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

Epicardial and pericoronary adipose tissue and coronary plaque burden in patients with Cushing's syndrome: a propensity score-matched study

PURPOSE

To assess coronary inflammation by measuring the volume and density of the epicardial adipose tissue (EAT), perivascular fat attenuation index (FAI) and coronary plaque burden in patients with Cushing's syndrome (CS) based on coronary computed tomography angiography (CCTA).

METHODS

This study included 29 patients with CS and 58 matched patients without CS who underwent CCTA. The EAT volume, EAT density, FAI and coronary plaque burden were measured. The high-risk plaque (HRP) was also evaluated. CS duration from diagnosis, 24-h urinary free cortisol (UFC), and abdominal visceral adipose tissue volume (VAT) of CS patients were recorded.

RESULTS

The CS group had higher EAT volume (146.9 [115.4, 184.2] vs. 119.6 [69.0, 147.1] mL, P = 0.006), lower EAT density (- 78.79 ± 5.89 vs. - 75.98 ± 6.03 HU, P = 0.042), lower FAI (- 84.0 ± 8.92 vs. - 79.40 ± 10.04 HU, P = 0.038), higher total plaque volume (88.81 [36.26, 522.5] vs. 44.45 [0, 198.16] mL, P = 0.010) and more HRP plaques (7.3% vs. 1.8%, P = 0.026) than the controls. The multivariate analysis suggested that CS itself (β [95% CI], 29.233 [10.436, 48.03], P = 0.014), CS duration (β [95% CI], 0.176 [0.185, 4.242], P = 0.033), and UFC (β [95% CI], 0.197 [1.803, 19.719], P = 0.019) were strongly associated with EAT volume but not EAT density, and EAT volume (β [95% CI] - 0.037[- 0.058, - 0.016], P = 0.001) not CS was strongly associated with EAT density. EAT volume, FAI and plaque burden increased (all P < 0.05) in 6 CS patients with follow-up CCTA. The EAT volume had a moderate correlation with abdominal VAT volume (r = 0.526, P = 0.008) in CS patients.

CONCLUSIONS

Patients with CS have higher EAT volume and coronary plaque burden but less inflammation as detected by EAT density and FAI. The EAT density is associated with EAT volume but not CS itself.

Relationship of cardiovascular risk factors, pericardial fat, and carotid thickness with coronary plaque type in patients with diabetes mellitus

Background

There is paucity of data on the potential predictors of coronary plaque types among patients with diabetes mellitus(DM).

Aims

To assess the association of cardiovascular risk factors, pericardial fat volume (PFV) assessed by multi-detector CT(MDCT)angiography, and internal carotid intima media thickness with coronary atherosclerotic plaque types in patients with type 2 DM.

Patients and methods

Patients with suspected coronary artery disease who underwent 64-slice MDCT angiography were enrolled in this retrospective study.

Results

A total of 784 patients were enrolled in this study, 198 of whom had DM and 586 of whom did not. The prevalence of calcified and mixed plaques was significantly higher in the DM group than without DM group, while no significant difference was found in the distribution of non-calcified plaque between groups. There was significant association between smoking [OR(CI) = 4(2-10),P = 0.001] and increased age[OR(CI) = 1.1(1-1.3),P = 0.023] and calcified plaque presence. Regarding mixed and non-calcified plaque, increased PFV[OR(CI) = 1.1(1-1.3),P = 0.001] and positive family history[OR(CI) = 4(2-12),P = 0.049] showed a significant association with coronary mixed plaque presence while no significant association was observed between cardiovascular risk factors, PFV, and internal carotid intima media thickness and non-calcified plaque presence in patients with DM.

Conclusion

Increased PFV showed significant and independent association with mixed coronary plaques development, which suggests that PFV may be used as an imaging marker for early detection of increased risk for future coronary events in patients with DM.

Epicardial Adipose Tissue in Patients with Coronary Artery Disease: A Meta-Analysis

Objective: The aim of this study is to assess the association between epicardial adipose tissue (EAT) and coronary artery disease (CAD) via meta−analysis. Methods: Specific searches of online databases from January 2000 to May 2022 were conducted. All observational studies evaluating the association between EAT and CAD in PubMed, Web of Science, and the Cochrane Library databases were screened. A meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta−Analyses guidelines (PRISMA). In total, 21 studies encompassing 4975 subjects met the inclusion criteria, including 2377 diagnosed and assigned as the CAD group, while the other 2598 were assigned as the non−CAD group. Subjects in the CAD group were further divided into the severe stenosis group (stenosis ≥ 50%, n = 846) and the mild/moderate stenosis group (stenosis < 50%, n = 577). Results: Both the volume and thickness of EAT in the CAD group were larger compared to the non−CAD group (p < 0.00001). In a subgroup analysis within the CAD group, the severe stenosis group had a larger volume and thickness with respect to EAT when compared to the mild/moderate group (p < 0.001). Conclusions: The enlargement of EAT presented in CAD patients with an association with CAD severity. Although limited by different CAD types and measuring methods for EAT, as well as a smaller sample size, our results suggest that EAT is a novel predictor and a potential therapeutic target for CAD.

Epicardial Adipose Tissue: A Novel Potential Imaging Marker of Comorbidities Caused by Chronic Inflammation

The observation of correlations between obesity and chronic metabolic and cardiovascular diseases has led to the emergence of strong interests in “adipocyte biology”, in particular in relation to a specific visceral adipose tissue that is the epicardial adipose tissue (EAT) and its pro-inflammatory role. In recent years, different imaging techniques frequently used in daily clinical practice have tried to obtain an EAT quantification. We provide a useful update on comorbidities related to chronic inflammation typical of cardiac adiposity, analyzing how the EAT assessment could impact and provide data on the patient prognosis. We assessed for eligibility 50 papers, with a total of 10,458 patients focusing the review on the evaluation of EAT in two main contexts: cardiovascular and metabolic diseases. Given its peculiar properties and rapid responsiveness, EAT could act as a marker to investigate the basal risk factor and follow-up conditions. In the future, EAT could represent a therapeutic target for new medications. The assessment of EAT should become part of clinical practice to help clinicians to identify patients at greater risk of developing cardiovascular and/or metabolic diseases and to provide information on their clinical and therapeutic outcomes.

Ventricular conduction improvement after pericardial fat reduction triggered by rapid weight loss in subjects with obesity undergoing bariatric surgery

BACKGROUND

Obesity is considered a major cardiovascular risk factor. The excess of pericardial fat (PF) in patients with obesity has been associated with a variety of electrocardiographic alterations. In previous studies, we demonstrated that rapid weight loss and bariatric interventions result in decreased PF.

OBJECTIVES

The aim of this study is to report the changes in PF after bariatric surgery and its effect on ventricular conduction.

SETTING

US hospital, academic institution.

METHODS

A linear measurement of PF thickness on computed tomography scans was obtained for 81 patients, as well as a retrospective review of electrocardiographic changes before and after bariatric surgery. We compared the changes in PF thickness and electrocardiographic components before and after procedures. Common demographics and co-morbidities were collected along with lipid profiles preoperative and postoperative.

RESULTS

A total of 81 patients had electrocardiograms done before and 1 year after bariatric surgery. Females comprised 67.9% (n = 55), and the average age for our population was 55.07 ± 14.17 years. Pericardial fat thickness before surgery was 5.6 ± 1.84 and 4.5 ± 1.62 mm after surgery (P = .0001). Ventricular conduction (QT and QT corrected [QTc] intervals) showed a significant improvement from 438.7 + 29 before to 426.8 + 25.3 after bariatric surgery (P = .006). We found a statistically significant association between the decrease in PF and the decrease in QTc intervals (P = .002).

CONCLUSION

Obesity is a risk factor for arrhythmias and sudden cardiac death. Bariatric surgery and its effect on PF produce an improvement in ventricular conduction, which may reduce the ventricular electrical instability in patients with obesity.

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.

Epicardial Adipose Tissue Volume As a Marker of Subclinical Coronary Atherosclerosis in Rheumatoid Arthritis

OBJECTIVE

To assess epicardial adipose tissue volume (EATV) and its link to coronary atherosclerosis and plaque morphology in patients with rheumatoid arthritis (RA) and in age- and sex-matched controls.

METHODS

Computed tomography angiography was used to evaluate EATV and coronary plaque in 139 RA patients and 139 non-RA controls. All models assessing the effect of EATV on plaque were adjusted for age, sex, hypertension, diabetes, dyslipidemia, smoking status, family history of coronary artery disease, and obesity (body mass index of ≥30 kg/m² ). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Mean ± SD log-transformed EATV was similar in patients with RA (4.69 ± 0.36) and controls (4.70 ± 0.42). EATV was higher in RA patients with atherosclerosis compared to those without atherosclerosis (P = 0.046). In stratified analyses, EATV was associated with the number of segments with plaque in RA patients (rate ratio 1.20 [95% CI 1.01-1.41] per 1-SD increment of log-unit increase in EATV) but not in controls (P for interaction = 0.089). Likewise, EATV (per 1-SD log-unit increase) was related to the presence of multivessel or obstructive disease (OR 1.63 [95% CI 1.04-2.61]), noncalcified plaque (OR 1.78 [95% CI 1.17-2.70]), and vulnerable plaque (OR 1.77 [95% CI 1.03-3.04]) in RA patients but not in controls (P for interaction ≤ 0.048 for each). Among RA patients, EATV was associated with the number of segments with plaque in those with RA for <10 years who did not develop any cardiovascular risk factors and who were not obese (P for interaction ≤ 0.017).

CONCLUSION

Despite similar EATVs in RA patients and controls, EATVs were associated with greater plaque burden and presence of plaques with a noncalcified component and vulnerability features only in RA patients. EAT may be more pathogenic in RA and play a role in early-stage atherosclerosis. Its value as a biomarker of subclinical atherosclerosis and cardiovascular risk in RA warrants further studies.

Trunk-to-peripheral fat ratio predicts a subsequent blood pressure in normal-weight pubertal boys: a 3-year follow-up of the Kitakata Kids Health Study

BACKGROUND

Limited evidence exists regarding the relationship between central-to-peripheral fat ratio measured by dual-energy X-ray absorptiometry (DXA) and subsequent cardiometabolic risk in both pediatric and adult populations.

METHODS

The present cohort study investigated the relationship between DXA-measured body fat distribution and cardiometabolic parameters. The source population was 275 4th-6th graders (aged 9.6-12.6 years) in the northeast region of Japan (Shiokawa area in Kitakata). A 3-year follow-up was conducted to obtain complete information from 155 normal-weight children (87 boys and 68 girls). Normal-weight children were identified using sex- and age-specific international cut-offs for body mass index (BMI) based on adult BMI values of 25 kg/m² and 18.5 kg/m², respectively. Body fat distribution was assessed using the trunk-to-appendicular fat ratio (TAR) and trunk-to-leg fat ratio (TLR) measured by DXA.

RESULTS

In boys, systolic blood pressure (SBP) at follow-up showed a significant relationship with TAR at baseline after adjusting for age, height, pubic hair appearance, SBP, and whole body fat at baseline (β = 0.24, P < 0.05), and SBP also showed a significant relationship with TLR after adjusting for confounding factors including whole body fat (β = 0.25, P < 0.05). In girls, there were no significant relationships between blood pressure and TAR/TLR.

CONCLUSION

Body fat distribution in normal-weight boys predicted subsequent blood pressure levels in adolescence. The relationship between fat distribution and blood pressure was independent of fat volume.

Epicardial adipose tissue volume and annexin A2/fetuin-A signalling are linked to coronary calcification in advanced coronary artery disease: Computed tomography and proteomic biomarkers from the EPICHEART study

BACKGROUND & AIMS

The role of epicardial adipose tissue (EAT) in the pathophysiology of late stage-coronary artery disease (CAD) has not been investigated. We explored the association of EAT volume and its proteome with advanced coronary atherosclerosis.

METHODS

The EPICHEART Study prospectively enrolled 574 severe aortic stenosis patients referred to cardiac surgery. Before surgery, EAT volume was quantified by computed tomography (CT). During surgery, epicardial, mediastinal (MAT) and subcutaneous (SAT) adipose tissue samples were collected to explore fat phenotype by analyzing the proteomic profile using SWATH-mass spectrometry; pericardial fluid and peripheral venous blood were also collected. CAD presence was defined as coronary artery stenosis ≥50% in invasive angiography and by CT-derived Agatston coronary calcium score (CCS).

RESULTS

EAT volume adjusted for body fat was associated with higher CCS, but not with the presence of coronary stenosis. In comparison with mediastinal and subcutaneous fat depots, EAT exhibited a pro-calcifying proteomic profile in patients with CAD characterized by upregulation of annexin-A2 and downregulation of fetuin-A; annexin-A2 protein levels in EAT samples were also positively correlated with CCS. We confirmed that the annexin-A2 gene was overexpressed in EAT samples of CAD patients and positively correlated with CCS. Fetuin-A gene was not detected in EAT samples, but systemic fetuin-A was higher in CAD than in non-CAD patients, suggesting that fetuin-A was locally downregulated.

CONCLUSIONS

In an elderly cohort of stable patients, CCS was associated with EAT volume and annexin-A2/fetuin-A signaling, suggesting that EAT might orchestrate pro-calcifying conditions in the late phases of CAD.

Epicardial adipose thickness in youth with type 1 diabetes

BACKGROUND AND OBJECTIVE

Epicardial adipose thickness (EAT) is increased in adults with type 1 diabetes (T1D) and is thought to contribute to cardiovascular disease (CVD) in this population. Given that CVD risk factors emerge early in life, the purpose of this study was to identify whether EAT is increased in pediatric patients with T1D compared with non-diabetic controls.

METHODS

Anthropometric data, blood pressure (BP), and EAT were evaluated in 20 youth with T1D and 20 age, sex, and body mass index (BMI) matched healthy controls between the ages of 5 and 18 years.

RESULTS

EAT was 18.5% higher among youth with T1D compared to healthy controls (1.65 ± 0.44 mm vs 1.37 ± 0.27 mm, P = .02). In the entire cohort, EAT was correlated with age (r = 0.71, P < .001), BMI (r = .69, P < .001), waist circumference (r = 0.60, P < .001), systolic BP (r = .34, P = .03), and diastolic BP (r = 0.41, P = .009). Among youth with T1D, there were no significant correlations between EAT and HbA1c (r = -0.16, P = .50), insulin dose (r = .09, P = .71), or duration of disease (r = 0.06, P = .82).

CONCLUSIONS

Youth with T1D exhibited significantly higher EAT compared to controls. Increased EAT was associated with adiposity and BP, but not duration of disease, insulin dose, or glycemic control. Increased EAT may represent a pathophysiologic mechanism leading to premature CVD in pediatric patients with T1D.

Epicardial Adipose Tissue and Renal Disease

Epicardial adipose tissue (EAT) is derived from splanchnic mesoderm, localized anatomically between the myocardium and pericardial visceral layer, and surrounds the coronary arteries. Being a metabolically active organ, EAT secretes numerous cytokines, which moderate cardiovascular morphology and function. Through its paracrine and vasocrine secretions, EAT may play a prominent role in modulating cardiac function. EAT protects the heart in normal physiological conditions by secreting a variety of adipokines with anti-atherosclerotic properties, and in contrast, secretes inflammatory molecules in pathologic conditions that may play a dynamic role in the pathogenesis of cardiovascular diseases by promoting atherosclerosis. Considerable research has been focused on comparing the anatomical and biochemical features of EAT in healthy people, and a variety of disease conditions such as cardiovascular diseases and renal diseases. The global cardiovascular morbidity and mortality in renal disease are high, and there is a paucity of concrete evidence and societal guidelines to detect early cardiovascular disease (CVD) in this group of patients. Here we performed a clinical review on the existing evidence and knowledge on EAT in patients with renal disease, to evaluate its application as a reliable, early, noninvasive biomarker and indicator for CVD, and to assess its significance in cardiovascular risk stratification.

Correlation between coronary atherosclerosis calcification and epicardial adipose tissue volume in patients with nephropathy

Correlation between coronary atherosclerosis calcification and epicardial adipose tissue (EAT) volume in patients with nephropathy was investigated. A total of 529 patients with high risk of coronary atherosclerotic nephropathy were selected from August 2013 to September 2016 in Xianyang Central Hospital to serve as research subjects, and their clinical data were retrospectively analyzed. All patients underwent coronary artery and EAT examination using dual-source CT. Correlation between EAT and severity of coronary atherosclerosis, calcification, lesions, and BMI were analyzed. Volume of EAT in patients with atherosclerosis was significantly higher than that in patients without atherosclerosis (p<0.05). EAT volume was positively correlated with BMI (r=0.61, p<0.05), calcification scores (r=0.72, p<0.05) and the number of coronary artery lesions (r=0.64, p<0.05) in patients with nephropathy. Coronary atherosclerosis calcification score, number of lesions and BMI are positively correlated with the EAT volume in patients with nephropathy. Detection of EAT volume may serve as a predictor of the occurrence and develop-ment of coronary atherosclerosis in the future.

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.

Association of Epicardial, Visceral, and Subcutaneous Fat With Cardiometabolic Diseases

BACKGROUND

Excess of visceral fat is a central factor in the pathogenesis of metabolic syndrome (MetS) and atherosclerosis. However, little is known about how much epicardial fat affects cardiometabolic disorders in comparison with visceral or subcutaneous fat.Methods and Results:Participants suspected as having angina pectoris underwent cardiac computed tomography (CT) imaging. Of them, 374 subjects were analyzed the association of clinical characteristics and CT-based fat distribution measured as epicardial fat volume (EFV), visceral fat area (VFA), and subcutaneous fat area (SFA). EFV was highly associated with VFA (R=0.58). Serum adiponectin was significantly decreased in high VFA subjects (VFA ≥100 cm²) and was also reduced in the high EFV group (EFV ≥80 cm³). Among the low VFA groups, the numbers of subjects with diabetes and coronary atherosclerosis were increased in high EFV group. Among the low EFV groups, the numbers of subjects with diabetes, hyperuricemia, and coronary atherosclerosis were increased among the high VFA subjects. In an age-, sex-, and body mass index (BMI)-adjusted model, EFV was associated with dyslipidemia and MetS, and VFA was significantly associated with hypertension, dyslipidemia, MetS, and coronary atherosclerosis, while SFA was not related with coronary risks and atherosclerosis.

CONCLUSIONS

Epicardial fat accumulation may be a risk for coronary atherosclerosis in subjects without visceral fat accumulation. Visceral fat is the strongest risk for cardiometabolic diseases among the 3 types of fat depot.

Relationship of Echocardiographic Epicardial Fat Thickness and Epicardial Fat Volume by Computed Tomography with Coronary Artery Calcification: Data from the CAESAR Study

BACKGROUND AND AIMS

No study has assessed the association between echocardiographic epicardial fat thickness (EFT) and computed tomography (CT)-based epicardial fat volume (EFV) and coronary artery calcification. The aim of this study is to evaluate the association between EFT and EFV and coronary artery calcification.

METHODS

Among the 2,299 individuals enrolled in the CArdiometabolic risk, Epicardial fat, and Subclinical Atherosclerosis Registry (CAESAR) study, 2,276 (1,851 men; mean age 45 ± 8.9 years) who underwent echocardiographic EFT and CT-based EFV measurements and obtained a coronary artery calcium score (CACS) were included in this study.

RESULTS

The overall prevalence of CAC >0 was 19.3%. EFT was significantly correlated with EFV (r = 0.374, p <0.001) but the k statistic showed only slight agreement (k = 0.146, p <0.001). Multivariate regression analyses adjusted for age, sex, body mass index, waist circumference, systolic blood pressure, daily alcohol intake, smoking status, and vigorous exercise and glucose, blood urea nitrogen, uric acid, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high-sensitivity C reactive protein, and hemoglobinA1c levels revealed that an increase in the absolute values of EFT and EFV was significantly associated with the presence of coronary artery calcium (ORs [95% CIs], 2.023 [1.282-3.193] and 1.785 [1.173-2.716], respectively) and CACS (standardized β values = 0.082 and 0.061, p = 0.001 and 0.042, respectively).

CONCLUSION

These results show that EFT and EFV are associated with coronary artery calcification in Korean adults despite the relatively weak correlation between EFT and EFV.

Role of Adipokines in Cardiovascular Disease

Cardiovascular disease (CVD) is the greatest cause of death, accounting for nearly one-third of all deaths worldwide. The increase in obesity rates over 3 decades is widespread and threatens the public health in both developed and developing countries. Obesity, the excessive accumulation of visceral fat, causes the clustering of metabolic disorders, such as type 2 diabetes, dyslipidemia, and hypertension, culminating in the development of CVD. Adipose tissue is not only an energy storage organ, but an active endocrine tissue producing various biologically active proteins known as adipokines. Since leptin, a central regulator of food intake and energy expenditure, was demonstrated to be an adipose-specific adipokine, attention has focused on the identification and characterization of unknown adipokines to clarify the mechanisms underlying obesity-related disorders. Numerous adipokines have been identified in the past 2 decades; most adipokines are upregulated in the obese state. Adipokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and resistin are pro-inflammatory, and exacerbate various metabolic and cardiovascular diseases. However, a small number of adipokines, including adiponectin, are decreased by obesity, and generally exhibit antiinflammatory properties and protective functions against obesity-related diseases. Collectively, an imbalance in the production of pro- and antiinflammatory adipokines in the obese condition results in multiple complications. In this review, we focus on the pathophysiologic roles of adipokines with cardiovascular protective properties.

Impact of the cardiovascular system-associated adipose tissue on atherosclerotic pathology

Cardiac obesity makes an important contribution to the pathogenesis of cardiovascular disease. One of the important pathways of this contribution is the inflammatory process that takes place in the adipose tissue. In this review, we consider the role of the cardiovascular system-associated fat in atherosclerotic cardiovascular pathology and a non-atherosclerotic cause of coronary artery disease, such as atrial fibrillation. Cardiovascular system-associated fat not only serves as the energy store, but also releases adipokines that control local and systemic metabolism, heart/vascular function and vessel tone, and a number of vasodilating and anti-inflammatory substances. Adipokine appears to play an important protective role in cardiovascular system. Under chronic inflammation conditions, the repertoire of signaling molecules secreted by cardiac fat can be altered, leading to a higher amount of pro-inflammatory messengers, vasoconstrictors, profibrotic modulators. This further aggravates cardiovascular inflammation and leads to hypertension, induction of the pathological tissue remodeling and cardiac fibrosis. Contemporary imaging techniques showed that epicardial fat thickness correlates with the visceral fat mass, which is an established risk factor and predictor of cardiovascular disease in obese subjects. However, this correlation is no longer present after adjustment for other covariates. Nevertheless, recent studies showed that pericardial fat volume and epicardial fat thickness can probably serve as a better indicator for atrial fibrillation.

Epicardial Adipose Tissue Contributes to the Development of Non-Calcified Coronary Plaque: A 5-Year Computed Tomography Follow-up Study

Aim: Epicardial adipose tissue (EAT) has been suggested as a contributing factor for coronary atherosclerosis based on the previous cross-sectional studies and pathophysiologic background. However, a causal relationship between EAT and the development of non-calcified coronary plaque (NCP) has not been investigated.

Methods: A total of 122 asymptomatic individuals (age, 56.0 ± 7.6 years; male, 80.3%) without prior history of coronary artery disease (CAD) or metabolic syndrome and without NCP or obstructive CAD at baseline cardiac computed tomography (CT) were enrolled. Repeat cardiac CT was performed with an interval of more than 5 years. Epicardial fat volume index (EFVi; cm³/m²) was assessed in relation to the development of NCP on the follow-up CT where the results were classified into “calcified plaque (CP),” “no plaque,” and “NCP” groups.

Results: On the follow-up CT performed with a median interval of 65.4 months, we observed newly developed NCP in 24 (19.7%) participants. Baseline EFVi was significantly higher in the NCP group (79.9 ± 30.3 cm³/m²) than in the CP group (63.7 ± 22.7 cm³/m²; P = 0.019) and in the no plaque group (62.5 ± 24.7 cm³/m²; P = 0.021). Multivariable logistic regression analysis demonstrated that the presence of diabetes (OR, 9.081; 95% CI, 1.682–49.034; P = 0.010) and the 3rd tertile of EFVi (OR, 4.297; 95% CI, 1.040–17.757; P = 0.044 compared to the 1st tertile) were the significant predictors for the development of NCP on follow-up CT.

Conclusions: Greater amount of EAT at baseline CT independently predicts the development of NCP in asymptomatic individuals.

Identifying Small Coronary Calcification in Non-Contrast 0.5-mm Slice Reconstruction to Diagnose Coronary Artery Disease in Patients with a Conventional Zero Coronary Artery Calcium Score

Aims: In a new-generation computed tomography (CT) scanner, coronary artery calcium (CAC) scores were measured using 3.0-mm slice reconstruction images originally acquired with 0.5 mm thickness scans in a single beat. This study investigated the usefulness of thin-slice (0.5 mm) reconstruction for identifying small calcifications in coronary arteries and evaluated the association with coronary plaques and stenosis compared to conventional 3.0-mm reconstruction images.

Methods: We evaluated 132 patients with zero CAC scores in conventional 3.0-mm Agatston method using a 320-slice CT. Then, 0.5-mm slice reconstruction was performed to identify small calcifications. The presence of stenosis and coronary plaques was assessed using coronary CT angiography.

Results: In total, 22 small calcifications were identified in 18 patients. There were 28 (21%) patients with any (≥ 25%) stenosis (34 lesions). Forty-seven coronary plaques were found in 33 patients (25%), including 7 calcified plaques in 7 patients (5%), 34 noncalcified plaques in 27 patients (20%), and 6 partially calcified plaques in 5 patients (4%). Patients with small calcifications had a significantly higher prevalence of noncalcified or partially calcified plaques (83% vs 14%; p < 0.001) and obstructive stenosis (33% vs 5.2%; p < 0.001) compared to those without small calcifications. The addition of small calcifications to the coronary risk factors when diagnosing stenosis significantly improved the diagnostic value.

Conclusion: Small calcifications detected by thin-slice 0.5-mm reconstruction are useful for distinguishing coronary atherosclerotic lesions in patients with zero CAC scores from conventional CT reconstruction.

Epicardial Adipose Tissue Is Associated with Plaque Burden and Composition and Provides Incremental Value for the Prediction of Cardiac Outcome. A Clinical Cardiac Computed Tomography Angiography Study

Objectives

We sought to investigate the association of epicardial adipose tissue (eCAT) volume with plaque burden, circulating biomarkers and cardiac outcomes in patients with intermediate risk for coronary artery disease (CAD).

Methods and Results

177 consecutive outpatients at intermediate risk for CAD and completed biomarker analysis including high-sensitive Troponin T (hs-TnT) and hs-CRP underwent 256-slice cardiac computed tomography angiography (CCTA) between June 2008 and October 2011. Patients with lumen narrowing ≥50% exhibited significantly higher eCAT volume than patients without any CAD or lumen narrowing <50% (median (interquartile range, IQR): 108 (73–167) cm³ vs. 119 (82–196) cm³, p = 0.04). Multivariate regression analysis demonstrated an independent association eCAT volume with plaque burden by number of lesions (R² = 0.22, r_partial = 0.29, p = 0.026) and CAD severity by lumen narrowing (R² = 0.22, r_partial = 0.23, p = 0.038) after adjustment for age, diabetes mellitus, hyperlidipemia, body-mass-index (BMI), hs-CRP and hs-TnT. Univariate Cox proportional hazards regression analysis identified a significant association for both increased eCAT volume and maximal lumen narrowing with all cardiac events. Multivariate Cox proportional hazards regression analysis revealed an independent association of increased eCAT volume with all cardiac events after adjustment for age, >3 risk factors, presence of CAD, hs-CRP and hs-TnT.

Conclusion

Epicardial adipose tissue volume is independently associated with plaque burden and maximum luminal narrowing by CCTA and may serve as an independent predictor for cardiac outcomes in patients at intermediate risk for CAD.

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.

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.