Association Between Visceral Adipose Tissue Area and Coronary Plaque Morphology Assessed by CT Angiography

Associations between visceral adipose and renal artery calcification: Results from the multi-ethnic study of atherosclerosis

Background

Visceral adipose tissue (VAT) has been associated with higher levels of atherosclerosis. Renal artery calcification (RAC) secondary to atherosclerosis has been found to be associated with an increase in all-cause mortality.

Methods

1 978 participants underwent CT imaging to measure VAT and RAC. Rate ratio regression was used to estimate prevalence ratios (PRs) for the presence of RAC, while linear regression was used to estimate linear coefficients for the severity of RAC.

Results

1 196 participants had complete VAT and RAC measurements. In adjusted models, VAT area was not associated with RAC presence (PR 1.02, 95 % CI 0.89, 1.16, p = 0.80), while greater VAT density was inversely, but not significantly, associated with RAC presence (PR 0.89, 95 % CI 0.78, 1.02, p = 0.10). Among 354 participants with RAC > 0, VAT area was significantly associated with RAC severity (slope 63.32, 95 % CI 11.84, 114.81, p = 0.02), while VAT density was not associated (slope 9.78, 95 % CI -40.87, 60.44, p = 0.71).

Conclusions

VAT area and density are not significantly associated with RAC presence, while greater VAT area is significantly associated with RAC severity among those with RAC > 0. Our results are the first describing the relationship between VAT and RAC, and are in contrast to previous literature demonstrating a significant association between VAT and coronary artery calcification.

Relationship Between Clinical Parameters and Histological Features of Epicardial Adipose Tissue and Aortic Valve Calcification Assessed on Computed Tomography

BACKGROUND

The relationships of the clinical and biological attributes of epicardial adipose tissue (EAT) with aortic valve calcification (AVC) have not been characterized. We evaluated the relationships of the clinical and histological features of EAT with AVC assessed using computed tomography (CT).

METHODS AND RESULTS

We enrolled 43 patients undergoing cardiac CT examination prior to elective cardiac surgery in whom AVC was identified on CT. EAT volume and density, coronary calcium score (CCS), AVC score (AVCS), and coronary atherosclerosis on CT angiography were evaluated in each patient. During cardiac surgery, 2 EAT samples were obtained for immunohistochemistry. The number of CD68- and CD11c-positive macrophages and osteocalcin-positive cells was counted in 6 random high-power fields of EAT sections. EAT density, but not EAT volume normalized to body surface area, was positively correlated with the number of macrophages and osteocalcin-positive cells in EAT. There was a positive correlation between ln(AVCS), but not ln(CCS+1), and the number of macrophages and osteocalcin-positive cells in EAT. Multivariate analysis revealed significant positive correlations for ln(AVCS) with EAT density (β=0.42; P=0.0072) and the number of CD68-positive macrophages (β=0.57; P=0.0022), CD11c-positive macrophages (β=0.62; P=0.0003), and osteocalcin-positive cells (β=0.52; P=0.0021) in EAT.

CONCLUSIONS

Inflammation and osteogenesis in EAT, reflected by high CT density, are associated with the severity of AVC representing aortic valve degeneration.

Construction of vulnerable plaque prediction model based on multimodal vascular ultrasound parameters and clinical risk factors

The rupture of vulnerable plaque (VP) are significant pathogenic factors leading to cardiovascular and cerebrovascular diseases. This study aims to construct a vulnerable plaque prediction model (VPPM) by combining multimodal vascular ultrasound parameters and clinical risk factors, and to validate it. A total of 196 atherosclerotic patients who underwent carotid endarterectomy (CEA) from January 2017 to December 2023 were collected and divided into a modeling group (n = 137) and a validation group (n = 59). Clinical information including: hypertension, diabetes, smoking history, and body mass index (BMI) was included in the analysis. All patients underwent carotid ultrasound and contrast-enhanced ultrasound (CEUS) examination after admission, with main ultrasound parameters including thickness, echogenicity types, stenosis degree, and CEUS neovascularization grading of plaques. Independent risk factors for VP in CEA patients were screened through binary Logistic regression analysis, and a prediction model was established along with a nomogram. The calibration curve, receiver-operating characteristic curve (ROC), and decision curve analysis (DCA) were employed to assess the calibration, diagnostic efficacy, and clinical utility of the VPPM model. There were no significant statistical differences in multimodal vascular ultrasound parameters and clinical risk factors between the modeling and validation groups (P > 0.05). Binary Logistic regression analysis identified plaque thickness, echo type, CEUS neovascularization grading, BMI, and smoking history as 5 variables entering the prediction model. The VPPM model showed good diagnostic efficacy, with an area under the ROC curve of 0.959 (95% CI 0.915-0.999). Using the nomogram with a VPPM risk assessment score of 135.42 as the diagnostic cutoff value in the modeling group, the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and Youden index were 88.1%, 94.1%, 14.98, 0.126, and 82.2%, respectively. In the DCA curve, the VPPM model curve was significantly better than two extreme lines, indicating good clinical utility. The VPPM model constructed by integrating multimodal ultrasound parameters and clinical key risk factors has high diagnostic efficacy and is expected to be an auxiliary tool for clinical diagnosis of vulnerable plaques.

Association between Pericarotid Fat Density and Positive Remodeling in Patients with Carotid Artery Stenosis

Background/Objectives: The underlying mechanism of the potential involvement of inflammatory crosstalk between pericarotid fat and vascular layers in atherosclerosis pathogenesis is unclear. We investigated the association between pericarotid fat density and positive remodeling and inflammatory markers in carotid stenosis. We hypothesized that pericarotid fat density might serve as a marker of plaque inflammation in a clinical setting. Methods: We evaluated the stenosis degree and pericarotid fat density in 258 patients with carotid plaques. Plaque composition was examined, and the correlation between pericarotid fat density and expansive remodeling was investigated. Pearson's product-moment correlation coefficient was used to examine the relationship between pericarotid fat density and the expansive remodeling ratio. We also evaluated the relationship of pericarotid fat density with plaque composition, degree of stenosis, and macrophage and microvessel counts by. The subgroup analysis compared these factors between symptomatic mild carotid stenosis. Results: The pericarotid fat density was -63.0 ± 11.1 HU. The carotid fat densities were -56.8 ± 10.4 HU in symptomatic and -69.2 ± 11.4 HU in asymptomatic lesions. The pericarotid fat density values in intraplaque hemorrhage, lipid-rich necrotic core, and fibrous plaque were -51.6 ± 10.4, -59.4 ± 12.8, and -74.2 ± 8.4 HU, respectively. Therefore, the expansive remodeling ratio was 1.64 ± 0.4. Carotid fat density and expansive remodeling ratio were correlated. Immunohistochemistry showed high macrophage and microvessel levels (143.5 ± 61.3/field and 121.2 ± 27.7/field, respectively). In symptomatic mild carotid stenosis, pericarotid fat density was correlated with other inflammatory factors. The pericarotid fat density and expansive remodeling ratio (2.08 ± 0.21) were high in mild stenosis (-50.1 ± 8.4 HU). Conclusions: Pericarotid fat and intraplaque components were well correlated. Carotid fat density may be a marker of plaque inflammation in carotid plaques.

Visceral Adipose Tissue Influence on Health Problem Development and Its Relationship with Serum Biochemical Parameters in Middle-Aged and Older Adults: A Literature Review

Background

The amount of visceral adipose tissue (VAT) tends to increase with age and is associated with several health problems, such as cardiometabolic diseases, increased infections, and overall mortality.

Objectives

This review provides a general assessment of how visceral adiposity correlates with the development of health problems and changes in serum biochemical parameters in middle-aged and older adults.

Methods

We searched specific terms in the Virtual Health Library (VHL) databases for VAT articles published in the English language between 2009 and 2019 related to older adults.

Results

The search found twenty-three publications in this period, of which nine were excluded. The publications had a population aged between 42 and 83 years and correlated the VAT area ratio with several comorbidities (such as pancreatitis, depression, cancer, and coronary heart disease) and serum biochemical parameters.

Conclusion

Further research on the association between visceral obesity and the emergence of health problems and the relationship between VAT and changes in serum biochemical parameters in older individuals should deepen the understanding of this connection and develop preventive actions.

Associations of Visceral Adipose Tissue, Circulating Protein Biomarkers, and Risk of Cardiovascular Diseases: A Mendelian Randomization Analysis

Aim: To evaluate the genetic associations of visceral adipose tissue (VAT) mass with metabolic risk factors and cardiovascular disease (CVD) endpoints and to construct a network analysis about the underlying mechanism using Mendelian randomization (MR) analysis.

Methods and Results: Using summary statistics from genome-wide association studies (GWAS), we conducted the two-sample MR to assess the effects of VAT mass on 10 metabolic risk factors and 53 CVD endpoints. Genetically predicted VAT mass was associated with metabolic risk factors, including triglyceride (odds ratio, OR, 1.263 [95% confidence interval, CI, 1.203–1.326]), high-density lipoprotein cholesterol (OR, 0.719 [95% CI, 0.678–0.763]), type 2 diabetes (OR, 2.397 [95% CI, 1.965–2.923]), fasting glucose (OR, 1.079 [95% CI, 1.046–1.113]), fasting insulin (OR, 1.194 [95% CI, 1.16–1.229]), and insulin resistance (OR, 1.204 [95% CI, 1.16–1.25]). Genetically predicted VAT mass was associated with CVD endpoints, including atrial fibrillation (OR, 1.414 [95% CI, 1.332 = 1.5]), coronary artery disease (OR, 1.573 [95% CI, 1.439 = 1.72]), myocardial infarction (OR, 1.633 [95% CI, 1.484 =1.796]), heart failure (OR, 1.711 [95% CI, 1.599–1.832]), any stroke (OR, 1.29 [1.193–1.394]), ischemic stroke (OR, 1.292 [1.189–1.404]), large artery stroke (OR, 1.483 [1.206–1.823]), cardioembolic stroke (OR, 1.261 [1.096–1.452]), and intracranial aneurysm (OR, 1.475 [1.235–1.762]). In the FinnGen study, the relevance of VAT mass to coronary heart disease, stroke, cardiac arrhythmia, vascular diseases, hypertensive heart disease, and cardiac death was found. In network analysis to identify the underlying mechanism between VAT and CVDs, VAT mass was positively associated with 23 cardiovascular-related proteins (e.g., Leptin, Hepatocyte growth factor, interleukin-16), and inversely with 6 proteins (e.g., Galanin peptides, Endothelial cell-specific molecule 1). These proteins were further associated with 32 CVD outcomes.

Conclusion: Mendelian randomization analysis has shown that VAT mass was associated with a wide range of CVD outcomes including coronary heart disease, cardiac arrhythmia, vascular diseases, and stroke. A few circulating proteins may be the mediators between VAT and CVDs.

The waist-to-body mass index ratio as an anthropometric predictor for cardiovascular outcome in subjects with established atherosclerotic cardiovascular disease

Obesity is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). However, ‘obesity paradox’ is observed in patients with coronary artery disease while defining obesity by body mass index (BMI). The purpose of this study is to identify a better anthropometric parameter to predict cardiovascular events in patients with ASCVD. The study was conducted using the Taiwanese Secondary Prevention for patients with AtheRosCLErotic disease (T-SPARCLE) Registry. A total of 6,920 adult patients with stable ASCVD, enrolled from January 2010 to November 2014, were included, with a mean age of 65.9 years, 73.9% males, and a mean BMI of 26.3 kg/m² at baseline. These patients were followed up for a median of 2.5 years. The study endpoint was the composite major adverse cardiovascular event (MACE), defined as cardiovascular death, nonfatal myocardial infarction or stroke, or cardiac arrest with resuscitation. Multivariable Cox proportional hazards regression showed a significant positive association between waist-to-BMI ratio and MACE (adjusted hazard ratio 1.69 per cm‧m²/kg increase in waist-to-BMI ratio, 95% CI 1.12–2.49, p = 0.01) after adjusting for potential risk factors and confounders. Traditional anthropometric parameters, such as BMI, weight, waist and waist-hip ratio, or newer waist-based indices, such as body roundness index and a body shape index, did not show any significant linear associations (p = 0.09, 0.30, 0.89, 0.54, 0.79 and 0.06, respectively). In the restricted cubic spline regression analysis, the positive dose–response association between waist-to-BMI ratio and MACE persisted across all the range of waist-to-BMI ratio. The positive dose–response association was non-linear with a much steeper increase in the risk of MACE for waist-to-BMI ratio > 3.6 cm‧m²/kg. In conclusion, waist-to-BMI ratio may function as a positive predictor for the risk of MACE in established ASCVD patients.

Methodology, clinical applications, and future directions of body composition analysis using computed tomography (CT) images: A review

PURPOSE OF THE REVIEW

We aim to review the methods, current research evidence, and future directions in body composition analysis (BCA) with CT imaging.

RECENT FINDINGS

CT images can be used to evaluate muscle tissue, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) compartments. Manual and semiautomatic segmentation methods are still the gold standards. The segmentation of skeletal muscle tissue and VAT and SAT compartments is most often performed at the level of the 3rd lumbar vertebra. A decreased amount of CT-determined skeletal muscle mass is a marker of impaired survival in many patient populations, including patients with most types of cancer, some surgical patients, and those admitted to the intensive care unit (ICU). Patients with increased VAT are more susceptible to impaired survival / worse outcomes; however, those patients who are critically ill or admitted to the ICU or who will undergo surgery appear to be exceptions. The independent significance of SAT is less well established. Recently, the roles of the CT-determined decrease of muscle mass and increased VAT area and epicardial adipose tissue (EAT) volume have been shown to predict a more debilitating course of illness in patients suffering from severe acute respiratory syndrome coronavirus 2 (COVID-19) infection.

SUMMARY

The field of CT-based body composition analysis is rapidly evolving and shows great potential for clinical implementation.

Gender Difference in the Relationship Between Pulse Pressure and Visceral Adiposity Index in Korean Adults

Background: This study was conducted to assess the association of pulse pressure (PP) and visceral adiposity index (VAI) by gender in Korean adults. Methods: This study used the data of 4960 adults at age ≥20 years, from the 2015 Korean National Health and Nutrition Examination Survey. Results: In the overall population (n = 4960), after adjustment for related variables and with quartile 1 of VAI as a reference, the odds ratios of high PP (PP >60 mmHg) was significantly higher in quartile 3 [1.32 (95% confidence interval [CI], 1.02-1.71)] and quartile 4 of VAI [1.40 (95% CI, 1.07-1.83)]. In women (n = 2784), the OR of high PP, with quartile 1 of VAI as a reference, was significantly higher in quartile 3 [2.36 (95% CI, 1.55-3.61)] and quartile 4 of VAI [2.70 (95% CI, 1.77-4.12)]. In men (n = 2176), high PP was not associated with the quartiles of VAI. In addition, after adjustment for related variables, the PP level was positively associated with the quartiles of VAI in the overall population (P < 0.001) and women (P < 0.001), but not in men (P = 0.316). Conclusions: VAI was positively associated with PP in Korean women, but not in Korean men.

Anthropometric Indicators as a Tool for Diagnosis of Obesity and Other Health Risk Factors: A Literature Review

Obesity is characterized by the accumulation of an excessive amount of fat mass (FM) in the adipose tissue, subcutaneous, or inside certain organs. The risk does not lie so much in the amount of fat accumulated as in its distribution. Abdominal obesity (central or visceral) is an important risk factor for cardiovascular diseases, diabetes, and cancer, having an important role in the so-called metabolic syndrome. Therefore, it is necessary to prevent, detect, and appropriately treat obesity. The diagnosis is based on anthropometric indices that have been associated with adiposity and its distribution. Indices themselves, or a combination of some of them, conform to a big picture with different values to establish risk. Anthropometric indices can be used for risk identification, intervention, or impact evaluation on nutritional status or health; therefore, they will be called anthropometric health indicators (AHIs). We have found 17 AHIs that can be obtained or estimated from 3D human shapes, being a noninvasive alternative compared to X-ray-based systems, and more accessible than high-cost equipment. A literature review has been conducted to analyze the following information for each indicator: definition; main calculation or obtaining methods used; health aspects associated with the indicator (among others, obesity, metabolic syndrome, or diabetes); criteria to classify the population by means of percentiles or cutoff points, and based on variables such as sex, age, ethnicity, or geographic area, and limitations.

Impact of the distribution of epicardial and visceral adipose tissue on left ventricular diastolic function

Although epicardial adipose tissue (EAT) and abdominal visceral adipose tissue (VAT) can contribute to left ventricular diastolic dysfunction (LVDD), the impact of these distribution has not been fully understood. A total of 235 patients who underwent cardiac computed tomography angiography and Doppler echocardiography was included in this study. We evaluated the association of indexed EAT volume and VAT area with septal and lateral early diastolic mitral annular velocity (e'). The VAT area index was significantly associated with septal and lateral e' velocity after adjusted for conventional cardiovascular risk factors and obstructive coronary artery disease (β-estimate; - 0.015 and - 0.019, both p = 0.01). The natural logarithmic EAT volume index (ln EAT volume index) also showed a significant association with septal and lateral e' (β-estimate; - 1.72 and - 0.99, both p < 0.01). The significant association of ln EAT volume index with septal and lateral e' was observed even after adjusting for VAT area index (β-estimate; - 0.79 and - 1.52, both p < 0.03). In the subgroup analysis, there were significant association of ln EAT volume index with both septal and lateral e' in the lower VAT group (β-estimate; - 1.40 and - 1.53, both p < 0.03) and with lateral e' in the higher VAT group (β-estimate - 1.64, p = 0.006). In contrast, ln EAT volume index was not associated with septal e' in the higher VAT group (p = 0.98). EAT accumulation was significantly associated with LVDD independently of obstructive coronary artery disease and abdominal VAT. The impact of EAT on LVDD may vary depending on the amount of abdominal VAT.

Predictive Value of Abdominal Fat Distribution on Coronary Artery Disease Severity Stratified by Computed Tomography-Derived SYNTAX Score

This study aimed to evaluate the association between abdominal fat distribution (AFD) and coronary artery disease (CAD) complexities using the computed tomography (CT)-derived SYNTAX score (CT-SXscore). Coronary computed tomographic angiography (CCTA) was performed in patients with suspected CAD. Plain abdominal CT was performed to measure visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas. To assess AFD, VAT/SAT (V/S) ratios were calculated. The CT-SXscore was calculated in patients with significant stenoses assessed by CCTA. Of 942 enrolled patients, 310 (32.9%) had 1 or more significant stenoses. The CT-SXscore showed a positive correlation with the V/S ratio (r = 0.33, p < 0.001). In the multivariate regression analysis, the V/S ratio was the only independent predictor for CAD severity based on the CT-SXscore (β = 0.25; t = 4.14; p < 0.001), even though the absolute SAT and VAT areas showed no relationship to the CT-SXscore. Regarding the 4 CAD-patient groups divided according to their median VAT and SAT areas, the CT-SXscore was significantly higher for the high VAT/low SAT group than for any other group (19.6 ± 11.5 vs 13.3 ± 9.6 in the low VAT/low SAT, 10.1 ± 8.5 in the low VAT/high SAT, and 12.2 ± 8.7 in the high VAT/high SAT groups; p < 0.001 for all). In conclusion, it was found that the V/S ratio is a useful index for predicting CAD severity and that AFD may be a more important risk factor for CAD than the absolute amount of each abdominal fat.

Obesity and Cardiovascular Disease: A Scientific Statement From the American Heart Association

The global obesity epidemic is well established, with increases in obesity prevalence for most countries since the 1980s. Obesity contributes directly to incident cardiovascular risk factors, including dyslipidemia, type 2 diabetes, hypertension, and sleep disorders. Obesity also leads to the development of cardiovascular disease and cardiovascular disease mortality independently of other cardiovascular risk factors. More recent data highlight abdominal obesity, as determined by waist circumference, as a cardiovascular disease risk marker that is independent of body mass index. There have also been significant advances in imaging modalities for characterizing body composition, including visceral adiposity. Studies that quantify fat depots, including ectopic fat, support excess visceral adiposity as an independent indicator of poor cardiovascular outcomes. Lifestyle modification and subsequent weight loss improve both metabolic syndrome and associated systemic inflammation and endothelial dysfunction. However, clinical trials of medical weight loss have not demonstrated a reduction in coronary artery disease rates. In contrast, prospective studies comparing patients undergoing bariatric surgery with nonsurgical patients with obesity have shown reduced coronary artery disease risk with surgery. In this statement, we summarize the impact of obesity on the diagnosis, clinical management, and outcomes of atherosclerotic cardiovascular disease, heart failure, and arrhythmias, especially sudden cardiac death and atrial fibrillation. In particular, we examine the influence of obesity on noninvasive and invasive diagnostic procedures for coronary artery disease. Moreover, we review the impact of obesity on cardiac function and outcomes related to heart failure with reduced and preserved ejection fraction. Finally, we describe the effects of lifestyle and surgical weight loss interventions on outcomes related to coronary artery disease, heart failure, and atrial fibrillation.

Non-Invasive Prediction of Coronary Artery Disease by Multiple Abdominal Fat and Anthropometric Indices: Revisit

Purpose

The aim of this study was to evaluate the efficiency of multiple abdominal fat indices measured by ultrasound and anthropometric indices to predict the presence and severity of coronary artery disease (CAD) assessed by coronary angiography.

Patients and Methods

All participants subjected to clinical and laboratory assessments. Anthropometric measurements were taken followed by an ultrasound examination to measure fat thickness at multiple abdominal areas. Lastly, selective coronary angiography performed by the Judkins technique. Statistical analysis was performed to detect the association between all variables and CAD, followed by regression analysis, and Odds ratio (OR) was used to quantifies the strength of the association between two events.

Results

From the abdominal indices, the posterior right perinephric fat thickness (PRPFT) above the best cutoff value had the highest hazard ratio (HR: 12.3, p = 0.001), followed by visceral adipose tissue volume (VAT) (HR: 10.7, p < 0.001), waist circumference (WC) (HR: 6.7, p = 0.001), visceral fat thickness (VFT) (HR: 5.7, p = 0.002), and body mass index (BMI) (HR: 5.48, p = 0.017). It also showed an independent association between the severity of CAD and WC (HR: 4.28, p = 0.012), VFT (HR: 3.7, p = 0.032), VAT (HR: 3.7, p = 0.034), and waist to height ratio (WHtR) (HR: 3.3, p = 0.033).

Conclusion

Posterior perinephric fat thickness and visceral adipose tissue volume measured by ultrasound are strong noninvasive predictors for coronary artery disease, followed by body mass index, waist circumference and visceral fat thickness.

Roles of Epicardial Adipose Tissue in the Pathogenesis of Coronary Atherosclerosis - An Update on Recent Findings

Adipose tissue serves not only as an energy store or a mechanical cushion, but also as an endocrine organ. Recent evidence revealed that perivascular adipose tissue is involved in vascular homeostasis and pathophysiology of adjacent arteries by producing various adipokines. Epicardial adipose tissue (EAT) is located between the surface of the heart and the visceral layer of the pericardium and surrounds the coronary arteries. Many clinical studies suggest that an increase in EAT volume is associated with coronary artery disease. It has been reported that exercise and some antidiabetic drugs can reduce EAT volume. In this review, we outline recent findings on the roles of EAT in the pathogenesis of coronary atherosclerosis.

Chronic inflammation in psoriasis promotes visceral adiposity associated with noncalcified coronary burden over time

BACKGROUND

Psoriasis is a chronic inflammatory skin disease associated with increased obesity, noncalcified coronary artery burden (NCB), and incident myocardial infarction. Here, we sought to assess the relationship among inflammation, visceral adipose tissue (VAT), and NCB. Furthermore, we evaluated whether improvement in VAT would be associated with reduction in NCB over time in psoriasis.

METHODS

Consecutive psoriasis patients underwent coronary CT angiography to quantify NCB and abdominal CT to calculate VAT at baseline (n = 237), 1 year (n = 176), and 4 years (n = 50).

RESULTS

Patients with high levels of high-sensitivity C-reactive protein (hs-CRP) had significantly greater visceral adiposity (17,952.9 ± 849.2 cc³ vs. 13370.7 ± 806.8 cc³, P < 0.001) and noncalcified coronary burden (1.26 ± 0.03 vs. 1.07 ± 0.02 mm²) than those with low levels of hs-CRP. Those with higher levels of VAT had more systemic inflammation (hs-CRP, median [IQR], 2.5 mg/L [1.0–5.3 mg/L] vs. 1.2 mg/L [0.6–2.9 mg/L]), with approximately 50% higher NCB (1.42 ± 0.6 mm² vs. 0.91 ± 0.2 mm², P < 0.001). VAT associated with NCB in fully adjusted models (β = 0.47, P < 0.001). At 1-year follow-up, patients who had worsening hs-CRP had an increase in VAT (14,748.7 ± 878.1 cc³ to 15,158.7 ± 881.5 cc³; P = 0.03), whereas those who had improved hs-CRP improved their VAT (16,876.1 ± 915.2 cc³ to 16310.4 ± 889.6 cc³; P = 0.04). At 1 year, there was 10.3% reduction in NCB in those who had decreased VAT (β = 0.26, P < 0.0001), which persisted in a subset of patients at 4 years (β = 0.39, P = 0.003).

CONCLUSIONS

Inflammation drives development of VAT, increased cardiometabolic risk, and NCB in psoriasis. Reduction of inflammation associated with reduction in VAT and associated with longitudinal improvement in NCB. These findings demonstrate the important role of inflammation in the development of VAT in humans and its effect on early atherogenesis.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01778569.

FUNDING

This study was supported by the National Heart, Lung, and Blood Institute Intramural Research Program (HL006193-05), the NIH Medical Research Scholars Program, a public-private partnership supported jointly by the NIH and contributions to the Foundation for the NIH from the Doris Duke Charitable Foundation (no. 2014194), the American Association for Dental Research, the Colgate-Palmolive Company, Genentech, and Elsevier as well as private donors.

Inflammation is associated with development of visceral adiposity and coronary artery disease in humans.

Association of glucose uptake of visceral fat and acute myocardial infarction: a pilot 18F-FDG PET/CT study

Background

Inflamed visceral adipose tissue (VAT) facilitates chronic inflammation in atherosclerotic lesions thereby leading to increased risk of coronary artery disease (CAD). In this study, we evaluated the glucose uptake of VAT and the carotid artery with ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET/CT) and their association with CAD, including acute myocardial infarction (AMI).

Methods

A total of 90 participants were enrolled (32 with AMI, 33 with chronic stable angina; CSA, and 25 control participants) and undertook ¹⁸F-FDG PET/CT. VAT glucose uptake was measured by using maximum standardized uptake value (SUVmax) of VAT region. The target-to-background ratio (TBR) of carotid artery was defined as the SUVmax of carotid artery divided by the SUVmax of jugular vein. The SUVmax of spleen, bone-marrow (BM), and high-sensitivity C-reactive protein (hsCRP) were used for the assessment of systemic inflammatory activity.

Results

VAT SUVmax was highest in participants with AMI, intermediate in participants with CSA, and lowest in control participants. Carotid artery TBR and systemic inflammatory surrogate markers including spleen SUVmax, BM SUVmax, and hsCRP were also higher in the AMI group than in the CSA or control group. Furthermore, VAT SUVmax showed significant positive correlation with carotid artery TBR, spleen SUVmax, BM SUVmax, and hsCRP. In multivariate linear regression and logistic regression analyses, VAT SUVmax was independently associated with carotid artery TBR and AMI.

Conclusions

Glucose uptake of VAT assessed by ¹⁸F-FDG PET/CT was associated with the severity of CAD and synchronized with the carotid artery inflammation in participants with CAD.

Association between abdominal fat distribution and coronary plaque instability in patients with acute coronary syndrome

BACKGROUND AND AIMS

This study aimed to assess possible association of detailed abdominal fat profiles with coronary plaque characteristics in patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

In 60 patients with ACS, culprit arteries were evaluated at 1-mm intervals (length analyzed: 66 ± 28 mm) by grayscale and integrated backscatter intravascular ultrasound (IB-IVUS) before percutaneous coronary intervention. Standard IVUS indexes (as a volume index: volume/length), plaque components (as percent tissue volume) and fibrous cap thickness (FCT) were assessed by IB-IVUS. Plain abdominal computed tomography was performed to evaluate subcutaneous adipose tissue (SAT) area, visceral adipose tissue (VAT) area, and VAT/SAT ratio. While SAT area only correlated with vessel volume (r = 0.27, p = 0.04), VAT area correlated positively with vessel (r = 0.30, p = 0.02) and plaque (r = 0.33, p = 0.01) volumes and negatively with FCT (r = -0.26, p = 0.049), but not with percent plaque volume and plaque tissue components. In contrast, higher VAT/SAT ratio significantly correlated with higher percent lipid (r = 0.34, p = 0.008) and lower percent fibrous (r = -0.34, p = 0.007) volumes with a trend toward larger percent plaque volume (r = 0.19, p = 0.15), as well as thinner FCT (r = -0.53, p < 0.0001). In the multiple regression analysis, higher VAT/SAT ratio was independently associated with higher percent lipid with lower percent fibrous volumes (p = 0.03 for both) and thinner fibrous cap thickness (p = 0.0001).

CONCLUSION

Coronary plaque vulnerability, defined as increased lipid content with thinner fibrous cap thickness, appears to be more related to abnormal abdominal fat distribution, or so-called hidden obesity, compared with visceral or subcutaneous fat amount alone in patients with ACS.

Relationship between coronary arterial 18F-sodium fluoride uptake and epicardial adipose tissue analyzed using computed tomography

PURPOSE

¹⁸F-Sodium fluoride (¹⁸F-NaF) positron emission tomography (PET) has the potential to detect high-risk coronary plaques. Epicardial adipose tissue (EAT) reportedly correlates with coronary atherosclerosis progression. We evaluated the relationship between coronary arterial ¹⁸F-NaF uptake and EAT findings using computed tomography (CT).

METHODS

We studied 40 patients with ≥ 1 coronary plaque detected on cardiac CT who underwent ¹⁸F-NaF PET/CT. EAT volume was measured using CT and indexed to body surface area in each patient. Each plaque was evaluated for CT-based luminal stenosis and high-risk features. The mean EAT density surrounding each plaque was calculated as perilesional EAT density (PLED) using non-contrast CT images. Focal ¹⁸F-NaF uptake in each plaque was quantified using the maximum tissue-to-background ratio (TBR_max).

RESULTS

EAT volume index was similar between patients with TBR_max ≥ 1.28 (previously reported optimal cutoff to predict coronary events) and those with lower TBR_max, but patients with TBR_max ≥ 1.28 showed higher maximum PLED per patient (- 86 ± 12 Hounsfield units (HU) versus - 98 ± 11 HU, P = 0.0044). In the lesion-based analysis (n = 92), PLED was positively correlated with TBR_max, and the optimal PLED cutoff to identify TBR_max ≥ 1.28 was - 97 HU. On multivariate analysis adjusted for lesion location, obstructive stenosis, and high-risk plaque on CT, PLED ≥ - 97 HU remained a significant predictor of TBR_max ≥ 1.28.

CONCLUSIONS

Increased PLED was associated with significant coronary arterial ¹⁸F-NaF uptake. Step-by-step analyses of EAT density on CT and coronary arterial ¹⁸F-NaF uptake on PET may offer novel strategies for risk prediction in coronary artery disease.

Volumes of coronary plaque disease in relation to body mass index, waist circumference, truncal fat mass and epicardial adipose tissue in patients with type 2 diabetes mellitus and controls

OBJECTIVES

Coronary atherosclerosis in patients with type 2 diabetes mellitus may be promoted by regional fat distribution. We investigated the association between anthropometric measures of obesity, truncal fat mass, epicardial adipose tissue and coronary atherosclerosis in asymptomatic patients and matched controls.

METHODS

We examined 44 patients and 59 controls [mean (standard deviation) age 64.4 ± 9.9 vs 61.8 ± 9.7, male 50% vs 47%, diabetes duration mean (standard deviation) 7.7 ± 1.5] with coronary computed tomography angiography. Coronary plaques were quantified as total, calcified, non-calcified and low-density non-calcified plaque volumes (mm³). Regional fat distribution was assessed by dual-energy X-ray absorptiometry, body mass index (kg/m²), waist circumference (cm) and epicardial fat volume (mm³). Endothelial function and systemic inflammation were evaluated by peripheral arterial tonometry (log transformed Reactive Hyperemia Index) and C-reactive protein (mg/L).

RESULTS

Body mass index and waist circumference (p < 0.02) were associated with coronary plaque volumes. Body mass index was associated with low-density non-calcified plaque volume after adjustment for age, sex and diabetes status (p < 0.01). Truncal fat mass (p > 0.51), waist circumference (p > 0.06) and epicardial adipose tissue (p > 0.17) were not associated with coronary plaque volumes in adjusted analyses.

CONCLUSION

Body mass index is associated with coronary plaque volumes in diabetic as well as non-diabetic individuals.

New Insights into the Association between Fibrinogen and Coronary Atherosclerotic Plaque Vulnerability: An Intravascular Optical Coherence Tomography Study

BACKGROUND

Fibrinogen levels have been associated with coronary plaque vulnerability in experimental studies. However, it has yet to be determined if serum fibrinogen levels are independently associated with coronary plaque vulnerability as detected by optical coherence tomography (OCT) in patients with coronary heart disease.

METHODS

Patients with coronary heart disease (CHD) who underwent coronary angiography and OCT in our department from January 2015 to August 2018 were included in this study. Coronary lesions were categorized as ruptured plaque, nonruptured with thin-cap fibroatheroma (TCFA), and nonruptured and non-TCFA. Presence of ruptured plaque and nonruptured with TCFA was considered to be vulnerable lesions. Determinants of coronary vulnerability were evaluated by multivariable logistic regression analyses.

RESULTS

A total of 154 patients were included in this study; 17 patients had ruptured plaques, 15 had nonruptured plaques with TCFA, and 122 had nonruptured plaques with non-TCFA. Results of univariate analyses showed that being male, diabetes, current smoking, high body mass index (BMI), and clinical diagnosis of acute coronary syndrome (ACS) were associated with coronary vulnerability. No significant differences were detected in patient characteristics, coronary angiographic findings, and OCT results between patients with higher and normal fibrinogen. Results of multivariate logistic analyses showed that diabetes and ACS were associated with TCFA, while diabetes, higher BMI, and ACS were associated with plaque rupture.

CONCLUSIONS

Diabetes, higher BMI, and ACS are independently associated with coronary vulnerability as detected by OCT. Serum fibrinogen was not associated with coronary vulnerability in our cohort.

Comparative Proteome Analysis of Epicardial and Subcutaneous Adipose Tissues from Patients with or without Coronary Artery Disease

BACKGROUND AND AIMS

Owing to its unique anatomical structure and metabolism, epicardial adipose tissue (EAT) has attracted amount of attention in coronary artery disease (CAD) research. Here, we analyzed differences in proteome composition in epicardial (EAT) and subcutaneous adipose tissues (SAT) from patients with or without CAD.

METHODS

EAT and SAT samples were collected from 6 CAD patients and 6 non-CAD patients. Isobaric Tagging for Relative and Absolute Quantitation (iTRAQ) analysis combined with liquid chromatography tandem-mass spectrometry (LC-MS/MS) was performed to identify the differentially expressed proteins.

RESULTS

In total, 2348 proteins expressed in EAT and 2347 proteins expressed in SAT were separately identified. 385 differentially expressed proteins were found in EAT and 210 proteins were found in SAT in CAD patients compared to non-CAD patients. Many proteins differentially expressed in EAT of CAD patients were involved in biological functions associated with CAD development such as cell-to-cell signaling and interaction, inflammatory response, and lipid metabolism. Differential expressions of proteins (MMP9, S100A9, and clusterin) in EAT or SAT were involved in several signaling pathways such as mitochondrial dysfunction, acute phase inflammation, and LXR/RXR activation, which was confirmed by western blotting, and similar results were obtained.

CONCLUSIONS

The largest profiles of differentially expressed proteins in EAT and SAT between CAD patients and non-CAD patients were identified. The significant signal pathways, mitochondrial dysfunction, and LXR/RXR activation, which differential proteins were involved in, were firstly found to play roles in EAT of CAD patients, and clusterin was firstly found to be upregulated in EAT of CAD patients.

Epicardial fat thickness can predict severity and multivessel distribution in Egyptian patients with atherosclerotic coronary artery stenosis

Background

Epicardial fat, in addition to its secretory function, may have an important role in predicting and stratifying cardiovascular risk. There is a paucity of data regarding correlation between epicardial fat thickness and coronary artery disease in Egypt.

Aim of the study

To study the relationship between epicardial fat thickness (EFT) measured by trans-thoracic echocardiography (TTE) and severity of coronary artery disease (CAD) and its distribution in Egyptian population.

Methods

Our study was a prospective observational case control study that was conducted upon 150 patients with stable CAD presented to the cardiology departments in Ain Shams University hospitals and Al-Zaitoun Specialized hospital from March to October, 2015. EFT was measured by TTE for all patients at the same day of performing invasive coronary angiography (CA). We studied the statistical correlation between EFT and presence of CAD, also we tried to find if EFT is related to severity of CAD (according to Gensini score) or its distribution.

Results

The study population was divided according to CA results to 2 groups; patients’ group having atherosclerotic CAD consisting of 100 patients and control group consisting of 50 patients with normal coronaries. All the well- known risk factors of CAD (male sex, smoking, hypertension, diabetes, dyslipidemia, increased body mass index) were significantly more prevalent in the patients’ group. Patients had significantly lower systolic and diastolic functions. EFT was significantly correlated to presence of CAD (P < 0.001) with a cut-off value of 5.5 mm. EFT was significantly correlated to severity of CAD assessed by Gensini score (P < 0.001). Also we found a significant positive correlation between EFT and number of vessels affected (P <  0.001).

Conclusion

EFT is a good predictor of CAD severity and multivessel affection in Egyptian patients. It is also a potentially promising predictor for the presence of CAD.

Personalized Statin Therapy and Coronary Atherosclerotic Plaque Burden in Asymptomatic Low/Intermediate-Risk Individuals

BACKGROUND

Current guidelines for the primary prevention of atherosclerotic cardiovascular disease are based on the estimation of a predicted 10-year cardiovascular disease risk and the average relative risk reduction estimates from statin trials. In the clinical setting, however, decision-making is better informed by the expected benefit for the individual patient, which is typically lacking. Consequently, a personalized statin benefit approach based on absolute risk reduction over 10 years (ARR10 benefit threshold ≥2.3%) has been proposed as a novel approach. However, how this benefit threshold relates with coronary plaque burden in asymptomatic individuals with low/intermediate cardiovascular disease risk is unknown.

AIMS

In this study, we compared the predicted ARR10 obtained in each individual with plaque burden detected by coronary computed tomography angiography.

METHODS AND RESULTS

Plaque burden (segment volume score, segment stenosis score, and segment involvement score) was assessed in prospectively recruited asymptomatic subjects (n = 70; 52% male; median age 56 years [interquartile range 51-64 years]) with low/intermediate Framingham risk score (< 20%). The expected ARR10 with statin in the entire cohort was 2.7% (1.5-4.6%) with a corresponding number needed to treat over 10 years of 36 (22-63). In subjects with an ARR10 benefit threshold ≥2.3% (vs. < 2.3%), plaque burden was significantly higher (p = 0.02).

CONCLUSION

These findings suggest that individuals with higher coronary plaque burden are more likely to get greater benefit from statin therapy even among asymptomatic individuals with low cardiovascular risk.

Association between histological features of epicardial adipose tissue and coronary plaque characteristics on computed tomography angiography

The means by which epicardial adipose tissue (EAT) could influence coronary plaque progression biologically remain unclear. We investigated the association between the histological findings of EAT and coronary plaque characteristics assessed by coronary computed tomography angiography (CCTA). We enrolled 34 patients in whom one or more coronary plaques containing non-calcified components were detected on CCTA before cardiac surgery [coronary artery bypass graft (CABG) or non-CABG]. We evaluated visceral adipose tissue (VAT) area, EAT volume, and coronary plaque characteristics including minimum computed tomography density (CTD) and vascular Remodeling Index (RI). Lower CTD and higher RI were considered as high-risk characteristics, and coronary plaque with both CTD < 39 Hounsfield units and RI > 1.05 was defined as two-characteristic plaque (2-CP). The numbers of CD68⁺ macrophages and CD31⁺ microvessels were assessed in six random high-power fields (400×) of EAT samples obtained during cardiac surgery. The entire cohort showed a wide range of EAT volume, which were similar between patients with 2-CP and those without. Patients with 2-CP had more amounts of EAT macrophages (85 ± 38 versus 45 ± 22, p = 0.0005) and vascularity (62 ± 33 versus 37 ± 19, p = 0.013) than those without. On multivariate analyses adjusted for age, sex, coronary risk factors, statin use, type of surgery, VAT area, EAT volume, and coronary calcium score, the presence of 2-CP showed significant correlation with increased EAT macrophages (β = 0.65, p = 0.014) and vascularity (β = 0.74, p = 0.0053). Our findings support the hypothesis that EAT biologic activities are associated with coronary plaque vulnerability.

Morphometric measurements of systemic atherosclerosis and visceral fat: Evidence from an autopsy study

Background

Morphometric measurements of systemic atherosclerosis and direct quantification of visceral fat are only possible using materials from autopsy studies. However, the few autopsy studies that have investigated the association of visceral fat with atherosclerosis had small sample sizes and focused on coronary arteries of young or middle-aged White subjects. We aimed to investigate the association of pericardial fat (PF) and abdominal visceral fat (AVF) with atherosclerosis in the aorta, coronary, carotid, and cerebral arteries in a large autopsy study.

Materials and methods

We evaluated deceased subjects aged 30 years or above. We dissected and weighted the PF and the AVF and evaluated the atherosclerotic burden in the aorta, as well as the carotid, coronary, and cerebral arteries using morphometric measurements. We also investigated the interaction of PF and AVF with age regarding the atherosclerotic burden.

Results

The mean age of the 240 included subjects was 64.8±15.3 years, and 63% was male. Greater PF was associated with a higher degree of aortic atherosclerosis after adjusting for confounding variables (coefficient = 4.39, 95% CI = 0.83; 7.94, p = 0.02). Greater AVF was associated with a higher coronary stenosis index (coefficient = 1.49, 95% CI = 0.15; 2.83, p = 0.03) and a greater number of coronary plaques (coefficient = 0.71, 95% CI = 0.24; 1.19, p = 0.003). We did not find an association of PF or AVF with carotid or cerebral atherosclerotic burden. We found a significant interaction of AVF (coefficient = -0.08; 95% CI = -0.14; -0.02, p = 0.009) and PF (coefficient = -0.87, 95% CI = -1.70; -0.04, p = 0.04) with age regarding carotid artery atherosclerotic burden.

Conclusions

Greater AVF was associated with greater atherosclerotic burden and extent in coronary arteries, while greater PF correlated with a higher degree of atherosclerosis in the aorta.

Tumor Necrosis Factor-α Gene Expression in Epicardial Adipose Tissue is Related to Coronary Atherosclerosis Assessed by Computed Tomography

Aims: Tumor necrosis factor (TNF)-α reportedly has key pro-inflammatory properties in both atherosclerosis and adipocytes. To further investigate the biologic impact of epicardial adipose tissue (EAT) on coronary atherosclerosis, we evaluated the relationship between TNF-α gene expression in EAT and clinically-assessed coronary atherosclerosis on computed tomography (CT).

Methods: We studied 47 patients before cardiac surgery (coronary artery bypass grafting [CABG], n = 26; non-CABG, n = 21), assessing visceral adipose tissue (VAT) area, EAT volume, coronary calcium score (CCS), and the presence of non- and/or partially-calcified coronary plaque (NCP) on CT angiography. EAT and subcutaneous adipose tissue (SAT) samples were obtained during cardiac surgery. TNF-α mRNA in EAT was measured using quantitative real-time PCR, and normalized to that of SAT as control adipose tissue.

Results: There was no difference in the TNF-α expression level between patients scheduled for CABG and non-CABG surgery (p = 0.23), or among the subgroups based on CCS (p = 0.68), while patients with NCP had the higher TNF-α expression level than those without NCP (median [interquartile range], 2.50 [1.01–5.53] versus. 1.03 [0.64–2.16], p = 0.022). On multivariate analysis adjusted for age, sex, coronary risk factors, statin therapy, CABG versus non-CABG, VAT area, and EAT volume, the presence of NCP had close correlation with the elevated TNF-α expression level (β= 0.79, p = 0.003).

Conclusions: TNF-α expressed regionally in EAT may exert potent effects on the progression of coronary atherosclerosis, suggesting a contribution of EAT to coronary artery disease through behavior of molecule.

Adipose tissue location and contribution to postinjury hypercoagulability

OBJECTIVES

Obesity is associated with a hypercoagulable state at baseline and following injury. The anatomic location of adipose deposition may influence the type of thrombotic event, with visceral adipose tissue (VAT) associated with arterial thrombosis and subcutaneous adipose tissue (SAT) predisposing to venous thrombosis. We sought to determine whether adipose tissue amount and location correlated with measures of coagulation.

METHODS

All adult Level I trauma activations at our institution between January 2013 and August 2014 who underwent admission abdominal computed tomography scan and had admission rotational thromboelastometry measurements were included. Patients were excluded for history of anticoagulant use and known coagulopathy/hypercoagulable state. Admission computed tomography was used to obtain cross-sectional VAT and SAT areas at the umbilicus utilizing a novel software system; VAT and SAT measurements were associated with markers of coagulation utilizing Spearman correlation and stepwise linear regression with significance set at p < 0.05.

RESULTS

Two hundred forty-two patients met inclusion and exclusion criteria. Sixty-nine percent of patients sustained blunt injury, 79% were male, mean age was 40 years, 25% were obese or morbidly obese, and mean Injury Severity Scale score was 17. Seventeen percent of patients had acute deep venous thrombosis or pulmonary embolism during hospitalization. Neither SAT nor VAT correlated with prothrombin time, international normalized ratio, or partial thromboplastin time. Subcutaneous adipose tissue correlated positively with platelet count. Visceral adipose tissue and SAT correlated negatively with clot formation time and positively with TEM fibrinogen, α angle, maximum clot firmness, and lysis at 30 minutes; stronger correlations and greater significance were seen between SAT and these measures except for lysis at 30 minutes. Stepwise linear regression confirmed significant relationships between SAT and clot formation time, AA, and maximum clot firmness; VAT showed a significant relationship with TEM fibrinogen.

CONCLUSIONS

Increased adipose tissue correlates with relative hypercoagulability following trauma. Subcutaneous adipose tissue shows a stronger relationship with functional measures of coagulation, suggesting that SAT may be associated with hemorrhage resistance and hypercoagulability after injury.

LEVEL OF EVIDENCE

Prognostic study, level IV.

Reproducibility and Repeatability of Computer Tomography-based Measurement of Abdominal Subcutaneous and Visceral Adipose Tissues

Excessive accumulation of abdominal adipose tissue is a widely recognized as a major feature of obesity, and it can be quantified by dual-energy x-ray absorptiometry (DXA). However, in a phantom study, the inter- and intra-instrument reliability of DXA remains unpredictable. Thus, we attempted to determine the precision of estimates from computer tomography-based measurements and analysis with AZE Virtual Place software. To determine the inter-rater reproducibility and intra-rater repeatability of adipose tissue area estimates, we used the automatic boundary-tracing function of the AZE Virtual Place to generate cross-sectional areas of subcutaneous and visceral adipose tissues from the abdomen of reconstructed CT images. The variability of inter-rater and intra-rater estimates expressed as the coefficient of variation ranged from 0.47% to 1.43% for subcutaneous adipose tissue and 1.08% to 2.20% for visceral adipose tissue; the optimal coefficient of variation of the fat rate calculation ranged from 0.55% to 1.13%, respectively. There was high and significant correlation between adipose tissue areas as estimated in 40 obese subjects by two raters or repeatedly on 20 obese subjects by either rater. This indicates excellent reproducibility and repeatability via a computer tomography-based measurement of abdominal subcutaneous and visceral adipose tissues.

Imaging of coronary atherosclerosis in various susceptible groups

Coronary artery disease (CAD) is the leading cause of death and disability worldwide. Atherosclerosis, which is the primary pathophysiologic mechanism for the development of plaque leading to CAD, is a multifactorial process resulting from a complex interplay between genetic susceptibility and various risk factors such as hypertension (HT), dyslipidaemia, diabetes mellitus (DM) and smoking. In addition, influences from other disease states such as chronic kidney disease (CKD), obesity and the metabolic syndrome as well as gender and ethnic diversity also contribute to the disease process. Insights from pathological observations and advances in cellular and molecular biology have helped us understand the process of plaque formation, progression and rupture leading to events. Several intravascular imaging techniques such as intravascular ultrasound (IVUS), Virtual histology IVUS (VH-IVUS) and optical coherence tomography (OCT) allow in vivo assessment of plaque burden, plaque morphology and response to therapy. In addition, non invasive assessment using coronary artery calcium (CAC) score allows risk stratification and plaque burden assessment whilst computed tomography coronary angiography (CTCA) allows evaluation of luminal stenosis, plaque characterisation and quantification. This review aims to summarise the results of invasive and non-invasive imaging studies of coronary atherosclerosis seen in various high-risk populations including DM, metabolic syndrome, obesity, CKD and, gender differences and ethnicity. Understanding the phenotype of plaques in various susceptible groups may allow potential development of personalised therapies.

Impact of adipose tissue composition on cardiovascular risk assessment in patients with stable coronary artery disease

BACKGROUND AND AIMS

Visceral adipose tissue (VAT), unlike subcutaneous adipose tissue (SAT), is highly correlated with cardiovascular risk factors. This study aimed to evaluate the predictive value of adipose tissue composition, as measured by computed tomography, for cardiovascular events in patients with stable coronary artery disease.

METHODS

357 consecutive patients who underwent 64-slice computed tomography and elective percutaneous coronary intervention (PCI) were recruited. The ratio of visceral to subcutaneous adipose tissue (VAT/SAT) was calculated. Patients were divided into three groups in accordance with VAT/SAT (low VAT/SAT, <0.55 [<25th percentile]; moderate VAT/SAT, 0.55-1.03 [25th-75th percentile]; high VAT/SAT, ≥1.03 [≥75th percentile]). The investigated risk factors were hypertension, hyperglycaemia, and dyslipidaemia. We analysed the incidence of major adverse cardiovascular events (MACE), defined as the composite of cardiac death, myocardial infarction, and any revascularization.

RESULTS

The rate of patients with two or more concomitant risk factors was significantly higher in the high VAT/SAT group (p = 0.006). During 1480 person-years, 109 events were documented. There was a significant association between the incidence of MACE and VAT/SAT, with the worst event-free survival rate in the high VAT/SAT group (log-rank, p = 0.01). In Cox analysis, the hazard ratio of high VAT/SAT for MACE was 2.72 (95% confidence interval 1.04-7.09, p = 0.04) compared with the low VAT/SAT after adjustment for confounding factors.

CONCLUSIONS

Increased VAT/SAT is independently associated with the incidence of MACE, indicating that adipose tissue composition is a useful predictor of cardiovascular outcome, after elective PCI.

Epicardial fat thickness: A surrogate marker of coronary artery disease - Assessment by echocardiography

OBJECTIVE

Epicardial fat is considered as indicator of cardiovascular risk. Several studies have tested the association between epicardial fat thickness (EFT) and coronary artery disease. The aim of our study is to test the hypothesis that echocardiographic EFT is a marker of coronary artery disease.

METHODS

One hundred and ten patients (70 males and 40 females with mean age of 51.5±10.6 and 52.6±9.6, respectively) admitted for coronary angiogram underwent assessment of epicardial fat thickness by echocardiography. Routine clinical examination, evaluation of risk factor profile, and anthropometric variables were also done. Epicardial fat thickness was measured on the free wall of right ventricle in parasternal long- and short-axis views at end-systole for 3 cardiac cycles.

RESULTS

Mean epicardial fat thickness in angiographically normal patients and acute coronary syndromes were 4.4±1.2 and 6.9±1.9, respectively. Epicardial fat thickness in males and females were not statistically different. Burden of coronary arterial lesions denoted by Gensini score shows linear association with epicardial fat thickness and the severity of the coronary disease.

CONCLUSION

Epicardial fat is independently and linearly associated with CAD and its severity.

Data set for volumetric and pathological findings of epicardial adipose tissue

This article contains the data regarding clinically-assessed visceral adipose tissue (VAT) area and epicardial adipose tissue (EAT) volume on computed tomography (CT) images and EAT pathology, represented by inflammation and neoangiogenesis, complementing the data reported by Kitagawa et al. [1]. In 45 patients scheduled for cardiac surgery, we studied CT images obtained prior to surgery and the numbers of CD68+ individual macrophages and CD31+ neovessels in EAT samples subsequently obtained during surgery. The data revealed a moderate correlation between VAT area and EAT volume, and a strong correlation between EAT macrophage infiltration and neoangiogenesis.

The relationship between inflammation and neoangiogenesis of epicardial adipose tissue and coronary atherosclerosis based on computed tomography analysis

OBJECTIVE

Previous studies indicate that epicardial adipose tissue (EAT) biologically contributes to the progression of coronary atherosclerosis. We evaluated the relationship between EAT pathology, represented by inflammation and neoangiogenesis, and coronary atherosclerosis on computed tomography (CT) images.

METHODS

We performed CT examination in 45 patients scheduled for cardiac surgery (coronary artery bypass graft [CABG], n = 21; non-CABG, n = 24) to assess visceral adipose tissue (VAT) area, EAT volume, coronary calcium score (CCS), and presence of non-calcified coronary plaque (NCP) on CT angiography. Each patient was assessed with the numbers of CD68(+) individual macrophages and CD31(+) neovessels in six random high-power fields (400×) of EAT samples subsequently obtained during cardiac surgery.

RESULTS

In three groups based on CCS (mild, 0-100; moderate, 101-400; severe, >400), the moderate group had the most extensive macrophage infiltration (p = 0.0025) and neoangiogenesis (p = 0.0036) in EAT. The patients with NCP had more extensive macrophage infiltration (p = 0.010) and neoangiogenesis (p = 0.0043) in EAT than those without. On multivariate analysis adjusted for age, sex, CABG versus. non-CABG, VAT area, and EAT volume, moderate CCS and the presence of NCP showed significant correlations with increased macrophage infiltration (β = 0.65; p < 0.0001, and β = 0.49; p = 0.0089, respectively) and neoangiogenesis (β = 0.55; p = 0.0011, and β = 0.53; p = 0.012, respectively) in EAT.

CONCLUSION

Inflammation and neoangiogenesis in EAT independently correlate with moderate coronary calcification and presence of NCP, suggesting that these two factors may have a role in promoting coronary atherosclerosis.

Visceral adipose tissue influences on coronary artery calcification at young and middle-age groups using computed tomography angiography

Purpose:

The purpose of the study was to evaluate the impact of excessive visceral adipose tissue (VAT) on subclinical coronary atherosclerosis and coronary artery calcifications (CAC) in young and middle-age groups using multislice computed tomography.

Methods:

This study is a single center, cross-sectional study. Eligible patients (n = 159), who under the age of 61 years, with chest pain and mild to moderate probability to have coronary artery disease (CAD) were enrolled. Coronary calcium score and epicardial adipose tissue (EAT) were measured at the level of the left main coronary artery while VAT was measured at the level of the iliac crest.

Results:

The average age was (48 ± 8 years). The mean VAT was (38 ± 21 cm²) with no significant difference between men and women (38 ± 22 vs. 37 ± 19 P = 0.8) respectively. Student's t-test analysis showed significantly higher VAT in patients with detectable CAC than patients with no CAC (48 ± 24 vs. 33 ± 18 P = 0.00002), respectively. Univariate regression analysis showed that VAT and EAT, are strong predictor for CAC (hazard ratio [HR] 1.034, 95% confidence interval [CI: 1.016–1.052]. P <0.001 and [HR] 1.344, 95% CI: [1.129–1.601] P = 0.001), respectively.

Conclusion:

Excessive VAT is significantly associated with positive CAC. VAT can strongly predict subclinical CAD in individuals at young and middle-age groups.

CT Dose Reduction for Visceral Adipose Tissue Measurement: Effects of Model-Based and Adaptive Statistical Iterative Reconstructions and Filtered Back Projection

OBJECTIVE

The objective of our study was to evaluate the effects of radiation dose reduction and the reconstruction algorithm used--filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), or model-based iterative reconstruction (MBIR)--on the measurement of abdominal visceral fat using CT.

SUBJECTS AND METHODS

Standard-dose and low-dose abdominal CT examinations were performed simultaneously with automatic exposure control in 59 patients; the noise index for a 5-mm slice thickness was 12 for routine-dose CT and 24 for low-dose CT. The routine-dose CT images were reconstructed using FBP (reference standard), and the low-dose CT images were reconstructed using FBP, ASIR (so-called hybrid iterative reconstruction [IR]), and MBIR (so-called pure IR). In the 236 image series obtained, the visceral fat area was measured. Data were analyzed by the Pearson correlation coefficient test and a Bland-Altman difference analysis.

RESULTS

The radiation dose of the low-dose abdominal CT examinations was 73.0% (mean) lower than that of routine-dose CT examinations. Excellent correlations were observed between the visceral fat areas measured on the routine-dose FBP images and those measured on the low-dose FBP, low-dose ASIR, and low-dose MBIR images (r = 0.998, 0.998, and 0.998, respectively; p < 0.001). A Bland-Altman difference analysis revealed excellent agreements, with mean biases of -0.47, -0.41, and 0.18 cm(2) for the visceral fat area between the routine-dose FBP images and the low-dose FBP, low-dose ASIR, and low-dose MBIR images, respectively.

CONCLUSION

A 73.0% reduction of the radiation dose would be possible in CT for the measurement of the abdominal visceral fat regardless of which reconstruction algorithm is used (i.e., FBP, hybrid IR, or pure IR).

Relationships between components of metabolic syndrome and coronary intravascular ultrasound atherosclerosis measures in women without obstructive coronary artery disease: the NHLBI-Sponsored Women's Ischemia Syndrome Evaluation Study

OBJECTIVE

In women, metabolic syndrome (MetS) is associated with higher risk of ischemic heart disease-related adverse outcomes versus individual components. We examined the relationship of MetS to subclinical coronary atherosclerosis.

METHODS

Women (n = 100) undergoing coronary angiography for suspected ischemia but without obstructive coronary artery disease (CAD) underwent intravascular ultrasound (IVUS) of a segment of the left coronary artery. A core lab, masked to other findings, assessed IVUS measures and normalized volume measures to pull-back length. MetS [defined using ATPIII criteria (fasting glucose ≥ 100 mg/dl per revised NCEP guideline)] and its components were entered into multiple regression models to assess associations with IVUS measures.

RESULTS

Detailed IVUS measurements were available in 87 women. Mean age was 54 ± 10 years, 36% had MetS, and 78% had atheroma. Comparing women with MetS versus without MetS, significant differences were observed for seven IVUS atherosclerosis measures, but were not significant after adjusting for the MetS components. Systolic blood pressure and waist circumference components remained independently positively associated with the IVUS measures after adjusting for age, diabetes, CAD family history, dyslipidemia, smoking, and hormone replacement.

CONCLUSION

In women with signs and symptoms of ischemia and no obstructive CAD, MetS is associated with coronary atherosclerosis presence and severity. However, these associations appear largely driven by components of waist circumference and systolic blood pressure versus MetS cluster. This supports the concept that MetS is a convenient clustering of risk factors rather than an independent risk predictor, and emphasizes that the critical factors for coronary atherosclerosis are potentially modifiable.

Effects of growth hormone-releasing hormone on visceral fat, metabolic, and cardiovascular indices in human studies

Increased visceral adipose tissue (VAT) is associated with reductions in endogenous GH secretion, possibly as a result of hyperinsulinemia, increased circulating free fatty acid, increased somatostatin tone, and reduced ghrelin. Reduced GH may, in turn, further exacerbate visceral fat accumulation because of decreased hormone-sensitive lipolysis in this depot. Data from multiple populations demonstrate that both reduced GH and increased VAT appear to contribute independently to dyslipidemia, increased systemic inflammation, and increased cardiovascular risk. The reductions in GH in states of visceral adiposity are characterized by reduced basal and pulsatile GH secretion with intact pulse frequency. Treatment with GH-releasing hormone (GHRH) provides a means to reverse these abnormalities, increasing endogenous basal and pulsatile GH secretion without altering pulse frequency. This review describes data from HIV-infected individuals and individuals with general obesity showing that treatment with GHRH significantly reduces visceral fat, ameliorates dyslipidemia, and reduces markers of cardiovascular risk. Further research is needed regarding the long-term efficacy and safety of this treatment modality.

Increased regional epicardial fat volume associated with reversible myocardial ischemia in patients with suspected coronary artery disease

Epicardial adipose tissue is a source of pro-inflammatory cytokines and has been linked to the development of coronary artery disease. No study has systematically assessed the relationship between local epicardial fat volume (EFV) and myocardial perfusion defects. We analyzed EFV in patients undergoing SPECT myocardial perfusion imaging combined with computed tomography (CT) for attenuation correction. Low-dose CT without contrast was performed in 396 consecutive patients undergoing SPECT imaging for evaluation of coronary artery disease. Regional thickness, cross-sectional areas, and total EFV were assessed. 295 patients had normal myocardial perfusion scans and 101 had abnormal perfusion scans. Mean EFVs in normal, ischemic, and infarcted hearts were 99.8 ± 82.3 cm(3), 156.4 ± 121.9 cm(3), and 96.3 ± 102.1 cm(3), respectively (P < 0.001). Reversible perfusion defects were associated with increased local EFV compared to normal perfusion in the distribution of the right (69.2 ± 51.5 vs 46.6 ± 32.0 cm(3); P = 0.03) and left anterior descending coronary artery (87.1 ± 76.4 vs 46.7 ± 40.6 cm(3); P = 0.005). Our results demonstrate increased regional epicardial fat in patients with active myocardial ischemia compared to patients with myocardial scar or normal perfusion on nuclear perfusion scans. Our results suggest a potential role for cardiac CT to improve risk stratification in patients with suspected coronary artery disease.

Association of epicardial and abdominal visceral adipose tissue with coronary atherosclerosis in patients with a coronary artery calcium score of zero

BACKGROUND

We sought to examine whether epicardial and abdominal visceral adipose tissue distribution is associated with coronary atherosclerosis in patients with a coronary artery calcium (CAC) score of zero, assessed by coronary computed tomography angiography (CCTA).

METHODS AND RESULTS

We studied 352 patients with suspected coronary artery disease (mean age 61±11 years, 57% male) with a CAC score of zero who had undergone CCTA. Non-calcified coronary plaques (NCPs) were detected in 102 patients (29%); those causing ≥50% stenosis were found in 15 patients (4%). Patients were divided into 4 groups on the basis of CT-based epicardial adipose tissue (EAT) volume and abdominal visceral adipose tissue (VAT) area using the sex-specific median value. Multivariate analysis showed that the adjusted odds ratios for the presence of NCPs in the high VAT area/low EAT volume group, and the high VAT area/high EAT volume group were 2.80 (95% confidence interval [95% CI]: 1.25-6.35, P=0.01) and 2.68 (95% CI: 1.36-5.45, P=0.004), respectively. Interestingly, the low VAT area/high EAT volume group showed an equivalent adjusted odds ratio of 3.02 (95% CI: 1.33-6.90, P=0.008).

CONCLUSIONS

EAT volume is eligible as a marker to be evaluated in addition to VAT area in patients with a CAC score of zero.

Epicardial adipose tissue reflects the presence of coronary artery disease: comparison with abdominal visceral adipose tissue

Accumulation of visceral adipose tissue is associated with a risk of coronary artery disease (CAD). The aim of this study was to examine whether different types of adipose tissue depot may play differential roles in the progression of CAD. Consecutive 174 patients who underwent both computed tomography (CT) and echocardiography were analyzed. Cardiac and abdominal CT scans were performed to measure epicardial and abdominal visceral adipose tissue (EAT and abdominal VAT, resp.). Out of 174 patients, 109 and 113 patients, respectively, presented coronary calcification (CC) and coronary atheromatous plaque (CP). The EAT and abdominal VAT areas were larger in patients with CP compared to those without it. Interestingly, the EAT area was larger in patients with CC compared to those without CC, whereas no difference was observed in the abdominal VAT area between patients with CC and those without. Multivariable logistic regression analysis revealed that the presence of echocardiographic EAT was an independent predictor of CP and CC, but the abdominal VAT area was not. These results suggest that EAT and abdominal VAT may play differential pathological roles in CAD. Given the importance of CC and CP, we should consider the precise assessment of CAD when echocardiographic EAT is detected.

Imaging of atherosclerotic plaques in obesity: excessive fat accumulation, plaque progression and vulnerability

Obesity is becoming a major health issue in the world due to sedentary lifestyles and increasing intake of Western diets. Obesity is associated with metabolic abnormalities and atherosclerotic cardiovascular diseases. Adipose tissue has been increasingly considered to play a critical role in inducing metabolic disturbances and promoting atherogenesis. Arterial wall imaging permits direct visualization of atheroma burden in various vascular beds. In addition, recent advances in imaging technology help characterize components, microstructures and functional features of atherosclerotic plaques. These imaging modalities have contributed to elucidating factors associated with atherosclerosis in obese patients. Also, it provides opportunities to evaluate the effect of novel therapies on plaques in the setting of obesity. The findings of recent imaging studies and the clinical implications will be reviewed.

Differential association of visceral adipose tissue with coronary plaque characteristics in patients with and without diabetes mellitus

Background

Excess visceral adipose tissue (VAT) is closely associated with the presence of coronary artery plaques that are vulnerable to rupture. Patients with diabetes mellitus (DM) have more VAT than patients without DM, but the extent to which VAT contributes to the characteristics of coronary plaques before and after the development of DM is not fully understood.

Methods

We retrospectively evaluated 456 patients (60% male, age 64 ± 16 years) who were suspected to have cardiovascular disease and underwent 64-slice computed tomography angiography (CTA). Seventy-one (16%) patients had vulnerable plaques (CT density < 50 Hounsfield Units, positive remodeling index > 1.05, and adjacent spotty areas of calcification).

Results

Patients were divided into tertiles according to the VAT area. There were stepwise increases in noncalcified and vulnerable plaques with increasing tertiles of VAT area in patients without DM, but not in patients with DM. Multivariate analysis showed that a larger VAT area was significantly associated with a higher risk of vulnerable plaque in patients without DM (odds ratio 3.17, 95% confidence interval 1.08–9.31, p = 0.04), but not in patients with DM.

Conclusions

The VAT area is associated with the characteristics of coronary plaques on CTA in patients without DM, but not in patients with DM. VAT may be a significant cardiometabolic risk factor that is associated with plaque vulnerability before the development of DM. CTA findings may help to improve risk stratification in such patients.

Visceral fat accumulation is associated with cerebral small vessel disease

BACKGROUND AND PURPOSE

Obesity is associated with the risk of coronary artery disease and stroke. Visceral fat plays a significant role in the atherogenic effects of obesity. Whether visceral fat accumulation, as measured by computed tomography (CT), is an independent risk factor for the presence of cerebral small vessel disease (SVD) was investigated.

METHODS

This study comprised 506 Japanese subjects 35-74 years of age (mean 55.3 years) without a history of symptomatic cerebrovascular disease who underwent health screening tests, including brain magnetic resonance imaging, carotid echography and measurements of the visceral fat area (VFA) and subcutaneous fat area (SFA) on abdominal CT. Visceral fat accumulation was defined as VFA ≥ 100 cm(2) . Logistic regression analysis was performed to examine the associations between visceral fat accumulation and cerebral SVD such as white matter lesions (WMLs) and silent lacunar infarction (SLI).

RESULTS

The prevalence of WMLs and SLI but not carotid plaque were significantly higher in subjects with VFA ≥ 100 cm(2) than those with VFA < 100 cm(2) . A VFA ≥ 100 cm(2) was associated with WMLs and SLI independent of age, cardiovascular risk factors and other measurements of obesity, such as waist circumference and body mass index. A large waist circumference was independently associated with SLI. SFA, the combination of VFA and SFA, and body mass index were not associated with WMLs or SLI.

CONCLUSIONS

Visceral fat accumulation was independently associated with the presence of cerebral SVD in subjects without a history of symptomatic cerebrovascular disease.

Visceral adipose tissue area is associated with coronary stenosis and noncalcified plaques

OBJECTIVE

Few studies have investigated the relationships between visceral adipose tissue (VAT) and coronary stenosis and noncalcified plaques at the subclinical stage. The aim of this study was to investigate relationship between VAT and coronary lesions assessed by coronary computed tomography (CT) in an apparently healthy population.

DESIGN

Retrospective cross-sectional study.

SUBJECTS

One thousand six hundred and fifty-eight subjects free of cardiovascular disease underwent coronary CT and abdominal fat CT as part of a routine medical examination.

MEASUREMENT

VAT area was measured at the level of the umbilicus using CT. Coronary stenoses and plaques were evaluated using coronary CT.

RESULTS

The mean age of the study population was 55.9±8.0 years, and 1198 (72.3%) subjects were men. There were 201 subjects (12.1%) with coronary stenosis <50% and 144 (8.7%) had significant stenosis. Noncalcified plaques were observed in 108 (6.5%) subjects. Coronary stenosis <50% and noncalcified plaques increased steadily as the VAT area increased (P<0.001). The 4th quartile of VAT area was significantly associated with prevalence of coronary stenosis <50% and the presence of noncalcified plaques when compared with the first through third VAT quartiles in the cardiovascular risk factor-adjusted model (odds ratio (OR): 1.58, 95% confidence interval (CI): 1.09-2.30 and OR: 1.66; 95% CI: 1.02-2.68, respectively).

CONCLUSION

Excess VAT area was associated with coronary stenosis <50% and noncalcified plaques, independent of traditional cardiovascular risk factors, in an asymptomatic population without a history of coronary artery disease.

Visceral adipose tissue as a source of inflammation and promoter of atherosclerosis

The current epidemic of obesity with the associated increasing incidence of insulin resistance, diabetes mellitus and atherosclerosis affecting a large proportion of the North American and Western populations, has generated a strong interest in the potential role of visceral adipose tissue in the development of atherosclerosis and its complications. The intra-abdominal and epicardial space are two compartments that contain visceral adipose tissue with a similar embryological origin. These visceral fats are highly inflamed in obese patients, patients with the metabolic syndrome and in those with established coronary artery disease; additionally they are capable of secreting large quantities of pro-inflammatory cytokines and free fatty acids. There is accumulating evidence to support a direct involvement of these regional adipose tissue deposits in the development of atherosclerosis and its complicating events, as will be reviewed in this article.

Coronary CT angiography in coronary artery disease: correlation between virtual intravascular endoscopic appearances and left bifurcation angulation and coronary plaques

The aim of this study is to investigate the relationship between intraluminal appearances of coronary plaques and left coronary bifurcation angle and plaque components using coronary CT virtual intravascular endoscopy (VIE). Fifty patients suspected of coronary artery disease undergoing coronary CT angiography were included in the study. The left bifurcation angle in patients with diseased left coronary artery which was measured as 94.3° ± 16.5 is significantly larger than that in patients with normal left coronary artery, which was measured as 76.5° ± 15.9 (P < 0.001). Irregular VIE appearances were found in 10 out of 11 patients with mixed plaques in the left anterior descending (LAD) and left circumflex (LCx), while, in 29 patients with calcified plaques in the LAD and LCx, irregular VIE appearances were only noticed in 5 patients. Using 80° as a cut-off value to determine coronary artery disease, smooth VIE appearances were found in 95% of patients (18/19) with left bifurcation angle of less than 80°, while irregular VIE appearances were observed in nearly 50% of patients (15/31) with left bifurcation angle of more than 80°. This preliminary study shows that VIE appearances of the coronary lumen are directly related to the types of plaques.