaque vulnerability in advanced human carotid atherosclerosis.

Methods

A total of 55 individuals who underwent carotid endarterectomy (CEA) were included in the study (mean age: 65±7 years; female: 9.1%). CIMT and CIT were examined at the common carotid artery (CCA). Plaque textural features, such as the gray-scale median (GSM), superb microvascular imaging (SMI) level, and total plaque area (TPA), were also identified. A Spearman correlation coefficient analysis was performed to examine the relationship between CIT and the ultrasonic parameters of CP. The CIT of various plaque types was compared. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic values of the ultrasound characteristics to evaluate CP vulnerability.

Results

The mean CIT of all the participants was 0.382±0.095 mm, the mean CIT of the participants with stable plaques was 0.328±0.031 mm, and the mean CIT of participants with vulnerable plaques was 0.424±0.106 mm (P<0.001). CIT was associated with the SMI level (Spearman's correlation coefficient: r=0.392, P=0.005), TPA (Spearman's correlation coefficient: r=0.337, P=0.012). Patients with thicker CIT had larger lipid cores, higher levels of plaque vulnerability, and more intraplaque hemorrhages (IPHs). The areas under the ROCs (AUCs) with 95% confidence interval (CI) for CIMT, CIT, the SMI level, the GSM, the TPA, and the combined model for identifying vulnerable plaques were 0.673 (0.533-0.793), 0.849 (0.727-0.932), 0.771 (0.629-0.879), 0.669 (0.529-0.790), 0.858 (0.738-0.938), and 0.949 (0.854-0.990), respectively.

Conclusions

CIT was associated with both the histology and ultrasonic features of CP. CIT may be helpful in the detection of severe CP development.

Utility of carotid ultrasound on prediction of 1-year mortality in emergency department patients with neurological deficits: A 10-year population-based cohort study

BACKGROUND

This study aimed to investigate the association between the carotid ultrasound results and 1-yr mortality of patients with neurological deficits in the emergency department (ED).

METHODS

This study included patients with neurological symptoms who presented to the ED between January 1, 2009 and December 31, 2018, and underwent sonographic imaging of the bilateral carotid bulb, common carotid artery (CCA), internal carotid artery (ICA), and external carotid arteries. A stenosis degree of >50% was defined as significant carotid stenosis. Carotid plaque score (CPS) was calculated by adding the score of stenosis severity of all segments. The association between carotid ultrasound results and 1-yr mortality was investigated using the Cox regression model.

RESULTS

The analysis included 7,961 patients (median age: 69 yr; men: 58.7%). Among them, 247 (3.1%) passed away from cardiovascular (CV)-related causes, and 746 (9.4%) died within a year. The mortality group presented with more significant carotid stenosis of the carotid bulb, CCA, or ICA and had a higher median CPS. A higher CPS was associated with a greater 1-yr all-cause mortality (adjusted hazard ratio [aHR] = 1.08; 95% confidence interval [CI] = 1.03-1.13; p = 0.001; log-rank p < 0.001) and CV-related mortality (aHR = 1.13; 95% CI = 1.04-1.22; p = 0.002, log-rank p < 0.001). Significant stenosis of either carotid artery segment did not result in a higher risk of 1-yr mortality.

CONCLUSIONS

We comprehensively investigated the utility of carotid ultrasound parameters on predicting mortality in this 10-yr population-based cohort, which included over 7,000 patients with acute neurological deficits presented to the ED. The result showed that CPS could be used as risk stratification tools for 1-yr all-cause and CV mortality.

Hypertension as a risk factor for atherosclerosis: Cardiovascular risk assessment

Atherosclerosis is a predecessor of numerous cardiovascular diseases (CVD), which often lead to morbidity and mortality. Despite the knowledge of the pathogenesis of atherosclerosis, an essential gap in our understanding is the exact trigger mechanism. A wide range of risk factors have been discovered; however, a majority of them are too general to clarify the launching mechanism of atherogenesis. Some risk factors are permanent (age, gender, genetic heritage) and others can be modified [tobacco smoking, physical inactivity, poor nutrition, high blood pressure, type 2 diabetes (T2D), dyslipidemia, and obesity]. All of them have to be taken into account. In the scope of this review, our attention is focused on hypertension, which is considered the most widespread among all modifiable risk factors for atherosclerosis development. Moreover, high blood pressure is the most investigated risk factor. The purpose of this review is to summarize the data on hypertension as a risk factor for atherosclerosis development and the risk assessment.

An intensive follow-up in subjects with cardiometabolic high-risk

BACKGROUND AND AIM

Addressing chronic problems requires a model of care that promotes self-management of the disease and facilitates adherence to treatment. This project was designed to enhance patient's clinical and functional outcomes through a Comprehensive Model to be implemented in our health system and to evaluate the results.

METHODS AND RESULTS

Different population stratification tools were tested and designed to classify subjects according to different variables. We have developed a program to detect and screen cardiometabolic risk by integrating most of the Chronic Care Model recommendations through in-house developed management software (MoviHealth®). From the results, 1317 subjects were evaluated (27% of the whole population) during the first year of follow-up which significantly improved for all variables along the follow-up period. The blood pressure of the hypertensive population in 2010 and 2015 showed the importance of enrollment of subjects and the optimization of the blood pressure control. The result of HbA1c observed in 2010 decreased progressively to 7.1 ± 1.4% in 2015, and dyslipidemia levels improved gradually. The number of cardiovascular events requiring hospitalization decreased significantly (48%), from 1.9 events per 100 subjects in 2011 to 0.98 in 2015.

CONCLUSION

Our program has combined strategies for the prevention and control of non-communicable diseases, incorporating interventions to control risk factors and to reduce morbidity and mortality. It also had improvements in life quality, accessibility to health-care services, and the promotion of self-care.

Deep Learning-Based Measurement of Total Plaque Area in B-Mode Ultrasound Images

Measurement of total-plaque-area (TPA) is important for determining long term risk for stroke and monitoring carotid plaque progression. Since delineation of carotid plaques is required, a deep learning method can provide automatic plaque segmentations and TPA measurements; however, it requires large datasets and manual annotations for training with unknown performance on new datasets. A UNet++ ensemble algorithm was proposed to segment plaques from 2D carotid ultrasound images, trained on three small datasets (n = 33, 33, 34 subjects) and tested on 44 subjects from the SPARC dataset (n = 144, London, Canada). The ensemble was also trained on the entire SPARC dataset and tested with a different dataset (n = 497, Zhongnan Hospital, China). Algorithm and manual segmentations were compared using Dice-similarity-coefficient (DSC), and TPAs were compared using the difference ( ∆TPA), Pearson correlation coefficient (r) and Bland-Altman analyses. Segmentation variability was determined using the intra-class correlation coefficient (ICC) and coefficient-of-variation (CoV). For 44 SPARC subjects, algorithm DSC was 83.3-85.7%, and algorithm TPAs were strongly correlated (r = 0.985-0.988; p < 0.001) with manual results with marginal biases (0.73-6.75) mm ² using the three training datasets. Algorithm ICC for TPAs (ICC = 0.996) was similar to intra- and inter-observer manual results (ICC = 0.977, 0.995). Algorithm CoV = 6.98% for plaque areas was smaller than the inter-observer manual CoV (7.54%). For the Zhongnan dataset, DSC was 88.6% algorithm and manual TPAs were strongly correlated (r = 0.972, p < 0.001) with ∆TPA = -0.44 ±4.05 mm ² and ICC = 0.985. The proposed algorithm trained on small datasets and segmented a different dataset without retraining with accuracy and precision that may be useful clinically and for research.

Total plaque area and plaque echogenicity are novel measures of subclinical atherosclerosis in patients with systemic lupus erythematosus

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.

Quality of life of patients with central serous chorioretinopathy - a major cause of vision threat among middle-aged individuals

INTRODUCTION

The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was designed to measure the vision-related quality of life (QoL). We aimed to assess the effect of disease duration, disease type (i.e., acute vs. chronic and unilateral vs. bilateral), and selected sociodemographic data on the QoL of patients with central serous chorioretinopathy (CSC).

MATERIAL AND METHODS

The study included 79 patients diagnosed with CSC. The QoL was assessed using the NEI VFQ-25. The statistical analysis was performed using IBM SPSS Statistics 24.

RESULTS

A significant positive correlation was found between deterioration in peripheral vision as assessed by the NEI VFQ-25 and duration of CSC (r = -0.22, p = 0.046). Compared with women, men obtained higher scores on the scales assessing general health, mental health, ocular pain and role limitations (p = 0.018, p = 0.027, p = 0.009 and p = 0.007, respectively). Patients with acute CSC reported higher levels of social functioning as compared with those with chronic CSC (p = 0.04). There were no differences in any of the scales between patients with unilateral and bilateral CSC. Elderly patients obtained lower scores on 9 of the 12 analyzed scales, as compared with younger patients (p < 0.05).

CONCLUSIONS

Patients with CSC do not assess their QoL in negative terms, which may be related to the fact that the disease presents with transient symptoms. However, the QoL deteriorated with longer disease duration. Men with CSC have better vision-related QoL than women.

Three-dimensional ultrasonographic evaluation of carotid artery plaque surface irregularity

INTRODUCTION

The aim of this study was to evaluate 3-dimensional (3D) ultrasonography (US) in determining the surface irregularity of carotid artery plaques.

MATERIAL AND METHODS

This study included 50 patients (20 females and 30 males) aged between 56 and 82 years with plaques in the carotid artery which were detected during routine neck ultrasound. Simultaneously these cases were evaluated in terms of plaque echogenicities and surface characteristics with 2D and 3D US.

RESULTS

3D imaging was successfully performed in 45 of the 50 cases and the technical success rate was 90%. A single plaque was detected in 64.4% of the patients, with the remaining 35.6% having more than one plaque. The lengths of the plaques ranged from 2 to 12 mm (mean: 3.98 ±1.70 mm); the widths ranged from 1.8 to 3.2 mm (mean: 2.11 ±0.37 mm). No significant difference was found between 2D and 3D plaque echo-structures (observer 1, p = 0.317; observer 2, p = 0.276), but there were significant differences between 2D and 3D plaque surface irregularities (observer 1, p = 0.002; observer 2, p = 0.004). The inter-observer agreement on 2D and 3D plaque echo-structure and surface irregularity was very good (k coefficients were 0.89 and 0.83, respectively, for echo-structure, and 0.91 and 0.95, respectively, for surface irregularity).

CONCLUSIONS

The present study shows that 3D US examination is a valuable non-invasive method for investigation of surface irregularity of carotid artery plaques.

Increased carotid plaque burden in patients with family medical history of premature cardiovascular events in the absence of classical risk factors

INTRODUCTION

The hypothesis that relates atherosclerosis to traditional risk factors (TRF) seems to be not as adequate as previously thought; other risk factors (RF) need to be considered to prevent atherosclerosis progression. Although a family medical history of premature cardiovascular events (FHx) has been considered the putative RF for decades, it has not been incorporated routinely into cardiovascular risk evaluation along with another RF. The objective of this study was to investigate whether FHx is associated with a higher atherosclerotic burden, measured as carotid total plaque area (TPA) in a population having no traditional RF.

MATERIAL AND METHODS

The study included 4,351 primary care patients in Argentina. After excluding a personal history of cardiovascular disease (CVD) and TRF: hypertension, diabetes mellitus, hypercholesterolemia, smoking history, and body mass index (BMI) > 25 kg/cm², 34 patients with FHx were identified. Compared to 56 matched controls TPA was 86% higher in FHx patients (p < 0.05). A second analysis performed in hypertensive patients but no other TRF; 32 patients with FHx were identified.

RESULTS

Compared with 44 matched controls, TPA was 77% higher in FHx patients (p < 0.05). A final analysis using a generalized linear model with TPA progression as the response variable suggests that TPA progresses more rapidly in FHx patients compared to controls.

CONCLUSIONS

The FHx was associated with increased TPA burden and progression in the absence of other TRF. This supports ultrasound screening in FHx patients in order to detect high-risk patients who may benefit from early intervention.

Atherosclerosis in Chronic Kidney Disease: More, Less, or Just Different?

Patients with chronic kidney disease (CKD) are at an increased risk of premature mortality, mainly from cardiovascular causes. The association between CKD on hemodialysis and accelerated atherosclerosis was described >40 years ago. However, more recently, it has been suggested that the increase in atherosclerosis risk is actually observed in early CKD stages, remaining stable thereafter. In this regard, interventions targeting the pathogenesis of atherosclerosis, such as statins, successful in the general population, have failed to benefit patients with very advanced CKD. This raises the issue of the relative contribution of atherosclerosis versus other forms of cardiovascular injury such as arteriosclerosis or myocardial injury to the increased cardiovascular risk in CKD. In this review, the pathophysiogical contributors to atherosclerosis in CKD that are shared with the general population, or specific to CKD, are discussed. The NEFRONA study (Observatorio Nacional de Atherosclerosis en NEFrologia) prospectively assessed the prevalence and progression of subclinical atherosclerosis (plaque in vascular ultrasound), confirming an increased prevalence of atherosclerosis in patients with moderate CKD. However, the adjusted odds ratio for subclinical atherosclerosis increased with CKD stage, suggesting a contribution of CKD itself to subclinical atherosclerosis. Progression of atherosclerosis was closely related to CKD progression as well as to the baseline presence of atheroma plaque, and to higher phosphate, uric acid, and ferritin and lower 25(OH) vitamin D levels. These insights may help design future clinical trials of stratified personalized medicine targeting atherosclerosis in patients with CKD. Future primary prevention trials should enroll patients with evidence of subclinical atherosclerosis and should provide a comprehensive control of all known risk factors in addition to testing any additional intervention or placebo.

The association of endothelin-1 gene polymorphism and its plasma levels with hypertension and coronary atherosclerosis

INTRODUCTION

Endothelin-1 (ET-1) is the most potent among all vasoconstrictors, and its association with cardiovascular diseases has been reported before. Our aim was to investigate the association of ET-1 plasma level and its gene polymorphisms (rs5370 and rs10478694) with hypertension and coronary atherosclerosis (CA).

MATERIAL AND METHODS

This study was carried out on 128 women and 132 men, who were divided into 4 groups: hypertensive without atherosclerosis (H+A-); hypertensive with atherosclerosis (H+A+); non-hypertensive with atherosclerosis (H-A+); and non-hypertensive without atherosclerosis (control group). Endothelin-1 plasma levels were measured by ELISA, and gene polymorphisms were detected by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) methods. Coronary artery diseases (CAD) were then defined based on angiography data.

RESULTS

The ET-1 plasma level was significantly higher in the H+A+ group in comparison with the other groups, especially H+A-. Comparing people with CA and those without it, the highest frequency level of the T allele of rs5370 was found in people with CA. Significantly higher frequencies of the 3A allele were detected in hypertensive patients in comparison with non-hypertensive individuals, when analyzing rs10478694.

CONCLUSIONS

Endothelin-1 plasma level shows a direct association with the risk of CA development. The T allele of rs5370 can be regarded as a risk factor for CA development. The 3A allele of rs10478694 can be associated with the risk of hypertension; therefore, it can be concluded that ET-1 and its gene polymorphisms play an important role in CA development and hypertension observed in the south-eastern populations of Iran.

Geometric Total Plaque Area Is an Equally Powerful Phenotype Compared With Carotid Intima-Media Thickness for Stroke Risk Assessment: A Deep Learning Approach

Currently, carotid intima-media thickness (cIMT) and geometric total plaque area (gTPA) are computed manually and thus are tedious and prone to interobserver and intraobserver variabilities. This study presents an intelligence-based automated deep learning (DL)–based technique for carotid wall interface detection, cIMT, and lumen diameter (LD) measurements, followed by a 3D cylindrical approach for TPA measurement. The observers were used for manual tracings of which were then used for the design of two DL-based systems. The DL boundaries for inner lumen wall and outer interadventitial borders were used for computing the cIMT and LD. Using cylindrical approach, we computed the gTPA. Furthermore, we compute the 10-year image-based cIMT and gTPA, using the progression rates. A total of 396 B-mode ultrasound right and left common carotid artery images were taken from 203 patients. The mean cIMT and gTPA using DL1 and DL2 is 0.91 mm, 20.52 mm2 and 0.88 mm, 19.44 mm2, respectively. The coefficient of correlation between gTPA and cIMT using DL1 and DL2 is 0.92 ( P < .001) and 0.94 ( P < .001), respectively. The area under the curve (AUC) for gTPA showed an improvement over cIMT by 14.36% and 12.57% for DL1 and DL2, respectively. The corresponding 10-year risk improvements were 9.09% and 6.26%. Our statistical significance tests successfully passed t test, Mann-Whitney, Wilcoxon, Kolmogorov-Smirnov, and Friedman. The study shows gTPA as an equally powerful carotid risk biomarker like cIMT. Given the cIMT and LD, cylindrical fitting is a fast method for gTPA measurements.

Association between Carotid Wall Shear Rate and Arterial Stiffness in Patients with Hypertension and Atherosclerosis of Peripheral Arteries

Aim

To evaluate carotid wall shear rate (WSR) in association with local and regional vascular stiffness in patients with hypertension (HTN) and atherosclerosis of peripheral arteries and to study the pattern of change of WSR in patients with HTN with increasing severity of peripheral artery atherosclerosis.

Materials and Methods

Study involved 133 patients with HTN, 65 men and 48 women, aged in average 57.9±10.8 years. All patients were divided into four groups in accordance with ultrasound morphologic classification of vessel wall. Duplex scanning of carotid and lower limb arteries was performed. Carotid-femoral (cfPWV) and carotid-radial (crPWV) pulse wave velocity (PWV) were measured. Local carotid stiffness was evaluated by carotid ultrasound.

Results

WSR of patients with plaques without and with hemodynamic disturbance was 416±128 s^-1 and 405±117 s^-1, respectively, which was significantly less than the WSR in patients with intact peripheral arteries - 546±112 s^-1. Decreased carotid WSR was associated with increased crPVW, cfPWV, Peterson's elastic modulus, decreased distensibility, and distensibility coefficient.

Conclusion

In patients with HTN and atherosclerotic lesions of peripheral arteries, it is registered that the carotid WSR decreased with increasing severity of atherosclerosis. Decreased carotid WSR is associated with increased local carotid stiffness, regional vascular stiffness of muscular, and elastic vessels.

Fractal analysis of plaque border, a novel method for the quantification of atherosclerotic plaque contour irregularity, is associated with pro-atherogenic plasma lipid profile in subjects with non-obstructive carotid stenoses

BACKGROUND AND AIMS

Plaque border irregularity is a known imaging characteristic of vulnerable plaques, but its evaluation heavily relies on subjective evaluation and operator expertise. Aim of the present work is to propose a novel fractal-analysis based method for the quantification of atherosclerotic plaque border irregularity and assess its relation with cardiovascular risk factors.

METHODS AND RESULTS

Forty-two asymptomatic subjects with carotid stenosis underwent ultrasound evaluation and assessment of cardiovascular risk factors. Total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) plasma cholesterol and triglycerides concentrations were measured for each subject. Fractal analysis was performed in all the carotid segments affected by atherosclerosis, i.e. 147 segments. The resulting fractal dimension (FD) is a measure of irregularity of plaque profile on long axis view of the plaque. FD in the severest stenosis (main plaque FD,mFD) was 1.136±0.039. Average FD per patient (global FD,gFD) was 1.145±0.039. FD was independent of other plaque characteristics. mFD significantly correlated with plasma HDL (r = -0.367,p = 0.02) and triglycerides-to-HDL ratio (r = 0.480,p = 0.002).

CONCLUSIONS

Fractal analysis is a novel, readily available, reproducible and inexpensive technique for the quantitative measurement of plaque irregularity. The correlation between low HDL levels and plaque FD suggests a role for HDL in the acquisition of morphologic features of plaque instability. Further studies are needed to validate the prognostic value of fractal analysis in carotid plaques evaluation.

Factors predicting cardiovascular events in chronic kidney disease patients. Role of subclinical atheromatosis extent assessed by vascular ultrasound

Patients with chronic kidney disease (CKD) have an increased incidence of cardiovascular events (CVE). The contribution of subclinical atheromatosis extent, including femoral arteries, to CVE in CKD patients has not been investigated. In this paper, we examine the prognostic value of subclinical atheromatosis extent, assessed as the number of arterial territories with plaque, in predicting the incidence of major and minor CVE. The NEFRONA is a multicenter, prospective cohorts study that recruited 2445 CKD subjects and 559 controls, free from previous cardiovascular disease, in 81 medical centers across Spain. The presence of atheroma plaque was assessed by arterial ultrasound in ten arterial territories (carotid and femoral). The predictive power of the presence or absence of atheroma plaque in any territory was compared with the quantification of atheroma extent as the number of territories with plaque. During the median follow up of 48 months, 216 CVE were reported. Factors predicting the incidence of CVE in the whole cohort were being male, CKD patient, lower levels of 25(OH) vitamin D, higher levels of cholesterol and the extent of subclinical atheromatosis, yielding a higher concordance (C) index than the presence or absence of plaque. In stratified analysis including specific factors of CKD patients not on dialysis, the variables predicting CVE were the same as in the whole cohort, plus higher levels of potassium. Again, the inclusion of the information about atheromatosis as number of territories with plaque, presented a higher C index than the presence or absence of plaque. In the dialysis population, significant variables were older age, diabetes, dialysis vintage and higher levels of cholesterol and phosphate. In this case the higher C index was obtained with the information about plaque presence.

Subclinical atheromatosis extent, including femoral arteries, influences CVE in CKD and its detection could improve the prediction of cardiovascular events.

Cardiovascular risk assessment in patients with diabetes

Although patients with diabetes have 2 to 4 times increased risk of cardiovascular morbidity and mortality than individuals without diabetes, recent studies indicate that a significant part of patients are in a lower cardiovascular risk category. Men younger than 35 years, women younger than 45 years, patients with diabetes duration of less than 10 years without other risk factors have a much lower risk than patients who have traditional cardiovascular risk factors, and subclinical or established coronary artery disease (CAD). These patients are not risk equivalent as stated in previous studies. On the contrary, when in the presence of traditional risk factors or evidence of subclinical coronary disease (e.g. high coronary calcium score), the coronary risk is much increased and patients may be classified at a higher-risk category. Recent guidelines do not anymore consider diabetes as a CAD risk equivalent and recommend cardiovascular risk stratification for primary prevention. Stratification of diabetic patients improves accuracy in prediction of subclinical CAD, silent ischemia and future cardiovascular events. Stratification also discriminates higher from lower risk patients who may need intensive statin or aspirin prevention, while avoiding overtreatment in lower risk cases. It may also allow the clinician to decide whether to intensify risk reduction actions through specific newer drugs for glucose control such as SGLT-2 inhibitors or GLP-1 agonists, which recently have shown additional cardiovascular protector effect. This review addresses the assessment of cardiovascular disease risk using traditional and non-traditional cardiovascular risk factors. It also reviews the use of risk calculators and new reclassification tools, focusing on the detection of subclinical atherosclerosis as well as silent ischemia in the asymptomatic patients with diabetes.

Automated segmental-IMT measurement in thin/thick plaque with bulb presence in carotid ultrasound from multiple scanners: Stroke risk assessment

BACKGROUND AND OBJECTIVES

Standardization of the carotid IMT requires a reference marker in ultrasound scans. It has been shown previously that manual reference marker and manually created carotid segments are used for measuring IMT in these segments. Manual methods are tedious, time consuming, subjective, and prone to errors. Bulb edge can be considered as a reference marker for measurements of the cIMT. However, bulb edge can be difficult to locate in ultrasound scans due to: (a) low signal to noise ratio in the bulb region as compared to common carotid artery region; (b) uncertainty of bulb location in craniocaudal direction; and (c) variability in carotid bulb shape and size. This paper presents an automated system (a class of AtheroEdge™ system from AtheroPoint™, Roseville, CA, USA) for locating the bulb edge as a reference marker and further develop segmental-IMT (sIMT) which measures IMT in 10mm segments (namely: s1, s2 and s3) proximal to the bulb edge.

METHODS

The patented methodology uses an integrated approach which combines carotid geometry and pixel-classification paradigms. The system first finds the bulb edge and then measures the sIMT proximal to the bulb edge. The system also estimates IMT in bulb region (bIMT). The 649 image database consists of varying plaque (light, moderate to heavy), image resolutions, shapes, sizes and ethnicity.

RESULTS

Our results show that the IMT contributions in different carotid segments are as follows: bulb-IMT 34%, s1-IMT 29.46%, s2-IMT 11.48%, and s3-IMT 12.75%, respectively. We compare our automated results against reader's tracings demonstrating the following performance: mean lumen-intima error: 0.01235 ± 0.01224mm, mean media-adventitia error: 0.020933 ± 0.01539mm and mean IMT error: 0.01063 ± 0.0031mm. Our system's Precision of Merit is: 98.23%, coefficient of correlation between automated and Reader's IMT is: 0.998 (p-value < 0.0001). These numbers are improved compared to previous publications by Suri's group which is automated multi-resolution conventional cIMT.

CONCLUSIONS

Our fully automated bulb detection system reports 92.67% precision against ideal bulb edge locations as marked by the reader in the bulb transition zone.