Epicardial adipose tissue is an independent predictor of coronary atherosclerotic burden

The Role of Epicardial Adipose Tissue in Acute Coronary Syndromes, Post-Infarct Remodeling and Cardiac Regeneration

Epicardial adipose tissue (EAT) is a fat deposit surrounding the heart and located under the visceral layer of the pericardium. Due to its unique features, the contribution of EAT to the pathogenesis of cardiovascular and metabolic disorders is extensively studied. Especially, EAT can be associated with the onset and development of coronary artery disease, myocardial infarction and post-infarct heart failure which all are significant problems for public health. In this article, we focus on the mechanisms of how EAT impacts acute coronary syndromes. Particular emphasis was placed on the role of inflammation and adipokines secreted by EAT. Moreover, we present how EAT affects the remodeling of the heart following myocardial infarction. We further review the role of EAT as a source of stem cells for cardiac regeneration. In addition, we describe the imaging assessment of EAT, its prognostic value, and its correlation with the clinical characteristics of patients.

Epicardial adipose tissue as an independent predictor of long-term outcome in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

BACKGROUND

Accurate risk stratification is important to improve patient selection and outcome of patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). As epicardial adipose tissue (EAT) is discussed to be involved in cardiovascular disease, it could be useful as a marker of poor prognosis in patients with severe AS undergoing TAVR.

METHODS

A total of 416 patients diagnosed with severe AS by transthoracic echocardiography were assigned for TAVR and enrolled for systematic assessment. Patients underwent clinical surveys and 5-year long-term follow-up, with all-cause mortality as the primary endpoint. EAT volume was quantified on pre-TAVR planning CTs. Patients were retrospectively dichotomized at the median of 74 cm3 of EAT into groups with low EAT and high EAT volumes. Mortality rates were compared using Kaplan-Meyer plots and uni- and multivariable cox regression analyses.

RESULTS

A total number of 341 of 416 patients (median age 80.9 years, 45% female) were included in the final analysis. Patients with high EAT volumes had similar short-term outcome (p = 0.794) but significantly worse long-term prognosis (p = 0.023) compared to patients with low EAT volumes. Increased EAT volumes were associated with worse long-term outcome (HR1.59; p = 0.031) independently from concomitant cardiovascular risk factors, general type of AS, and functional echocardiography parameters of AS severity (HR1.69; p = 0.013).

CONCLUSION

Increased EAT volume is an independent predictor of all-cause mortality in patients with severe AS undergoing TAVR. It can be easily obtained from pre-TAVR planning CTs and may thus qualify as a novel marker to improve prognostication and management of patient with severe AS.

TRIAL REGISTRATION

DRKS, DRKS00024479.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Epicardial adipose tissue as a prognostic marker in acute pulmonary embolism

BACKGROUND

Epicardial adipose tissue (EAT) has been established as a quantitative imaging biomarker associated with disease severity in coronary heart disease. Our aim was to use this prognostic marker derived from computed tomography pulmonary angiography (CTPA) for the prediction of mortality and prognosis in patients with acute pulmonary embolism.

METHODS

The clinical database was retrospectively screened for patients with acute pulmonary embolism between 2015 and 2021. Overall, 513 patients (216 female, 42.1%) were included in the analysis. The study end-point was 30-day mortality. Epicardial adipose tissue was measured on the diagnostic CTPA in a semiquantitative manner. The volume and density of EAT were measured for every patient.

RESULTS

Overall, 60 patients (10.4%) died within the 30-day observation period. The mean EAT volume was 128.3 ± 65.0 cm3 in survivors and 154.6 ± 84.5 cm3 in nonsurvivors (p = 0.02). The density of EAT was -79.4 ± 8.3 HU in survivors and -76.0 ± 8.4 HU in nonsurvivors (p = 0.86), and EAT density was associated with 30-day mortality (odds ratio [OR] = 1.07; 95% confidence interval [CI]: 1.03; 1.1, p < 0.001) but did not remain statistically significant in multivariable analysis. No association was identified between EAT volume and 30-day mortality (OR = 1.0; 95% CI: 1.0; 1.0, p = 0.48).

CONCLUSION

There might be an association between EAT density and mortality in patients with acute pulmonary embolism. Further studies are needed to elucidate the prognostic relevance of EAT parameters in patients with acute pulmonary embolism.

The association between obesity indicators and metabolic risk factors in type-2 diabetic patients

Rationale and objectives

Obesity, accumulation of adipose tissue, is a global disease that can lead to cardiovascular and metabolic complications. The aim of this study was to investigate the relationship between obesity indicators and metabolic risk factors in type 2 diabetes mellitus (T2DM) patients.

Materials and methods

A total of 337 T2DM subjects were included in our study. The metabolic risk factors including diabetes duration, fast plasma glucose (FPG), height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), estimated average glucose (eAG), glycated hemoglobin (HbA1c), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c), triglyceride (TG), blood urea nitrogen (BUN), serum creatinine (Scr), free fatty acid (FFA), uric acid (UA), cystatin c (cysc), albumin (Alb), urinary albumin creatinine ratio (UACR) were recorded. The obesity indicators included body surface area (BSA), body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), para-perirenal fat thickness (PRFT), total abdominal fat (TAF), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT). The association between obesity indicators and metabolic risk factors was investigated by univariate and multivariate analysis.

Results

HDL-c was independently associated with WHR and PRFT (β = -0.126 vs. -0.214, both p < 0.05). TG and Scr were both independently associated with PRFT (β = 0.173 vs. 0.218, both p < 0.01, respectively). UA was independently associated with BSA (β = 0.172, p < 0.01) and PRFT (β = 0.151, p < 0.01). cysc, Alb and UACR were independently associated with WC (β = 0.274 vs. 0.204 vs. 0.182, all p < 0.01).

Conclusion

In T2DM patients, obesity indicators were significantly associated with metabolic risk factors.

The quantity and quality of cardiovascular fat at mid-life and future cognitive performance among women: The SWAN cardiovascular fat ancillary study

INTRODUCTION

Cardiovascular fat is a novel risk factor that may link to dementia. Fat volume and radiodensity are measurements of fat quantity and quality, respectively. Importantly, high fat radiodensity could indicate healthy or adverse metabolic processes.

METHODS

The associations of cardiovascular fat (including epicardial, paracardial, and thoracic perivascular adipose tissue [PVAT]) quantity and quality assessed at mean age of 51 with subsequent cognitive performance measured repeatedly over 16 years of follow-up were examined using mixed models among 531 women.

RESULTS

Higher thoracic PVAT volume was associated with a higher future episodic memory (β[standard error (SE)] = 0.08 [0.04], P = 0.033), while higher thoracic PVAT radiodensity with lower future episodic (β[SE] = -0.06 [0.03], P = 0.045) and working (β[SE] = -0.24 [0.08], P = 0.003) memories. The latter association is prominent at higher volume of thoracic PVAT.

DISCUSSION

Mid-life thoracic PVAT may have a distinct contribution to future cognition possibly due to its distinct adipose tissue type (brown fat) and anatomical proximity to the brain circulation.

HIGHLIGHTS

Higher mid-life thoracic perivascular adipose tissue (thoracic PVAT) volume is related to a better future episodic memory in women. Higher mid-life thoracic PVAT radiodensity is related to worse future working and episodic memories. Negative association of high thoracic PVAT radiodensity with working memory is prominent at higher thoracic PVAT volume. Mid-life thoracic PVAT is linked to future memory loss, an early sign of Alzheimer's disease. Mid-life women's epicardial and paracardial fat are not related to future cognition.

Epicardial Fat Volume as a Good Predictor for Multivessel Coronary Artery Disease

INTRODUCTION

Epicardial adipose tissue may have an important role in the pathogenesis of coronary artery disease (CAD).

AIM

We aimed to study the association between epicardial fat volume (EFV) and presence of obstructive as well as multivessel CAD.

METHODS

A total of 87 adult subjects with suspected CAD who underwent both quantified by multidetector computerized tomography (MDCT) and Invasive Coronary Angiography (ICA) were enrolled in this observational study. EVF was measured by MDCT by calculating the sum of cross- sectional areas of fat multiplied by slice thickness. EFV measurement and its association with the presence of obstructive CAD (defined as coronary artery stenosis > 70%) was evaluated.

RESULTS

Overall, 89.6% patients had obstructive CAD with higher EFV as compared to 10.3% patients with non-obstructive CAD (57 ± 20.14 cm3 vs. 44 ± 7.4 cm3; P < 0.001). Furthermore, EFV was significantly increased in group II as compared with group I (74 ± 24.3 ml vs. 53 ± 16.2 ml; P < 0.003). On the hand, the coronary calcium score (CAC) was insignificantly increased in group II as compared with group I (486.1 vs. 211.2; P = 0.10). Multivariate analysis revealed that, EFV might be an independent risk factor for not only the presence of obstructive CAD (odds ratio [OR], 1.062; 95% CI 1.018- 1.108; P < 0.005) but also in predicting multivessel disease affection.

CONCLUSIONS

Our results demonstrated that, EFV was significantly increased not only with obstructive CAD, independent of other traditional risk factors and CAC score, but also it can be considered a good predictor of multivessel disease occurrence.

Whole-Body Composition Features by Computed Tomography in Ovarian Cancer: Pilot Data on Survival Correlations

BACKGROUND

The primary objective of this study was to assess the associations of computed tomography (CT)-based whole-body composition values with overall survival (OS) and progression-free survival (PFS) in epithelial ovarian cancer (EOC) patients. The secondary objective was the association of body composition with chemotherapy-related toxicity.

METHODS

Thirty-four patients (median age 64.9 years; interquartile range 55.4-75.4) with EOC and thorax and abdomen CT scans were included. Clinical data recorded: age; weight; height; stage; chemotherapy-related toxicity; and date of last contact, progression and death. Automatic extraction of body composition values was performed by dedicated software. Sarcopenia was defined according to predefined cutoffs. Statistical analysis included univariate tests to investigate associations of sarcopenia and body composition with chemotoxicity. Association of body composition parameters and OS/PFS was evaluated by log-rank test and Cox proportional hazard model. Multivariate models were adjusted for FIGO stage and/or age at diagnosis.

RESULTS

We found significant associations of skeletal muscle volume with OS (p = 0.04) and PFS (p = 0.04); intramuscular fat volume with PFS (p = 0.03); and visceral adipose tissue, epicardial and paracardial fat with PFS (p = 0.04, 0.01 and 0.02, respectively). We found no significant associations between body composition parameters and chemotherapy-related toxicity.

CONCLUSIONS

In this exploratory study, we found significant associations of whole-body composition parameters with OS and PFS. These results open a window to the possibility to perform body composition profiling without approximate estimations.

Echocardiographic Association of Epicardial Adipose Tissue with Ascending Aorta Elasticity in Patients with Type 2 Diabetes Mellitus

Epicardial adipose tissue (EAT) is an emerging cardiovascular risk factor located between the myocardium and visceral pericardium. In order to investigate the association between EAT and ascending aorta elasticity in patients with type 2 diabetes mellitus (T2DM), we prospectively enrolled a total of 135 T2DM patients and 63 age- and gender-matched non-T2DM controls in this study. They all underwent transthoracic echocardiography to measure EAT thickness and ascending aorta inner diameters which were used to calculate ascending aorta elastic parameters: compliance (C), distensibility (D), strain (S), stiffness index (SI), and Peterson's elastic modulus (EM). We found that the values of C, D, and S were significantly lower, while SI, EM, and EAT thickness were significantly higher in T2DM patients compared with non-T2DM controls. Compared with T2DM patients with EAT < 5 mm group, C, D, and S were significantly reduced, SI and EM were significantly increased in T2DM patients with EAT ≥ 5 mm group (all P < .05). Bivariate correlation and multivariate linear regression analysis revealed that EAT was independently associated with ascending aorta elasticity. Our findings suggest that thickened EAT in patients with T2DM is associated with ascending aorta elasticity, independent of blood glucose.

Cardiovascular risk factors and pericardial fat volume as predictors of coronary atherosclerosis burden in postmenopausal women: A retrospective, single center study

Background and Aims

Little is known about the clinical relevance of pericardial fat volume (PFV), compared to other conventional cardiovascular risk factors, as predictors of coronary atherosclerosis severity among postmenopausal women. Our main aim was to assess the association of PFV and cardiovascular risk factors with coronary atherosclerosis burden, including occlusive coronary artery disease (CAD) (luminal stenosis >50%), coronary artery calcium score (CAC) >100, and plaque types in postmenopausal women.

Methods

Patients who had chest pain of angina and referred for 64‐slice multi‐detector CT (MDCT) angiography examination to exclude occlusive CAD presence were enrolled in this retrospective study.

Results

A total of 241 women with absence of menses for more than 2 consecutive years and not taking hormone replacement therapy were enrolled in the present study. Increased PFV (OR [CI] = 1.1 [1−1.3], p = 0.004), age (OR [CI] = 1.1 [1−1.4], p = 0.002), and diabetes mellitus (OR [CI] = 2 [1−4], p = 0.025) were significant predictors of occlusive CAD presence. Increased PFV (OR [CI] = 1.1 [1−1.4], p = 0.017) and increased age (OR [CI] = 1.2 [1.1−1.4], p < 0.001) were better predictors of CAC >100 than other cardiovascular risk factors. Regarding coronary plaque types, increased age (OR [CI] = 1.1 [1.1−1.3], p = 0.001) showed a significant association with coronary calcified plaque presence while increased body mass index(OR [CI] = 1.2 [1−1.4], p = 0.018) showed a significant association with coronary non‐calcified plaque presence.

Conclusion

Higher PFV values showed an independent association with occlusive CAD and significant coronary calcification. This may imply that increased PFV is likely associated with the development of advanced and severe phenotype of coronary atherosclerosis among postmenopausal women with suspected CAD.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Associations between coronary/aortic 18F-sodium fluoride uptake and pro-atherosclerosis factors in patients with multivessel coronary artery disease

BACKGROUND

18F-NaF PET/CT is a novel approach to detect and quantify microcalcification in atherosclerosis. We aimed to explore the underlying systematic vascular osteogenesis in the coronary artery and aorta in patients with multivessel coronary artery disease (CAD).

METHODS

Patients with multivessel CAD prospectively underwent 18F-NaF PET/CT. The coronary microcalcification activity (CMA) and aortic microcalcification activity (AMA) were calculated based on both the volume and intensity of 18F-NaF PET activity. Peri-coronary adipose tissue (PCAT) density was measured in adipose tissue surrounding the coronary arteries and the 18F-NaF tissue-to-blood ratio (TBR) was measured in the coronary arteries.

RESULTS

100 patients with multivessel CAD were prospectively recruited. The CMA was significantly associated with the AMA (r = 0.70; P < .001). After multivariable adjustment, the CMA was associated with the AMA (Beta = 0.445 per SD increase; P < .001). The coronary TBR was also significantly associated with the PCAT density (r = 0.56; P < .001). The PCAT density was independently associated with the coronary TBR after adjusting confounding factors.

CONCLUSIONS

Coronary 18F-NaF uptake was significantly associated with the PCAT density. There was a significant relationship between the coronary and the aortic 18F-NaF uptake. It might indicate an underlying systematic vascular osteogenesis in patients with multivessel CAD.

Epicardial adipose tissue volume is not an independent predictor of atrial fibrillation recurrence after catheter ablation

INTRODUCTION AND OBJECTIVES

Previous studies have suggested that epicardial adipose tissue (EAT) could exert a paracrine effect in the myocardium. However, few studies have assessed its role in the risk of atrial fibrillation (AF) recurrence. This study aimed to evaluate the association between EAT volume, and its attenuation, with the risk of AF recurrence after AF ablation.

METHODS

A total of 350 consecutive patients who underwent AF ablation were included. The median age was 57 [IQR 48-65] years and 21% had persistent AF. Epicardial fat was quantified by multidetector computed tomography using Syngo.via Frontier-Cardiac Risk Assessment software, measuring pericardial fat volume (PATV), EAT volume, and attenuation of EAT posterior to the left atrium. AF recurrence was defined as any documented episode of AF, atrial flutter, or atrial tachycardia more than 3 months after the procedure.

RESULTS

After a median follow-up of 34 [range, 12-57] months, 114 patients (33%) had AF recurrence. Univariable Cox regression showed that patients with an EAT volume ≥ 80mL had an increased risk of AF recurrence (HR, 1.65; 95%CI, 1.14-2.39; P=.007). However, after multivariable adjustment, EAT volume did not remain an independent predictor of AF recurrence (HR, 1.24; 95%CI, 0.83-1.87; P=.3). Similar results were observed with PATV. Patients with lower attenuation of EAT did not have a higher risk of AF recurrence (log-rank test, P=.75).

CONCLUSIONS

EAT parameters including the evaluation of EAT volume, PATV and EAT attenuation were not independent predictors of AF recurrence after catheter ablation.

Epicardial fat volume is related to the degree of cardiac allograft vasculopathy

Objectives

Increasing evidence suggests a role for epicardial fat in the development of coronary artery disease in the general population. Heart transplantation patients are at increased risk of developing a specific form of coronary artery disease, cardiac allograft vasculopathy (CAV), which has far-reaching consequences in terms of morbidity and mortality. Until now, the role of epicardial fat volume (EFV) in the development of CAV remains unknown. Hence, we investigated the relationship between EFV and CAV as well as the influence of donor/recipient sex on EFV.

Methods

Adult heart transplant patients who underwent coronary computed tomography angiography (CCTA) for CAV screening who were four or more years post-HT were included. Using the CT examinations, we quantified the EFV and the degree of CAV. Ordinal and linear regression models were used to assess the association of EFV with CAV.

Results

In total, 149 (median age 44.5 years, 36% women) patients were included. The median time between HT and the CT scan was 11.0 (7.3–16.1) years. CAV grade 0, 1, 2 and 3 were seen in 85 (57%), 32 (22%), 14 (9%), and 18 (12%) patients, respectively. The median EFV was 208.4 (128.9–276.0) mL. Larger EFV were related to higher degrees of CAV (median of 164.7 to 290.6 mL for CAV grade 0 and 3, respectively, OR 5.23 (2.47–11.06), p < 0.001). Male recipients had significantly more EFV than female recipients irrespective of the donor sex (232.7 mL vs. 147.2 mL respectively, p < 0.001). Determinants for EFV were recipient sex, number of rejections, donor age, time between HT and CT scan, recipient BMI, and diabetes mellitus.

Conclusions

EFV was associated with higher degrees of CAV. The recipient sex influenced the EFV more than the donor sex.

Key Points

• Patients after heart transplantation have a high amount of epicardial fat while larger amounts of epicardial fat are related to higher grades of cardiac allograft vasculopathy.

• Determinants of higher epicardial fat volume included recipient sex, number of rejections, donor age, time between HT and CT scan, recipient BMI, and diabetes mellitus.

• Longitudinal studies are needed to further disentangle the role of epicardial fat in the development and progression of cardiac allograft vasculopathy.

Graphical abstract

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.

Serum and Adipose Dipeptidyl Peptidase 4 in Cardiovascular Surgery Patients: Influence of Dipeptidyl Peptidase 4 Inhibitors

Dipeptidyl peptidase 4 (DPP-4) is a novel adipokine and may be involved in the association between adipose tissue and metabolic syndrome. We investigated DPP-4 and adiponectin levels in the serum, subcutaneous adipose tissue (SAT), and epicardial adipose tissue (EAT), and their relationship with preoperative factors, as well as comparing the DPP-4 levels in SAT and EAT with and without DPP-4 inhibitors. This study included 40 patients (25 men, age 67.5 ± 13.8 years). The serum adipokine, DPP-4, and adiponectin levels in SAT and EAT were measured using ELISA and Western blotting. The DPP-4 and adiponectin levels were significantly higher in the SAT than in the EAT. The serum DPP-4 and DPP-4 activity levels had no correlation with the DPP-4 levels in the SAT and EAT, but the DPP-4 levels in the SAT and EAT had a positive correlation. The DPP-4 levels in the SAT were positively correlated with atherosclerosis, diabetes mellitus, DPP-4-inhibitor use, and fasting blood glucose. The DPP-4 levels in the EAT showed a negative correlation with eGFR and a positive correlation with atrial fibrillation. The DPP-4 activity in the serum had a lower tendency in the group taking DPP-4 inhibitors than in the group not taking them. DPP-4 inhibitors may suppress angiogenesis and adipose-tissue hypertrophy.

Diabesity in Elderly Cardiovascular Disease Patients: Mechanisms and Regulators

Cardiovascular disease (CVD) is the leading cause of death in the world. In 2019, 550 million people were suffering from CVD and 18 million of them died as a result. Most of them had associated risk factors such as high fasting glucose, which caused 134 million deaths, and obesity, which accounted for 5.02 million deaths. Diabesity, a combination of type 2 diabetes and obesity, contributes to cardiac, metabolic, inflammation and neurohumoral changes that determine cardiac dysfunction (diabesity-related cardiomyopathy). Epicardial adipose tissue (EAT) is distributed around the myocardium, promoting myocardial inflammation and fibrosis, and is associated with an increased risk of heart failure, particularly with preserved systolic function, atrial fibrillation and coronary atherosclerosis. In fact, several hypoglycaemic drugs have demonstrated a volume reduction of EAT and effects on its metabolic and inflammation profile. However, it is necessary to improve knowledge of the diabesity pathophysiologic mechanisms involved in the development and progression of cardiovascular diseases for comprehensive patient management including drugs to optimize glucometabolic control. This review presents the mechanisms of diabesity associated with cardiovascular disease and their therapeutic implications.

Quantification of epicardial adipose tissue in obese patients using an open-bore MR scanner

Background

Our aim was to evaluate the reproducibility of epicardial adipose tissue (EAT) volume, measured on scans performed using an open-bore magnetic resonance scanner.

Methods

Consecutive patients referred for bariatric surgery, aged between 18 and 65 years who agreed to undergo cardiac imaging (MRI), were prospectively enrolled. All those with cardiac pathology or contraindications to MRI were excluded. MRI was performed on a 1.0-T open-bore scanner, and EAT was segmented on all scans at both systolic and diastolic phase by two independent readers (R1 with four years of experience and R2 with one year). Data were reported as median and interquartile range; agreement and differences were appraised with Bland-Altman analyses and Wilcoxon tests, respectively.

Results

Fourteen patients, 11 females (79%) aged 44 (41–50) years, underwent cardiac MRI. For the first and second readings, respectively, EAT volume was 86 (78–95) cm³ and 85 (79–91) cm³ at systole and 82 (74–95) cm³ and 81 (75–94) cm³ at diastole for R1, and 89 (79–99) cm³ and 93 (84–98) cm³ at systole and 92 (85–103) cm³ and 93 (82–94) cm³ at diastole for R2. R1 had the best reproducibility at diastole (bias 0.3 cm³, standard deviation of the differences (SD) 3.3 cm³). R2 had the worst reproducibility at diastole (bias 3.9 cm³, SD 12.1 cm³). The only significant difference between systole and diastole was at the first reading by R1 (p = 0.016). The greatest bias was that of inter-reader reproducibility at diastole (-9.4 cm³).

Conclusions

Reproducibility was within clinically acceptable limits in most instances.

Association between epicardial adipose tissue and left ventricular function in type 2 diabetes mellitus: Assessment using two-dimensional speckle tracking echocardiography

BACKGROUND AND AIMS

Epicardial adipose tissue (EAT) is the visceral fat between the myocardium and the visceral pericardium. Dysfunctional EAT can cause cardiovascular diseases. The aim of this study was to investigate the association between EAT and left ventricular function in type 2 diabetes mellitus (T2DM) patients by two-dimensional speckle tracking echocardiography (2D-STE).

METHODS

We prospectively enrolled 116 T2DM patients who were divided into two groups according to their left ventricular global longitudinal strain (GLS): 53 with GLS <18% and 63 with GLS ≥18%. The thickness of EAT was measured as the echo-free space between the free wall of the right ventricle and the visceral layer of pericardium at end-systole. LV systolic function was evaluated by GLS measured by 2D-STE. LV diastolic function was defined as the ratio of the early diastolic transmitral flow velocity (E) to average mitral annular velocity (e¯).

RESULTS

Compared with patients with GLS ≥18% group, the age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-C), glycosylated hemoglobinA1c (HbA1c), E/e¯, and thickness of EAT were higher in patients with GLS <18% group (all P < 0.05). Multivariate linear regression analysis revealed that the thickness of EAT was independently associated with left ventricular GLS and E/e¯.

CONCLUSIONS

Thickened EAT is associated with impaired left ventricular function in T2DM patients. To investigate the association between EAT and left ventricular function can help us gain a deeper understanding of the pathogenesis of impaired cardiac function in T2DM patients.

ANGPTL4 Expression Is Increased in Epicardial Adipose Tissue of Patients with Coronary Artery Disease

Epicardial adipose tissue (EAT) is known to affect atherosclerosis and coronary artery disease (CAD) pathogenesis, persistently releasing pro-inflammatory adipokines that affect the myocardium and coronary arteries. Angiopoietin-like 4 (ANGPTL4) is a protein secreted from adipose tissue and plays a critical role in the progression of atherosclerosis. Here, the expression of ANGPTL4 in EAT was investigated in CAD subjects. Thirty-four consecutive patients (13 patients with significant CAD; 21 patients without CAD) undergoing elective open-heart surgery were recruited. EAT and pericardial fluid were obtained at the time of surgery. mRNA expression and ANGPTL4 and IL-1β levels were evaluated by qRT-PCR and ELISA. The expression of ANGPTL4 (p = 0.0180) and IL-1β (p < 0.0001) in EAT significantly increased in the CAD group compared to that in the non-CAD group and positively correlated (p = 0.004). Multiple regression analysis indicated that CAD is a contributing factor for ANGPTL4 expression in EAT. IL-1β level in the pericardial fluid was significantly increased in patients with CAD (p = 0.020). Moreover, the expression of ANGPTL4 (p = 0.004) and IL-1β (p < 0.001) in EAT was significantly increased in non-obese patients with CAD. In summary, ANGPTL4 expression in EAT was increased in CAD patients.

Adipokine gene expression in adipocytes isolated from different fat depots of coronary artery disease patients

To compare DPP4, LCN2, NAMPT, ITLN1, APLN mRNA levels in adipocytes isolated from the biopsies of subcutaneous, epicardial and perivascular fat obtained from 25 patients with coronary artery disease. Gene expression signature was determined by RT-qPCR with hydrolysis probes. We found DPP4 and APLN mRNA was higher expressed only in adipocytes isolated from epicardial adipose tissue compared to the subcutaneous fat. The ITLN1 gene was overexpressed in epicardial adipose tissue compared to both subcutaneous and perivascular tissues. APLN mRNA expression was positively correlated with total and LDL cholesterol plasma level, and DPP4 mRNA expression - with VLDL cholesterol concentration. Thus, adipocytes isolated from different adipose depots are characterised by differential gene expression of adipokines. Epicardial adipose tissue is of particular interest in the context of its function, molecular and genetic mechanisms of regulation of the cardiovascular system and as a therapeutic target for correction of adipose tissue-induced effects on health.

Additive value of epicardial adipose tissue quantification to coronary CT angiography-derived plaque characterization and CT fractional flow reserve for the prediction of lesion-specific ischemia

OBJECTIVES

Epicardial adipose tissue (EAT) from coronary CT angiography (CCTA) is strongly associated with coronary artery disease (CAD). We investigated the additive value of EAT volume to coronary plaque quantification and CT-derived fractional flow reserve (CT-FFR) to predict lesion-specific ischemia.

METHODS

Patients (n = 128, 60.6 ± 10.5 years, 61% male) with suspected CAD who had undergone invasive coronary angiography (ICA) and CCTA were retrospectively analyzed. EAT volume and plaque measures were derived from CCTA using a semi-automatic software approach, while CT-FFR was calculated using a machine learning algorithm. The predictive value and discriminatory power of EAT volume, plaque measures, and CT-FFR to identify ischemic CAD were assessed using invasive FFR as the reference standard.

RESULTS

Fifty-five of 152 lesions showed ischemic CAD by invasive FFR. EAT volume, CCTA ≥ 50% stenosis, and CT-FFR were significantly different in lesions with and without hemodynamic significance (all p < 0.05). Multivariate analysis revealed predictive value for lesion-specific ischemia of these parameters: EAT volume (OR 2.93, p = 0.021), CCTA ≥ 50% (OR 4.56, p = 0.002), and CT-FFR (OR 6.74, p < 0.001). ROC analysis demonstrated incremental discriminatory value with the addition of EAT volume to plaque measures alone (AUC 0.84 vs. 0.62, p < 0.05). CT-FFR (AUC 0.89) showed slightly superior performance over EAT volume with plaque measures (AUC 0.84), however without significant difference (p > 0.05).

CONCLUSIONS

EAT volume is significantly associated with ischemic CAD. The combination of EAT volume with plaque quantification demonstrates a predictive value for lesion-specific ischemia similar to that of CT-FFR. Thus, EAT may aid in the identification of hemodynamically significant coronary stenosis.

KEY POINTS

• CT-derived EAT volume quantification demonstrates high discriminatory power to identify lesion-specific ischemia. • EAT volume shows incremental diagnostic performance over CCTA-derived plaque measures in detecting lesion-specific ischemia. • A combination of plaque measures with EAT volume provides a similar discriminatory value for detecting lesion-specific ischemia compared to CT-FFR.

Relationship between epicardial fat volume measured by multi-detector computed tomography and coronary artery disease

Background

The association between epicardial fat thickness and coronary artery disease (CAD) has been evaluated previously using echocardiography. Recently, multidetector computed tomography (MDCT), as a valuable tool in cardiovascular CT imaging, can improve characterization of CAD and give a more accurate volumetric quantitation of EF. The purpose of our study was to evaluate the relationship between the epicardial fat volume and CAD using multi-detector row CT.

Results

Out of the studied 120 patients, 22 patients were negative for CAD, while 98 patients had positive CAD. There was significant difference between both groups as regard epicardial fat volume (p < 0.001), and good relation was found between the amount of epicardial fat volume and coronary calcium score, number of affected vessel, plaque burden and degree of stenosis (p =  < 0.001).

Conclusion

EAT volume was larger in the presence of obstructive CAD and atheromatous plaques. These data suggest that EAT is associated with the development of coronary atherosclerosis and potentially the most dangerous types of plaques.

Epicardial adipose tissue radiodensity is associated with all-cause mortality in patients undergoing hemodialysis

The radiodensity and volume of epicardial adipose tissue (EAT) on computed tomography angiography (CTA) may provide information regarding cardiovascular risk and long-term outcomes. EAT volume is associated with mortality in patients undergoing incident hemodialysis. However, the relationship between EAT radiodensity/volume and all-cause mortality in patients with end-stage renal disease (ESRD) undergoing maintenance hemodialysis remains elusive. In this retrospective study, EAT radiodensity (in Hounsfield units) and volume (in cm³) on coronary CTA were quantified for patients with ESRD using automatic, quantitative measurement software between January 2012 and December 2018. All-cause mortality data (up to December 2019) were obtained from the Korean National Statistical Office. The prognostic values of EAT radiodensity and volume for predicting long-term mortality were assessed using multivariable Cox regression models, which were adjusted for potential confounders. A total of 221 patients (mean age: 64.88 ± 11.09 years; 114 women and 107 men) with ESRD were included. The median follow-up duration (interquartile range) after coronary CTA was 29.63 (range 16.67–44.7) months. During follow-up, 82 (37.1%) deaths occurred. In the multivariable analysis, EAT radiodensity (hazard ratio [HR] 1.055; 95% confidence interval [CI] 1.015–1.095; p = 0.006) was an independent predictor of all-cause mortality in patients with ESRD. However, EAT volume was not associated with mortality. Higher EAT radiodensity on CTA is associated with higher long-term all-cause mortality in patients undergoing prevalent hemodialysis, highlighting its potential as a prognostic imaging biomarker in patients undergoing hemodialysis.

Epicardial adipocyte-derived TNF-α modulates local inflammation in patients with advanced coronary artery disease

BACKGROUND

Epicardial adipose tissue (EAT) surrounds the epicardium and can mediate harmful effects related to coronary artery disease (CAD).

OBJECTIVE

We explored the regional differences between adipose stores surrounding diseased and non-diseased segments of coronary arteries in patients with advanced CAD.

METHODS

We enrolled 32 patients with known CAD who underwent coronary artery bypass graft (CABG) surgery. Inflammatory mediators were measured in EAT biopsies collected from a region of the left anterior descending artery (LAD) with severe stenosis (diseased segment) and without stenosis (non-diseased segment).

RESULTS

Mean age was 64.3±11.1 years, and mean EAT thickness was 7.4±1.9 mm. Dyslipidemia was the most prevalent comorbidity (81% of the patients). Out of a total of 11 cytokines, resistin (p=0.039), matrix metallopeptidase 9 (MMP-9) (p=0.020), C-C motif chemokine ligand 5 (CCL-5) (p=0.021), and follistatin (p=0.038) were significantly increased in the diseased compared with the non-diseased EAT segments. Indexed tumor necrosis factor-alpha (TNF-α), defined as the diseased to non-diseased cytokine levels ratio, was significantly correlated with increased EAT thickness both in the whole cohort (p=0.043) and in a subpopulation of patients with dyslipidemia (p=0.009). Treatment with lipid-lowering agents significantly decreased indexed TNF-α levels (p=0.015). No significant alterations were observed in the circulating levels of these cytokines with respect to CAD-associated comorbidities.

CONCLUSION

Perivascular EAT is a source of cytokine secretion in distinct areas surrounding the coronary arteries in patients with advanced CAD. Adipocyte-derived TNF-α is a prominent mediator of local inflammation.

Epicardial adipose tissue volume is greater in men with severe psoriasis, implying an increased cardiovascular disease risk: A cross-sectional study

BACKGROUND

Patients with psoriasis have elevated risk of coronary artery disease.

OBJECTIVE

Do patients with severe psoriasis have larger epicardial adipose tissue volumes (EAT-V) that are associated with cardiovascular risk?

METHODS

For this cross-sectional study, we recruited dermatology patients with severe psoriasis and control patients without psoriasis or rheumatologic disease themselves or in a first-degree relative. Participants aged 34 to 55 years without known coronary artery disease or diabetes mellitus underwent computed tomography (CT); EAT-V was obtained from noncontrast CT heart images.

RESULTS

Twenty-five patients with psoriasis (14 men, 11 women) and 16 controls (5 men, 11 women) participated. Groups had no statistical difference in age, body mass index, various cardiovascular risk factors (except high-sensitivity C-reactive protein in men), CT-determined coronary artery calcium scores or plaque, or family history of premature cardiovascular disease. Mean EAT-V was greater in the psoriasis group compared to controls (P = .04). There was no statistically significant difference among women; however, male patients with psoriasis had significantly higher EAT-V than controls (P = .03), even when corrected for elevated high-sensitivity C-reactive protein (P = .05).

LIMITATIONS

A single-center convenience sample may not be representative.

CONCLUSION

Males with psoriasis without known coronary disease or diabetes had greater EAT-V than controls. EAT-V may be an early identifier of those at increased risk for cardiovascular events.

Association of epicardial fat with noncalcified coronary plaque volume and with low attenuation plaque in people with HIV

OBJECTIVES

People with HIV are exposed to a higher risk of coronary artery disease (CAD) compared with the general population. Epicardial fat may play a unique role in promoting coronary atherosclerosis. We measured epicardial fat in participants living with HIV and controls and investigated its association with coronary plaque volume and low attenuation plaque, a marker of plaque vulnerability.

DESIGN

This is a cross-sectional study, nested in the Canadian HIV and Aging Cohort Study, a large prospective cohort actively following participants with HIV and controls. Participants with low/intermediate cardiovascular risk without symptoms/history of CAD were invited to undergo cardiac computed tomography (CT).

METHODS

Volume of epicardial fat, coronary plaque and low attenuation component of the plaque were measured. Association between epicardial fat, coronary plaque volume and low attenuation component was tested using adjusted regression analysis.

RESULTS

A total of 169 participants with HIV and 81 controls underwent cardiac CT. Participants with HIV had a greater epicardial fat volume compared with controls (P = 0.019). In participants with HIV, epicardial fat volume was positively associated with duration of nonnucleoside reverse transcriptase inhibitors (NNRTI) (β=2.19, P = 0.004). After adjustment for cardiovascular risk factors, epicardial fat volume was positively associated to noncalcified plaque volume [odds ratio (OR) = 1.09, P = 0.028] and to the low-attenuation plaque component portion (β=0.38, P = 0.026).

CONCLUSION

The association of epicardial fat volume to noncalcified plaque volume and to low attenuation component plaque may suggest a potential mechanism by which epicardial fat could be a silent driver of CAD in the HIV population.

Ideal cardiovascular health metrics and epicardial adipose tissue volume in a Northern Chinese population: a cross-sectional study

Background

Coronary artery disease, fatty liver disease, cardiac abnormalities, the metabolic syndrome, and insulin resistance may all occur in association with an increase of epicardial adipose tissue volume (EATV). Previous studies have shown that some cardiovascular-risk factors and healthy behaviors were related to a lower risk of EATV increase. The main purpose of this study was to determine whether ideal cardiovascular health (CVH) metrics were correlated with the prevalence of high EATV.

Methods

The study commenced across 2013 and 2014 and involved volunteers from the Jidong (East Hebei) district. A cohort of 2,482 participants aged 45 years or older were randomly selected, of which 49.9% were women and none were diagnosed as having cancer, stroke, or heart diseases such as atrial fibrillation, heart failure, or myocardial infarction. The study collected information concerning seven CVH metrics; namely body mass index, dietary intake, smoking, blood pressure, physical activity, total cholesterol, and fasting blood glucose, and evaluated EATV based on computed tomography. Finally, an analysis of the relationship between ideal CVH metrics and the prevalence of high EATV was made applying multiple logistic regression.

Results

On the basis that age, gender, and other potential confounding factors are adjusted, comparing the participants having an ideal CVH index of 2, 3, 4, 5 and 6–7 with those having a 0–1 metric, the adjusted odds ratios (95% confidence interval) of high EATV were as follows: 0.893 (0.468–1.705), 0.581 (0.316–1.069), 0.368 (0.202–0.670), 0.218 (0.119–0.400), and 0.161 (0.085–0.306) (P trend less than 0.0001). Similar negative correlations were also seen in other cases of different age groups and gender groups, where all P trends were less than 0.0001.

Conclusions

The number of ideal CVH metrics in the northern Chinese population is negatively correlated with the prevalence of high EATV, supporting the greater use of EATV as a useful parameter in clinical practice.

Association of Epicardial Fat Volume With Increased Risk of Obstructive Coronary Artery Disease in Chinese Patients With Suspected Coronary Artery Disease

Background Epicardial adipose tissue may be associated with the pathogenesis of coronary artery disease (CAD), but its effect on obstructive CAD risk is uncertain. Therefore, we aimed to examine the relationship between epicardial adipose tissue and obstructive CAD in Chinese patients with suspected CAD. Methods and Results The present study enrolled 194 consecutive inpatients with suspected CAD who underwent both noncontrast computed tomography and coronary angiography. We measured epicardial fat volume (EFV) and evaluated its association with obstructive CAD, which was defined as coronary stenosis severity ≥70%. Overall, 44.3% patients had obstructive CAD and tend to have higher EFV. Age, body mass index, triglycerides, incidence of hypertension, and hyperlipidemia were higher across tertiles of EFV (P for trend <0.05). In univariate regression analysis, a per-SD increase in EFV was independently associated with obstructive CAD (odds ratio [OR], 2.31; 95% CI, 1.61-3.32; P<0.001). Consistent with these findings, EFV was still significantly related to obstructive CAD as continuous variable after adjustment for all traditional risk factors and coronary artery calcium (OR per SD, 2.82; 95% CI, 1.68-4.74; P<0.001). Generalized additive model indicated that EFV was linearly associated with risk of obstructive CAD. E-value analysis suggested robustness to unmeasured confounding. Conclusions Our results suggested that in Chinese patients with suspected CAD, EFV was significantly and positively associated with the risk of obstructive CAD, independent of traditional risk factors and coronary artery calcium.

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.

Quantification of epicardial fat using non contrast cardiac CT in an HIV population: Reproducibility and association with other body fat indices

•

Assessment of epicardial fat volume is highly reproducible.

•

Epicardial fat volume and epicardial fat area have a good correlation to BMI.

•

Epicardial fat volume correlates best with DEXA-derived total body fat and trunk fat.

•

Epicardial fat volume should be considered over other CT assessment methods when quantifying epicardial fat in HIV patients.

Purpose

To assess the reproducibility of different epicardial fat measurement and their association with other adiposity measurements in HIV-infected and non-HIV-infected patients.

Methods and materials

In this cross-sectional study, 167 HIV-infected and 58 non-HIV-infected consecutive participants (200 males; mean age 56 years) with low/intermediate cardiovascular risk were recruited between 2012 and 2017 from a large prospective cohort and underwent non-contrast cardiac CT. Two independent observers measured epicardial fat volume, area and thickness in all participants. For intra-observer agreement, one observer did a second assessment in a subset of 40 patients. Agreement was assessed with the intraclass correlation coefficient (ICC). Pearson's correlation was estimated to assess the association between epicardial fat, body-mass index (BMI) and dual-energy x-ray absorptiometry (DEXA) derived percentage of body fat.

Results

Inter-observer agreement was excellent for epicardial fat volume (ICC 0.75) and area (ICC 0.95) and good for epicardial fat thickness (ICC near the left anterior descending artery (LAD) 0.64, ICC near right coronary artery (RCA) 0.64). Intra-observer agreement was excellent for epicardial fat volume (ICC 0.97), area (ICC 0.99), thickness at LAD (ICC 0.71) and good for epicardial fat thickness at RCA (ICC 0.68). Epicardial fat volume had a better correlation to total body fat (r = 0.28, p < 0.001) and trunk fat (r = 0.37, p < 0.001), in comparison to other epicardial fat indices.

Conclusion

Assessment of epicardial fat volume is highly reproducible in both HIV-infected and non-HIV-infected patients and shows a superior correlation with DEXA-based body and trunk fat measurements. Epicardial fat volume should be considered over other CT assessment methods when quantifying epicardial fat in HIV patients.

Unraveling the Role of Epicardial Adipose Tissue in Coronary Artery Disease: Partners in Crime?

The role of epicardial adipose tissue (EAT) in the pathophysiology of coronary artery disease (CAD) remains unclear. The present systematic review aimed at compiling dysregulated proteins/genes from different studies to dissect the potential role of EAT in CAD pathophysiology. Exhaustive literature research was performed using the keywords "epicardial adipose tissue and coronary artery disease", to highlight a group of proteins that were consistently regulated among all studies. Reactome, a pathway analysis database, was used to clarify the function of the selected proteins and their intertwined association. SignalP/SecretomeP was used to clarify the endocrine function of the selected proteins. Overall, 1886 proteins/genes were identified from 44 eligible studies. The proteins were separated according to the control used in each study (EAT non-CAD or subcutaneous adipose tissue (SAT) CAD) and by their regulation (up- or downregulated). Using a Venn diagram, we selected the proteins that were upregulated and downregulated (identified as 27 and 19, respectively) in EAT CAD for both comparisons. The analysis of these proteins revealed the main pathways altered in the EAT and how they could communicate with the heart, potentially contributing to CAD development. In summary, in this study, the identified dysregulated proteins highlight the importance of inflammatory processes to modulate the local environment and the progression of CAD, by cellular and metabolic adaptations of epicardial fat that facilitate the formation and progression of atherogenesis of coronaries.

Quantitative Imaging of Body Composition

Body composition refers to the amount and distribution of lean tissue, adipose tissue, and bone in the human body. Lean tissue primarily consists of skeletal muscle; adipose tissue comprises mostly abdominal visceral adipose tissue and abdominal and nonabdominal subcutaneous adipose tissue. Hepatocellular and myocellular lipids are also fat pools with important metabolic implications. Importantly, body composition reflects generalized processes such as increased adiposity in obesity and age-related loss of muscle mass known as sarcopenia.In recent years, body composition has been extensively studied quantitatively to predict overall health. Multiple imaging methods have allowed precise estimates of tissue types and provided insights showing the relationship of body composition to varied pathologic conditions. In this review article, we discuss different imaging methods used to quantify body composition and describe important anatomical locations where target tissues can be measured.

Coronary Microvascular Dysfunction

Many patients with chest pain undergoing coronary angiography do not show significant obstructive coronary lesions. A substantial proportion of these patients have abnormalities in the function and structure of coronary microcirculation due to endothelial and smooth muscle cell dysfunction. The coronary microcirculation has a fundamental role in the regulation of coronary blood flow in response to cardiac oxygen requirements. Impairment of this mechanism, defined as coronary microvascular dysfunction (CMD), carries an increased risk of adverse cardiovascular clinical outcomes. Coronary endothelial dysfunction accounts for approximately two-thirds of clinical conditions presenting with symptoms and signs of myocardial ischemia without obstructive coronary disease, termed "ischemia with non-obstructive coronary artery disease" (INOCA) and for a small proportion of "myocardial infarction with non-obstructive coronary artery disease" (MINOCA). More frequently, the clinical presentation of INOCA is microvascular angina due to CMD, while some patients present vasospastic angina due to epicardial spasm, and mixed epicardial and microvascular forms. CMD may be associated with focal and diffuse epicardial coronary atherosclerosis, which may reinforce each other. Both INOCA and MINOCA are more common in females. Clinical classification of CMD includes the association with conditions in which atherosclerosis has limited relevance, with non-obstructive atherosclerosis, and with obstructive atherosclerosis. Several studies already exist which support the evidence that CMD is part of systemic microvascular disease involving multiple organs, such as brain and kidney. Moreover, CMD is strongly associated with the development of heart failure with preserved ejection fraction (HFpEF), diabetes, hypertensive heart disease, and also chronic inflammatory and autoimmune diseases. Since coronary microcirculation is not visible on invasive angiography or computed tomographic coronary angiography (CTCA), the diagnosis of CMD is usually based on functional assessment of microcirculation, which can be performed by both invasive and non-invasive methods, including the assessment of delayed flow of contrast during angiography, measurement of coronary flow reserve (CFR) and index of microvascular resistance (IMR), evaluation of angina induced by intracoronary acetylcholine infusion, and assessment of myocardial perfusion by positron emission tomography (PET) and magnetic resonance (CMR).

Association between non-alcoholic fatty liver disease and coronary calcification depending on sex and obesity

Non-alcoholic fatty liver disease (NAFLD) is considered a hepatic manifestation of metabolic syndrome and is associated with cardiovascular outcomes. We investigated whether NAFLD was associated with coronary artery calcification (CAC) in participants without a previous history of cardiovascular disease and whether this association differed according to sex and obesity status after adjustment for other atherosclerosis risk factors, alcohol intake, and liver enzyme levels. Among 67,441 participants, data from 8,705 participants who underwent a fatty liver status and CAC assessment during routine health screening were analysed. CAC scores were calculated using computed tomography. NAFLD was diagnosed in patients with evidence of liver steatosis on ultrasonography. Obesity was defined as a body mass index of ≥25 kg/m². Multivariate analysis showed a significant association between NAFLD and CAC in non-obese participants (odds ratio, 1.24 [95% confidence interval, 1.01–1.53]), whereas NAFLD and CAC were not associated in obese participants. Interaction analysis showed that the association between NAFLD and CAC was influenced by sex and obesity. Subgroup analysis revealed a significant association between NAFLD and CAC in non-obese male participants (odds ratio, 1.36 [1.07–1.75]), but not in female participants. Our study indicates that non-obese men with NAFLD are prone to CAC.

Perivascular Adipose Tissue and Coronary Atherosclerosis: from Biology to Imaging Phenotyping

PURPOSE OF REVIEW

Perivascular adipose tissue (PVAT) has a complex, bidirectional relationship with the vascular wall. In disease states, PVAT secretes pro-inflammatory adipocytokines which may contribute to atherosclerosis. Recent evidence demonstrates that pericoronary adipose tissue (PCAT) may also function as a sensor of coronary inflammation. This review details PVAT biology and its clinical translation to current imaging phenotyping.

RECENT FINDINGS

PCAT attenuation derived from routine coronary computed tomography (CT) angiography is a novel noninvasive imaging biomarker of coronary inflammation. Pro-inflammatory cytokines released from the arterial wall diffuse directly into the surrounding PCAT and inhibit adipocyte lipid accumulation in a paracrine manner. This can be detected as an increased PCAT CT attenuation, a metric which associates with high-risk plaque features and independently predicts cardiac mortality. There is also evidence that PCAT attenuation relates to coronary plaque progression and is modified by systemic anti-inflammatory therapies. Due to its proximity to the coronary arteries, PCAT has emerged as an important fat depot in cardiovascular research. PCAT CT attenuation has the potential to improve cardiovascular risk stratification, and future clinical studies should examine its role in guiding targeted medical therapy.

Epicardial Fat Volume Improves the Prediction of Obstructive Coronary Artery Disease Above Traditional Risk Factors and Coronary Calcium Score

BACKGROUND

Recent studies have demonstrated the tremendous potential of epicardial fat volume (EFV) to predict obstructive coronary artery disease. We aimed to develop a new model to estimate pretest probability of obstructive coronary artery disease using traditional risk factors with coronary calcium score and EFV and compare it with proposed models in Chinese patients who underwent coronary computed tomography angiography.

METHODS

The new models were derived from 5743 consecutive patients using multivariate logistic regression and validated in an internal cohort using invasive coronary angiography as the outcome and an external cohort with clinical outcome data. Hosmer-Lemeshow goodness-of-fit test, area under the receiver operating characteristic curve, integrated discrimination improvement and net reclassification improvement were calculated to validate and compare the performance of models.

RESULTS

EFV improved prediction above conventional risk factors and coronary calcium score (area under the receiver operating characteristic curve increased from 0.856 to 0.874, integrated discrimination improvement 0.0487, net reclassification improvement 0.1181, P<0.0001 for all). The final model included 5 predictors: age, sex, symptom, coronary calcium score, and EFV. Good internal validation and external validation of the new model were achieved, with positive net reclassification improvement and integrated discrimination improvement, excellent area under the receiver operating characteristic curve and favorable calibration. Further, the new model demonstrated a better prediction of clinical outcome, resulting in a more cost-effective risk stratification to optimize decision-making of downstream diagnosis and treatment.

CONCLUSIONS

Addition of EFV to conventional risk factors and coronary calcium score offered a more accurate and effective estimation for pretest probability of obstructive coronary artery disease, which may help to improve initial management of stable chest pain.

Perirenal fat thickness is associated with metabolic risk factors in patients with chronic kidney disease

Background

Adipose tissue accumulation in specific body compartments has been associated with diabetes, hypertension and dyslipidemia. Perirenal fat (PRF) may lead to have direct lipotoxic effects on renal function and intrarenal hydrostatic pressure. This study was undertaken to explore the association of PRF with cardiovascular risk factors and different stages of chronic kidney disease (CKD).

Methods

We studied 103 patients with CKD of different stages (1 to 5). PRF was measured by B-mode renal ultrasonography in the distal third between the cortex and the hepatic border and/or spleen.

Results

The PRF thickness was greater in CKD patients with impaired fasting glucose than in those with normal glucose levels (1.10 ± 0.40 cm vs. 0.85 ± 0.39 cm, P < 0.01). Patients in CKD stages 4 and 5 (glomerular filtration rate [GFR] < 30 mL/min/1.73 m²) had the highest PRF thickness. Serum triglyceride levels correlated positively with the PRF thickness; the PRF thickness was greater in patients with triglyceride levels ≥ 150 mg/dL (1.09 ± 0.40 cm vs. 0.86 ± 0.36 cm, P < 0.01). In patients with a GFR < 60 mL/min/1.73 m², uric acid levels correlated positively with the PRF thickness (P < 0.05).

Conclusion

In CKD patients, the PRF thickness correlated significantly with metabolic risk factors that could affect kidney function.

Effects of dapagliflozin on human epicardial adipose tissue: modulation of insulin resistance, inflammatory chemokine production, and differentiation ability

Aims

In patients with cardiovascular disease, epicardial adipose tissue (EAT) is characterized by insulin resistance, high pro-inflammatory chemokines, and low differentiation ability. As dapagliflozin reduces body fat and cardiovascular events in diabetic patients, we would like to know its effect on EAT and subcutaneous adipose tissue (SAT).

Methods and results

Adipose samples were obtained from 52 patients undergoing heart surgery. Sodium-glucose cotransporter 2 (SGLT2) expression was determined by real-time polymerase chain reaction (n = 20), western blot, and immunohistochemistry. Fat explants (n = 21) were treated with dapagliflozin and/or insulin and glucose transporters expression measured. Glucose, free fatty acid, and adipokine levels (by array) were measured in the EAT secretomes, which were then tested on human coronary endothelial cells using wound healing assays. Glucose uptake was also measured using the fluorescent glucose analogue (6NBDG) in differentiated stromal vascular cells (SVCs) from the fat pads (n = 11). Finally, dapagliflozin-induced adipocyte differentiation was assessed from the levels of fat droplets (AdipoRed staining) and of perilipin. SGLT2 was expressed in EAT. Dapagliflozin increased glucose uptake (20.95 ± 4.4 mg/dL vs. 12.97 ± 4.1 mg/dL; P < 0.001) and glucose transporter type 4 (2.09 ± 0.3 fold change; P < 0.01) in EAT. Moreover, dapagliflozin reduced the secretion levels of chemokines and benefited wound healing in endothelial cells (0.21 ± 0.05 vs. 0.38 ± 0.08 open wound; P < 0.05). Finally, chronic treatment with dapagliflozin improved the differentiation of SVC, confirmed by AdipoRed staining [539 ± 142 arbitrary units (a.u.) vs. 473 ± 136 a.u.; P < 0.01] and perilipin expression levels (121 ± 10 vs. 84 ± 11 a.u.).

Conclusions

Dapagliflozin increased glucose uptake, reduced the secretion of pro-inflammatory chemokines (with a beneficial effect on the healing of human coronary artery endothelial cells), and improved the differentiation of EAT cells. These results suggest a new protective pathway for this drug on EAT from patients with cardiovascular disease.

Quantification of intrathoracic fat adds prognostic value in women undergoing myocardial perfusion imaging

AIM

Amongst patients with coronary artery disease (CAD), women experience relatively worse outcomes as compared to men. Evidence to date has failed to explore unique female imaging targets as major determinants of cardiovascular risk. We sought to assess the prognostic value of epicardial (EFV) and intrathoracic fat volume (IFV) quantification in women and men with suspected and known CAD.

METHODS AND RESULTS

Intrathoracic fat volume and EFV were calculated from non-contrast CT and analyzed in a propensity-matched cohort of 190 patients (95 women, mean age 62.5 ± 11.3 years) undergoing myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) for evaluation of CAD. IFV and EFV were significantly lower in women as compared to men (198.2 ± 78.4 vs 293.2 ± 114.7 cm³ and 105.6 ± 48.9 vs 135.8 ± 60.9 cm³, p < 0.001) and showed a strong association with coronary artery calcium score (CACS) and obstructive CAD in women (p < 0.05), but not in men. Fat volumes were not related to abnormal MPI in either population (p = NS). During a median follow-up of 2.8 years, high IFV was associated with reduced event free survival (log rank = 0.019 vs low IFV) in women, but not in men. Accordingly, a multivariate Cox regression model adjusted for cardiovascular risk factors, CACS, CCTA, and MPI findings selected IFV as a significant predictor of major adverse cardiovascular events (MACE) in women (HR 1.32, 95%CI 1.18-1.55, p = 0.001).

CONCLUSION

Quantification of IFV provides incremental prognostic value for MACE in women, beyond that provided by traditional risk factors and imaging findings.

Quantification of epicardial fat with cardiac CT angiography and association with cardiovascular risk factors in symptomatic patients: from the ALTER-BIO (Alternative Cardiovascular Bio-Imaging markers) registry

PURPOSE

We aimed to assess the association between features of epicardial adipose tissue and demographic, morphometric and clinical data, in a large population of symptomatic patients with clinical indication to cardiac computed tomography (CT) angiography.

METHODS

Epicardial fat volume (EFV) and adipose CT density of 1379 patients undergoing cardiac CT angiography (918 men, 66.6%; age range, 18-93 years; median age, 64 years) were semi-automatically quantified. Clinical variables were compared between diabetic and nondiabetic patients to assess potential differences in EFV and adipose CT density. Multiple regression models were calculated to find the clinical variables with a significant association with EFV and adipose CT density.

RESULTS

The median EFV in diabetic patients (112.87 mL) was higher compared with nondiabetic patients (82.62 mL; P < 0.001). The explanatory model of the multivariable analysis showed the strongest associations between EFV and BMI (β=0.442) and age (β=0.365). Significant yet minor association was found with sex (β=0.203), arterial hypertension (β=0.072), active smoking (β=0.068), diabetes (β=0.068), hypercholesterolemia (β=0.046) and cardiac height (β=0.118). The mean density of epicardial adipose tissue was associated with BMI (β=0.384), age (β=0.105), smoking (β=0.088), and diabetes (β=0.085).

CONCLUSION

In a large population of symptomatic patients, EFV is higher in diabetic patients compared with nondiabetic patients. Clinical variables are associated with quantitative features of epicardial fat.

Epicardial Adipose Tissue and Cardiovascular Disease

PURPOSE OF REVIEW

Epicardial adipose tissue has been associated with the development/progression of cardiovascular disease. We appraise the strength of the association between epicardial adipose tissue and development/progression of cardiovascular diseases like coronary artery disease, atrial fibrillation, and heart failure with preserved ejection fraction.

RECENT FINDINGS

Cross-sectional clinical and translational correlative studies have established an association between epicardial adipose tissue and progression of coronary artery disease. Recent studies question this association and underline the need for longitudinal studies. Epicardial adipose tissue also plays a definite role in the pathobiology of atrial fibrillation and its recurrence after ablation. In contrast to an early paradigm, epicardial adipose tissue does not appear to play a key role in the pathogenesis of heart failure with preserved ejection fraction in obese patients. The association of epicardial adipose tissue with atrial fibrillation is robust. In contrast, the association of epicardial adipose tissue with coronary artery disease and heart failure with preserved ejection fraction is tenuous. Additional research, including longitudinal studies, is needed to confirm or refute these proposed associations.

Epicardial Adipose Tissue Role as a Marker of Higher Vulnerability in Patients with Coronary Artery Disease

Background: Epicardial adipose tissue (EAT) has been recently identified as a major player in the development of the atherosclerotic process. This study aimed to investigate the role of EAT as a marker associated with a higher vulnerability of atheromatous coronary plaques in patients with acute myocardial infarction (AMI) as compared to patients with stable angina.

Material and methods: This analysis enrolled a total of 89 patients, 47 with stable angina (SA) and 42 with AMI, who underwent echocardiographic investigations and epicardial fat measurement in 2D-parasternal long axis view. The study lot was divided as follows: Group 1 included patients with prior AMI, and Group 2 included patients with SA.

Results: There were no significant differences between the two groups regarding cardiovascular risk factors, excepting smoking status, which was recorded more frequently in Group 1 as compared to Group 2 (36.17% vs. 11.63%, p = 0.02). The mean epicardial fat diameter was 9.12 ± 2.28 mm (95% CI: 8.45–9.79 mm) in Group 1 and 6.30 ± 2.03 mm (95% CI: 5.675–6.93 mm) in Group 2, the difference being highly significant statistically (p <0.0001). The mean value of left ventricular ejection fraction was significantly lower in patients with AMI (Group 1 – 47.60% ± 7.96 vs. Group 2 – 51.23% ± 9.05, p = 0.04). EAT thickness values showed a weak but significant positive correlation with the level of total cholesterol (r = −0.22, p = 0.03) and with the value of end-systolic left ventricle diameter (r = 0.33, = 0.001).

Conclusions: The increased thickness of EAT was associated with other serum- or image-based biomarkers of disease severity, such as the left ventricular ejection fraction, end-systolic diameter of the left ventricle, and total cholesterol. Our results indicate that EAT is significantly higher in patients with acute coronary syndrome, proving that EAT could serve as a marker of vulnerability in cardiovascular diseases.

The relationship between epicardial adipose tissue and coronary artery stenosis by sex and menopausal status in patients with suspected angina

Background

Evidence suggests that epicardial adipose tissue (EAT) is closely related to coronary artery stenosis (CAS). However, sexual dimorphism may be present in adipose tissue, and its influence on CAS between men and women is controversial. We assessed the relationship between EAT and CAS by sex and menopausal status in patients with suspected angina.

Methods

Six hundred twenty-eight consecutive patients (men/women n = 257/371; mean age = 59.9 ± 10.2 years) who had chest pain for angina and underwent coronary angiography were included. CAS was defined as > 50% luminal narrowing of at least one epicardial coronary artery. EAT thickness was measured by transthoracic echocardiography.

Results

Of the 628 patients, 52.1% (n = 134) of men and 35.3% (n = 131) of women had CAS. The mean EAT thickness was not different between men and women and was larger in patients with CAS (8.04 ± 2.39 vs 6.58 ± 1.88 mm, P < 0.001). EAT thickness was independently associated with CAS in both sexes (P < 0.001). The odds ratio (OR) of EAT for the presence of CAS was higher in men (OR = 1.43, 95% confidence interval [CI] 1.21–1.69) than in women (OR = 1.24, 95% CI 1.10–1.40). EAT thickness was larger in postmenopausal women than in premenopausal women (7.59 ± 2.25 vs 5.80 ± 1.57 mm, P < 0.001) and was independently related with CAS (OR = 1.24, 95% CI 1.09–1.41). This was not the case in premenopausal women.

Conclusion

In patients with suspected angina, an increase in EAT thickness was independently related to the presence of CAS in both men and women, with it being stronger in men. According to menopausal status in women, EAT thickness is significantly associated with CAS only in postmenopausal women.