The role of epicardial and perivascular adipose tissue in the pathophysiology of cardiovascular disease

Application of ultrasound for quantitative assessment of body fat mass

BACKGROUND & AIMS

Obesity is a significant health concern associated with various diseases. Accurate measurement of body fat mass (BFM) and local fat thickness (FT) is crucial for health assessment. Ultrasound offers a non-invasive, portable, and cost-effective alternative for measuring FT, but its application for quantitative BFM estimation has not been fully explored. This study aimed to develop and validate a quantitative estimation algorithm for BFM based on local FT measured by ultrasound.

METHODS

A total of 179 volunteers were randomly divided into modeling and verification groups. BFM was measured using bioelectrical impedance analysis (BIA), and FT was measured at 10 sites throughout the body using ultrasound. In the modeling group, the correlation between FT and BFM at different sites was analyzed, and a BFM estimation algorithm based on FT was developed using multiple linear regression. The accuracy of the estimation equation was validated in the verification group.

RESULTS

Men had lower BFM than women (P < 0.05). At most sites, the FT of males was less than that of females (P < 0.001). Significant positive correlations were observed between FT at various sites (site 1 to 10) and BFM across all groups (P < 0.01). The estimation algorithm revealed that FT at 4 sites (intra-abdominal, posterior right perinephric, abdominal subcutaneous, and anterior upper arm) contributed to BFM estimation for men, while two additional sites (pre-peritoneal and posterior lower leg) were valuable for women. The R2 for the algorithms was 0.882 for men and 0.907 for women, with the standard error of estimate of 2.04 kg for both. The intraclass correlation coefficient between ultrasound-derived estimated BFM and the BFM measured by BIA in the verification group was 0.848 (P < 0.001).

CONCLUSIONS

BFM can be quantitatively estimated using a fitting algorithm based on ultrasound-derived local FT.

Characterizing cardiac adipose tissue in post-acute myocardial infarction patients via CT imaging: a comparative cross-sectional study

AIMS

To identify differences in CT-derived perivascular adipose tissue (PVAT) and epicardial adipose tissue (EAT) characteristics that may indicate inflammatory status differences between post-treatment acute myocardial infarction (AMI) and stable coronary artery disease (CAD) patients.

METHODS AND RESULTS

A cohort of 205 post-AMI patients (age 59.8 ± 9.2, 92.2% male) was propensity-matched with 205 stable CAD patients (age 60.5 ± 10.0, 90.2% male). Coronary CT angiography and non-contrast CT scans were performed to assess PVAT mean attenuation across major coronary segments and EAT mean attenuation and volumes, respectively. For post-AMI patients, CT scans were conducted 28.6 ± 13.8 days after the AMI incidence. Post-AMI patients showed higher non-culprit PVAT and EAT mean attenuation than stable CAD patients (8.01 HU, 95% CI 5.90-10.11 HU, P < 0.001, 2.48 HU, 95% CI 0.83-4.13 HU, P = 0.003, respectively). The EAT volume percentage at higher attenuation levels was higher in post-AMI patients compared with stable CAD (33.93 cm3, 95% CI 16.86-51.00 cm3, P < 0.001), with the difference maximized at the -70 HU threshold (4.75%, 95% CI 3.64%-5.87%, P < 0.001). PVAT mean attenuation positively correlated with EAT mean attenuations and the percentage of EAT volume > -70 HU (P < 0.001 for both).

CONCLUSION

Post-AMI patients showed higher PVAT and EAT attenuation than stable CAD patients, potentially indicating AMI-associated inflammatory cardiac adipose tissue changes. A total of -70 HU can act as a potential cut-off for inflamed EAT. These findings highlight the potential of using CT-derived adipose tissue characteristics to assess inflammation and guide post-AMI management strategies.

Evaluating Epicardial Fat Density Using ROI-Based Analysis: A Feasibility Study

Epicardial fat density (EFD) is implicated in cardiovascular diseases. This study aimed to assess the regional variability of epicardial fat density (EFD) using coronary computed tomography (CCT) and evaluate the feasibility of ROI-based measurements as an alternative to full segmentation. A retrospective analysis was conducted on 171 patients undergoing coronary CCT. EFD was measured on non-contrast scans acquired globally and in three predefined regions of interest (ROIs) for coronary calcium scoring: the aortic bulb, right posterolateral wall, and cardiac apex. Global EFD was quantified using semi-automated segmentation software (3D Slicer 5.6.2), while regional EFD values were manually determined. Statistical analyses were performed to compare global and regional EFD measurements. Global EFD averaged -83.92 ± 5.19 HU, while regional EFD showed significant variability. The aortic bulb had lower EFD values (-97.54 ± 12.80 HU) compared to the apex (-93.42 ± 18.94 HU) and right posterolateral wall (-94.99 ± 12.16 HU). Paired t-tests confirmed statistically significant differences between global and regional EFD values (p < 0.000). This study highlights significant regional variability in EFD across specific cardiac regions, suggesting that ROI-based assessments may not reliably reflect global EFD characteristics.

Epicardial Fat in Heart Failure with Preserved Ejection Fraction Compared with Reduced Ejection Fraction

Background: The role of epicardial adipose tissue (EAT) in heart failure with preserved ejection fraction (HFpEF) remains to be defined. Methods: A consecutive series of outpatients with chronic heart failure-heart failure with reduced ejection fraction (HFrEF) and HFpEF and/or diastolic dysfunction-had EAT assessed by echocardiographic measurement and related to indices of cardiac structure and function. Results: Epicardial fat thickness was significantly (p < 0.05) greater in HFpEF (N = 141) with a mean of 6.7 ± 1.6 mm compared with a mean of 5.1 ± 1.0 mm in HFrEF (n = 40). After adjusting for the relationship with BMI, in HFpEF, epicardial fat was significantly (p < 0.05) negatively correlated with left ventricular internal diameter end diastole (LVIDd), left ventricular internal diameter end systole (LVIDs), left ventricular (LV) end-diastolic volume (EDV) index, lateral e', septal e', right atrial (RA) volume index, and hemoglobin (Hgb). The association with Hgb was no longer significant after adjusting for the effect of age. HFpEF was associated with smaller LVIDd, LVIDs, LV EDV indexes, and left atrial (LA) and RA volume indexes. Conclusions: Epicardial fat is significantly (p < 0.05) greater in HFpEF than HFrEF. Epicardial fat is associated with smaller cardiac chamber sizes in HFpEF suggesting that epicardial fat acts as a constraint to cardiac dilation.

Epicardial adipose tissue density predicts the presence of atrial fibrillation and its recurrence after catheter ablation: three-dimensional reconstructed image analysis

Epicardial adipose tissue (EAT) induces inflammation in the atria and is associated with atrial fibrillation (AF). Several studies have examined the relationship between EAT volume (EAT-V) and density (EAT-D) and the presence of AF after catheter ablation. However, conclusions have been inconsistent. This study included 43 consecutive patients who underwent catheter ablation for AF and 30 control patients. EAT-V and EAT-D around the entire heart, entire atrium, left atrium (LA), and right atrium (RA) were measured in detail using reconstructed three-dimensional (3D) EAT images from dual-source computed tomography (CT). None of the measurements of EAT-V differed significantly between patients with AF and controls or between patients with recurrent AF and those without. On the other hand, all measurements of EAT-D were higher in patients with AF than in controls (entire atrium, p < 0.001; RA, p < 0.001; LA, p = 0.002). All EAT-D measurements were associated with the presence of AF. Among patients with AF who underwent ablation, all EAT-D measurements were higher in patients with recurrent AF than in those without. The difference was significant for EATRA-D (p = 0.032). All atrial EAT-D values predicted recurrent AF (EATRA-D: hazard ratio [HR], 1.208; 95% confidence interval [95% CI], 1.053-1.387; p = 0.007; EATLA-D: HR, 1.108; 95% CI 1.001-1.225; p = 0.047; EATatrial-D: HR, 1.174; 95% CI 1.040-1.325; p = 0.010). The most sensitive cutoffs for predicting recurrent AF were highly accurate for EATRA-D (area under the curve [AUC], 0.76; p < 0.01) and EATatrial-D (AUC = 0.75, p < 0.05), while the cutoff for EATLA-D had low accuracy (AUC, 0.65; p = 0.209). For predicting the presence of AF and recurrent AF after catheter ablation, 3D analysis of atrial EAT-D, rather than EAT-V, is useful.

Biomarker for cardiorenal syndrome risk in patients with liver cirrhosis and type 2 diabetes in Saudi Arabia

OBJECTIVES

To evaluate the correlation between different attributes, levels of biomarkers, and the probability of developing cardiorenal syndrome (CRS) in patients who have been diagnosed with type 2 diabetes mellitus (T2DM) and liver cirrhosis (LC). The hypothesis suggests that liver illness may be linked to renal impairment, cardiac dysfunction, and the development of cardiorenal syndrome METHODS: The current study retrospectively assessed the medical records of patients who had LC and T2DM diagnoses and were hospitalized at Al Madina Al Munwara hospitals in 2022 and 2023.

RESULTS

This research investigated T2DM patients with physician-confirmed to have LC. Poor glycemic control is indicated by high blood glucose and glycated hemoglobin (HbA1c) readings in research participants. High blood pressure, atherogenic plasma indicator (AIP), and obesity plagued most of these individuals. High creatinine, moderate estimated Glomerular Filtration Rate (eGFR) decline, and a modest urinary albumin-to-creatinine (UACR) rise were the most prevalent variables in LC and T2DM patients. Cardiorenal syndrome risk factors, including elevated blood pressure, triglyceride levels, body mass index (BMI), and high-sensitivity C-reactive protein (hs-CRP) concentrations, were identified through logistic regression. It has been demonstrated that the prevalence of these risk factors increases with age; women may be at a greater risk for developing CRS. Specific biomarker evaluations classified 108 (22.6%) LC and T2DM patients at high risk for chronic kidney disease (CKD), 100 (20%) at risk for cardiovascular disease (CVD), and 91 (18.2%) at risk for CRS.

CONCLUSION

The current assessment included 500 patients with T2DM and LC. The risk factors for CRS identified in this study included elevated cholesterol and triglyceride levels, high BMI, and elevated blood pressure, with age being a significant factor, particularly in female patients. Early identification of these characteristics in patients with LC and T2DM could aid in mitigating the progression of chronic illnesses and their associated complications.

Lipidomics Reveals Myocardial Lipid Composition in a Murine Model of Insulin Resistance Induced by a High-Fat Diet

Ectopic fat accumulation in non-adipose tissues is closely related to diabetes-related myocardial dysfunction. Nevertheless, the complete picture of the lipid metabolites involved in the metabolic-related myocardial alterations is not fully characterized. The aim of this study was to characterize the specific lipid profile in hearts in an animal model of obesity/insulin resistance induced by a high-fat diet (HFD). The cardiac lipidome profiles were assessed via liquid chromatography-mass spectrometry (LC-MS)/MS-MS and laser desorption/ionization-mass spectrometry (LDI-MS) tissue imaging in hearts from C57BL/6J mice fed with an HFD or standard-diet (STD) for 12 weeks. Targeted lipidome analysis identified a total of 63 lipids (i.e., 48 triacylglycerols (TG), 5 diacylglycerols (DG), 1 sphingomyelin (SM), 3 phosphatidylcholines (PC), 1 DihydroPC, and 5 carnitines) modified in hearts from HFD-fed mice compared to animals fed with STD. Whereas most of the TG were up-regulated in hearts from animals fed with an HFD, most of the carnitines were down-regulated, thereby suggesting a reduction in the mitochondrial β-oxidation. Roughly 30% of the identified metabolites were oxidated, pointing to an increase in lipid peroxidation. Cardiac lipidome was associated with a specific biochemical profile and a specific liver TG pattern. Overall, our study reveals a specific cardiac lipid fingerprint associated with metabolic alterations induced by HFD.

Pericoronary adipose tissue attenuation in patients with acute aortic dissection based on coronary computed tomography angiography

Background

Periaortic fat is associated with coronary disease. Thus, it was hypothesized that the inflammation associated with acute aortic dissection (AAD) spreads to pericoronary adipose tissue (PCAT) via thoracic periaortic fat. Pericoronary adipose tissue attenuation (PCATa) serves as a marker for inflammation of perivascular adipose tissue (PVAT). This study sought to examine PCATa in individuals diagnosed with AAD.

Methods

Consecutive patients with chest pain from May 2020 to September 2022 were prospectively enrolled in this study and underwent coronary computed tomography angiography (CCTA) and/or aorta computed tomography angiography (CTA). Based on the results of the CTA, the patients were divided into the following two groups: (I) the AAD group; and (II) the non-AAD group. PCATa of the right coronary angiography (RCA), left anterior descending (LAD), and left circumflex (LCx) was quantified for each patient using semi-automated software. The PCATa values were compared between the AAD and non-AAD patients according to the atherosclerosis of the coronary arteries. Similarly, the PCATa values of the AAD patients were compared between the preoperative and postoperative steady states.

Results

A total of 136 patients (42 female, 94 male; mean age: 63.3±11.9 years) were divided into the two groups according to the presence of aortic dissection on CTA. The RCAPCATa, LADPCATa, and LCxPCATa values were significantly higher in the AAD subjects than the non-AAD subjects, regardless of the presence or absence of atherosclerosis in the coronary arteries [-85.1±9.3 vs. -92.9±10.0 Hounsfield unit (HU); -83.2±7.4 vs. -89.9±9.1 HU; -77.5±8.4 vs. -85.6±7.9 HU, all P<0.001). The preoperative RCAPCATa, LADPCATa, and LCxPCATa values were higher in the AAD patients than the postoperative steady-state patients (-82.9±8.7 vs. -97.6±8.8 HU; -79.8±7.6 vs. -92.8±6.8 HU; -74.6±7.1 vs. -87.7±6.9 HU, all P<0.001). According to the multivariable logistic regression analysis, high RCAPCATa and LADPCATa values were associated with AAD regardless of the degree of stenosis [odds ratio (OR) =0.014; 95% confidence interval (CI): 0.001-0.177; P=0.001 and OR =0.010; 95% CI: 0.001-0.189; P=0.002].

Conclusions

PCATa on computed tomography was increased in patients with AAD regardless of the presence or absence of coronary artery disease (CAD). This suggests that vascular inflammation is present in AAD independent of CAD. Further research should be conducted to investigate the potential of this imaging biomarker to predict AAD and monitor patients' responses to therapies for AAD.

An Overview of the Mechanism behind Excessive Volume of Pericardial Fat in Heart Failure

Heart failure (HF) is a clinical syndrome characterized by myocardial dysfunction leading to inefficient blood filling or ejection. Regardless of the etiology, various mechanisms, including adipokine hypersecretion, proinflammatory cytokines, stem cell proliferation, oxidative stress, hyperglycemic toxicity, and autonomic nervous system dysregulation in the pericardial fat (PCF), contribute to the development of HF. PCF has been directly associated with cardiovascular disease, and an increased PCF volume is associated with HF. The PCF acts as neuroendocrine tissue that is closely linked to myocardial function and acts as an energy reservoir. This review aims to summarize each mechanism associated with PCF in HF.

Increased Levels of VCAM-1 in Patients with High Cardiovascular Risk and Obstructive Sleep Apnea Syndrome

(1) Background: Although obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity, the link between OSA and cardiovascular disease (CVD) is not completely elucidated. Thus, we aim to assess cardiovascular risk (CVR) using SCORE 2 and SCORE 2 for older persons (SCORE 2OP), and to evaluate the association between the endothelial biomarkers VCAM-1, ICAM-1, epicardial fat, and sleep study parameters in order to improve current clinical practices and better understand the short-and long-term CVRs in OSA patients. (2) Methods: 80 OSA patients and 37 healthy volunteers were enrolled in the study. SCORE2 and SCORE 2 OP regional risk charts (validated algorithms to predict the 10-year risk of first-onset CVD) were used for the analysis of CVR. Two-dimensional echocardiography was performed on all patients and epicardial fat thickness was measured. VCAM-1 and ICAM-1 serum levels were assessed in all patients. (3) Results: OSA patients were classified as being at high CVR, regardless of the type of score achieved. Increased EFT was observed in the OSA group. VCAM-1 was associated with a high CVR in OSA patients, but no significant correlation was observed between adhesion molecules and epicardial fat thickness. (4) Conclusions: OSA patients have a high CVR according to the SCORE 2 and SCORE 2OP risk scores. VCAM-1 may be associated with a high CVR in OSA patients. Extending conventional risk stratification scores by adding other potential biomarkers improves the risk stratification and guide treatment eligibility for CVD prevention in the OSA population.

Visceral fat and cardiometabolic future in children and adolescents: a critical update

Cardiovascular disease (CVD) is a process whose pathogenetic mechanisms start very early in life. Recently, the importance of visceral adipose tissue (VAT) has been highlighted in the development of CVD. VAT does not always depend on body mass index (BMI) and has been implicated in unfavorable metabolic activity and cardiovascular adverse events. Abnormally high deposition of VAT is associated with metabolic syndrome, obesity-associated phenotype, and cardiometabolic risk factors. Although the importance of visceral fat has not been studied broadly or extensively in long-term studies in children and adolescents, it appears that it does not have the same behavior as in adults, it is related to the appearance of cardiac risk factors. In adolescents, it plays a role in the pathogenesis of CVD that occur later in adulthood. Excess body weight and adiposity may lead to the development of early myocardial and pathological coronary changes in childhood. The purpose of this review is to summarize the risk factors, the clinical significance, and the prognostic role of visceral obesity in children and adolescents. In addition, extensive reference is made to the most commonly used techniques for the evaluation of VAT in clinical settings. IMPACT: Visceral obesity, plays an important role in cardiovascular health from very early in an individual's life. Visceral adipose tissue (VAT) distribution is not entirely related to body mass index (BMI) and provides additional prognostic information. There is a need to pay more attention to the assessment of VAT in young people, to develop methods that would go beyond the measurement of only BMI in clinical practice and to identify individuals with excess visceral adiposity and perhaps to monitor its changes.

Epicardial fat in patients with metabolic syndrome: A systematic review and meta-analysis

PURPOSE

Abnormally increased epicardial fat appears to be associated with an additional risk of major adverse cardiovascular events (MACEs) in the context of metabolic syndrome (MetS). However, evidence on the relationship between epicardial fat volumes (EFVs), epicardial fat thickness (EFT) and MetS remains inconsistent.

METHODS

Specific searches of electronic databases from 1 January 2000 to 31 October 2022 were independently performed by two researchers. In this study, two quantification measures of epicardial fat were included: comparison of total computed tomography-based EFVs and EFT between two groups (individuals with and without MetS), estimating standardized mean difference (SMD) with corresponding 95 % confidence intervals (CIs) through a random-effects model analysis. The heterogeneity in the included studies was explored by meta-regression and subgroup analyses.

RESULTS

The EFVs were significantly increased in MetS subjects compared with non-MetS subjects (SMD: 1.07, 95 % CI: 0.69-1.45, p < 0.001), and the EFT was also significantly larger in MetS patients than in the Non-MetS (SMD: 1.12, 95 % CI: 0.84-1.41, p < 0.001). We compared the Caucasian and American subgroups with the Asian and African subgroups, and the EFT was greater in the former subgroups (SMD: 1.32, 95 % CI: 0.44-2.20, p < 0.001). When comparing the EFT among the age subgroups, there was a significant SMD between adolescents and adults or elderly individuals (SMD: 1.21, 95 % CI: 0.84-1.52, p < 0.001).

CONCLUSIONS

MetS patients tend to present greater EFT near the right ventricular free wall and greater total EFVs. Increased epicardial fat, an imaging biomarker, independently affects the onset of MetS.

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.

Epicardial adipose tissue in patients with chronic obstructive pulmonary disease: systematic review with meta‑analysis and trial sequential analysis

BACKGROUND

Limited data suggest that chronic obstructive pulmonary disease (COPD) patients have pathologic elevated epicardial adipose tissue (EAT), which is splanchnic fat tissue with anti-inflammatory properties and regulating free fatty acids functions. Therefore, there is a need for meta-analysis to explore the relationship between EAT and COPD.

METHODS

Online databases were systematically searched for studies about EAT in COPD patients published up to October 5th, 2022. The EAT data of the COPD patient group and the control group were included. Trial sequential analysis (TSA) and meta-analysis were applied to assess the difference in EAT between patients with and without COPD. TSA software and Stata 12.0 were used in all statistical analyses.

RESULTS

The final analysis included 5 studies (n = 596 patients). COPD patients had significantly more EAT than control subjects (SMD: 0.0.802; 95% CI: 0.231, 1.372; P = 0.006; TSA-adjusted 95% CI 1.20, 1.80; P < 0.0001). And higher CRP levels in COPD patients than non-COPD patients, whereas triglycerides and LDL were not significantly different between patients with and without COPD.

CONCLUSION

EAT is abnormally elevated in COPD patients, which may be related to systemic inflammatory responses in COPD.

PROSPERO NUMBER

CRD42021228273.

Potential impact of epicardial fat thickness, pentraxin-3, and high-sensitive C-reactive protein on the risk of non-proliferative diabetic retinopathy

Purpose

We tried to clarify the potential association between systemic inflammatory markers like high-sensitive C-reactive protein (Hs-CRP), pentraxin-3 (PTX3), and epicardial fat thickness (EFT) with the non-proliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes mellitus (T2D). Previous studies dealt with diabetic retinopathy as a whole entity rather than early stages of diabetic retinopathy. Early detection of various determinants of NPDR is prioritized in clinical practice.

Methods

A case-control study was conducted at Mansoura University Hospital, included 207 Egyptian subjects divided into 3 groups; 69 diabetic patients without retinopathy, 69 diabetic patients with NPDR, and 69 healthy control subjects. Participants were subjected to clinical history taking, physical examination, and laboratory assessment of Hs-CRP and plasma PTX3. Transthoracic echocardiography was applied to estimate EFT.

Results

Hs-CRP, PTX3, and EFT were significantly higher in patients with T2D without retinopathy than control cohort (p = 0.033, p < 0.00 and p < 0.00, respectively). Moreover, patients with NPDR showed significantly higher values of Hs-CRP, PTX3, and EFT than diabetic comparators without retinopathy (p = 0.002, p = 0.012, and p < 0.001, respectively). Although, NPDR was positively correlated with Hs-CRP, PTX3, and EFT (p < 0.001), Hs-CRP was not an independent determinant of NPDR meanwhile, EFT (OR = 1.094, 95%CI: 1.036-1.154, P = 0.001) and PTX3 (OR = 16.145, 95%CI: 1.676-155.551, P = 0.016) were.

Conclusion

Plasma pentraxin-3 and epicardial fat thickness showed more significant association with NPDR than high-sensitive C-reactive protein in patients with type 2 diabetes mellitus.

Associations of aortic stiffness and intra-aortic flow parameters with epicardial adipose tissue in patients with type-2 diabetes

Background

It has been shown that increased aortic stiffness is related to type-2 diabetes (T2D) which is considered as a risk factor for cardiovascular disease. Among other risk factors is epicardial adipose tissue (EAT) which is increased in T2D and is a relevant biomarker of metabolic severity and adverse outcome.

Purpose

To assess aortic flow parameters in T2D patients as compared to healthy individuals and to evaluate their associations with EAT accumulation as an index of cardiometabolic severity in T2D patients.

Materials and methods

Thirty-six T2D patients as well as 29 healthy controls matched by age and sex were included in this study. Participants had cardiac and aortic MRI exams at 1.5 T. Imaging sequences included cine SSFP for left ventricle (LV) function and EAT assessment and aortic cine and phase-contrast imaging for strain and flow parameters quantification.

Results

In this study, we found LV phenotype to be characterized by concentric remodeling with decreased stroke volume index despite global LV mass within a normal range. EAT was increased in T2D patients compared to controls (p<0.0001). Moreover, EAT, a biomarker of metabolic severity, was negatively correlated to ascending aortic (AA) distensibility (p=0.048) and positively to the normalized backward flow volume (p=0.001). These relationships remained significant after further adjustment for age, sex and central mean blood pressure. In a multivariate model, presence/absence of T2D and AA normalized backward flow (BF) to forward flow (FF) volumes ratio are both significant and independent correlates of EAT.

Conclusion

In our study, aortic stiffness as depicted by an increased backward flow volume and decreased distensibility seems to be related to EAT volume in T2D patients. This observation should be confirmed in the future on a larger population while considering additional biomarkers specific to inflammation and using a longitudinal prospective study design.

Prospects of potential adipokines as therapeutic agents in obesity-linked atherogenic dyslipidemia and insulin resistance

BACKGROUND

In normal circumstances, AT secretes anti-inflammatory adipokines (AAKs) which regulates lipid metabolism, insulin sensitivity, vascular hemostasis, and angiogenesis. However, during obesity AT dysfunction occurs and leads to microvascular imbalance and secretes several pro-inflammatory adipokines (PAKs), thereby favoring atherogenic dyslipidemia and insulin resistance. Literature suggests decreased levels of circulating AAKs and increased levels of PAKs in obesity-linked disorders. Importantly, AAKs have been reported to play a vital role in obesity-linked metabolic disorders mainly insulin resistance, type-2 diabetes mellitus and coronary heart diseases. Interestingly, AAKs counteract the microvascular imbalance in AT and exert cardioprotection via several signaling pathways such as PI3-AKT/PKB pathway. Although literature reviews have presented a number of investigations detailing specific pathways involved in obesity-linked disorders, literature concerning AT dysfunction and AAKs remains sketchy. In view of the above, in the present contribution an effort has been made to provide an insight on the AT dysfunction and role of AAKs in modulating the obesity and obesity-linked atherogenesis and insulin resistance.

MAIN BODY

"Obesity-linked insulin resistance", "obesity-linked cardiometabolic disease", "anti-inflammatory adipokines", "pro-inflammatory adipokines", "adipose tissue dysfunction" and "obesity-linked microvascular dysfunction" are the keywords used for searching article. Google scholar, Google, Pubmed and Scopus were used as search engines for the articles.

CONCLUSIONS

This review offers an overview on the pathophysiology of obesity, management of obesity-linked disorders, and areas in need of attention such as novel therapeutic adipokines and their possible future perspectives as therapeutic agents.

Long-term association of pericardial adipose tissue with incident diabetes and prediabetes: the Coronary Artery Risk Development in Young Adults Study

OBJECTIVES

We examined whether pericardial adipose tissue (PAT) is predictive of prediabetes and type 2 diabetes over time.

METHODS

In total, 2,570 adults without prediabetes/diabetes from the Coronary Artery Risk Development in Young Adults Study were followed up over 15 years. PAT volume was measured by computed tomography scans, and the new onset of prediabetes/diabetes was examined 5 years, 10 years, and 15 years after the PAT measurements. Multivariable Cox regression models were used to examine the association between the tertile of PAT and incident prediabetes/diabetes up to 15 years later. The predictive ability of PAT (vs. waist circumference [WC], body mass index [BMI], waist-to-height ratio [WHtR]) for prediabetes/diabetes was examined by comparing the area under the receiver operating characteristic curve (AUC).

RESULTS

The highest tertile of PAT was associated with a 1.56 times (95% confidence interval [CI], 1.03 to 2.34) higher rate of diabetes than the lowest tertile; however, no association was found between the highest tertile of PAT and prediabetes in the fully adjusted models, including additional adjustment for BMI or WC. In the fully adjusted models, the AUCs of WC, BMI, WHtR, and PAT for predicting diabetes were not significantly different, whereas the AUC of WC for predicting prediabetes was higher than that of PAT.

CONCLUSIONS

PAT may be a significant predictor of hyperglycemia, but this association might depend on the effect of BMI or WC. Additional work is warranted to examine whether novel adiposity indicators can suggest advanced and optimal information to supplement the established diagnosis for prediabetes/diabetes.

Cellular cross talk between epicardial fat and cardiovascular risk

A variety of fat compartments have several local and systemic effect and play a crucial role in the maintenance of health and development of disease. For the past few years, special attention has been paid to epicardial fat. It is the visceral fat compartment of the heart and has several local and systemic effects. It can perform a role in the development of cardiometabolic risk. The epicardial adipose tissue (EAT) is a unique and multifunctional fat compartment of the heart. It is located between the myocardium and the visceral pericardium. During normal physiological conditions, the EAT has metabolic, thermogenic, and mechanical (cardioprotective) characteristics. The EAT can produce several adipocytokines and chemokines depending on microenvironments. It can influence through paracrine and vasocrine mechanism and participate in the development and progression of cardiovascular (CVS) diseases. In addition, metabolic disease leads to changes in both thickness and volume of the EAT, and it can modify the structure and the function of heart. It has been associated with various CVS diseases such as, cardiomyopathy, atrial fibrillation, and coronary artery disease. Therefore, EAT is a potential therapeutic target for CVS risk.

Segmentation and volume quantification of epicardial adipose tissue in computed tomography images

BACKGROUND

Many cardiovascular diseases are closely related to the composition of epicardial adipose tissue (EAT). Accurate segmentation of EAT can provide a reliable reference for doctors to diagnose the disease. The distribution and composition of EAT often have significant individual differences, and the traditional segmentation methods are not effective. In recent years, deep learning method has been gradually introduced into EAT segmentation task.

PURPOSE

The existing EAT segmentation methods based on deep learning have a large amount of computation and the segmentation accuracy needs to be improved. Therefore, the purpose of this paper is to develop a lightweight EAT segmentation network, which can obtain higher segmentation accuracy with less computation and further alleviate the problem of false positive segmentation.

METHODS

Firstly, the obtained Computed Tomography (CT) was preprocessed. That is, the threshold range of EAT was determined to be (-190, -30) HU according to prior knowledge, and the non-adipose pixels were excluded by threshold segmentation to reduce the difficulty of training. Secondly, the image obtained after thresholding was input into the lightweight RDU-Net network to perform the training, validating, and testing process. RDU-Net uses a residual multi-scale dilated convolution block in order to extract a wider range of information without changing the current resolution. At the same time, the form of residual connection is adopted to avoid the problem of gradient expansion or gradient explosion caused by too deep network, which also makes the learning easier. In order to optimize the training process, this paper proposes PNDiceLoss, which takes both positive and negative pixels as learning targets, fully considers the class imbalance problem and appropriately highlights the status of positive pixels.

RESULTS

In this paper, 50 CCTA images were randomly selected from the hospital, and the commonly used Dice similarity coefficient (DSC), Jaccard similarity (JS), Accuracy (ACC), Specificity (SP), Precision (PC), and Pearson correlation coefficient are used as evaluation metrics. Bland-Altman analysis results show that the extracted EAT volume is consistent with the actual volume. Compared with the existing methods, the segmentation results show that the proposed method achieves better performance on these metrics, achieving the DSC of 0.9262. The number of false positive pixels has been reduced by more than half. Pearson correlation coefficient reached 0.992, and linear regression coefficient reached 0.977 when measuring the volume of EAT obtained. In order to verify the effectiveness of the proposed method, experiments are carried out in the cardiac fat database of VisualLab. On this database, the proposed method also achieved good results, and the DSC value reached 0.927 in the case of only 878 slices.

CONCLUSIONS

A new method to segment and quantify EAT is proposed. Comprehensive experiments show that compared with some classical segmentation algorithms, the proposed method has the advantages of shorter time-consuming, less memory required for operations, and higher segmentation accuracy. The code is available at https://github.com/lvanlee/EAT_Seg/tree/main/EAT_seg. This article is protected by copyright. All rights reserved.

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.

The pathobiology of perivascular adipose tissue (PVAT), the fourth layer of the blood vessel wall

The perivascular adipose tissue (PVAT) is an adipose tissue depot which surrounds most human blood vessels. It is metabolically active and has both a protective and a pathogenic role in vascular biology and pathobiology. It regulates vascular homeostasis and promotes vascular dysfunction. The purpose of this review is to consider the origin, structure, function, and dysfunction of this unique adipose depot consisting of white (WAT), brown (BAT) and beige adipose tissue, to support the concept that PVAT may be considered the fourth layer of the normal arterial wall (tunica adiposa), in which dysfunction creates a microenvironment that regulates, in part, the initiation and growth of the fibro-inflammatory lipid atherosclerotic plaque. Experimental in-vivo and in-vitro studies and human investigations show that the adipocytes, extracellular matrix, nerve fibers and vasa vasorum found in PVAT form a functional adipose tissue unit adjacent to, but not anatomically separated from, the adventitia. PVAT maintains and regulates the structure and function of the normal arterial wall through autocrine and paracrine mechanisms, that include modulation of medial smooth muscle cell contractility and secretion of anti-inflammatory molecules. PVAT shows regional phenotypic heterogeneity which may be important in its effect on the wall of specific sections of the aorta and its muscular branches during perturbations and various injuries including obesity and diabetes. In atherosclerosis, a pan-vascular microenvironment is created that functionally links the intima-medial atherosclerotic plaque to the adventitia and PVAT beneath the plaque, highlighting the local impact of PVAT on atherogenesis. PVAT adipocytes have inflammatory effects which in response to injury show activation and phenotypic changes, some of which are considered to have direct and indirect effects on the intima and media during the initiation, growth, and development of complicated atherosclerotic plaques. Thus, it is important to maintain the integrity of the full vascular microenvironment so that design of experimental and human studies include investigation of PVAT. The era of discarding PVAT tissue in both experimental and human research and clinical vascular studies should end.

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.

The Role of Epicardial Adipose Tissue in the Development of Atrial Fibrillation, Coronary Artery Disease and Chronic Heart Failure in the Context of Obesity and Type 2 Diabetes Mellitus: A Narrative Review

Cardiovascular diseases (CVDs) are a significant burden globally and are especially prevalent in obese and/or diabetic populations. Epicardial adipose tissue (EAT) surrounding the heart has been implicated in the development of CVDs as EAT can shift from a protective to a maladaptive phenotype in diseased states. In diabetic and obese patients, an elevated EAT mass both secretes pro-fibrotic/pro-inflammatory adipokines and forms intramyocardial fibrofatty infiltrates. This narrative review considers the proposed pathophysiological roles of EAT in CVDs. Diabetes is associated with a disordered energy utilization in the heart, which promotes intramyocardial fat and structural remodeling. Fibrofatty infiltrates are associated with abnormal cardiomyocyte calcium handling and repolarization, increasing the probability of afterdepolarizations. The inflammatory phenotype also promotes lateralization of connexin (Cx) proteins, undermining unidirectional conduction. These changes are associated with conduction heterogeneity, together creating a substrate for atrial fibrillation (AF). EAT is also strongly implicated in coronary artery disease (CAD); inflammatory adipokines from peri-vascular fat can modulate intra-luminal homeostasis through an “outside-to-inside” mechanism. EAT is also a significant source of sympathetic neurotransmitters, which promote progressive diastolic dysfunction with eventual cardiac failure. Further investigations on the behavior of EAT in diabetic/obese patients with CVD could help elucidate the pathogenesis and uncover potential therapeutic targets.

Association of epicardial adipose tissue with different stages of coronary artery disease: A cross-sectional UK Biobank cardiovascular magnetic resonance imaging substudy

Objective

Increased epicardial adipose tissue (EAT) has been identified as a risk factor for the development of coronary artery disease (CAD). However, the exact role of EAT in the development of CAD is unclear. This study aims to compare EAT volumes between healthy controls and individuals with stable CAD and a history of myocardial infarction (MI). Furthermore, associations between clinical and biochemical parameters with EAT volumes are examined.

Methods

This retrospective cross-sectional study included 171 participants from the United Kingdom Biobank (56 healthy controls; 60 stable CAD; 55 post MI), whom were balanced for age, sex and body mass index (BMI). EAT volumes were quantified on end-diastolic cardiac magnetic resonance (CMR) imaging short-axis slices along the left and right ventricle and indexed for body surface area (iEAT) and iEAT volumes were compared between groups.

Results

iEAT volumes were comparable between control, CAD and MI cases (median [IQR]: 66.1[54.4-77.0] vs. 70.9[55.8-85.5] vs. 67.6[58.6-82.3] mL/m2, respectively (p > 0.005 for all). Increased HDL-cholesterol was associated with decreased iEAT volume (β = -14.8, CI = -24.6 to -4.97, p = 0.003) and suggestive associations (P-value < 0.05 and ≥ 0.005) were observed between iEAT and triglycerides (β = 3.26, CI = 0.42 to 6.09, p = 0.02), Apo-lipoprotein A (β = -16.3, CI = -30.3 to -2.24, p = 0.02) and LDL-cholesterol (β = 3.99, CI = -7.15 to -0.84, p = 0.01).

Conclusions

No significant differences in iEAT volumes were observed between patients with CAD, MI and healthy controls. Our results indicate the importance of correcting for confounding by CVD risk factors, including circulating lipid levels, when studying the relationship between EAT volume and CAD. Further mechanistic studies on causal pathways and the role of EAT composition are warranted.

Functions and origins of cardiac fat

Triglyceride droplets can be stored within cardiac adipocytes (CAs) and cardiomyocytes in the heart. Cardiac adipocytes reside in three distinct regions: pericardial, epicardial, and intramyocardial adipose tissues. In healthy individuals, cardiac adipose tissues modulate cardiovascular functions and energy partitioning, which are, thus, protective. However, ectopic deposition of cardiac adipose tissues turns them into adverse lipotoxic, prothrombotic, and pro-inflammatory tissues with local and systemic contribution to the development of cardiovascular disorders. Accumulation of triglyceride droplets in cardiomyocytes may lead to lipotoxic injury of cardiomyocytes and contribute to the development of cardiac hypertrophy and dysfunction. Here, we summarize the roles of CAs and myocardial triglyceride droplets under physiological and pathological conditions and review the cellular sources of CAs in heart development and diseases. Understanding the functions and cellular origins of cardiac fat will provide clues for future studies on pathophysiological processes and treatment of cardiovascular diseases.

Dysregulated Epicardial Adipose Tissue as a Risk Factor and Potential Therapeutic Target of Heart Failure with Preserved Ejection Fraction in Diabetes

Cardiovascular (CV) disease and heart failure (HF) are the leading cause of mortality in type 2 diabetes (T2DM), a metabolic disease which represents a fast-growing health challenge worldwide. Specifically, T2DM induces a cluster of systemic metabolic and non-metabolic signaling which may promote myocardium derangements such as inflammation, fibrosis, and myocyte stiffness, which represent the hallmarks of heart failure with preserved ejection fraction (HFpEF). On the other hand, several observational studies have reported that patients with T2DM have an abnormally enlarged and biologically transformed epicardial adipose tissue (EAT) compared with non-diabetic controls. This expanded EAT not only causes a mechanical constriction of the diastolic filling but is also a source of pro-inflammatory mediators capable of causing inflammation, microcirculatory dysfunction and fibrosis of the underlying myocardium, thus impairing the relaxability of the left ventricle and increasing its filling pressure. In addition to representing a potential CV risk factor, emerging evidence shows that EAT may guide the therapeutic decision in diabetic patients as drugs such as metformin, glucagon-like peptide‑1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 inhibitors (SGLT2-Is), have been associated with attenuation of EAT enlargement.

Expression Profiles of Long Noncoding and Messenger RNAs in Epicardial Adipose Tissue-Derived from Patients with Coronary Atherosclerosis

BACKGROUND

Given its close anatomical location to the heart and its endocrine properties, attention on epicardial adipose tissue (EAT) has increased.

OBJECTIVE

This study investigated the expression profiles of long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) in EAT derived from patients with coronary artery disease (CAD).

METHODS

EAT samples from 8 CAD, and 8 non-CAD patients were obtained during open-heart surgery, respectively. The expression of lncRNAs and mRNAs in each EAT sample was investigated using microarray analysis and further verified using reverse transcription-quantitative polymerase chain reaction.

RESULTS

Overall, 1,093 differentially expressed mRNAs and 2,282 differentially expressed lncRNAs were identified in EAT from CAD vs. non-CAD patients. Analysis using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes showed that these differentially expressed genes were mainly enriched in various inflammatory, immune, and metabolic processes. They were also involved in osteoclast differentiation, B cell receptor and adipocytokine signaling, and insulin resistance pathways. Additionally, lncRNA-mRNA and lncRNA-target pathway networks were built to identify potential core genes (e.g., Lnc-CCDC68-2:1, AC010148.1, NONHSAT104810) involved in atherosclerotic pathogenesis.

CONCLUSION

In summary, lncRNA and mRNA profiles in EAT were markedly different between CAD and non-CAD patients. Our study identifies several potential key genes and pathways that may participate in atherosclerosis development.

Epicardial adipose tissue and risk of arrhythmia in nephrotic syndrome

BACKGROUND

Patients with nephrotic syndrome (NS) are at a high risk of cardiovascular disease, obesity, and dyslipidemia. The aim of this study was to evaluate the formation of epicardial adipose tissue (EAT) and investigate electrocardiographic (ECG) parameters in patients.

METHODS

Thirty-two patients aged 0-18 years and 15 control patients were compared. In the patient group, physical examination and laboratory parameters were recorded. Atrial depolarization and ventricular repolarization parameters in ECG were compared between the groups. EAT was evaluated with M-mode measurements on echocardiography.

RESULTS

There was no difference between the groups in terms of sex, age, body mass index, systolic and diastolic BP. EAT was found to be significantly higher in the patient group. In ECG evaluations it was determined that atrial depolarization and ventricular repolarization parameters increased in the patient group.

CONCLUSIONS

Cardiovascular morbidity and mortality are high in kidney diseases. Measurement and follow-up of EAT and ECG findings as a noninvasive parameter can provide information in NS.

Physiological Changes and Pathological Pain Associated with Sedentary Lifestyle-Induced Body Systems Fat Accumulation and Their Modulation by Physical Exercise

A sedentary lifestyle is associated with overweight/obesity, which involves excessive fat body accumulation, triggering structural and functional changes in tissues, organs, and body systems. Research shows that this fat accumulation is responsible for several comorbidities, including cardiovascular, gastrointestinal, and metabolic dysfunctions, as well as pathological pain behaviors. These health concerns are related to the crosstalk between adipose tissue and body systems, leading to pathophysiological changes to the latter. To deal with these health issues, it has been suggested that physical exercise may reverse part of these obesity-related pathologies by modulating the cross talk between the adipose tissue and body systems. In this context, this review was carried out to provide knowledge about (i) the structural and functional changes in tissues, organs, and body systems from accumulation of fat in obesity, emphasizing the crosstalk between fat and body tissues; (ii) the crosstalk between fat and body tissues triggering pain; and (iii) the effects of physical exercise on body tissues and organs in obese and non-obese subjects, and their impact on pathological pain. This information may help one to better understand this crosstalk and the factors involved, and it could be useful in designing more specific training interventions (according to the nature of the comorbidity).

Effect of exercise on epicardial adipose tissue in adults: a systematic review and meta-analyses

According to previous epidemiological studies, we can reduce the thickness of epicardial fat and improve cardiovascular risk factors through exercise, and the changes may depend on the form of exercise. We systemically reviewed published studies that evaluated exercise intervention on epicardial adipose tissue (EAT) levels. We included randomized controlled trials (RCTs) comparing one exercise with another exercise or diet for the treatment to reduce EAT. We used fixed effects models for meta-analyses; effects of exercise on outcomes were described as mean differences (MD) or standardized difference of means (SMD) was used, their 95% confidence intervals (CI). Five RCTs were included (n = 299), 156 in exercise group and 143 in the control. In comparison to the control group, exercise significantly reduced EAT (SMD - 0.57, 95%CI - 0.97 to - 0.18) and waist circumference (MD - 2.95 cm, 95%CI - 4.93 to - 0.97). Exercise did not have an effect on BMI (MD - 0.23 kg/m2, 95%CI - 0.73 to 0.27), weight (MD - 0.06 kg, 95%CI - 1.46 to 1.34), or HDL (SMD 0.26, 95%CI - 0.06 to 0.57).VO2 was significantly increased by exercise (SMD 1.58, 95%CI 1.17 to 1.99). Risk of bias was high for 3 studies, and GRADE quality of evidence was very low to moderate. Exercise reduced epicardial adipose tissue and waist circumference, and did not have effect on weight, BMI, or HDL. Newer trials with better design and methods are necessary to improve the quality of the evidence. PROSPERO registration number (CRD42018096581).

The relationship between global cardiac and regional left atrial sympathetic innervation and epicardial fat in patients with atrial fibrillation

AIM

To investigate the relationship between epicardial adipose tissue (EAT) volume and distribution and the parameters of global cardiac and regional left atrial (LA) sympathetic activity in patients with atrial fibrillation (AF).

METHODS AND RESULTS

The data of the 45 consecutive patients scheduled for an index catheter ablation (CA) for AF were analyzed. Total and peri-atrial EAT volumes were measured by cardiac CT. Parameters of global cardiac sympathetic activity and discrete sympathetic regions around LA were assessed by 123I-mIBG SPECT/CT. The patients were followed up for AF recurrences assessment during 12 months after CA. A total of 133 (mean per patient 2.96 ± 1.07) discrete 123I-mIBG uptake areas (DUAs), corresponding to typical anatomical locations of LA ganglionated plexi (GP), were identified. Peri-atrial EAT volume was associated with the number of DUAs (regression estimate, 5.1 [95% CI, 0.3-9.9], p = 0.03). There was no statistically significant association between either total or peri-atrial EAT volumes and risks of AF recurrence. The washout rate (WR) was associated with reduced risk of AF recurrence (HR = 0.95; 95% CI 0.92-0.99; p = 0.01), while left ventricular (LV) myocardium 123I-mIBG summed defect score (SDS) was linked to increased hazards of AF recurrence (HR = 1.04; 95% CI 1.01-1.08; p = 0.03).

CONCLUSION

Peri-atrial EAT volume is associated with regions of sympathetic activity corresponding to typical anatomical locations of LA GP. The WR was associated with reduced risk of AF recurrence while LV myocardial SDS was linked to increased hazards of AF recurrence.

Potential Therapeutic Benefits of Sodium-Glucose Cotransporter 2 Inhibitors in the Context of Ischemic Heart Failure: A State-Of-The-Art Review

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of anti-diabetic agents that block the reabsorption of glucose in the proximal convoluted tubule of the nephron, thereby contributing to glycosuria and lowering blood glucose levels. SGLT2 inhibitors have been associated with improved cardiovascular outcomes in patients with diabetes, including a reduced risk of cardiovascular death and hospitalizations for heart failure. Recently, DAPA-HF and EMPEROR REDUCED trials showed the beneficial cardiovascular effect of SGLT2 inhibitors in patients with heart failure with consistently reduced ejection fraction (HFrEF) regardless of the presence of diabetes. Moreover, some exploratory studies suggested that these drugs improve Left Ventricular (LV) systolic function and oppose LV adverse remodeling in patients with HFrEF. However, the exact mechanisms that mediated for this benefit are not fully understood. Beyond glycemic control, enhanced natriuresis, increased erythropoiesis, improved endothelial function, changes in myocardial metabolism, anti-inflammatory and anti-oxidative properties may all play an active role in SGLT2 inhibitors' cardiovascular benefits. A deep understanding of the pathophysiological interplay is key to define which HF phenotype could benefit more from SGLT2 inhibitors. Current clinical evidence on the comparison of different HF etiologies is limited to posthoc subgroup analysis of DAPA-HF and EMPEROR-REDUCED, which showed similar outcomes in patients with or without ischemic HF. On the other hand, in earlier studies of patients suffering from diabetes, rates of classic ischemic endpoints, such as myocardial infarction, stroke or coronary revascularization, did not differ between patients treated with SGLT2 inhibitors or placebo. The aim of this review is to discuss whether SGLT2 inhibitors may improve prognosis in patients with ischemic HF, not only in terms of reducing re-hospitalizations and improving left ventricular function but also by limiting coronary artery disease progression and ischemic burden.

Browning of White Adipose Tissue as a Therapeutic Tool in the Fight against Atherosclerosis

Despite continuous medical advances, atherosclerosis remains the prime cause of mortality worldwide. Emerging findings on brown and beige adipocytes highlighted that these fat cells share the specific ability of non-shivering thermogenesis due to the expression of uncoupling protein 1. Brown fat is established during embryogenesis, and beige cells emerge from white adipose tissue exposed to specific stimuli like cold exposure into a process called browning. The consecutive energy expenditure of both thermogenic adipose tissues has shown therapeutic potential in metabolic disorders like obesity and diabetes. The latest data suggest promising effects on atherosclerosis development as well. Upon cold exposure, mice and humans have a physiological increase in brown adipose tissue activation and browning of white adipocytes is promoted. The use of drugs like β3-adrenergic agonists in murine models induces similar effects. With respect to atheroprotection, thermogenic adipose tissue activation has beneficial outcomes in mice by decreasing plasma triglycerides, total cholesterol and low-density lipoproteins, by increasing high-density lipoproteins, and by inducing secretion of atheroprotective adipokines. Atheroprotective effects involve an unaffected hepatic clearance. Latest clinical data tend to find thinner atherosclerotic lesions in patients with higher brown adipose tissue activity. Strategies for preserving healthy arteries are a major concern for public health.

Impact of Obesity-Induced Inflammation on Cardiovascular Diseases (CVD)

Overweight and obesity are key risk factors of cardiovascular disease (CVD). Obesity is currently presented as a pro-inflammatory state with an expansion in the outflow of inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), alongside the expanded emission of leptin. The present review aimed to evaluate the relationship between obesity and inflammation and their impacts on the development of cardiovascular disease. A literature search was conducted by employing three academic databases, namely PubMed (Medline), Scopus (EMBASE), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). The search presented 786 items, and by inclusion and exclusion filterers, 59 works were considered for final review. The Newcastle–Ottawa Scale (NOS) method was adopted to conduct quality assessment; 19 papers were further selected based on the quality score. Obesity-related inflammation leads to a low-grade inflammatory state in organisms by upregulating pro-inflammatory markers and downregulating anti-inflammatory cytokines, thereby contributing to cardiovascular disease pathogenesis. Because of inflammatory and infectious symptoms, adipocytes appear to instigate articulation and discharge a few intense stage reactants and carriers of inflammation. Obesity and inflammatory markers are strongly associated, and are important factors in the development of CVD. Hence, weight management can help prevent cardiovascular risks and poor outcomes by inhibiting inflammatory mechanisms.

Association Between Epicardial Adipose Tissue and Stroke

Epicardial adipose tissue (EAT) is correlated with endothelial dysfunction, metabolic syndrome, increased mortality and recent studies showed a possible association with the increased risk of stroke. We performed a systematic review of studies evaluating the association between EAT and stroke. Eighty studies met the inclusion criteria and were consequently analyzed. The review had Five main findings. First, the increased epicardial fat thickness (EFT) may be associated with the stroke episode. Second, regardless of the imaging method (echocardiography, MRI, and CT) this association remains. Third, the association of metabolic syndrome and atrial fibrillation seems to increase the risk of stroke. Fourth, this systematic review was considered as low risk of bias. Despite being unable to establish a clear association between EAT and stroke, we have organized and assessed all the research papers on this topic, analyzing their limitations, suggesting improvements in future pieces of research and pointing out gaps in the literature. Furthermore, the mechanistic links between increased EAT and stroke incidence remains unclear, thus, further research is warranted.

The bifurcated role of adiponectin in colorectal cancer

The association of adiponectin with metabolism and cancer is well established. Since its discovery in 1990, adiponectin, as one of the adipose tissue-secreted adipokines, has been very widely studied in biomedical research. Low levels of circulatory adiponectin have been reported in obesity, inflammatory diseases and various types of cancers including colorectal cancer (CRC), which is highly linked with obesity and gut inflammation. However, the function and underlying mechanisms of adiponectin in CRC is not well understood. In addition, there are contradictory reports on the role of adiponectin in cancer. Therefore, further investigation is needed. In this review, we explore the information available on the relationship between adiponectin and CRC with respect to proliferation, cell survival, angiogenesis and inflammation. We also highlighted the knowledge gaps, filling in which could help us better understand the function and mechanisms of adiponectin in CRC.

Cardiac Adiposity and Arrhythmias: The Role of Imaging

Increased cardiac fat depots are metabolically active tissues that have a pronounced pro-inflammatory nature. Increasing evidence supports a potential role of cardiac adiposity as a determinant of the substrate of atrial fibrillation and ventricular arrhythmias. The underlying mechanism appears to be multifactorial with local inflammation, fibrosis, adipocyte infiltration, electrical remodeling, autonomic nervous system modulation, oxidative stress and gene expression playing interrelating roles. Current imaging modalities, such as echocardiography, computed tomography and cardiac magnetic resonance, have provided valuable insight into the relationship between cardiac adiposity and arrhythmogenesis, in order to better understand the pathophysiology and improve risk prediction of the patients, over the presence of obesity and traditional risk factors. However, at present, given the insufficient data for the additive value of imaging biomarkers on commonly used risk algorithms, the use of different screening modalities currently is indicated for personalized risk stratification and prognostication in this setting.

Paracardial fat remodeling affects systemic metabolism through alcohol dehydrogenase 1

The relationship between adiposity and metabolic health is well established. However, very little is known about the fat depot, known as paracardial fat (pCF), located superior to and surrounding the heart. Here, we show that pCF remodels with aging and a high-fat diet and that the size and function of this depot are controlled by alcohol dehydrogenase 1 (ADH1), an enzyme that oxidizes retinol into retinaldehyde. Elderly individuals and individuals with obesity have low ADH1 expression in pCF, and in mice, genetic ablation of Adh1 is sufficient to drive pCF accumulation, dysfunction, and global impairments in metabolic flexibility. Metabolomics analysis revealed that pCF controlled the levels of circulating metabolites affecting fatty acid biosynthesis. Also, surgical removal of the pCF depot was sufficient to rescue the impairments in cardiometabolic flexibility and fitness observed in Adh1-deficient mice. Furthermore, treatment with retinaldehyde prevented pCF remodeling in these animals. Mechanistically, we found that the ADH1/retinaldehyde pathway works by driving PGC-1α nuclear translocation and promoting mitochondrial fusion and biogenesis in the pCF depot. Together, these data demonstrate that pCF is a critical regulator of cardiometabolic fitness and that retinaldehyde and its generating enzyme ADH1 act as critical regulators of adipocyte remodeling in the pCF depot.

Thoracic Visceral Adipose Tissue Area and Pulmonary Hypertension in Lung Transplant Candidates. The Lung Transplant Body Composition Study

Rationale: Obesity is associated with an increased risk of pulmonary hypertension (PH); however, regional adipose tissue deposition is heterogeneous with distinct cardiovascular phenotypes.Objectives: To determine the association of body mass index (BMI) and thoracic visceral and subcutaneous adipose tissue areas (VAT and SAT, respectively) with PH in patients with advanced lung disease referred for lung transplantation.Methods: We studied patients undergoing evaluation for lung transplantation at three centers from the Lung Transplant Body Composition Study. PH was defined as mean pulmonary artery pressure >20 mm Hg and pulmonary vascular resistance ≥3 Wood units. VAT and SAT were measured on chest computed tomography and normalized to height squared.Results: One hundred thirty-seven (34%) of 399 patients included in our study had PH. Doubling of thoracic VAT was associated with significantly lower pulmonary vascular resistance (β, -0.24; 95% confidence interval [95% CI], -0.46 to -0.02; P = 0.04), higher pulmonary arterial wedge pressure (β, 0.79; 95% CI, 0.32 to 1.26; P = 0.001), and decreased risk of PH (relative risk, 0.86; 95% CI, 0.74 to 0.99; P = 0.04) after multivariate adjustment. Vaspin levels were higher in patients without PH (median, 101.8 vs. 92.0 pg/ml; P < 0.001) but did not mediate the association between VAT and the risk of PH. SAT and BMI were not independently associated with risk of PH.Conclusions: Lower thoracic VAT was associated with a higher risk of PH in patients with advanced lung disease undergoing evaluation for lung transplantation. The role of adipokines in the pulmonary vascular disease remains to be evaluated.

Phylogenic Determinants of Cardiovascular Frailty, Focus on Hemodynamics and Arterial Smooth Muscle Cells

The evolution of the circulatory system from invertebrates to mammals has involved the passage from an open system to a closed in-parallel system via a closed in-series system, accompanying the increasing complexity and efficiency of life’s biological functions. The archaic heart enables pulsatile motion waves of hemolymph in invertebrates, and the in-series circulation in fish occurs with only an endothelium, whereas mural smooth muscle cells appear later. The present review focuses on evolution of the circulatory system. In particular, we address how and why this evolution took place from a closed, flowing, longitudinal conductance at low pressure to a flowing, highly pressurized and bifurcating arterial compartment. However, although arterial pressure was the latest acquired hemodynamic variable, the general teleonomy of the evolution of species is the differentiation of individual organ function, supported by specific fueling allowing and favoring partial metabolic autonomy. This was achieved via the establishment of an active contractile tone in resistance arteries, which permitted the regulation of blood supply to specific organ activities via its localized function-dependent inhibition (active vasodilation). The global resistance to viscous blood flow is the peripheral increase in frictional forces caused by the tonic change in arterial and arteriolar radius, which backscatter as systemic arterial blood pressure. Consequently, the arterial pressure gradient from circulating blood to the adventitial interstitium generates the unidirectional outward radial advective conductance of plasma solutes across the wall of conductance arteries. This hemodynamic evolution was accompanied by important changes in arterial wall structure, supported by smooth muscle cell functional plasticity, including contractility, matrix synthesis and proliferation, endocytosis and phagocytosis, etc. These adaptive phenotypic shifts are due to epigenetic regulation, mainly related to mechanotransduction. These paradigms actively participate in cardio-arterial pathologies such as atheroma, valve disease, heart failure, aneurysms, hypertension, and physiological aging.

Inflammatory and lipid regulation by cholinergic activity in epicardial stromal cells from patients who underwent open-heart surgery

The modulation of acetylcholine (ACh) release by botulinum toxin injection into epicardial fat diminishes atrial fibrillation (AF) recurrence. These results suggest an interaction between autonomic imbalance and epicardial fat as risk factors of AF. Our aim was to study the inflammatory, lipidic and fibroblastic profile of epicardial stroma from patients who underwent open-heart surgery, their regulation by cholinergic activity and its association with AF. We performed in vitro and ex vivo assays from paired subcutaneous and epicardial stromal cells or explants from 33 patients. Acute ACh effects in inflammation and lipid-related genes were analysed by qPCR, in intracellular calcium mobilization were performed by Fluo-4 AM staining and in neutrophil migration by trans-well assays. Chronic ACh effects on lipid accumulation were visualized by AdipoRed. Plasma protein regulation by parasympathetic denervation was studied in vagotomized rats. Our results showed a higher pro-inflammatory profile in epicardial regarding subcutaneous stromal cells. Acute ACh treatment up-regulated monocyte chemoattractant protein 1 levels. Chronic ACh treatment improved lipid accumulation within epicardial stromal cells (60.50% [22.82-85.13] vs 13.85% [6.17-23.16], P < .001). Additionally, patients with AF had higher levels of fatty acid-binding protein 4 (1.54 ± 0.01 vs 1.47 ± 0.01, P = .005). Its plasma levels were pronouncedly declined in vagotomized rats (2.02 ± 0.21 ng/mL vs 0.65 ± 0.23 ng/mL, P < .001). Our findings support the characterization of acute or chronic cholinergic activity on epicardial stroma and its association with AF.

An exploratory cross-sectional study of subclinical vascular damage in patients with polymyalgia rheumatica

The aim of the study was to investigate the presence of subclinical vascular damage in polymyalgia rheumatica (PMR). We enrolled PMR patients having major cardiovascular risk factors (MCVRF) and, as controls, patients with MCVRF. All underwent: color Doppler ultrasound to evaluate the common carotid intima-media thickness (IMT), the anterior–posterior abdominal aortic diameter (APAD), and the prevalence of carotid artery stenosis; the cardio-ankle vascular index (CAVI) to measure arterial stiffness together with the ankle-brachial index (ABI) to investigate the presence of lower-extremity peripheral arterial disease. Finally, we measured the serum levels of adipocytokines implicated in vascular dysfunction. As a result, 48 PMR and 56 MCVRF patients were included. An increase of IMT (1.07/0.8–1.2 vs 0.8/0.8–1.05; p = 0.0001), CAVI (8.7/7.8–9.3 vs 7.6/6.9–7.8; p < 0.0001) and APAD values (21.15/18.1–25.6 vs 18/16–22; p = 0.0013) was found in PMR patients with respect to controls. No differences were reported in the prevalence of carotid artery stenosis or ABI values between the two groups. A significant correlation between IMT and CAVI in PMR and MCVRF subjects (r² = 0.845 and r² = 0.556, respectively; p < 0.01) was found. Leptin levels (pg/mL; median/25th–75th percentile) were higher in PMR than in MCVRF subjects (145.1/67–398.6 vs 59.5/39.3–194.3; p = 0.04). Serum levels of adiponectin (ng/mL) were higher in PMR patients (15.9/10.65–24.1 vs 6.1/2.8–22.7; p = 0.01), while no difference in serum levels of resistin (ng/mL) was found between PMR and MCVRF subjects (0.37/0.16–0.66 vs 0.26/0.14–1.24). Our study shows an increased subclinical vascular damage in PMR patients compared to those with MCVRF, paving the way for further studies aimed at planning primary cardiovascular prevention in this population.

Automatic segmentation and quantification of epicardial adipose tissue from coronary computed tomography angiography

Epicardial adipose tissue (EAT) is a visceral fat deposit, that's known for its association with factors, such as obesity, diabetes mellitus, age, and hypertension. Segmentation of the EAT in a fast and reproducible way is important for the interpretation of its role as an independent risk marker intricate. However, EAT has a variable distribution, and various diseases may affect the volume of the EAT, which can increase the complexity of the already time-consuming manual segmentation work. We propose a 3D deep attention U-Net method to automatically segment the EAT from coronary computed tomography angiography (CCTA). Five-fold cross-validation and hold-out experiments were used to evaluate the proposed method through a retrospective investigation of 200 patients. The automatically segmented EAT volume was compared with physician-approved clinical contours. Quantitative metrics used were the Dice similarity coefficient (DSC), sensitivity, specificity, Jaccard index (JAC), Hausdorff distance (HD), mean surface distance (MSD), residual mean square distance (RMSD), and the center of mass distance (CMD). For cross-validation, the median DSC, sensitivity, and specificity were 92.7%, 91.1%, and 95.1%, respectively, with JAC, HD, CMD, MSD, and RMSD are 82.9% ± 8.8%, 3.77 ± 1.86 mm, 1.98 ± 1.50 mm, 0.37 ± 0.24 mm, and 0.65 ± 0.37 mm, respectively. For the hold-out test, the accuracy of the proposed method remained high. We developed a novel deep learning-based approach for the automated segmentation of the EAT on CCTA images. We demonstrated the high accuracy of the proposed learning-based segmentation method through comparison with ground truth contour of 200 clinical patient cases using 8 quantitative metrics, Pearson correlation, and Bland-Altman analysis. Our automatic EAT segmentation results show the potential of the proposed method to be used in computer-aided diagnosis of coronary artery diseases (CADs) in clinical settings.

Is epicardial fat thickness associated with acute ischemic stroke in patients with atrial fibrillation?

BACKGROUND

Atrial fibrillation (AF) is the most common etiology of acute ischemic stroke (AIS). In recent years, epicardial fat tissue (EFT) has been found to be associated with the presence and chronicity of AF. However, the potential association between EFT and AIS in AF patients has not been fully elucidated. The aim of this study was to evaluate the effectiveness of EFT on prediction of AIS in patients with AF.

METHODS

This cross-sectional study has included 80 AF patients with AIS and 80 age-gender matched AF controls without AIS. Echocardiographic evaluations were performed in the first three days after hospitalization between July 2019 and December 2019 in Sakarya University Education and Research Hospital. Echocardiographic measurement of EFT was conducted according to previously published methods.

RESULTS

In comparison with the control group, AF patients with AIS had significantly higher epicardial fat thickness (8.55 ± 1.08 vs 5.90 ± 1.35 mm; P < 0.0001). The multivariate regression analysis indicated that EFT independently predicts AIS in patients with AF.

CONCLUSIONS

The present study showed that, EFT is an independent predictor for the development of acute ischemic stroke in patients with AF.

Genome-wide screening of functional long noncoding RNAs in the epicardial adipose tissues of atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmias, and patients with AF are facing increased risk of heart failure and ischemic stroke. However, the AF pathogenesis, especially the long noncoding RNAs (lncRNA)-related mechanism, has not been fully understood. In this study, we collected RNA sequencing data of the epicardial adipose tissues (EAT) from 6 AF and 6 sinus rhythm (SR) to identify the differentially expressed protein-coding genes (PCGs) and lncRNAs. Functionally, the differentially expressed PCGs were significantly enriched in bone development disease, chronic kidney failure, and kidney disease. Particularly, we found that homeobox (HOX) genes, especially the antisense RNAs, HOTAIRM1, HOXA-AS2 and HOXB-AS2, were significantly downregulated in EAT of AF. The biological function predictions for the dysregulated lncRNAs revealed that TNF signaling pathway was the most frequent pathway that the lncRNAs might participate in. In addition, SNHG16 and RP11-471B22.2 might participate in TGF-beta signaling and ECM-receptor interaction by interacting with the proteins involved in the pathways, respectively. Collectively, we provided some potentially pathogenic lncRNAs in AF, which might be useful for the related researchers to study their functionality and develop new therapeutics.

Through fat and thin – a journey with the adipose tissues

The paper is based on the lecture that I gave on receiving the Nutrition Society's inaugural Gowland Hopkins Award for contributions to Cellular and Molecular Nutrition. It reviews studies on the adipose tissues, brown and white, conducted by the groups that I have led since entering nutrition research in 1975. The initial focus was on exploring metabolic factors that underpin the development of obesity using animal models. This resulted in an interest in non-shivering thermogenesis with brown adipose tissue being identified as the key effector of facultative heat production. Brown fat is less thermogenically active in various obese rodents, and major changes in activity are exhibited under physiological conditions such as lactation and fasting consistent with a general role for the tissue in nutritional energetics. My interests moved to white adipose tissue following the cloning of the Ob gene. Our initial contributions in this area included demonstrating nutritional regulation of Ob gene expression and circulating leptin levels, as well as a regulatory role for the sympathetic nervous system operating through β3-adrenoceptors. My interests subsequently evolved to a wider concern with the endocrine/signalling role of adipose tissue. Inflammation is a characteristic of white fat in obesity with the release of inflammation-related adipokines, and we proposed that hypoxia underlies this inflammatory state. O2-deprivation was shown to have substantial effects on gene expression and cellular function in white adipocytes. The hypoxia studies led to the proposition that O2 should be considered as a critical macronutrient.