Epicardial Fat Tissue Thickness Correlates with Endothelial Dysfunction and Other Cardiovascular Risk Factors in Patients with Metabolic Syndrome

Diverging role of epicardial adipose tissue across the entire heart failure spectrum

AIMS

Epicardial adipose tissue (EAT) is a metabolically highly active tissue modulating numerous pathophysiological processes. The aim of this study was to investigate the association between EAT thickness and endothelial function in patients with heart failure (HF) across the entire ejection fraction spectrum.

METHODS AND RESULTS

A total of 258 patients with HF with an ejection fraction across the entire spectrum [HF with reduced ejection fraction (HFrEF), n = 168, age 60.6 ± 11.2 years; HF with preserved ejection fraction (HFpEF), n = 50, mean age 65.1 ± 11.9 years; HF with mildly reduced ejection fraction (HFmrEF), n = 32, mean age 65 ± 12] were included. EAT was measured with transthoracic echocardiography. Vascular function was assessed with flicker-light-induced vasodilation of retinal arterioles (FIDart%) and flow-mediated dilatation (FMD%) in conduit arteries. Patients with HFrEF have less EAT compared with patients with HFpEF (4.2 ± 2 vs. 5.3 ± 2 mm, respectively, P < 0.001). Interestingly, EAT was significantly associated with impaired microvascular function (FIDart%; r = -0.213, P = 0.012) and FMD% (r = -0.186, P = 0.022), even after multivariate correction for confounding factors (age, body mass index, hypertension, and diabetes; standardized regression coefficient (SRC) = -0.184, P = 0.049 for FIDart% and SRC = -0.178, P = 0.043 for FMD%) in HFrEF but not in HFpEF.

CONCLUSIONS

Although less EAT is present in HFrEF than in HFpEF, only in HFrEF EAT is associated with vascular dysfunction. The diverging role of EAT in HF and its switch to a functionally deleterious tissue promoting HF progression provide the rationale to specifically target EAT, in particular in patients with reduced ejection fraction.

Exploring the Associations Between Non-Traditional Lipid Parameters and Epicardial Adipose Tissue Volume

The aim of this retrospective study was to determine the relationship between non-traditional lipid parameters and epicardial adipose tissue (EAT). A total of 770 patients with coronary computed tomography angiography examinations were included. The non-traditional lipid parameters included the atherogenic index of plasma (AIP), the atherogenic coefficient (AC), monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR), and lipoprotein combined index (LCI). To investigate the association between non-conventional lipid markers and the EAT-volume (EAT-v), a univariate and multivariate analyses were conducted. The receiver operating characteristic (ROC) analysis was used to compare the predictive ability among the four non-traditional lipid parameters. In the univariate analysis, we identified factors that might have effects on EAT-v (all P<.05) and adjusted for these in the multivariate analysis. We found that except for MHR, other non-traditional lipid parameters were still associated with high EAT-v after adjustment (all P<.05). In the ROC analysis, the area under the curve (AUC) of AIP was greater than that of other non-traditional lipid parameters and lipid profiles. There was an association between both non-traditional lipid parameters and EAT-v. After adjustment, the AIP remained an independent predictor of EAT-v and it outperformed other non-traditional lipid parameters.

The Different Pathways of Epicardial Adipose Tissue across the Heart Failure Phenotypes: From Pathophysiology to Therapeutic Target

Epicardial adipose tissue (EAT) is an endocrine and paracrine organ constituted by a layer of adipose tissue directly located between the myocardium and visceral pericardium. Under physiological conditions, EAT exerts protective effects of brown-like fat characteristics, metabolizing excess fatty acids, and secreting anti-inflammatory and anti-fibrotic cytokines. In certain pathological conditions, EAT acquires a proatherogenic transcriptional profile resulting in increased synthesis of biologically active adipocytokines with proinflammatory properties, promoting oxidative stress, and finally causing endothelial damage. The role of EAT in heart failure (HF) has been mainly limited to HF with preserved ejection fraction (HFpEF) and related to the HFpEF obese phenotype. In HFpEF, EAT seems to acquire a proinflammatory profile and higher EAT values have been related to worse outcomes. Less data are available about the role of EAT in HF with reduced ejection fraction (HFrEF). Conversely, in HFrEF, EAT seems to play a nutritive role and lower values may correspond to the expression of a catabolic, adverse phenotype. As of now, there is evidence that the beneficial systemic cardiovascular effects of sodium-glucose cotransporter-2 receptors-inhibitors (SGLT2-i) might be partially mediated by inducing favorable modifications on EAT. As such, EAT may represent a promising target organ for the development of new drugs to improve cardiovascular prognosis. Thus, an approach based on detailed phenotyping of cardiac structural alterations and distinctive biomolecular pathways may change the current scenario, leading towards a precision medicine model with specific therapeutic targets considering different individual profiles. The aim of this review is to summarize the current knowledge about the biomolecular pathway of EAT in HF across the whole spectrum of ejection fraction, and to describe the potential of EAT as a therapeutic target in HF.

Both epicardial and peri-aortic adipose tissue blunt heart rate recovery beyond body fat mass

Background

Epicardial adipose tissue (EAT) as a marker of metabolic disorders has been shown to be closely associated with a variety of unfavorable cardiovascular events and cardiac arrhythmias. Data on regional-specific visceral adiposity outside the heart and its modulation on autonomic dysfunction, particularly heart rate recovery after exercise, remain obscure.

Methods

We studied 156 consecutive subjects (mean age: 49.3 ± 8.0 years) who underwent annual health surveys and completed treadmill tests. Multi-detector computed tomography-based visceral adiposity, including EAT and peri-aortic fat (PAF) tissue, was quantified using dedicated software (Aquarius 3D Workstation, TeraRecon, San Mateo, CA, USA). We further correlated EAT and PAF with blood pressure and heart rate (HR) recovery information from an exercise treadmill test. Metabolic abnormalities were scored by anthropometrics in combination with biochemical data.

Results

Increased EAT and PAF were both associated with a smaller reduction in systolic blood pressure during the hyperventilation stage before exercise compared to supine status (β-coefficient (coef.): −0.19 and −0.23, respectively, both p < 0.05). Both visceral adipose tissue mediated an inverted relationship with heart rate recovery at 3 (EAT: β-coef.: −0.3; PAF: β-coef.: −0.36) and 6 min (EAT: β-coef.: −0.32; PAF: β-coef.: −0.34) after peak exercise, even after adjusting for baseline clinical variables and body fat composition (all p < 0.05).

Conclusion

Excessive visceral adiposity, whether proximal or distal to the heart, may modulate the autonomic response by lowering the rate of HR recovery from exercise after accounting for clinical metabolic index. Cardiac autonomic dysfunction may partly explain the increase in cardiovascular morbidity and mortality related to both visceral fats.

Increased epicardial adipose tissue thickness correlates with endothelial dysfunction in spondyloarthritis

INTRODUCTION

We aimed to investigate the relationship between epicardial adipose tissue (EAT) thickness, flow-mediated dilation (FMD), and carotid intima-media thickness (cIMT) in spondyloarthritis (SpA) patients compared to healthy controls.

METHODS

We performed a cross-sectional study including SpA patients aged ≤ 50 years without traditional cardiovascular risk factors and healthy controls matched for age and gender. Baseline characteristics, laboratory data, and SpA-related parameters were recorded. All participants underwent ultrasound examination with measurement of EAT thickness, FMD, and cIMT by both an experienced cardiologist and radiologist blinded to clinical data. The relationships between the ultrasound measurements were analyzed using Spearman's correlation coefficient and Person correlation.

RESULTS

The study included 94 subjects (47 SpA and 47 healthy controls). The sex-ratio was 2.35; the median age of patients was 36 years (IQR: 28-46), and the median disease duration was 11 years (IQR: 5-16). Compared to the control group, SpA patients had significantly higher values of EAT thickness (p = 0.001) and cIMT (p < 0.0001). FMD values were significantly lower in SpA patients compared to controls (p = 0.008). The univariate analysis detected a significant negative association between EAT thickness and FMD (p = 0.026; r =  - 0.325), and between left cIMT and FMD (p = 0.027; r =  - 0.322). No association was found between EAT thickness and cIMT.

CONCLUSION

EAT thickness, FMD, and cIMT were significantly impaired in SpA patients compared with healthy controls supporting evidence of accelerated atherosclerosis in SpA. EAT thickness was correlated to endothelial dysfunction suggesting the role of EAT in predicting the early reversible stages of atherosclerosis. Key Points • Spondyloarthritis is associated with impaired subclinical atherosclerosis markers accurately increased epicardial fat and carotid intima-media thickness and endothelial dysfunction. • Increased epicardial fat thickness is correlated with impaired endothelial function in spondyloarthritis patients.

The Relationship of Epicardial Adipose Tissue and Cardiovascular Disease in Chronic Kidney Disease and Hemodialysis Patients

Cardiovascular diseases remain the most common cause of morbidity and mortality in chronic kidney disease patients undergoing hemodialysis. Epicardial adipose tissue (EAT), visceral fat depot of the heart, was found to be associated with coronary artery disease in cardiac and non-cardiac patients. Additionally, EAT has been proposed as a novel cardiovascular risk in the general population and in end-stage renal disease patients. It has also been shown that EAT, more than other subcutaneous adipose tissue deposits, acts as a highly active organ producing several bioactive adipokines, and proinflammatory and proatherogenic cytokines. Therefore, increased visceral adiposity is associated with proinflammatory activity, impaired insulin sensitivity, increased risk of atherosclerosis, and high morbidity and mortality in hemodialysis patients. In the present review, we aimed to demonstrate the role of EAT in the pathophysiological mechanisms of increased cardiovascular morbidity and mortality in hemodialysis patients.

Epicardial Adipose Tissue and Outcome in Heart Failure With Mid-Range and Preserved Ejection Fraction

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Epicardial adipose tissue (EAT) accumulation is thought to play a role in the pathophysiology of heart failure (HF) with mid-range and preserved ejection fraction, but its effect on outcome is unknown. We evaluated the prognostic value of EAT volume measured with cardiac magnetic resonance in patients with HF with mid-range ejection fraction and HF with preserved ejection fraction.

The role of inflammation and metabolic risk factors in the pathogenesis of calcific aortic valve stenosis

Given the epidemiologic increase of aged population in the world, aortic stenosis (AS) represents now the most common valvular heart disease in industrialized countries. It is a very challenging disease, representing an important cause of morbidity, hospitalization and death in the elderly population. It is widely recognized that AS is the result of a very complex active process, driven by inflammation and involving multifactorial pathological mechanisms promoting valvular calcification and valvular bone deposition. Several evidence suggest that epicardial adipose tissue (EAT), the visceral fat depot of the heart, represents a direct source of cytokines and could mediate the deleterious effects of systemic inflammation on the myocardium. Importantly, obesity and metabolic disorders are associated with chronic systemic inflammation leading to a significant increase of EAT amount and to a pro-inflammatory phenotypic shift of this fat depot. It has been hypothesized that the EAT inflammatory state can influence the structure and function of the heart, thus contributing to the pathogenesis of several cardiac diseases, including calcific AS. The current review will discuss the recently discovered mechanisms involved in the pathogenesis of AS, with particular attention to the role of inflammation, metabolic risk factors and pro-fibrotic and pro-osteogenic signal pathways promoting the onset and progression of the disease. Moreover, it will be explored the potential role of EAT in the AS pathophysiology.

The relation between epicardial fat tissue thickness and atrial fibrillation ın hemodialysis patients

The prevalence of arrhythmia has increased in hemodialysis (HD) patients and the most frequent is atrial fibrillation (AF). It was reported that the amount of epicardial fat tissue (EFT) in the population without renal disease is closely related to AF. In the present study of ours, the relation between EFT thickness and AF was examined in HD patients. A total of 79 patients who underwent HD for periods longer than 3 months were included in the study. The mean age of the patients was 53.6 ± 15.2 years and 50.6% were male. The mean EFT thicknesses were measured as 7.2 ± 2.3 mm (3-12). A positive correlation was found between the EFT thickness and age, C-reactive protein, and left ventricle rear wall thickness. AF was found in 18 (22.8%) patients in the Holter ECG examination. When the group with AF was compared with the non-AF group; although the mean HD duration of the group with AF was longer, there were no significant differences in terms of epicardial adipose tissue thickness and other parameters. In the present study, no relations were found between EFT thickness and AF frequency in HD patients. Further studies with a larger number of the patient population are needed in this regard.

BMPER is upregulated in obesity and seems to have a role in pericardial adipose stem cells

Pericardial adipose tissue (PAT), a visceral fat depot enveloping the heart, is an active endocrine organ and a source of free fatty acids and inflammatory cytokines. As in other fat adult tissues, PAT contains a population of adipose stem cells; however, whether these cells and/or their environment play a role in physiopathology is unknown. We analyzed several stem cell-related properties of pericardial adipose stem cells (PSCs) isolated from obese and ex-obese mice. We also performed RNA-sequencing to profile the transcriptional landscape of PSCs isolated from the different diet regimens. Finally, we tested whether these alterations impacted on the properties of cardiac mesoangioblasts isolated from the same mice. We found functional differences between PSCs depending on their source: specifically, PSCs from obese PSC (oPSC) and ex-obese PSC (dPSC) mice showed alterations in apoptosis and migratory capacity when compared with lean, control PSCs, with increased apoptosis in oPSCs and blunted migratory capacity in oPSCs and dPSCs. This was accompanied by different gene expression profiles across the cell types, where we identified some genes altered in obese conditions, such as BMP endothelial cell precursor-derived regulator (BMPER), an important regulator of BMP-related signaling pathways for endothelial cell function. The importance of BMPER in PSCs was confirmed by loss- and gain-of-function studies. Finally, we found an altered production of BMPER and some important chemokines in cardiac mesoangioblasts in obese conditions. Our findings point to BMPER as a potential new regulator of PSC function and suggest that its dysregulation could be associated with obesity and may impact on cardiac cells.

The Cutoff Pericardial Adipose Tissue Volume Associated with Metabolic Syndrome

Background

Metabolic syndrome (MS) is a well-known risk factor of cardiovascular diseases that is focused on central obesity. Recent studies have reported the association between pericardial adipose tissue (PAT) volume and MS. However, no studies have demonstrated the cutoff PAT volume that represents the best association with MS.

Methods

The data of 374 subjects were analyzed cross-sectionally to compare PAT, measured on coronary multidetector computed tomography, and various metabolic parameters according to MS. After PAT volumes were divided into tertiles, various metabolic parameters were compared among tertiles; furthermore, the odds ratio for developing MS was calculated. Finally, we demonstrated the cutoff PAT volume that represented the best association with MS by using the receiver-operating characteristic curve.

Results

We found that 27.5% of the subjects had MS, and the mean PAT volume was 123.9 cm³. PAT showed a significant positive correlation with body mass index, waist circumference, and levels of glucose, triglyceride, high-sensitivity C-reactive protein, uric acid, and homocysteine, but a negative correlation with high-density lipoprotein cholesterol. Furthermore, after dividing into tertiles, PAT volume was also significantly associated with various metabolic parameters. The odds ratio for having MS was 4.19 (95% confidence interval, 2.27–7.74) in the top tertile of PAT volumes after adjusting for age, sex, and smoking. The cutoff PAT volume that represented the best association with MS was 142.2 cm³.

Conclusion

PAT was significantly associated with MS and various metabolic parameters. The cutoff PAT volume of 142.2 cm³ showed the best association with MS.

Epicardial Adipose Tissue May Mediate Deleterious Effects of Obesity and Inflammation on the Myocardium

Epicardial adipose tissue has unique properties that distinguish it from other depots of visceral fat. Rather than having distinct boundaries, the epicardium shares an unobstructed microcirculation with the underlying myocardium, and in healthy conditions, produces cytokines that nourish the heart. However, in chronic inflammatory disorders (especially those leading to heart failure with preserved ejection fraction), the epicardium becomes a site of deranged adipogenesis, leading to the secretion of proinflammatory adipokines that can cause atrial and ventricular fibrosis. Accordingly, in patients at risk of heart failure with preserved ejection fraction, drugs that promote the accumulation or inflammation of epicardial adipocytes may lead to heart failure, whereas treatments that ameliorate the proinflammatory characteristics of epicardial fat may reduce the risk of heart failure. These observations suggest that epicardial adipose tissue is a transducer of the adverse effects of systemic inflammation and metabolic disorders on the heart, and thus, represents an important target for therapeutic interventions.

Omentin treatment of epicardial fat improves its anti-inflammatory activity and paracrine benefit on smooth muscle cells

OBJECTIVE

Epicardial adipose tissue (EAT) in coronary artery disease is insulin resistant and has a proinflammatory profile. This study examined the regulation of EAT by exogenous omentin and its consequence on vascular cells.

METHODS

Stromal vascular cells (SC) of EAT and subcutaneous adipose tissue (SAT) from patients who underwent heart surgery were cultured and exposed to adipogenic factors with or without omentin. Proinflammatory cytokine regulation by omentin was analyzed in SC and mature adipocytes. Glucose uptake by EAT and SAT explants was determined after insulin, omentin, or combined treatment. Human vascular cells were exposed to secretomes of SC, with and without omentin treatment. Migration of smooth muscle cells and expression of adhesion molecules were determined by wound healing or real-time polymerase chain reaction, respectively.

RESULTS

Omentin treatment raised adipogenesis-induced adiponectin levels on SC of EAT and reduced TNF-α expression levels (0.58 ± 0.14-fold change; P = 0.034) in mature adipocytes. Omentin improved the insulin activity of EAT and SAT explants from cardiovascular disease patients. Finally, secretomes of SC under omentin treatment reduced the migration of smooth muscle cells.

CONCLUSIONS

Exogenous omentin might support a cardioprotective role through its effect on EAT regarding glucose uptake, anti-inflammatory response, and its paracrine role on smooth muscle cells.

Possitive correlation between adipocyte fatty acid-binding protein and epicardial fat in patients with a family history of cardiovascular disesase

BACKGROUND

Adipocyte fatty acid-binding protein (A-FABP) is a promising link between metabolic syndrome and atherosclerosis. Epicardial fat (EPI) is an independent risk factor for cardiovascular disease (CVD).

OBJECTIVE

The aim of this pilot study was to evaluate the correlation between EPI and A-FABP in asymptomatic patients with a family history of CVD.

METHODS

59 subjects (39 males) (median = 54 years old) were enrolled in the study and their EPI thickness and A-FABP levels were assessed.

RESULTS

EPI was found in 46 patients (77.9%). There were positive correlations between EPI and A-FABP (r=0.336; P=0.010), age (r=0.526; P<0.001), fibrinogen (r=0.304; P=0.023) and systolic blood pressure (r=0.279; P=0.034). A positive correlation was found between EPI and A-FABP in a subgroup of overweight and obese patients (0.389; P=0.041, 0.407; P=0.004) and in the subgroup of patients with excluded CVD (r=0.368; P=0.006).

CONCLUSIONS

We found a positive correlation between EPI and A-FABP in a group of patients with a family history of CVD and in subgroups of overweight and obese patients.

Association between echocardiographic epicardial fat thickness and circulating endothelial progenitor cell level in patients with stable angina pectoris

BACKGROUND

Epicardial adipose tissue is associated with coronary artery disease (CAD). Circulating endothelial progenitor cell (EPC) level represents a marker of endothelial dysfunction and vascular health. However, the relationship between epicardial fat and circulating EPC remains unknown. This study aimed to investigate association between echocardiographic epicardial fat thickness (EFT) and circulating EPC level.

HYPOTHESIS

Epicardial fat causes inflammation and contributes to progression of CAD.

METHODS

We enrolled 213 consecutive patients with stable angina, and EFT was determined by echocardiography. Quantification of EPC markers (defined as CD34 ⁺ , CD34 ⁺ KDR ⁺ , CD34 ⁺ KDR ⁺ CD133 ⁺ cells) in peripheral blood samples was used to measure circulating EPCs. All patients were divided into 3 tertiles according to EFT levels: group 1, low tertile of EFT; group 2, middle tertile of EFT; and group 3, high tertile of EFT.

RESULTS

Among the 3 groups, CAD disease severity determined by SXscore was negatively correlated with EFT, but the difference did not reach statistical significance (P = 0.066). Additionally, patients in the high and middle tertiles of EFT had higher circulating EPC levels than did those in the low tertile of EFT (P = 0.001 and P < 0.001, respectively). In multivariate analysis, EPC level was significantly associated with echocardiographic EFT (standardized β = -0.233, P = 0.001), independent of multiple covariates.

CONCLUSIONS

Epicardial adipose tissue is associated with circulating EPC levels. There was a trend between epicardial fat and severity of CAD, though analysis did not reach statistical significance, and this may be attributed to the interaction between several risk factors of CAD.

Sexual dimorphism in obesity-related genes in the epicardial fat during aging

Aging increases the risk of cardiovascular disease and metabolic syndrome. Alterations in epicardial fat play an important pathophysiological role in coronary artery disease and hypertension. We investigated the impact of normal aging on obesity-related genes in epicardial fat. Sex-specific changes in obesity-related genes with aging in epicardial fat (EF) were determined in young (6 months) and old (30/36 months) female and male, Fischer 344 × Brown Norway hybrid (FBN) rats, using a rat obesity RT² PCR Array. Circulating sex hormone levels, body and heart weights were determined. Statistical significance was determined using two-tailed Student's t test and Pearson's correlation. Our results revealed sex-specific differences in obesity-related genes with aging. Dramatic changes in the expression profile of obesity-related genes in EF with aging in female, but not in male, FBN rats were observed. The older (30 months) female rats had more significant variations in the abundance of obesity-related genes in the EF compared to that seen in younger female rats or both age groups in male rats. A correlation of changes in obesity-related genes in EF to heart weights was observed in female rats, but not in male rats with aging. No correlation was observed to circulating sex hormone levels. Our findings indicate a dysfunctional EF in female rats with aging compared to male rats. These findings, with further functional validation, might help explain the sex differences in cardiovascular risk and mortality associated with aging observed in humans.

Assessment of epicardial adipose tissue and carotid/femoral intima media thickness in insulin resistance

BACKGROUND

Metabolic syndrome is a combination of multiple cardiovascular (CV) risk factors including insulin resistance (IR). Carotid, femoral intima media thickness (IMT), and epicardial fat thickness (EFT) are considered as novel cardiometabolic risk factors. We aimed to test the hypothesis that carotid, femoral IMT, and EFT are increased in patients with IR.

METHODS

We enrolled consecutively and prospectively 113 patients with IR. Then we collected data from an age- and sex-matched control group of 112 individuals without IR. Homeostasis model assessment (HOMA) index value >2.5 was accepted as IR. Patients with diabetes mellitus, CV diseases, systolic heart failure, chronic liver or renal diseases were excluded. On B-mode duplex ultrasound the mean IMT at the far wall of both left and right common carotid/femoral arteries were measured manually. EFT was measured on the free wall of the right ventricle at end-diastole from the parasternal long-axis views by standard transthoracic 2D echocardiography.

RESULTS

Both carotid IMT and EFT were significantly higher in patients with IR compared to controls (0.80±0.21mm vs 0.60±0.21mm; p<0.001 and 7.34±1.96mm vs 5.22±1.75mm; p<0.001, respectively). However, there were no significant differences in femoral IMT between the groups (0.74±0.20 vs 0.69±0.17; p=0.062). In multivariate linear regression analysis age (β=0.223, p=0.010), 2-h blood glucose (β=0.198, p=0.021), and IR (β=0.369, p<0.001) were independent predictors of EFT. On the other hand age (β=0.363, p<0.001) and IR (β=0.321, p<0.001) were independent predictors of carotid IMT.

CONCLUSIONS

Patients with IR have increased carotid IMT and EFT, but not femoral IMT. This apparent incoherence may be due to the involvement of carotid arteries prior to femoral arteries in patients with IR.

Assessment of Subclinical Atherosclerosis by Carotid Intima-Media Thickness and Epicardial Adipose Tissue Thickness in Prediabetes

Impaired fasting glucose (IFG) and impaired glucose intolerance (IGT) are predictors of cardiovascular disease (CVD). We tested the hypothesis that epicardial fat thickness (EFT) and carotid intima-media thickness (cIMT), as markers of early atherosclerosis, are increased in patients with prediabetes. We prospectively enrolled 246 patients (162 with prediabetes and 84 controls). Prediabetes was defined according to American Diabetes Association criteria, and patients were divided into 3 groups: group 1-IFG, group 2-IGT, and group 3-IFG + IGT. Both cIMT and EFT were significantly greater in patients with prediabetes compared with controls (0.81 ± 0.20 mm vs 0.68 ± 0.16 mm, P < .001 and 7.0 ± 2.0 mm vs 5.6 ± 1.6 mm, P < .001, respectively). This difference was mainly attributed to patients with IGT. Age, waist circumference, and 2-hour glucose independently predicted cIMT, while 2-hour glucose was the only independent predictor of EFT in multivariate analysis among other relevant parameters for cIMT and EFT. The cIMT and EFT (measured noninvasively) could be useful indicators of CVD risk in these patients. In order to prove this hypothesis, long-term prospective studies with greater patient numbers are required.

Evaluation oF Epicardial Fat and Carotid Intima-Media Thickness in Obese Children

Background:

Epicardial fat has a role in cardiovascular diseases.

Objectives:

To assess epicardial fat and its relation with carotid intima-media thickness (IMT) in obese adolescents with metabolic syndrome (MetS).

Patients and Methods:

The study included 60 obese adolescents and 25 control subjects. According to the presence or absence of MetS, obese subjects were divided into two subgroups. We measured weight, height, calculated Body Mass Index, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure and biochemical parameters (fasting glucose, total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol, High sensitivity C-reactive protein, fasting insulin, a homeostasis model assessment index of insulin resistance. plus an echocardiographic examination with measurement of epicardial adipose tissue thickness (EATT).

Results:

Left ventricular mass index measurements were significantly higher in MetS group than both non-MS and control groups. The MetS and non-MetS obese patients had significantly higher carotid IMT in comparison to the control group. Carotid IMT measurements were significantly higher in MetS group had than both non-MetS and control groups. Also, EATT was significantly increased in patients with MetS compared to control group. Among MetS obese group, EATT was positively correlated with body mass index-standard deviation score, waist circumference, fasting glucose, fasting insulin, insulin resistance, triglyceride levels, left ventricular thickness, left ventricular mass index and myocardial performance index. EATT was found to be the only predictor of carotid IMT.

Conclusions:

EATT is closely related to carotid IMT and early cardiac dysfunction in obese adolescents with MetS.

Epicardial adipose tissue volume but not density is an independent predictor for myocardial ischemia

BACKGROUND

Epicardial adipose tissue (EAT) volume is associated with plaque formation and cardiovascular event risk, its density may reflect tissue composition and metabolic activity.

OBJECTIVES

Global and regional associations between EAT volume and density, ischemia and coronary calcium were investigated using a novel automatic quantitative measurement software.

METHODS

71 patients with an intermediate pre-test probability for coronary artery disease and inducible ischemia by SPECT were matched to two same-gender controls (total of 213 patients, 90% male, age 60 ± 10 years). Non-contrast CT for assessment of EAT volume, density (in Hounsfield Unit [HU]) and coronary calcium score (CCS) was performed.

RESULTS

Global EAT volume was significantly increased in ischemic patients compared to controls (96 ± 49 vs. 82 ± 36 cm(3), p = 0.04), density showed no significant difference (-75.6 ± 4.3 vs. -75.1 ± 4.1HU, p = 0.63). EAT volume and density differed significantly between coronary territories (LAD: 37 ± 18 cm(3), -77.8 ± 4.5HU; LCx: 16 ± 9 cm(3), -73.9 ± 4.1HU; RCA: 36 ± 17 cm(3), -71.7 ± 4.8HU, p < 0.001). For regional ischemia, only LCx territory showed a significantly higher EAT volume (18 ± 8 vs. 16 ± 9 cm(3), p = 0.048). Multivariable logistic regression revealed a significant association with ischemia for EAT volume (OR 2.09 (1.0; 4.3), p = 0.049) and CCS (OR 1.43 (1.1; 1.9), p = 0.006). EAT volume significantly improved discrimination of ischemia over CCS (Integrated Discrimination Improvement: 3.5%, 95%CI: 1.1-6.1%, p = 0.004). Hypertension was the only risk factor significantly influencing EAT volume and density (98 ± 48 vs. 78 ± 31 cm(3), p = 0.002, -76.0 ± 4.1 vs. -74.5 ± 4.1 HU, p = 0.01).

CONCLUSIONS

EAT volume is associated with myocardial ischemia and improves the discriminative power for independent ischemia prediction over CCS. In hypertensive patients, EAT is characterized by lower density and higher volumes.

Chemerin is not associated with subclinical atherosclerosis markers in prediabetes and diabetes

OBJECTIVE

Chemerin is a novel adipokine that is correlated with adipocyte differentiation, glucose metabolism, and inflammation. We aimed to investigate the relation between serum chemerin level and subclinical atherosclerosis markers as exemplified by brachial artery pulse wave velocity (baPWV), carotid intima-media thickness (CIMT), epicardial fat thickness (EFT), and carotid plaque presence in diabetes and prediabetes.

METHODS

Age-, body mass index (BMI)-, and gender-matched patients with type 2 DM (n=30), prediabetes (n=25), and normal glucose tolerance (n=25) were included in this cross-sectional study. Serum chemerin level, lipid parameters, glucose metabolism marker, baPWV, CIMT, EFT, and anthropometric were recorded. The independent risk factors for atherosclerosis markers were determined by linear and/or multiple logistic regression analysis.

RESULTS

baPWV and carotid plaque presence were higher in the diabetes group than in prediabetes and control groups (p=0.039 and p=0.035 respectively), whereas serum chemerin levels were similar among groups (p=0.338). Chemerin levels were not correlated with PWV, CIMT, and epicardial fat thickness overall or in the subgroups. Overall and in the diabetes group, chemerin levels were positively correlated with the key components of metabolic syndrome as BMI, total body fat percentage, waist circumference, triglyceride, and systolic and diastolic blood pressure (BP). After adjusting for age, gender, and BMI, only the association between chemerin and systolic BP remained significant. Chemerin was not found as an independent risk factor for predicting atherosclerosis in diabetes and prediabetes.

CONCLUSION

Chemerin is not a predictive marker for atherosclerosis in diabetes and prediabetes, but correlates well with key aspects of the metabolic syndrome particularly in diabetes.

Thoracic fat volume is independently associated with coronary vasomotion

PURPOSE

Thoracic fat has been associated with an increased risk of coronary artery disease (CAD). As endothelium-dependent vasoreactivity is a surrogate of cardiovascular events and is impaired early in atherosclerosis, we aimed at assessing the possible relationship between thoracic fat volume (TFV) and endothelium-dependent coronary vasomotion.

METHODS

Fifty healthy volunteers without known CAD or major cardiovascular risk factors (CRFs) prospectively underwent a (82)Rb cardiac PET/CT to quantify myocardial blood flow (MBF) at rest, and MBF response to cold pressor testing (CPT-MBF) and adenosine (i.e., stress-MBF). TFV was measured by a 2D volumetric CT method and common laboratory blood tests (glucose and insulin levels, HOMA-IR, cholesterol, triglyceride, hsCRP) were performed. Relationships between CPT-MBF, TFV and other CRFs were assessed using non-parametric Spearman rank correlation testing and multivariate linear regression analysis.

RESULTS

All of the 50 participants (58 ± 10y) had normal stress-MBF (2.7 ± 0.6 mL/min/g; 95 % CI: 2.6-2.9) and myocardial flow reserve (2.8 ± 0.8; 95 % CI: 2.6-3.0) excluding underlying CAD. Univariate analysis revealed a significant inverse relation between absolute CPT-MBF and sex (ρ = -0.47, p = 0.0006), triglyceride (ρ = -0.32, p = 0.024) and insulin levels (ρ = -0.43, p = 0.0024), HOMA-IR (ρ = -0.39, p = 0.007), BMI (ρ = -0.51, p = 0.0002) and TFV (ρ = -0.52, p = 0.0001). MBF response to adenosine was also correlated with TFV (ρ = -0.32, p = 0.026). On multivariate analysis, TFV emerged as the only significant predictor of MBF response to CPT (p = 0.014).

CONCLUSIONS

TFV is significantly correlated with endothelium-dependent and -independent coronary vasomotion. High TF burden might negatively influence MBF response to CPT and to adenosine stress, even in persons without CAD, suggesting a link between thoracic fat and future cardiovascular events.

Quantification of epicardial fat: Which method can predict significant coronary artery disease?

AIM: To compare the predictive value of three methods of epicardial fat (EF) assessment for presence of significant coronary artery disease (CAD) [i.e., epicardial fat volume (EFV), EFV indexed with body surface area (EFV/BSA) and EFV indexed with body mass index (EFV/BMI)].

METHODS: The study was performed on 170 patients (85 women and 85 men) with clinical suspicion of CAD. They aged 26-89 years with a median age of 54 years. The patients were classified into three groups: Group 1: 58 patients with normal coronary arteries; group 2: 48 patients with non-significant CAD and group 3: 64 patients with significant CAD. The three methods for assessment of epicardial fat were retrospectively studied to determine the best method to predict the presence of significant CAD.

RESULTS: The three methods for epicardial fat quantification and measurements, i.e., EFV, EFV/BSA and EFV/BMI with post- hoc analysis showed a significant difference between patients with significant coronary artery disease compared to the normal group. Receiver operating characteristic curve analysis showed no significant difference between the three methods of epicardial fat measurements, the area under curve ranging between 0.6 and 0.62. The optimal cut-off was 80.3 cm³ for EFV, 2.4 cm³/m² for EFV indexed with BMI and 41.7 cm³/(kg/m²) for EFV indexed with BSA. For this cut-off the sensitivity ranged between 0.92 and 0.94, while specificity varied from 0.31 to 0.35.

CONCLUSION: Any one of the three methods for assessment of epicardial fat can be used to predict significant CAD since all have the same equivalent predictive value.

Epicardial adipose tissue thickness and its association with adiponectin in metabolic syndrome patients from Mérida, Venezuela

OBJECTIVE

To study the relationship between epicardial adipose tissue (EAT) thickness and plasma levels of adiponectin in Venezuelan patients.

SUBJECTS AND METHODS

Thirty-one patients diagnosed with metabolic syndrome (study group) and 27 controls were selected and tested for glycemia, lipids, and adiponectin. EAT thickness, ejection fraction, diastolic function, left ventricular mass (LVM), and left atrial volume (LAV) were determined by transthoracic echocardiography.

RESULTS

EAT thickness was greater in metabolic syndrome patients (5.69 ± 1.12 vs. 3.52 ± 0.80 mm; p = 0.0001), correlating positively with body mass index (BMI) (r = 0.661; p = 0.0001); waist circumference (WC) (r = 0.664; p = 0.0001); systolic (SBP) (r = 0.607; p = 0.0001), and diastolic blood pressure (DBP) (r = 0.447; p = 0.0001); insulin (r = 0.505; p = 0.0001); Tg/HDL-C ratio (r = 0.447; p = 0.0001), non-HDL-C (r = 0.353; p = 0.007); LAV (r = 0.432; p = 0.001), and LVM (r = 0.469; p = 0.0001). EAT thickness correlated negatively with adiponectin (r = -0.499; p = 0.0001).

CONCLUSION

A significant association exists between EAT thickness and both metabolic syndrome components and adiponectin concentration, a link that might be used as a biomarker for this disease.

Effects of restoration of the euthyroid state on epicardial adipose tissue and carotid intima media thickness in subclinical hypothyroid patients

Epicardial adipose tissue (EAT) thickness is a novel cardiovascular risk indicator, whereas carotid intima media thickness (CIMT) is a known marker of subclinical atherosclerosis. The aim of this study was to measure EAT thickness and CIMT in subclinical hypothyroid (SCH) patients and to determine the effect of restoration of the euthyroid state on these variables. The study included 43 patients with SCH (mean age: 35.2±10.7 years; F-M ratio: 42:1) and 30 healthy controls (mean age: 34.5±8.2 years; F-M ratio: 25:5). EAT thickness and CIMT were measured via conventional echocardiography and ultrasonography. Among the patients, 23 were followed up with L-thyroxine replacement until restoration of the euthyroid state and re-evaluated 6 months after baseline. Basal EAT thickness was higher in the SCH patients than in the controls (3.2±0.7 vs. 2.3±0.3 mm-p<0.0001), whereas CIMT was similar in both groups (0.50±0.09 vs. 0.48±0.04 mm). EAT thickness was correlated with CIMT in the patient group (r=0.39, p=0.01), but this correlation was not evident based on multivariate analysis when corrected for age and body mass index (r2=0.47 and p=0.0001 for the model). In the follow-up patient subgroup, both EAT thickness and CIMT decreased significantly following L-thyroxine treatment, when normal TSH levels were attained (3.4±0.7 vs. 2.3±0.5 mm-p=0.007 and 0.51±0.09 vs. 0.46±0.07 mm-p=0.01, respectively). EAT thickness was greater in the SCH patients than in controls, whereas CIMT was similar in both groups. Restoration of the euthyroid state with L-thyroxine treatment was associated with significant decreases in EAT thickness and CIMT in the group of patients that received L-thyroxine treatment and, as such, might reduce the cardiovascular risk associated with SCH.

Heart failure and atrial fibrillation: from basic science to clinical practice

Heart failure (HF) and atrial fibrillation (AF) are two growing epidemics associated with significant morbidity and mortality. They often coexist due to common risk factors and shared pathophysiological mechanisms. Patients presenting with both HF and AF have a worse prognosis and present a particular therapeutic challenge to clinicians. This review aims to appraise the common pathophysiological background, as well as the prognostic and therapeutic implications of coexistent HF and AF.

Epicardial fat, rather than pericardial fat, is independently associated with diastolic filling in subjects without apparent heart disease

BACKGROUND AND AIM

Epicardial and pericardial fat are separate fat depots surrounding the heart. Previous studies found epicardial fat to be associated with diastolic dysfunction, but they had some limitations. Pericardial fat association with diastolic dysfunction was not examined. Our aim was to assess the relation of epicardial and pericardial fat with diastolic filling.

METHODS AND RESULTS

In 73 volunteers without known heart disease or complaints, using echocardiography, we measured epicardial and pericardial fat thickness from long(LAX) and short(SAX) axis views and assessed diastolic filling: mitral inflow (E/A ratio, E wave deceleration time[DT]), pulmonary vein flow (systolic/diastolic ratio [S/D], systolic filling fraction[SFR], late retrograde velocity[Ar]), color M-mode flow propagation velocity [Vp], and tissue Doppler derived mitral early annular velocities at the septum [e' sep] and lateral wall [e'-lat]. By Spearman's correlation, epicardial fat from LAX had a weak, but statistically significant correlations with several diastolic filling indices (SFR{rs = 0.29, P = 0.02}, Ar{rs = 0.3, P = 0.01}, Vp{rs = -0.3, P = 0.01}, e' sep{rs = -0.23, P = 0.04}, e' lat{rs = -0.26, P = 0.03}). In multivariate logistic regression model adjusting for age, gender, diabetes, systolic blood pressure and left ventricle mass index, epicardial fat thickness from LAX (and not from SAX) was the only independent predictor of e' [e' sep < 8: OR = 1.8, 95%CI = 1.1-2.9; e' lat<10: OR = 1.6, 95%CI = 1.01-2.6]. After adjustment, Pericardial fat measured from LAX was independent predictor of e' lat only[e' lat < 10:OR = 1.3, 95% CI 1.03-1.6).

CONCLUSIONS

Epicardial fat measured from LAX is an independent predictor of myocardial relaxation. Pericardial fat independent association with diastolic filling is uncertain.

Does gestational diabetes history increase epicardial fat and carotid intima media thickness?

BACKGROUND

Gestational diabetes mellitus (GDM) is defined as glucose intolerance that has begun during pregnancy. Recent studies have proven that development of atherosclerosis may be established in this population even without presence of type 2 diabetes. For assessment of atherosclerosis, epicardial fat thickness (EFT) is recently being used as a surrogate marker. In this study, we aimed to prove that women with GDM history are more inclined to have higher EFT levels than women without GDM history.

METHODS

Sixty-two patients with previous GDM and 33 age- and sex-matched controls were allocated. Epicardial fat thicknesses of the subjects were measured with transthorasic echocardiography and carotid intima media thickness (c-IMT) was measured with ultrasound. Insulin resistance (IR) of each subject was assessed with Homeostasis model of assessment-insulin resistance (HOMA-IR).

RESULTS

Carotid IMT and EFT were significantly higher in previous GDM group than controls. Serum gamma-glutamyl transferase (GGT), uric acid, and high-sensitivity C-reactive protein (hs-CRP) levels were also found significantly higher in the patients with previous GDM as compared to the controls. We observed that carotid IMT (β = 310, P = 0.003), total cholesterol (β = 315, P = 0.002), BMI (β = 308, P = 0.002), HbA1c (β = 227, P = 0.018), and HOMA-IR (β = 184, P = 0.049) were independently correlated with EFT.

CONCLUSIONS

Although the number of patients included in this study is limited, high EFT results may indicate presence of atherosclerosis in women with previous GDM.

Relation of coronary collateral circulation with epicardial fat volume in patients with stable coronary artery disease

Objective

To investigated the relationship between epicardial fat volume (EFV) and coronary collateral circulation (CCC) in patients with stable coronary artery disease (CAD).

Methods

The study population consisted of 152 consecutive patients with CAD who underwent coronary angiography and were found to have at least 95% significiant lesion in at least one major coronary artery. EFV was assessed utilizing 64-multislice computed tomography. The patients were classifield into impaired CCC group (Group 1, Rentrop grades 0−1, n = 58), or adequate CCC (Group 2, Rentrop grades 2−3, n = 94).

Results

The EFV values were significantly higher in paitients with adequate CCC than in those with impaired CCC. In multivariate logistic regression analysis, EFV (OR = 1.059; 95% CI: 1.035−1.085; P = 0.001); and presence of angina were independent predictors of adequate CCC. In receiver-operating characteristic curve analysis, the EFV value > 106.5 mL yielded an area under the curve value of 0.84, with the test sensitivity of 49.3%, and with 98.3% specifity.

Conclusions

High EFV, and the presence of angina independently predict adequate CCC in patients with stable coronary artery disease. This association offers new diagnostic opportinities to assess collateral flow by conventional ultrasound techniques.

The relationship between epicardial fat and indices of obesity and the metabolic syndrome: a systematic review and meta-analysis

Epicardial fat (epicardial adipose tissue, EAT) has been implicated in the pathogenesis of coronary artery disease (CAD). The objective of this study was to examine the relationship between EAT and generalized obesity, central or visceral adipose tissue (VAT), and the components of the metabolic syndrome--systolic blood pressure (SBP), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and fasting blood glucose (FBG)--that are linked to CAD. A systematic review of the literature, following meta-analysis guidelines, was conducted until May, 2013, using the search strategy "Obesity" OR "abdominal obesity" OR "metabolic syndrome" OR "metabolic syndrome X" AND "epicardial fat". Thirty-eight studies fulfilled the criteria. There was a highly significant (P<0.00001) correlation between EAT and body mass index (BMI), waist circumference (WC), or VAT. The correlation between EAT and VAT was significantly (P<0.0001) greater than the correlation between EAT and WC, which in turn was significantly greater than the correlation between EAT and BMI. Overall, EAT was 7.5 ± 0.1 mm in thickness in the metabolic syndrome (n=427) compared to 4.0 ± 0.1 mm in controls (n=301). EAT correlated significantly (P<0.0001) with SBP, TGs, HDL, and FBG, but the strength of the association was less than one-half of the relationship of EAT to indices of obesity. The results of multivariate analysis were less consistent but show a relationship between EAT and metabolic syndrome independent of BMI. In summary, the very strong correlation between EAT and VAT suggests a relationship between these two adipose tissue depots. Measurement of EAT can be useful to indicate VAT. Whereas EAT correlates significantly with each of the components of the metabolic syndrome- SBP, TGs, HDL, or FBG-the magnitude of the relationship is considerably and significantly less than the relationship of EAT to BMI. These data show the strong relationship between EAT and BMI but especially with WC and VAT. They also demonstrate the smaller magnitude of the association of EAT with standard coronary risk factors, related to the metabolic syndrome, and suggest that the unique features of this adipose tissue warrant detailed investigation.

Periatrial epicardial fat is associated with markers of endothelial dysfunction in patients with atrial fibrillation

Background

Epicardial adipose tissue (EAT) is associated to atrial fibrillation (AF) burden and outcome after AF ablation. We intended to determine whether global or local EAT is associated with systemic and/or left atrial (LA) inflammation and markers of endothelial dysfunction in AF patients.

Methods and Results

Total, atrial, and ventricular EAT volume (EATtotal, EATatrial, EATventricular) were measured by multislice cardiac CT in 49 patients with paroxysmal (PAF, n=25) or persistent AF (PeF, n=24). Periatrial epicardial fat thickness at the esophagus (LA-ESO) and thoracic aorta (LA-ThA) were also measured. Vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), soluble intercellular adhesion molecule 1 (sICAM-1), transforming growth factor-β1 (TGF-β1), and von Willebrand Factor (vWF) levels were measured in peripheral and LA blood samples obtained during catheterization during AF ablation. Patients with PeF had higher EATatrial (P<0.05) and LA-ESO (P=0.04) than patients with PAF. VEGF, IL-8, and TGF-β1 were not associated with EAT. In contrast, after adjusting for LA volume and body mass index, higher LA-ThA was significantly associated with higher sICAM-1 and vWF levels, both in peripheral blood (P<0.05) and in LA (P<0.05). Similar results were found with LA-ESO. Body mass index, EATtotal and EATventricular were not associated with sICAM-1 and vWF.

Conclusions

Periatrial epicardial fat showed a significant positive association with increased levels of sICAM-1 and vWF, which are biomarkers of endothelial dysfunction. No such associations were found when considering body mass index or EATtotal. These results suggest that local EAT rather than regional or total adiposity may modulate endothelial dysfunction in patients with AF.

Relationships between total and regional adiposity and epicardial fat in obese women: how can dual-energy X-ray absorptiometry be associated with echocardiographic epicardial fat measurements?

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Obesity is an increasingly prevalent metabolic disorder and it is associated with a large number of comorbidities, including cardiovascular diseases. Adipose tissue is an active endocrine organ and its ectopic depots and distribution have different metabolic meanings on risks for health; as a matter of fact, epicardial fat seems to play a specific role in cardiovascular diseases. The use of dual-energy X-ray absorptiometry (DXA) to evaluate and follow-up patients affected by obesity is becoming a very important point in the management of the disease.

WHAT THIS STUDY ADDS

An investigation of the association between epicardial fat and regional adiposity by DXA in female obese patients. The total amount of central (trunk) fat mass is more strongly correlated than android visceral fat mass to epicardial thickness in obese women. In the interpretation of whole-body DXA data, physician should consider trunk fat mass for good and independent predictivity on epicardial fat depots. Our aim was to analyse in a population of obese women the relationship between the amount of epicardial fat as measured by transthoracic echocardiography (US) and the parameters of regional adiposity by dual-energy X-ray absorptiometry (DXA), with particular reference to a new software for visceral fat assessment and to a new 'heart-suited' regions of interests (ROIs). Sixty patients who satisfied technical inclusion criteria underwent whole-body DXA scan and US on the same day. Total and android fat mass (FM) and FM percentage (FM%) were considered as well as visceral fat (VAT) subcompartment in the android region; moreover, six new ROIs were designed on whole-body DXA images for the investigation of adiposity parameters at heart level. US provided epicardial fat thickness (EPI-thickness) and area (EPI-area), as measured following previously validated methods. Body mass index (BMI), gynoid and lower limbs (FM and FM%) were found not statistically correlated with EPI-thickness. The highest correlation was achieved by trunk FM (and FM%, with r = 0.544 and 0.480 respectively, P < 0.001), followed by ROI-1 FM (ROI-1 was drawn following thoroughly the cardiac profile), and android FM. Multivariate analysis including age, weight, BMI, trunk FM and the new ROIs (added one by one), retained in the final model trunk FM. Correlations of DXA with EPI-area were superimposable. In obese women, VAT or other new-designed ROIs are not better correlated than traditional ROIs (i.e. trunk) with epicardial fat amount.

Increased epicardial adipose tissue thickness as a predictor for hypertension: a cross-sectional observational study

The aim of the study was to determine whether epicardial adipose tissue thickness (EAT), a new cardiometabolic risk factor, is associated with essential hypertension. The sample included 127 asymptomatic patients with one or more cardiovascular risk factors consecutively referred for cardiac computed tomography angiography. Data were collected retrospectively and compared between hypertensive (n=39) and normotensive (n=88) patients. The hypertensive patients had a significantly higher mean EAT thickness than the normotensive group (2.81±1.6 mm vs 2.07±1.43 mm; P=.011) and a significantly elevated mean coronary artery calcium score (316.8±512.6 vs 108.73±215; P=.0257). The odds ratio for a patient with tissue thickness ≥2.4 mm having hypertension was 1.396 (95% confidence interval, 1.033-1.922). Factors independently associated with hypertension were body mass index, low-density lipoprotein, and age. A model score was developed using the logistic regression coefficients for calculation of individual risk. Hypertensive patients have significantly higher than normal EAT thickness. Epicardial adipose tissue thickness may serve as a risk indicator for hypertension and cardiovascular morbidity.

Relationship of epicardial adipose tissue thickness with early indicators of atherosclerosis and cardiac functional changes in obese adolescents with metabolic syndrome

OBJECTIVE

Epicardial adipose tissue thickness (EATT) is suggested as a new cardiometabolic risk factor. Carotid intima-media thickness (IMT) is a potential indicator of subclinical atherosclerosis in patients with metabolic syndrome (MS). We investigated the association of EATT with carotid IMT and cardiac functional changes in obese adolescents with MS.

METHODS

One hundred thirty-eight obese adolescents and 63 lean subjects were enrolled in the study. The obese subjects were divided into two subgroups based on the presence or absence of MS (MS group and non-MS group). All subjects underwent transthoracic echocardiographic examination for determination of left ventricular (LV) function, LV mass index (LVMI), and myocardial performance index (MPI). EATT and carotid IMT were also measured during echocardiography.

RESULTS

The average LVMI measurements were higher in both MS and non-MS obese patients in comparison with the lean children. The MS group had significantly higher LVMI measurements than the non-MS and lean groups (88.5±23.0, 67.5±24.8 g/m2, and 62.4±18.2 g/m2, respectively; p<0.01). Carotid IMT was higher in both the MS and non-MS obese patients in comparison with the lean group. The MS group had significantly higher carotid IMT measurements than the non-MS and lean groups (0.91±0.23, 0.78±0.18, and 0.52±0.08 mm, respectively; p<0.01). The EATT was also increased significantly in patients with MS compared to lean adolescents (7.42±1.55 vs. 4.28±0.79mm; p=0.001). EATT was positively correlated with body mass index-SDS, waist circumference, fasting glucose, insulin, homeostasis model assessment-insulin resistance, triglyceride levels, LV thickness, LVMI, and MPI in the MS obese group. EATT was the only independent predictor of carotid IMT in the multivariate analysis (β= 0.69, p<0.001).

CONCLUSION

The findings of the present study demonstrate a close relationship of EATT with carotid IMT and early cardiac dysfunction in obese adolescents with MS. Assessment of EATT and carotid IMT in routine echocardiographic examinations is suggested as a feasible and reliable method for the evaluation of obesity with MS and its related cardiovascular risks in children and adolescents.

Echocardiographically measured epicardial fat predicts restenosis after coronary stenting

OBJECTIVE

Epicardial adipose tissue (EAT), deposited around subepicardial coronary vessels, may contribute directly to perivascular inflammation and smooth muscle cell proliferation. This study assessed the relationship between EAT and in-stent restenosis.

METHODS

Four hundred and seven patients had received successful coronary intervention. EAT thickness was measured by echocardiography. Angiographic follow-up was obtained between 6 months and 2 years. Restenosis was defined as target lesion revascularization (TLR). EAT thickness of patients was compared by TLR controlling for additional well-known predictors of restenosis. The TLR-free survival analysis according to EAT thickness was estimated using the Kaplan-Meier method and the differences between groups were assessed by the log-rank test.

RESULTS

Median EAT thickness was significantly increased in patients undergoing TLR compared with those without restenosis (3.7 vs. 3.0 mm, p = 0.001). EAT thickness was one of the independent factors associated with restenosis (Odds ratio = 1.19, 95% confidence interval = 1.01-1.33, p = 0.007). The TLR-free survival of patients with thick EAT was significantly worse than patients with thin EAT (log-rank p = 0.001).

CONCLUSIONS

EAT thickness is related with restenosis and may provide additional information for future restenosis.

From the epicardial adipose tissue to vulnerable coronary plaques

Thin cap fibroatheromas (TCFAs) are thought to be the most common underlying substrate in patients suffering acute coronary thrombotic events. Recently, an interesting association between TCFAs and a particular depot of visceral fat called epicardial adipose tissue (EAT) has been suggested. In this article, we discuss some basic and clinical aspects of this association and then briefly review some of the pathophysiological characteristics attributed to EAT that explain why this particular depot of fat has been attracting the attention of the cardiological scientific community in recent years. Finally we discuss the value of optical coherence tomography in the diagnosis of TCFAs and the role of multislice computed tomography to assess EAT.

Associations of epicardial fat with coronary calcification, insulin resistance, inflammation, and fibroblast growth factor-23 in stage 3-5 chronic kidney disease

BACKGROUND

Epicardial fat, quantified in a single multi-slice computed tomography (MSCT) slice, is a reliable estimate of total epicardial fat volume (EFV). We sought to determine risk factors for EFV detected in a single-slice MSCT measurement (ssEFV) in pre-dialysis chronic kidney disease (CKD) patients. Our primary objective was to determine the association between ssEFV and coronary artery calcification (CAC).

METHODS

94 pre-dialysis stage 3-5 CKD patients underwent MSCT to measure ssEFV and CAC. ssEFV was quantified at the level of the left main coronary artery. Measures of inflammation, traditional and kidney-related cardiovascular disease risk factors were collected.

RESULTS

Mean age: 63.7 ± 14 years, 56% male, 39% had diabetes, and mean eGFR: 25.1 ± 11.9 mL/min/1.73 m2. Mean ssEFV was 5.03 ± 2.4 cm3. By univariate analysis, body mass index (BMI) (r = 0.53; P = <0.0001), abdominal obesity (r = 0.51; P < 0.0001), high density lipoprotein (HDL) cholesterol (r = - 0.39; P = <0.0001), insulin resistance (log homeostasis model assessment of insulin resistance (log HOMA-IR)) (r = 0.38, P = 0.001), log interleukin-6 (IL-6) (r = 0.34; P = 0.001), and log urinary albumin to creatinine ratio (UACR) (r = 0.30, P = 0.004) demonstrated the strongest associations with ssEFV. Log coronary artery calcification (log CAC score) (r = 0.28, P = 0.006), and log fibroblast growth factor-23 (log FGF-23) (r = 0.23, P = 0.03) were also correlated with ssEFV. By linear regression, log CAC score (beta =0.40; 95% confidence interval (CI), 0.01-0.80; P = 0.045), increasing levels of IL-6 (beta = 0.99; 95% CI, 0.38 - 1.61; P = 0.002), abdominal obesity (beta = 1.86; 95% CI, 0.94 - 2.8; P < 0.0001), lower HDL cholesterol (beta = -2.30; 95% CI, - 3.68 to -0.83; P = 0.002) and albuminuria (log UACR, beta = 0.81; 95% CI, 0.2 to 1.4; P = 0.01) were risk factors for increased ssEFV.

CONCLUSIONS

In stage 3-5 CKD, coronary calcification and IL-6 and were predictors of ssEFV. Further studies are needed to clarify the mechanism by which epicardial fat may contribute to the pathogenesis of coronary disease, particularly in the CKD population.

Epicardial fat tissue thickness in preeclamptic and normal pregnancies

Background. Epicardial fat tissue, another form of visceral adiposity, has been proposed as a new cardiometabolic risk factor, and the possible association of epicardial fat with hypertension has been shown in some recent studies. Although epicardial fat thickness (EFT) is associated with hypertension, the relationship between preeclampsia and EFT is still unknown. The purpose of this paper is to investigate the association between the echocardiographic EFT and the severity of preeclampsia in pregnant women. Methods. Forty women with preeclampsia were recruited and thirty-five normal pregnant women were matched for both maternal age and gestastional age served as control. The materials were collected immediately after delivery of the fetus, before placenta expulsion and before clamping of the umblical cord in patients and controls whom were in fasting state. Total cholesterol, high-density lipoprotein cholesterol (HDL), and triglyceride levels (TG) and low-density-lipoprotein cholesterol (LDL), and homeostatic model assessment of insulin resistance (HOMA-IR) levels were assessed. EFT was measured by using transthoracic echocardiography. Results. Among the preeclamptic women, 12 were diagnosed with severe preeclampsia and 28 mild preeclampsia. There were no statistically significant differences between patients with preeclampsia and normal pregnancy except when they are divided according to systolic and diastolic blood pressure, proteinuria levels, and parity and EFT levels. Among women with preeclampsia (n = 40), 30% had severe disease. Women with mild and severe preeclampsia had significiantly higher blood pressures at delivery and earlier gestational ages in comparison to control subjects. Although TG, VLDL and LDL, HDL, and HOMA-IR levels (P > 0.05) were comparable between preeclampsia and normal pregnancies, EFT levels were significiantly higher in patients with preeclampsia. Moreover, in subgroup analysis, patients with severe preeclampsia had higher EFT levels (P < 0.05) in comparison with mild preeclampsia. Conclusions. EFT levels measured at delivery were increased in patients with preeclampsia, and patients with increased levels of EFT levels had a substantially higher probability of the disease severity in comparison to those with mild preeclampsia and controls.

Association of epicardial fat thickness with the severity of obstructive sleep apnea in obese patients

BACKGROUND

The correlation between obesity and severity of obstructive sleep apnea (OSA) is controversial. Although fat excess is a predisposing factor for the development of OSA, it has not been determined whether fat distribution rather than obesity per se is associated with OSA severity. Epicardial fat thickness (EFT) is an independent index of visceral adiposity and cardiometabolic risk. We investigated the relation between fat distribution and cardiometabolic risk factors, including EFT and common carotid intima-media thickness (cIMT), with the severity of OSA in obese patients.

METHODS

One hundred and fifteen obese patients (56 males, 59 females) with polysomnographic evidence of OSA (≥ 5 apnea/hypopnea events per hour) of various degrees, without significant differences in grade of obesity as defined by body mass index (BMI), were evaluated. The following parameters were measured: BMI, body composition by dual energy X-ray absorptiometry, EFT, right ventricular end-diastolic diameter (RVEDD) and cIMT by ultrasound, and parameters of metabolic syndrome (waist circumference, arterial blood pressure, fasting glucose, HDL-cholesterol and triglycerides).

RESULTS

EFT, RVEDD, cIMT and trunk/leg fat mass ratio showed a positive correlation with OSA severity in univariate analysis (r=0.536, p<0.001; r=0.480, p<0.001; r=0.345, p<0.001; r=0.330, p<0.001, respectively). However, multiple linear regression analysis showed that EFT was the most significant independent correlate of the severity of OSA (R(2)=0.376, p=0.022).

CONCLUSIONS

The present study suggests that, in obese patients, EFT may be included among the clinical parameters associating with OSA severity. The association of EFT with OSA, both cardiovascular risk factors, is independent of obesity as defined by classical measures.

Relation of epicardial adipose tissue and carotid intima-media thickness in patients with nonalcoholic fatty liver disease

OBJECTIVE

Currently, nonalcoholic fatty liver disease (NAFLD) itself has been accepted as an atherosclerotic risk factor and related to increased cardiovascular disease risk. In this study, we aimed to investigate the relationship of epicardial fat thickness (EFT), a parameter associated with atherosclerosis in recent years, with carotid artery intima-media thickness (C-IMT), another parameter of subclinical atherosclerosis.

DESIGN AND METHODS

We investigated 57 patients with biopsy-proven NAFLD and 30 age-matched and sex-matched controls. EFT was obtained by transthoracic echocardiography and C-IMT was evaluated by an ultrasonographic measurement using a linear type B-mode probe.

RESULTS

EFT and C-IMT were significantly higher in NAFLD patients compared with the controls (EFT: 0.58 ± 0.18 vs. 0.36 ± 0.17 cm, P<0.001 and C-IMT: 0.64 ± 0.1 vs. 0.52 ± 0.1 mm, P<0.001, respectively). We found a statistically significant correlation between EFT and BMI, C-IMT, waist circumference, homeostasis model assessment of insulin resistance, and nonalcoholic steatohepatitis scores in both groups. Stepwise regression analysis showed that C-IMT (β=0.36, t=2.86, P=0.006) and waist circumference (β=0.3, t=2.44, P=0.018), in the order they entered into the model, were independent predictors of EFT in patients with NAFLD.

CONCLUSION

Our findings indicate that EFT and C-IMT were significantly higher in patients with NAFLD compared with the controls and waist circumference and C-IMT are independent predictors for EFT in patients with NAFLD.

Echocardiographic epicardial adipose tissue predicts subclinical atherosclerosis: epicardial adipose tissue and atherosclerosis

We examined the relationship between coronary flow rate and epicardial adipose tissue (EAT) in patients with slow coronary flow (SCF) and normal coronary arteries. The study included 40 consecutive patients with stable angina pectoris who had normal coronary arteries. All patients underwent echocardiography. To determine the SCF, thrombolysis in myocardial infarction (TIMI) frame count method was used. Half of the patients had SCF at least in 1 coronary artery. Thrombolysis in myocardial infarction frame counts, the mean TIMI frame count, and EAT thickness were significantly higher in patients with SCF. Slow coronary flow showed a significantly positive correlation with EAT thickness. Epicardial adipose tissue thickness was the only independent predictor of SCF. Our findings suggest that there is a significant correlation between the SCF and EAT. Therefore, echocardiographic EAT may become a predictor of subclinical atherosclerosis in patients with stable angina pectoris.

Association of low plasma adiponectin with early diastolic dysfunction

Diastolic dysfunction (DD) with preserved left ventricular (LV) ejection fraction (EF) has been linked to obesity. Adiponectin is a cytokine related to obesity and obesity-linked cardiovascular complications. The authors aimed to determine the independent association of DD with adiponectin. Fifty patients with impaired relaxation DD and a normal EF and age-matched normal controls were recruited. Plasma levels of total and high molecular weight (HMW) adiponectin were measured. Mid and low molecular weight (MMW+LMW) fractions of adiponectin were calculated by subtracting HMW fraction from total adiponectin. The DD group had significantly lower total (median, 4.4 vs 12.7 μg/mL; P=.001), HMW fraction (median, 1.3 vs 3.4 μg/mL; P=.02), and MMW+LMW fraction of adiponectin (median, 3.8 vs 7.2 μg/mL; P=.01). Body mass index (BMI) negatively correlated with total (r:-0.46, P=.003), HMW (r:-0.32, P=.038), and MMW+LMW (r:-0.40, P=.006) fractions of adiponectin. DD had an independent association with both BMI (P<.05) and total adiponectin (P<.001) in linear regression model using sex, BMI, blood pressure, and total adiponectin as covariates. DD was associated with BMI (P=.02), HMW fraction (P=.03), and MMW+LMW fraction (P=.004) in similar linear regression analyses. Adiponectin deficiency may be one explanation for the adiposity-related cardiac oxidation known to be involved in the pathogenesis of DD.

Threshold for the upper normal limit of indexed epicardial fat volume: derivation in a healthy population and validation in an outcome-based study

Epicardial fat volume (EFV) quantified on noncontrast cardiac computed tomography relates to cardiovascular prognosis. We sought to define the upper normal limit of body surface area (BSA)-indexed EFV (EFVi) in a healthy population and to validate it as a predictor of major adverse cardiovascular events (MACE). We analyzed noncontrast cardiac computed tomography scans of 226 healthy subjects with a low Framingham Risk Score (FRS; ≤6%) performed for coronary calcium scoring (CCS). EFV was quantified using validated software and indexed to BSA. We defined the 95th percentile as the upper normal limit. Subsequently, we reanalyzed a separate cohort of 232 participants from a previously published case-control study with 4-year follow-up and 58 cases of MACE to test the additive value of an abnormally high EFVi for predicting MACE. Of the 226 healthy participants 51% were men (mean age 52 ± 9 years). EFV correlated to BSA (r = 0.373, p <0.0001). Median, range, and 25th and 75th percentiles of the non-normally distributed EFVi were 33.3, 10.8 to 96.6, and 24.5 and 45.5 cm(3)/m(2). The 95th percentile definition of the upper normal limit of EFVi was 68.1 cm(3)/m(2). For prediction of MACE, EFVi values higher than the newly defined threshold emerged as a significant and independent predictor after controlling for confounders (odds ratio 2.8, 95% confidence interval 1.3 to 6.4, p = 0.012) and trended in its additive value to the combination of CCS ≥400 and FRS (area under the receiver operating characteristic curve 0.714 vs 0.675, p = 0.1277). In conclusion, in a healthy population we determined 68.1 cm(3)/m(2) as the 95th percentile threshold for abnormally high EFVi. EFVi exceeding this value independently predicted MACE and trended to add to CCS and FRS in this prediction.

Epicardial adipose tissue thickness in type 1 diabetic patients

Insulin resistance is getting important in the course of type 1 diabetes mellitus. Visceral fat depot is associated with insulin resistance and assessment of epicardial fat thickness is a way of measuring visceral fat. The aim of the study was to measure epicardial adipose tissue (EAT) thickness and to determine its relationship with waist-hip-ratio (WHR) and estimated glucose disposal rate (eGDR) in adult type 1 diabetic patients. Thirty-six type 1 diabetic patients (aged 31±8 years; Female/Male: 22/14) and 43 age, gender and BMI matched healthy controls were included. Fasting blood glucose (FBG), hemoglobin A1c, and lipid profiles were measured. Waist-hip-ratio (WHR) was calculated. Daily insulin dose/kg of patients were recorded and eGDR of all subjects was calculated. Epicardial adipose tissue (EAT) thickness was evaluated by echocardiography. EAT thickness of the type 1 diabetic patients was significantly higher than controls (3.30±1.06 vs. 2.30±0.34 mm, P<0.0001). EAT thickness was correlated with age (P=0.05; r=0.35), WHR (P=0.003; r=0.67), daily insulin dose/kg (r=0.45, P=0.005), and eGDR (r=-0.55, P=0.0004). Multivariate analysis revealed WHR and eGDR to be related to EAT among age, WHR, daily insulin dose/kg, eGDR, FBG, and hemoglobin A1c (r2 of the model=0.64). Epicardial adipose tissue thickness is increased in type 1 diabetic patients compared to controls and is related to WHR and eGDR in this group of patients. This measurement may point to the presence of insulin resistance in type 1 diabetic patients.