Epicardial adipose tissue in patients with heart failure

Association of epicardial adipose tissue volume with heart weight in post-mortem cases

Epicardial adipose tissue (EAT) deposition has been long associated with heart weight. However, recent research has failed to replicate this association. We aimed to determine the association of EAT volume with heart weight in post-mortem cases and identify potential confounding variables. EAT volume derived from post-mortem computed tomography (PMCT) and heart weight were measured in post-mortem cases (N = 87, age: 56 ± 16 years, 28% female). Cases with hypertrophied heart weights (N = 44) were determined from reference tables. Univariable associations were tested using Spearman correlation and simple linear regression. Independence was determined with stepwise regression. In the total cohort, EAT volume (median 66 ± 45 cm3) was positively associated with heart weight (median 435 ± 132 g) at the univariable level (r = 0.6, P < 0.0001) and after adjustment for age, female sex, and various body size metrics (R2 adjusted = 0.41-0.57). Median EAT volume was 1.9-fold greater in cases with hypertrophic hearts (P < 0.0001) but with considerably greater variability, especially in cases with extreme EAT volume or heart weight. As such, EAT volume was not associated with heart weight in hypertrophic cases, while a robust independent association was found in non-hypertrophic cases (R2 adjusted = 0.62-0.86). EAT mass estimated from EAT volume found that EAT comprised approximately 13% of overall heart mass in the total cases. This was significantly greater in cases with hypertrophy (median 15.5%; range, 3.6-36.6%) relative to non-hypertrophied cases (12.5%, 3.3-24.3%) (P = 0.04). EAT volume is independently and positively associated with heart weight in post-mortem cases. Excessive heart weight significantly confounded this association.

Association of cardiometabolic and vascular atherosclerosis phenotypes on non-contrast chest CT with incident heart failure in patients with severe hypercholesterolemia

BACKGROUND

Coronary artery calcium (CAC), thoracic aorta calcification (TAC), non-alcoholic fatty liver disease (NAFLD), and epicardial adipose tissue (EAT) are associated with atherosclerotic cardiovascular disease (ASCVD) and heart failure (HF).

OBJECTIVES

We aimed to determine whether these cardiometabolic and atherosclerotic risk factors identified by non-contrast chest computed tomography (CT) are associated with HF hospitalizations in patients with LDL-C≥ 190 mg/dL.

METHODS

We conducted a retrospective cohort analysis of patients with LDL-C ≥190 mg/dL, aged ≥40 years without established ASCVD or HF, who had a non-contrast chest CT within 3 years of LDL-C measurement. Ordinal CAC, ordinal TAC, EAT, and NAFLD were measured. Kaplan-Meier curves and multivariable Cox regression models were built to ascertain the association with HF hospitalization.

RESULTS

We included 762 patients with median age 60 (53-68) years, 68% (n=520) female, and median LDL-C level of 203 (194-216) mg/dL. Patients were followed for 4.7 (interquartile range 2.75-6.16) years, and 107 (14%) had a HF hospitalization. Overall, 355 (47%) patients had CAC=0, 210 (28%) had TAC=0, 116 (15%) had NAFLD, and median EAT was 79 mL (49-114). Moderate-Severe CAC (log-rank p<0.001) and TAC (log-rank p=0.006) groups were associated with increased HF hospitalizations. This association persisted when considering myocardial infarction (MI) as a competing risk. NAFLD and EAT volume were not associated with HF.

CONCLUSIONS

In patients without established ASCVD and LDL-C≥190 mg/dL, CAC was independently associated with increased HF hospitalizations while TAC, NAFLD, and EAT were not.

Epicardial Adipose Tissue and Heart Failure, Friend or Foe?

Heart failure (HF) management guidelines recommend individualized assessments based on HF phenotypes. Adiposity is a known risk factor for HF. Recently, there has been an increased interest in organ-specific adiposity, specifically the role of the epicardial adipose tissue (EAT), in HF risk. EAT is easily assessable through various imaging modalities and is anatomically and functionally connected to the myocardium. In pathological conditions, EAT secretes inflammatory cytokines, releases excessive fatty acids, and increases mechanical load on the myocardium, resulting in myocardial remodeling. EAT plays a pathophysiological role in characterizing both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). In HFrEF, EAT volume is reduced, reflecting an impaired metabolic reservoir, whereas in HFpEF, the amount of EAT is associated with worse biomarker and hemodynamic profiles, indicating increased EAT activity. Studies have examined the possibility of therapeutically targeting EAT, and recent studies using sodium glucose cotransporter 2 inhibitors have shown potential in reducing EAT volume. However, further research is required to determine the clinical implications of reducing EAT activity in patients with HF.

Epicardial fat and ventricular arrhythmias

The arrhythmogenic role of epicardial adipose tissue (EAT) in atrial arrhythmias is well established, but its effect on ventricular arrhythmias has been significantly less investigated. Since ventricular arrhythmias are thought to cause 75%-80% of cases of sudden cardiac death, this is not a trivial issue. We provide an overview of clinical data as well as experimental and molecular data linking EAT to ventricular arrhythmias, attempting to dissect possible mechanisms and indicate future directions of research and possible clinical implications. However, despite a wealth of data indicating the role of epicardial and intramyocardial fat in the induction and propagation of ventricular arrhythmias, unfortunately there is currently no direct evidence that indeed EAT triggers arrhythmia or can be a target for antiarrhythmic strategies.

Assessment of Epicardial Fat in Children: Its Role as a Cardiovascular Risk Factor and How It Is Influenced by Lifestyle Habits

Epicardial adipose tissue (EAT) stands out as a distinctive repository of visceral fat, positioned in close anatomical and functional proximity to the heart. EAT has emerged as a distinctive reservoir of visceral fat, intricately interlinked with cardiovascular health, particularly within the domain of cardiovascular diseases (CVDs). The aim of our overview is to highlight the role of EAT as a marker for cardiovascular risk in children. We also explore the influence of unhealthy lifestyle habits as predisposing factors for the deposition of EAT. The literature data accentuate the consequential impact of lifestyle choices on EAT dynamics, with sedentary behavior and unwholesome dietary practices being contributory to a heightened cardiovascular risk. Lifestyle interventions with a multidisciplinary approach are therefore pivotal, involving a nutritionally balanced diet rich in polyunsaturated and monounsaturated fatty acids, regular engagement in aerobic exercise, and psychosocial support to effectively mitigate cardiovascular risks in children. Specific interventions, such as high-intensity intermittent training and circuit training, reveal favorable outcomes in diminishing the EAT volume and enhancing cardiometabolic health. Future clinical studies focusing on EAT in children are crucial for advancing our understanding and developing targeted strategies for cardiovascular risk management in this population.

The Value of Epicardial Adipose Tissue for Patients Treated with Percutaneous Coronary Intervention: A Systemic Review and Meta-analysis

BACKGROUND

Recently, some clinical researches have shown epicardial adipose tissue to play a pivotal role in prognosis for patients treated with percutaneous coronary intervention (PCI), but the results are still controversial. A systematic review and meta-analysis was conducted to investigate the value of epicardial adipose tissue for the prognosis of patients treated with PCI.

METHOD

A systematic search was performed using PubMed, Web of Science, and the Cochrane Library for studies evaluating the association of EAT and patients treated with PCI published up to January 2023. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the studies. Meta-analysis was performed using Review Manager V.5.3.

RESULT

Thirteen studies enrolling 3683 patients were eventually included in our study. The thickness or volume of EAT measured were significantly higher in the ISR group compared to those in the non-ISR group (the standard mean difference of 0.34, 95% CI, 0.18-0.49, p<0.0001; I2=36%). The incidence of no-reflow was significantly higher in the thicker EAT group compared to the thin EAT group (pooled relative ratio 1.52, 95% CI 1.29-1,80, p<0.0001; I2 =0%). Thicker EAT was significantly associated with MACEs (pooled relative ratio 1.50, 95% 1.18-1.90, p=0.008). A lower EAT volume was associated with larger infarct size in STEMI patients treated with primary PCI (standard mean difference -5.45, 95% CI -8.10, -2.80; p<0.0001; I2=0%).

CONCLUSION

In summary, our systemic review and meta-analysis suggests that high EAT is related to a significantly increased risk of non-reflow, MACEs, and decreased infarct size in patients with CAD treated with PCI. This paradox phenomenon demonstrates that the quality of EAT may play a more important role than the sole thickness or volume of EAT.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Association Between Epicardial Adipose Tissue and Left Atrial and Ventricular Function in Patients With Heart Failure: A Systematic Review and Meta-Analysis

Existing evidence suggested that the role of epicardial adipose tissue (EAT) in heart failure with reduced and preserved ejection fraction (HFrEF/HFpEF) might be divergent. Here, we conducted a systematic review and meta-analysis to evaluate the association between EAT and HF. Several databases were searched from their inception to January 20, 2023. We calculated the standard mean difference (SMD) in EAT between the HF and control groups, as well as the correlation coefficient between EAT and left atrial (LA) and left ventricular (LV) function. This meta-analysis included 23 studies, involving 1563 HFrEF and 1351 HFpEF patients. Our findings indicated that EAT was significantly higher in HFpEF patients (SMD: 0.61, 95% CI: 0.27-0.94), but not in total HF or HFrEF patients compared to controls. In HFrEF, EAT was positively correlated with LVEF, LV end-diastolic volume index (LVEDVI), LA global longitudinal strain (LAGLS), and negatively correlated with N-terminal pro-B-type natriuretic peptide (NT-ProBNP). However, no significant relationship existed between EAT and LV mass index (LVMI) or LVGLS. For HFpEF, EAT correlated positively with LVMI, LVEDVI, LV end-systolic volume index (LVESVI), LA volume index (LAVI), cardiac troponin T, and extracellular volume (ECV), but negatively with LVGLS and LAGLS. EAT was shown to be higher in HFpEF, but not in HFrEF. Less EAT was linked with worse LA function but not worse LV function in HFrEF, while more EAT was associated with worse LA/LV function in HFpEF.

Concomitant aortic regurgitation predicts better left ventricular reverse remodeling after transcatheter aortic valve replacement

BACKGROUND

We aim to determine predictors of inadequate left ventricular mass index (LVMi) regression at mid-term after transcatheter aortic valve replacement (TAVR), including the potential role of epicardial adipose tissue (EAT).

METHODS

We retrospectively reviewed patients with both echocardiographic assessments and multi-slice computed tomography (MSCT) obtained one year after TAVR. The change of LVMi, the volume and the average CT attenuation of EAT from baseline to one-year follow-up was calculated. Patients were divided into two groups by the percentage change of LVMi at a cut-off of 15%.

RESULTS

A total of 152 patients were included with a median age of 74 years (interquartile range [IQR] 69-78 years) and 56.6% being male. LVMi decreased (P < 0.0001) while EAT volume increased and the average CT attenuation decreased (both P < 0.0001) at one year. Baseline atrial fibrillation (P = 0.042), mitral regurgitation ≥ mild (P = 0.006), aortic regurgitation (AR) > mild (P = 0.001) and the change in the average CT attenuation of EAT (P = 0.026) were different between the decrease of LVMi ≥ 15% and < 15%. AR > mild at baseline was the only statistically significant predictor of a decrease of LVMi < 15% at one year (OR 0.33, 95% CI: 0.13 to 0.84, P = 0.021) in multivariate regression.

CONCLUSIONS

Concomitant more-than-mild AR might predict better left ventricular reverse remodeling regression after TAVR.

Epicardial Adipose Tissue Assessed by Computed Tomography and Echocardiography Are Associated With Adverse Cardiovascular Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

Epicardial adipose tissue (EAT) has garnered attention as a prognostic and risk stratification factor for cardiovascular disease. This study, via meta-analyses, evaluates the associations between EAT and cardiovascular outcomes stratified across imaging modalities, ethnic groups, and study protocols.

METHODS

Medline and Embase databases were searched without date restriction on May 2022 for articles that examined EAT and cardiovascular outcomes. The inclusion criteria were (1) studies measuring EAT of adult patients at baseline and (2) reporting follow-up data on study outcomes of interest. The primary study outcome was major adverse cardiovascular events. Secondary study outcomes included cardiac death, myocardial infarction, coronary revascularization, and atrial fibrillation.

RESULTS

Twenty-nine articles published between 2012 and 2022, comprising 19 709 patients, were included in our analysis. Increased EAT thickness and volume were associated with higher risks of cardiac death (odds ratio, 2.53 [95% CI, 1.17-5.44]; P=0.020; n=4), myocardial infarction (odds ratio, 2.63 [95% CI, 1.39-4.96]; P=0.003; n=5), coronary revascularization (odds ratio, 2.99 [95% CI, 1.64-5.44]; P<0.001; n=5), and atrial fibrillation (adjusted odds ratio, 4.04 [95% CI, 3.06-5.32]; P<0.001; n=3). For 1 unit increment in the continuous measure of EAT, computed tomography volumetric quantification (adjusted hazard ratio, 1.74 [95% CI, 1.42-2.13]; P<0.001) and echocardiographic thickness quantification (adjusted hazard ratio, 1.20 [95% CI, 1.09-1.32]; P<0.001) conferred an increased risk of major adverse cardiovascular events.

CONCLUSIONS

The utility of EAT as an imaging biomarker for predicting and prognosticating cardiovascular disease is promising, with increased EAT thickness and volume being identified as independent predictors of major adverse cardiovascular events.

REGISTRATION

URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42022338075.

Coronary Computed Tomography Angiography: Beyond Obstructive Coronary Artery Disease

Nowadays, coronary computed tomography angiography (CCTA) has a role of paramount importance in the diagnostic algorithm of ischemic heart disease (IHD), both in stable coronary artery disease (CAD) and acute chest pain. Alongside the quantification of obstructive coronary artery disease, the recent technologic developments in CCTA provide additional relevant information that can be considered as "novel markers" for risk stratification in different settings, including ischemic heart disease, atrial fibrillation, and myocardial inflammation. These markers include: (i) epicardial adipose tissue (EAT), associated with plaque development and the occurrence of arrhythmias; (ii) late iodine enhancement (LIE), which allows the identification of myocardial fibrosis; and (iii) plaque characterization, which provides data about plaque vulnerability. In the precision medicine era, these emerging markers should be integrated into CCTA evaluation to allow for the bespoke interventional and pharmacological management of each patient.

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

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

Association between epicardial adipose tissue and incident heart failure mediating by alteration of natriuretic peptide and myocardial strain

BACKGROUND

Epicardial adipose tissue (EAT) has been suggested to exert deleterious effects on myocardium and cardiovascular disease (CVD) consequence. We evaluated the associations of EAT thickness with adverse outcomes and its potential mediators in the community.

METHODS

Participants without heart failure (HF) who had undergone cardiac magnetic resonance (CMR) to measure EAT thickness over the right ventricular free wall from the Framingham Heart Study were included. The correlation of EAT thickness with 85 circulating biomarkers and cardiometric parameters was assessed in linear regression models. The occurrence of HF, atrial fibrillation, coronary heart disease (CHD), and other adverse events was tracked since CMR was implemented. Their associations with EAT thickness and the mediators were evaluated using Cox regression and causal mediation analysis.

RESULTS

Of 1554 participants, 53.0% were females. Mean age, body mass index, and EAT thickness were 63.3 years, 28.1 kg/m², and 9.8 mm, respectively. After fully adjusting, EAT thickness positively correlated with CRP, LEP, GDF15, MMP8, MMP9, ORM1, ANGPTL3, and SERPINE1 and negatively correlated with N-terminal pro-B-type natriuretic peptide (NT-proBNP), IGFBP1, IGFBP2, AGER, CNTN1, and MCAM. Increasing EAT thickness was associated with smaller left ventricular end-diastolic dimension, thicker left ventricular wall thickness, and worse global longitudinal strain (GLS). During a median follow-up of 12.7 years, 101 incident HF occurred. Per 1-standard deviation increment of EAT thickness was associated with a higher risk of HF (adjusted hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.19-1.72, P < 0.001) and the composite outcome consisting of myocardial infarction, ischemic stroke, HF, and death from CVD (adjusted HR [95% CI], 1.23 [1.07-1.40], P = 0.003). Mediation effect in the association between thicker EAT and higher risk of HF was observed with NT-proBNP (HR [95% CI], 0.95 [0.92-0.98], P = 0.011) and GLS (HR [95% CI], 1.04 [1.01-1.07], P = 0.032).

CONCLUSIONS

EAT thickness was correlated with inflammation and fibrosis-related circulating biomarkers, cardiac concentric change, myocardial strain impairment, incident HF risk, and overall CVD risk. NT-proBNP and GLS might partially mediate the effect of thickened EAT on the risk of HF. EAT could refine the assessment of CVD risk and become a new therapeutic target of cardiometabolic diseases.

TRIAL REGISTRATION

URL: https://clinicaltrials.gov . Identifier: NCT00005121.

Proteomic profiling of epicardial fat in heart failure with preserved versus reduced and mildly reduced ejection fraction

In order to explore the proteomic signatures of epicardial adipose tissue (EAT) related to the mechanism of heart failure with reduced and mildly reduced ejection fraction (HFrEF/HFmrEF) and heart failure (HF) with preserved ejection fraction (HFpEF), a comprehensive proteomic analysis of EAT was made in HFrEF/HFmrEF (n = 5) and HFpEF (n = 5) patients with liquid chromatography-tandem mass spectrometry experiments. The selected differential proteins were verified between HFrEF/HFmrEF (n = 20) and HFpEF (n = 40) by ELISA (enzyme-linked immunosorbent assay). A total of 599 EAT proteins were significantly different in expression between HFrEF/HFmrEF and HFpEF. Among the 599 proteins, 58 proteins increased in HFrEF/HFmrEF compared to HFpEF, whereas 541 proteins decreased in HFrEF/HFmrEF. Of these proteins, TGM2 in EAT was down-regulated in HFrEF/HFmrEF patients and was confirmed to decrease in circulating plasma of the HFrEF/HFmrEF group (p = 0.019). Multivariate logistic regression analysis confirmed plasma TGM2 could be an independent predictor of HFrEF/HFmrEF (p = 0.033). Receiver operating curve analysis indicated that the combination of TGM2 and Gensini score improved the diagnostic value of HFrEF/HFmrEF (p = 0.002). In summary, for the first time, we described the proteome in EAT in both HFpEF and HFrEF/HFmrEF and identified a comprehensive dimension of potential targets for the mechanism behind the EF spectrum. Exploring the role of EAT may offer potential targets for preventive intervention of HF.

Epicardial Fat Volume, Cardiac Function, and Incident Heart Failure: The Rotterdam Study

Background Larger epicardial fat volume (EFV) has been associated with increased risks of cardiovascular disease and atrial fibrillation. Yet, evidence on the association of EFV with cardiac function and incident heart failure (HF) remains scarce. Methods and Results We included 2103 participants (mean age, 68 years; 54.4% women) from the prospective population-based RS (Rotterdam Study) with computed tomography-based EFV and repeated echocardiography-based assessment of left ventricular (LV) systolic and diastolic function. Linear mixed effects and Cox-proportional hazard regression models, adjusted for cardiovascular risk factors, were used to assess the associations of EFV with repeated measurements of echocardiographic parameters and with incident HF. During a median follow-up of 9.7 years, 124 HF events occurred (incidence rate, 6.37 per 1000 person-years). For LV systolic function, 1-SD larger EFV was associated with 0.76 (95% CI, 0.54-0.98) mm larger LV end-diastolic dimension, 0.66 (95% CI, 0.47-0.85) mm larger LV end-systolic dimension, and 0.56% (95% CI, -0.86% to -0.27%) lower LV ejection fraction. Interactions between EFV and time were small. For LV diastolic function, 1-SD larger EFV was associated with 1.02 (95% CI, 0.78-1.27) mm larger left atrial diameter. Larger EFV was also associated with incident HF (hazard ratio per 1-SD increase in EFV, 1.34 [95% CI, 1.07-1.68] per 1-SD larger EFV). Conclusions We report an independent association between EFV with new-onset HF in the general population. EFV seems to exert its influence on HF through different pathways contributing to deteriorations in systolic function and larger left atrial size in part, likely through mechanical restraint and hypertrophy.

Epicardial adipose tissue thickness is associated with reduced peak oxygen consumption and systolic reserve in patients with type 2 diabetes and normal heart function

AIM

To investigate the impact of epicardial adipose tissue (EAT) thickness on cardiopulmonary performance in patients with type 2 diabetes (T2D) and normal heart function.

MATERIALS AND METHODS

We analysed EAT thickness in subjects with T2D and normal biventricular systo-diastolic functions undergoing a maximal cardiopulmonary exercise test combined with stress echocardiography, speckle tracking and pulmonary function assessment, as well as serum N-terminal pro B-type natriuretic peptide (NT-proBNP).

RESULTS

In the 72 subjects enrolled, those with EAT thickness above the median (> 5 mm) showed higher body fat mass, smaller indexed left ventricular dimensions and marginally reduced diastolic function variables at rest. Higher EAT thickness was associated with lower peak oxygen uptake (VO_2peak 17.1 ± 3.6 vs. 21.0 ± 5.7 ml/min/kg, P = .001), reduced systolic reserve (ΔS' 4.6 ± 1.6 vs. 5.8 ± 2.5 m/s, P = .02) and higher natriuretic peptides (NT-proBNP 64 [29-165] vs. 31 [26-139] pg/ml, P = .04), as well as chronotropic insufficiency and impaired heart rate recovery. Ventilatory variables and peripheral oxygen extraction were not different between groups. EAT was independently associated with VO_2peak and linearly and negatively correlated with peak heart rate, heart rate recovery, workload, VO₂ at the anaerobic threshold and at peak, and cardiac power output, and was directly correlated with natriuretic peptides.

CONCLUSION

Higher EAT thickness in T2D is associated with worse cardiopulmonary performance and multiple traits of subclinical cardiac systolic dysfunction.

Computed tomography measured epicardial adipose tissue and psoas muscle attenuation: new biomarkers to predict major adverse cardiac events (MACE) and mortality in patients with heart disease and critically ill patients. Part I: Epicardial adipose tissue

Over the last two decades, the potential role of epicardial adipocyte tissue (EAT) as a marker for major adverse cardiovascular events has been extensively studied. Unlike other visceral adipocyte tissues (VAT), EAT is not separated from the adjacent myocardium by a fascial layer and shares the same microcirculation with the myocardium. Adipocytokines, secreted by EAT, interact directly with the myocardium through paracrine and vasocrine pathways. The role of the Randle cycle, linking VAT accumulation to insulin resistance, and the relevance of blood flow and mitochondrial function of VAT, are briefly discussed. The three available imaging modalities for the assessment of EAT are discussed. The advantages of echocardiography, cardiac CT, and cardiac magnetic resonance (CMR) are compared. The last section summarises the current stage of knowledge on EAT as a clinical marker for major adverse cardiovascular events (MACE). The association between EAT volume and coronary artery disease (CAD) has robustly been validated. There is growing evidence that EAT volume is associated with computed tomography coronary angiography (CTCA) assessed high-risk plaque features. The EAT CT attenuation coefficient predicts coronary events. Many studies have established EAT volume as a predictor of atrial fibrillation after cardiac surgery. Moreover, EAT thickness has been independently associated with severe aortic stenosis and mitral annular calcification. Studies have demonstrated that EAT volume is associated with heart failure. Finally, we discuss the potential role of EAT in critically ill patients admitted to the intensive care unit. In conclusion, EAT seems to be a promising new biomarker to predict MACE.

T lymphocyte characteristics and immune repertoires in the epicardial adipose tissue of heart failure patients

Background

Epicardial adipose tissue (EAT) acts as an active immune organ and plays a critical role in the pathogenesis of heart failure (HF). However, the characteristics of immune cells in EAT of HF patients have rarely been elucidated.

Methods

To identify key immune cells in EAT, an integrated bioinformatics analysis was performed on public datasets. EAT samples with paired subcutaneous adipose tissue (SAT), heart, and peripheral blood samples from HF patients were collected in validation experiments. T cell receptor (TCR) repertoire was assessed by high-throughput sequencing. The phenotypic characteristics and key effector molecules of T lymphocytes in EAT were assessed by flow cytometry and histological staining.

Results

Compared with SAT, EAT was enriched for immune activation-related genes and T lymphocytes. Compared with EAT from the controls, activation of T lymphocytes was more pronounced in EAT from HF patients. T lymphocytes in EAT of HF patients were enriched by highly expanded clonotypes and had greater TCR clonotype sharing with cardiac tissue relative to SAT. Experiments confirmed the abundance of IFN-γ⁺ effector memory T lymphocytes (T_EM) in EAT of HF patients. CCL5 and GZMK were confirmed to be associated with T lymphocytes in EAT of HF patients.

Conclusion

EAT of HF patients was characterized by pronounced immune activation of clonally expanded IFN-γ⁺ T_EM and a generally higher degree of TCR clonotypes sharing with paired cardiac tissue.

Connecting epicardial adipose tissue and heart failure with preserved ejection fraction: mechanisms, management and modern perspectives

Obesity is very common in patients with heart failure with preserved ejection fraction (HFpEF) and it has been suggested that obesity plays an important role in the pathophysiology of this disease. While body mass index defines the presence of obesity, this measure provides limited information on visceral adiposity, which is probably more relevant in the pathophysiology of HFpEF. Epicardial adipose tissue is the visceral fat situated directly adjacent to the heart and recent data demonstrate that accumulation of epicardial adipose tissue is associated with the onset, symptomatology and outcome of HFpEF. However, the mechanisms by which epicardial adipose tissue may be involved in HFpEF remain unclear. It is also questioned whether epicardial adipose tissue may be a specific target for therapy for this disease. In the present review, we describe the physiology of epicardial adipose tissue and the pathophysiological transformation of epicardial adipose tissue in response to chronic inflammatory diseases, and we postulate conceptual mechanisms on how epicardial adipose tissue may be involved in HFpEF pathophysiology. Lastly, we outline potential treatment strategies, knowledge gaps and directions for further research.

Impact of Dysfunctional Adipose Tissue Depots on the Cardiovascular System

Obesity with its associated complications represents a social, economic and health problem of utmost importance worldwide. Specifically, obese patients carry a significantly higher risk of developing cardiovascular disease compared to nonobese individuals. Multiple molecular mechanisms contribute to the impaired biological activity of the distinct adipose tissue depots in obesity, including secretion of proinflammatory mediators and reactive oxygen species, ultimately leading to an unfavorable impact on the cardiovascular system. This review summarizes data relating to the contribution of the main adipose tissue depots, including both remote (i.e., intra-abdominal, hepatic, skeletal, pancreatic, renal, and mesenteric adipose fat), and cardiac (i.e., the epicardial fat) adipose locations, on the cardiovascular system. Finally, we discuss both pharmacological and non-pharmacological strategies aimed at reducing cardiovascular risk through acting on adipose tissues, with particular attention to the epicardial fat.

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.

Epicardial Adipose Tissue Was Highly Associated with Reduction in Left Ventricular Diastolic Function as Early as in Adolescence

BACKGROUND

Epicardial adipose tissue (EAT) is increased in adolescents with obesity and may play a role in early cardiovascular pathophysiological changes. There is a lack of evidence focusing on the association between EAT and cardiac function in adolescents. This study explored associations between EAT, left ventricle (LV) geometric, and LV functional changes in adolescents.

METHODS

Adolescent volunteers between 10 and 20 years of age were included. Body mass index (BMI) was presented as age- and sex-specific BMI z-scores. Blood samples for glucose metabolism, lipid profiles, and high-sensitivity C-reactive protein (hs-CRP) were obtained. EAT thickness, LV hypertrophy, and LV diastolic function were measured by echocardiography.

RESULTS

The mean age of the 276 adolescents was 13.51 ± 2.44 years. BMI z-score was strongly associated with EAT thickness (r = 0.77; p < 0.001). Multivariable analysis revealed that age, insulin resistance, total cholesterol to high-density lipoprotein cholesterol ratio, and hs-CRP were independent predictors of increased EAT thickness. After adjusting for sex, age, and BMI z-score by multivariable analysis, EAT thickness was a strong predictor of higher LV mass indexed to height^2.7, higher relative wall thickness, lower mitral annulus e'/a', and higher E/e' of the mitral annulus. There was no association between EAT and LV ejection fraction.

CONCLUSIONS

EAT was highly associated with LV hypertrophy and reduction in LV diastolic function, independent of BMI z-score in the enrolled adolescents. Of note, the negative impacts of EAT on LV geometry and diastolic function occurred as early as in adolescence. This highlights the importance of preventing obesity and EAT deposition early in life.

Quantification of Cardiac Adipose Tissue in Failing and Nonfailing Human Myocardium

Background

Because body mass index (BMI) is generally used clinically to define obesity and to estimate body adiposity, BMI likely is positively correlated with epicardial adipose tissue (EAT) level. Based on echocardiography, previous outcomes on this matter have varied from almost absent to rather strong correlations between BMI and EAT. The purpose of our study was to unambiguously examine EAT content and determine if correlations exist between EAT content and BMI, cause of heart failure, or contractile force.

Methods and Results

We qualitatively scored 150 human hearts ex vivo on EAT distribution. From each heart, multiple photographs of the heart were taken, and both atrial and ventricular adipose tissue levels were semiquantitatively scored. Main findings include a generally higher EAT content on nonfailing hearts compared with end‐stage failing hearts (atrial adipose tissue level 5.70±0.13 vs. 5.00±0.12, P<0.001; ventricular adipose tissue level 5.14±0.16 vs. 4.57±0.12, P=0.0048). The results also suggest that EAT quantity is not strongly correlated with BMI in nonfailing (atrial adipose tissue level r=0.069, ventricular adipose tissue level r=0.14) or failing (atrial adipose tissue level r=−0.022, ventricular adipose tissue level r=0.051) hearts. Atrial EAT is closely correlated with ventricular EAT in both nonfailing (r=0.92, P<0.001) and failing (r=0.87, P<0.001) hearts.

Conclusions

EAT volume appears to be inversely proportional to severity of or length of time with heart failure based on our findings. Based on a lack of correlation with BMI, it is incorrect to assume high EAT volume given high body fat percentage.

The Quantity of Epicardial Adipose Tissue in Patients Having Ablation for Atrial Fibrillation With and Without Heart Failure

The distribution of epicardial adipose tissue (EAT) across the spectrum of heart failure (HF) has yet to be fully elucidated. The present study investigated the distribution of EAT in an HF spectrum and its association with clinical and echocardiographic parameters. A total of 326 patients who underwent contrast-enhanced computed tomography before transcatheter atrial fibrillation ablation with and without HF symptoms, and a wide range of left ventricular (LV) ejection fractions (LVEF) were included. EAT mass was quantified on contrast-enhanced computed tomography using dedicated software. A total of 36 patients had HF with reduced LVEF (HFrEF) (11.0%), 46 had HF with mid-range LVEF (HFmrEF) (14.1%), 53 had HFpEF (16.3%), and 191 did not have HF symptoms (58.6%) and were considered controls. Patients with HFpEF had the largest EAT mass, significantly higher than the control group (128 ± 36 g vs 95 ± 35 g, p <0.001), the HFmrEF group (101 ± 37 g, p <0.001), and the HFrEF group (103 ± 37 g, p = 0.002). However, there were no differences in EAT mass between patients with HFrEF, HFmrEF, and controls. EAT was independently associated with E/e', LV mass index, and tricuspid regurgitation velocity. Male gender, body mass index, and C-reactive protein levels were independently associated with EAT. In conclusion, patients with HFpEF had more EAT than patients with HFmrEF, patients with HFpEF, and controls. EAT was associated with worse LV diastolic dysfunction, whereas C-reactive protein levels were independently associated with EAT, suggesting an active inflammatory component.

Epicardial Adipose Tissue related to Left Atrial and Ventricular Function in Heart Failure with Preserved (HFpEF) versus Reduced and Mildly Reduced Ejection Fraction (HFrEF/HFmrEF)

BACKGROUND

Different associations between epicardial adipose tissue (EAT) and cardiac function have been suggested in patients with heart failure with preserved (HFpEF) versus reduced and mildly reduced ejection fraction (HFrEF/HFmrEF). However, few studies have directly compared the association between EAT and left atrial (LA) and ventricular (LV) function in patients with HFpEF and HFrEF/HFmrEF.

METHODS

We studied EAT thickness using transthoracic echocardiography in a multicenter cohort of 149 community-dwelling controls without HF, 99 patients with HFpEF, and 366 patients with HFrEF/HFmrEF. EAT thickness was averaged from parasternal long-axis and short-axis views, respectively, and off-line speckle tracking analysis was performed to quantify LA and LV function. Data were validated in an independent cohort of 626 controls, 243 patients with HFpEF, and 180 patients with HFrEF/HFmrEF. For LV function, LV global longitudinal strain (GLS) was measured in both derivation and validation cohorts. For the LA function, LAGLS at reservoir, contractile and conduit phase were measured in the derivation cohort, and only LAGLS at reservoir phase was measured in the validation cohort.

RESULTS

In the derivation cohort, EAT thickness was lower in HFrEF/HFmrEF (7.3±2.5mm) compared to HFpEF (8.3±2.6mm, p<0.05) and controls (7.9±1.8mm, p<0.05). Greater EAT thickness was associated with better LV and contractile LA function in HFrEF/HFmrEF, but not in HFpEF (p for interaction < 0.05). These findings were confirmed in the validation cohort, where EAT thickness was lower in HFrEF/HFmrEF (6.7±1.4mm) compared to HFpEF (9.6±2.8mm; p<0.05) and controls (7.7±2.3mm; p<0.05). Greater EAT thickness was associated with better LV and reservoir LA function in patients with HFrEF/HFmrEF but worse LV and reservoir LA function in patients with HFpEF (p for interaction <0.05). Thickened EAT (EAT thickness >10mm) was associated with LA dysfunction (LAGLS at reservoir phase<23%) in HFpEF, but not in HFrEF/HFmrEF.

CONCLUSION

EAT thickness is greater in patient with HFpEF than HFrEF/HFmrEF. Increased EAT thickness is associated with worse LA and LV function in HFpEF but the opposite in HFrEF/HFmrEF. This article is protected by copyright. All rights reserved.

Epicardial adipose tissue in contemporary cardiology

Interest in epicardial adipose tissue (EAT) is growing rapidly, and research in this area appeals to a broad, multidisciplinary audience. EAT is unique in its anatomy and unobstructed proximity to the heart and has a transcriptome and secretome very different from that of other fat depots. EAT has physiological and pathological properties that vary depending on its location. It can be highly protective for the adjacent myocardium through dynamic brown fat-like thermogenic function and harmful via paracrine or vasocrine secretion of pro-inflammatory and profibrotic cytokines. EAT is a modifiable risk factor that can be assessed with traditional and novel imaging techniques. Coronary and left atrial EAT are involved in the pathogenesis of coronary artery disease and atrial fibrillation, respectively, and it also contributes to the development and progression of heart failure. In addition, EAT might have a role in coronavirus disease 2019 (COVID-19)-related cardiac syndrome. EAT is a reliable potential therapeutic target for drugs with cardiovascular benefits such as glucagon-like peptide 1 receptor agonists and sodium–glucose co-transporter 2 inhibitors. This Review provides a comprehensive and up-to-date overview of the role of EAT in cardiovascular disease and highlights the translational nature of EAT research and its applications in contemporary cardiology.

In this Review, Iacobellis provides a comprehensive overview of the role of epicardial adipose tissue (EAT) in cardiovascular disease, including coronary artery disease, heart failure and atrial fibrillation, discusses imaging techniques for EAT assessment and highlights the therapeutic potential of targeting EAT in cardiovascular disease.

Epicardial adipose tissue (EAT) has anatomical and functional interactions with the heart owing to the shared circulation and the absence of muscle fascia separating the two organs.

EAT can be clinically measured with cardiac imaging techniques that can help to predict and stratify cardiovascular risk.

Regional distribution of EAT is important because pericoronary EAT and left atrial EAT differently affect the risk of coronary artery diseases and atrial fibrillation, respectively.

EAT has a role in the development of several cardiovascular diseases through complex mechanisms, including gene expression profile, pro-inflammatory and profibrotic proteome, neuromodulation, and glucose and lipid metabolism.

EAT could be a potential therapeutic target for novel cardiometabolic medications that modulate adipose tissue such as glucagon-like peptide 1 receptor agonists and sodium–glucose co-transporter 2 inhibitors.

EAT might be a reservoir of severe acute respiratory syndrome coronavirus 2 and an amplifier of coronavirus disease 2019 (COVID-19)-related cardiac syndrome.

Epicardial adipose tissue in obesity-related cardiac dysfunction

Obesity is associated with the development of heart failure and is a major risk factor for heart failure with preserved ejection fraction (HFpEF). Epicardial adipose tissue (EAT) is a unique visceral fat in close proximity to the heart and is of particular interest to the study of cardiac disease. Small poorly differentiated adipocytes with altered lipid:water content are associated with a proinflammatory secretome and may contribute to the pathophysiology observed in HFpEF. Multimodality imaging approaches can be used to quantify EAT volume and characterise EAT composition. Current research studies remain unclear as to the magnitude of effect that EAT plays on myocardial dysfunction and further work using multimodality imaging techniques is ongoing. Pharmacological interventions, including glucagon-like peptide 1 receptor agonists and sodium-dependent glucose linked transporter 2 inhibitors have shown promise in attenuating the deleterious metabolic and inflammatory changes seen in EAT. Clinical studies are ongoing to explore whether these therapies exert their beneficial effects by modifying this unique adipose deposit.

Magnetic Resonance Imaging Quantification of Accumulation of Epicardial Adipose Tissue Adds Independent Risks for Diastolic Dysfunction among Dialysis Patients

BACKGROUND

Diastolic dysfunction (DD) frequently occurs in dialysis patients; however, the risk factors of DD remain to be further explored in such a population. Epicardial adipose tissue (EAT) volume has proven to be an independent clinical risk factor for multiple cardiac disorders.

PURPOSE

To assess whether EAT volume is an independent risk factor for DD in dialysis patients.

STUDY TYPE

Case-control study.

POPULATION

A total of 113 patients (mean age: 54.5 ± 14.4 years; 41 women) who had underwent dialysis for at least 3 months due to uremia.

FIELD STRENGTH

A 3 T, steady-state free precession (SSFP) sequence for cine imaging, modified Look-Locker imaging (MOLLI) for T1 mapping and gradient-recalled-echo for T2*.

ASSESSMENT

All participants were performed cardiac magnetic resonance imaging (MRI) and echocardiogram. For MRI images analysis, borders of the EAT were manually delineated, as well as, pericardial adipose tissue (PeAT) and paracardial adipose tissue (PaAT), T1 mapping, T2* mapping, global longitudinal strain (GLS), and left atrial strain. For echocardiogram assessments, the thickness of PaAT, e' velocity, E velocity, E/e ratio, A velocity, and deceleration time were measured.

STATISTICAL TESTS

Univariate and multivariate logistic regressions were performed to explore the independent risk factors for DD. P value less than 0.05 was considered as significant.

RESULTS

Compared with the DD(-) group, the DD(+) group had significantly more epicardial tissue fat (18.5 ± 1.3 vs. 30.9 ± 2.3) In addition, EAT volumes increased significantly with the grades of DD (grade 1 vs. grade 2 and 3: 27.9 ± 15.9 vs. 35.4 ± 13.1). Moreover, EAT had significant correlations with T1 mapping, T2* mapping, GLS, left atrial strain, e' velocity, and E/e ratio. EAT accumulation added an independent risk for DD (Odds Ratio = 1.03) over conventional clinical risk factors including age, diabetes mellitus, and hemodialysis.

DATA CONCLUSION

EAT was associated with diastolic function, and its accumulation may be an independent risk factor for DD among dialysis patients.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

A systematic review exploring the significance of measuring epicardial fat thickness in correlation to B-type natriuretic peptide levels as prognostic and diagnostic markers in patients with or at risk of heart failure

Emerging evidence suggests that epicardial fat thickness (EFT) may be a critical feature to understand cardiac health and determine the risk of heart failure. The current review critically assesses and discusses evidence on the efficiency of measuring EFT, in comparison to the well-known markers B-type natriuretic peptide (BNP) and its N-terminal fragment pro-B-type natriuretic peptide (NT-proBNP), as a prognostic and diagnostic approach in individuals with or at risk of heart failure. A systematic approach was undertaken to search major databases, PubMed, Scopus, Google Scholar and the Cochrane library to identify studies that quantified EFT and serum BNP/NT-proBNP levels in individuals with or at risk of heart failure. Twelve studies met the inclusion criteria and a total of 1983 participants were included in this systematic review. Evidence shows a clear association between increased EFT and elevated BNP/NT-proBNP levels in individuals with metabolic disease and suggests that both methods can be used for heart failure diagnosis and prognosis. However, due to the broad spectrum of challenges linked with measuring EFT, BNP/Pro-BNP is the predominant method used for heart failure diagnosis and prognosis in clinical practice. Nonetheless, measuring EFT provides a powerful and reproducible diagnostic tool for risk stratification and heart failure diagnosis and prognosis. Importantly, measuring EFT proves valuable to validate BNP/NT-proBNP levels to predict heart failure, especially due to its non-invasive nature.

Impact of epicardial adipose tissue on cardiovascular haemodynamics, metabolic profile, and prognosis in heart failure

AIMS

We evaluated the impact of echocardiographic epicardial adipose tissue (EAT) on cardiovascular haemodynamics, metabolic profile and prognosis in heart failure (HF) using combined cardiopulmonary-echocardiography exercise stress.

METHODS AND RESULTS

We analysed EAT thickness of HF patients with reduced (HFrEF, n = 205) and preserved (HFpEF, n = 188) ejection fraction, including 44 controls. HFpEF patients displayed the highest EAT, while HFrEF patients had lower values than controls. EAT showed an inverse correlation with natriuretic peptides, troponin T and C-reactive protein in HFrEF, while having a direct association with troponin T and C-reactive protein in HFpEF. EAT was independently associated with peak oxygen consumption (VO₂ ) and peripheral extraction (AVO₂ diff), regardless of body mass index. EAT was inversely correlated with peak VO₂ and AVO₂ diff in HFpEF, while a direct association was observed in HFrEF, where lower EAT values were associated with worse left ventricular systolic dysfunction. In HFpEF, increased EAT was related to right ventriculo-arterial (tricuspid annular plane systolic excursion/systolic pulmonary artery pressure) uncoupling. After 21 months of follow-up, 146 HF hospitalizations and 34 cardiovascular deaths were recorded in the HF population. Cox multivariable analysis supported an independent differential role of EAT in HF cohorts (interaction P = 0.01): higher risk of adverse events for increasing EAT in HFpEF [hazard ratio (HR) 1.12, 95% confidence interval (CI) 1.04-1.37] and for decreasing EAT in HFrEF (HR 0.75, 95% CI 0.54-0.91).

CONCLUSION

In HFpEF, EAT accumulation is associated with worse haemodynamic and metabolic profile, also affecting survival. Conversely, lower EAT values imply higher left ventricular dysfunction, global functional impairment and adverse prognosis in HFrEF.

Deleterious Effects of Epicardial Adipose Tissue Volume on Global Longitudinal Strain in Patients With Preserved Left Ventricular Ejection Fraction

Background: It is known that epicardial adipose tissue (EAT) volume is linked to cardiac dysfunction. However, it is unclear whether EAT volume (EATV) is closely linked to abnormal LV strain. We examined the relationship between EATV and global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) in patients with preserved LV function.

Methods: Notably, 180 consecutive subjects (68 ± 12 years; 53% men) underwent 320-slice multi-detector computed tomography coronary angiography and were segregated into coronary artery disease (CAD) (≥1 coronary artery branch stenosis ≥50%) and non-CAD groups. GLS, GCS, and GRS were evaluated by 2-dimensional speckle tracking in patients with preserved left ventricular (LV) ejection fraction (LVEF) ≥50%.

Results: First, GLS, but not GRS and GCS, was lower in the high EATV group though the LVEF was comparable to the low EATV group. Frequency of GLS ≤18 was higher in the high EATV group. Second, multiple regression model showed that EATV, age, male sex, and CAD, were determinants of GLS. Third, the cutoff points of EATV were comparable (~116–117 mL) in both groups. The cutoff of EATV ≥116 showed a significant correlation with GLS ≤18 in overall subjects.

Conclusions: Increasing EATV was independently associated with global longitudinal strain despite the preserved LVEF and lacking obstructive CAD. Our findings suggest an additional role of EAT on myocardial systolic function by impaired LV longitudinal strain.

New stroke prognostic factors

Background

Understanding ischemic stroke pathogenesis helps in prevention, prognosis, and treatment. Stroke is greatly related to inflammation and thrombo-genesis as inflammatory cells (as neutrophils-lymphocytes) and thrombo-genic agents as von Willebrand factor antigen (VWF: Ag) and epicardial fat.

Objectives of the study

Evaluation of epicardial fat thickness (EFT), neutrophil/lymphocytic ratio (NLR), and (VWF: Ag) levels as predisposing and prognostic factors of ischemic stroke.

Patients and methods

Sixty acute ischemic stroke patients were subjected to clinical assessment (Oxford stroke sheet), National Institute Health Stroke Scale: NIHSS), Modified Rankin Scale (MRS), NLR and VWF: Ag levels, transthoracic echo, duplex on carotid and vertebro-basilar arteries, and brain computed tomography (CT). Thirty-five healthy controls matched for age and sex were subjected to the same steps except NIHSS and MRS.

Results

EFT, NLR, and VWF among patients were significantly higher than control group. NLR ≥ 2 and VWF: Ag were significant risk factors among stroke patients with VWF: Ag had the higher risk than NLR ≥ 2. NLR was a high valid prognostic marker in predicting stroke outcome (MRS) with (optimal cutoff value 2.05) for prediction of primary unfavorable outcome. There was no statistical significance between (MRS) and EFT or VWF: Ag level.

Conclusion

EFT represents inexpensive and readily available clinical marker that may be useful in estimating risk of ischemic stroke. NLR is non-expensive easy marker for predicting stroke severity and primary unfavorable outcome. High VWF level increases ischemic stroke risk.

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.

Macrophage Accumulation and Angiogenesis in Epicardial Adipose Tissue in Cardiac Patients with or without Chronic Heart Failure

Routinely measuring epicardial fat had become a novel tool for cardiovascular risk stratification. Structural changes in epicardial adipose tissue (EAT), including fat thickness, inflammation, and angiogenesis, have been described in coronary artery disease (CAD) patients. We proposed to measure EAT thickness and characterize inflammatory infiltrate and angiogenesis in epicardial adipose tissue in CAD patients with and without chronic heart failure (CHF), established by cardiac dysfunction on echocardiography (left ventricular ejection fraction, LVEF ≤ 50%) and symptoms of heart failure (New York Heart Association (NYHA) functional class II or III).The study included 15 patients with CAD (demonstrated by coronary angiography),, who underwent right atrial appendages (RAA) excision during coronary artery bypass graft (CABG). The study was performed by histopathological, immunohistochemical (IHC), and morphometrical analysis. EAT thickness was assessed by using morphometry applied on routine histological stains. Inflammatory cell infiltration and angiogenesis were investigated immunohistochemically by using antibodies against CD68 and CD34 markers. Diminished EAT thickness in the CAD patients with CHF was associated with increased macrophage infiltration and reduced angiogenesis of the EAT as compared to CAD patients without CHF. In conclusion, the present study on epicardial fat samples of the RAA suggested that high expression of CD68 appeared to be associated with severe deterioration of heart function in CAD patients who underwent myocardial revascularization consisting of CABG.

Cardiac magnetic resonance in heart failure with preserved ejection fraction: myocyte, interstitium, microvascular, and metabolic abnormalities

Heart failure (HF) with preserved ejection fraction (HFpEF) is a chronic cardiac condition whose prevalence continues to rise, with high social and economic burden, but with no specific approved treatment. Patients diagnosed with HFpEF have a high prevalence of comorbidities and exhibit a high misdiagnosis rate. True HFpEF is likely to have multiple pathophysiological causes - with these causes being clinically ill-defined due to limitations of current measurement techniques. Myocyte, interstitium, microvascular, and metabolic abnormalities have been regarded as key components of the pathophysiology and potential therapeutic targets. Cardiac magnetic resonance (CMR) has the capability to look deeper with a number of tissue characterization techniques which are closer to the underlying specific abnormalities and which could be linked to personalized medicine for HFpEF. This review aims to discuss the potential role of CMR to better define HFpEF phenotypes and to infer measurable therapeutic targets.

Effects of Dapagliflozin on Epicardial Fat Thickness in Patients with Type 2 Diabetes and Obesity

OBJECTIVE

Epicardial adipose tissue (EAT) thickness is a marker of visceral fat and an emerging therapeutic target. Dapagliflozin, a selective sodium-glucose cotransporter 2 inhibitor, improves glucose control and induces moderate weight loss in patients with type 2 diabetes mellitus. Dapagliflozin has recently been shown to reduce cardiovascular risk. Nevertheless, whether dapagliflozin could reduce EAT thickness is unknown.

METHODS

This hypothesis was tested in a 24-week, randomized, double-blind, placebo-controlled clinical trial in 100 patients with type 2 diabetes mellitus with BMI ≥ 27 kg/m² and a hemoglobin A1c level ≤ 8% on metformin monotherapy. Individuals were randomly assigned to 2 groups to receive additional dapagliflozin up to 10 mg once daily or to remain on metformin up to 1,000 mg twice daily. Ultrasound-measured EAT thickness was measured at baseline, 12 weeks, and 24 weeks.

RESULTS

In the dapagliflozin group, EAT decreased by 20% from baseline to 24 weeks, by 15% after 12 weeks, and by 7% between 12 and 24 weeks, respectively (P < 0.01 for all), whereas in the metformin group, there was a significant but smaller EAT reduction. There was no statistically significant correlation between EAT and body weight changes.

CONCLUSIONS

Dapagliflozin causes a rapid and significant EAT reduction that could be independent of weight loss.

Mechanisms linking adipose tissue inflammation to cardiac hypertrophy and fibrosis

Adipose tissue is classically recognized as the primary site of lipid storage, but in recent years has garnered appreciation for its broad role as an endocrine organ comprising multiple cell types whose collective secretome, termed as adipokines, is highly interdependent on metabolic homeostasis and inflammatory state. Anatomical location (e.g. visceral, subcutaneous, epicardial etc) and cellular composition of adipose tissue (e.g. white, beige, and brown adipocytes, macrophages etc.) also plays a critical role in determining its response to metabolic state, the resulting secretome, and its potential impact on remote tissues. Compared with other tissues, the heart has an extremely high and constant demand for energy generation, of which most is derived from oxidation of fatty acids. Availability of this fatty acid fuel source is dependent on adipose tissue, but evidence is mounting that adipose tissue plays a much broader role in cardiovascular physiology. In this review, we discuss the impact of the brown, subcutaneous, and visceral white, perivascular (PVAT), and epicardial adipose tissue (EAT) secretome on the development and progression of cardiovascular disease (CVD), with a particular focus on cardiac hypertrophy and fibrosis.

Expression of Sfrp5/Wnt5a in human epicardial adipose tissue and their relationship with coronary artery disease

Secreted frizzled-related protein 5 (Sfrp5) primarily acts in combination with wingless-type family member 5a (Wnt5a), to inhibits chronic inflammation and repress atherosclerosis and other metabolic disorders. Epicardial adipose tissue (EAT), surrounding the heart and coronary arteries, has been found to be highly related to the progression of coronary artery disease through adipokines production. However, little is known about EAT-derived Sfrp5 and Wnt5a in humans. We aimed to investigate whether the EAT-derived Sfrp5/Wnt5a levels are altered in patients with CAD. Fifty-eight patients with CAD and 29 patients without CAD who underwent cardiac surgery were enrolled. Serum samples and paired adipose biopsies from EAT and subcutaneous adipose tissue (SAT) were collected, and Sfrp5 and Wnt5a levels were detected. Correlation and multivariate regression analyses were performed to determine the relationship between Sfrp5/Wnt5a expression and CAD and other clinical risk factors. According to the results, the CAD group had lower Sfrp5 and higher Wnt5a levels in EAT and serum (all p < 0.05). Serum Sfrp5 levels were significantly lower in CAD patients with impaired myocardial function. EAT Sfrp5 mRNA levels and serum Sfrp5 levels were both negatively associated with the presence of CAD, after adjustment for known biomarkers, EAT mRNA and serum Wnt5a levels correlated positively with the presence of CAD. Thus, we concluded that low Sfrp5 and high Wnt5a levels are associated with the presence of CAD, independent of other conventional risk factors.

Epicardial adipose tissue: an emerging biomarker of cardiovascular complications in type 2 diabetes?

Type 2 diabetes (T2D) is associated with an increased risk of cardiovascular disease and heart failure, which highlights the need for improved understanding of factors contributing to the pathophysiology of these complications as they are the leading cause of mortality in T2D. Patients with T2D have high levels of epicardial adipose tissue (EAT). EAT is known to secrete inflammatory factors, lipid metabolites, and has been proposed to apply mechanical stress on the cardiac muscle that may accelerate atherosclerosis, cardiac remodeling, and heart failure. High levels of EAT in patients with T2D have been associated with atherosclerosis, diastolic dysfunction, and incident cardiovascular events, and this fat depot has been suggested as an important link coupling diabetes, obesity, and cardiovascular disease. Despite this, the predictive potential of EAT in general, and in patients with diabetes, is yet to be established, and, up until now, the clinical relevance of EAT is therefore limited. Should this link be established, importantly, studies show that this fat depot can be modified both by pharmacological and lifestyle interventions. In this review, we first introduce the role of adipose tissue in T2D and present mechanisms involved in the pathophysiology of EAT and pericardial adipose tissue (PAT) in general, and in patients with T2D. Next, we summarize the evidence that these fat depots are elevated in patients with T2D, and discuss whether they might drive the high cardiometabolic risk in patients with T2D. Finally, we discuss the clinical potential of cardiac adipose tissues, address means to target this depot, and briefly touch upon underlying mechanisms and future research questions.

Cardiac MRI measurements of pericardial adipose tissue volumes in patients on in-centre nocturnal hemodialysis

BACKGROUND

Conversion from conventional hemodialysis (CHD) to in-centre nocturnal hemodialysis (INHD) is associated with left ventricular (LV) mass regression, but the underlying mechanisms are not fully understood. Using cardiac MRI (CMR), we examined the effects of INHD on epicardial adipose tissue (EAT) and paracardial adipose tissue (PAT), and the relationships between EAT, PAT and LV remodeling, biomarkers of nutrition, myocardial injury, fibrosis and volume.

METHODS

We conducted a prospective multicenter cohort study of 37 patients transitioned from CHD to INHD and 30 patients on CHD (control). Biochemical markers and CMR were performed at baseline and 52 weeks. CMR images were analyzed by independent readers, blinded to order and treatment group.

RESULTS

Among 64 participants with complete CMR studies at baseline (mean age 54; 43% women), there were no significant differences in EAT index (60.6 ± 4.3 mL/m² vs 64.2 ± 5.1 mL/m², p = 0.99) or PAT index (60.0 ± 5.4 mL/m² vs 53.2 ± 5.9 mL/m², p = 0.42) between INHD and CHD groups. Over 52 weeks, EAT index and PAT index did not change significantly in INHD and CHD groups (p = 0.21 and 0.14, respectively), and the changes in EAT index and PAT index did not differ significantly between INHD and CHD groups (p = 0.30 and 0.16, respectively). Overall, changes in EAT index inversely correlated with changes in LV end-systolic volume index (LVESVI) but not LV end-diastolic volume index (LVEDVI), LV mass index (LVMI), and LV ejection fraction (LVEF). Changes in PAT index inversely correlated with changes in LVESVI, LVMI and positively correlated with changes in LVEF. There were no correlations between changes in EAT index or PAT index with changes in albumin, LDL, triglycerides, troponin-I, FGF-23, or NT-proBNP levels over 52 weeks (all p > 0.30).

CONCLUSIONS

INHD was not associated with any changes in EAT index and PAT index over 12 months. Changes in EAT index were not significantly associated with changes in markers of LV remodeling, nutrition, myocardial injury, fibrosis, volume status. In contrast, changes in PAT index, which paradoxically is expected to exert less paracrine effect on the myocardium, were correlated with changes in LVESVI, LVMI and LVEF. Larger and longer-term studies may clarify the role of PAT in cardiac remodeling with intensified hemodialysis. CLINICALTRIALS.

GOV IDENTIFIER

NCT00718848.

Association of Volumetric Epicardial Adipose Tissue Quantification and Cardiac Structure and Function

Background Epicardial adipose tissue ( EAT ) is in immediate apposition to the underlying myocardium and, therefore, has the potential to influence myocardial systolic and diastolic function or myocardial geometry, through paracrine or compressive mechanical effects. We aimed to review the association between volumetric EAT and markers of myocardial function and geometry. Methods and Results PubMed, Medline, and Embase were searched from inception to May 2018. Studies were included only if complete EAT volume or mass was reported and related to a measure of myocardial function and/or geometry. Meta-analysis and meta-regression were used to evaluate the weighted mean difference of EAT in patients with and without diastolic dysfunction. Heterogeneity of data reporting precluded meta-analysis for systolic and geometric associations. In the 22 studies included in the analysis, there was a significant correlation with increasing EAT and presence of diastolic dysfunction and mean e' (average mitral annular tissue Doppler velocity) and E/e' (early inflow / annular velocity ratio) but not E/A (ratio of peak early (E) and late (A) transmitral inflow velocities), independent of adiposity measures. There was a greater EAT in patients with diastolic dysfunction (weighted mean difference, 24.43 mL; 95% confidence interval, 18.5-30.4 mL; P<0.001), and meta-regression confirmed the association of increasing EAT with diastolic dysfunction ( P=0.001). Reported associations of increasing EAT with increasing left ventricular mass and the inverse correlation of EAT with left ventricular ejection fraction were inconsistent, and not independent from other adiposity measures. Conclusions EAT is associated with diastolic function, independent of other influential variables. EAT is an effect modifier for chamber size but not systolic function.

Effect of Empagliflozin on Cardiac Function, Adiposity, and Diffuse Fibrosis in Patients with Type 2 Diabetes Mellitus

Empagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, significantly improves cardiovascular outcomes in diabetic patients; however, the mechanism is unclear. We hypothesized that empagliflozin might have beneficial effects on cardiac function, structure, adiposity, and myocardial diffuse fibrosis. This prospective study enrolled 35 patients (48.6% men, age 63.5 ± 9.7 years) with type 2 diabetes mellitus (T2DM) from June 1, 2017, to November 31, 2018. The patients received an SGLT2 inhibitor (empagliflozin 25 or 12.5 mg/d) for 6 months in addition to stable oral hypoglycaemic treatment. All patients underwent cardiac magnetic resonance imaging (CMRI) before and after empagliflozin treatment. Left ventricular (LV) function and structure were quantified using cine CMRI. Cardiac adiposity was defined based on pericardial fat and intracardiac triglyceride contents, whereas myocardial diffuse fibrosis was indicated by extracellular volume (ECV). The statistical significance of parameter changes was assessed using paired t-test and stepwise multiple linear regression. There were no significant differences in LV function and structure changes. Cardiac adiposity and diffuse fibrosis indices were also not different before and after empagliflozin treatment. Concerning clinical parameters, only a significant decrease in systolic blood pressure (by 6.4 mmHg) was observed (p = 0.013). Stepwise multiple linear regression revealed that worse baseline MRI parameters were associated with better improvements. Intracardiac triglyceride content decrease was inversely associated with baseline intracardiac triglyceride content (p < 0.001). Pericardial fat changes were negatively correlated with baseline pericardial fat (p < 0.001) and ECV changes (p = 0.028). ECV changes were inversely associated with baseline ECV (p < 0.001), baseline LV ejection fraction (p < 0.001), and LV mass index changes (p = 0.020). This study demonstrated that 6 months of empagliflozin treatment did not significantly improve the LV function, structure, adiposity, and diffuse fibrosis in patients with T2DM. Further, the beneficial effects of empagliflozin treatment might be more evident in patients with worse baseline LV substrate and structure.

Myocardial adipose deposition and the development of heart failure with preserved ejection fraction

AIMS

It has been proposed that an increase of myocardial adiposity is related to left ventricular (LV) diastolic dysfunction. The specific roles of myocardial steatosis including epicardial fat and intramyocardial fat for diastolic function are unknown in those patients suffering heart failure (HF) with reduced (HFrEF) or preserved ejection fraction (HFpEF). This study aims to determine the complex relationship between myocardial adiposity in patients with HFrEF or HFpEF.

METHODS AND RESULTS

Using cardiac magnetic resonance imaging (CMRI), myocardial steatosis was measured in 305 subjects (34 patients with HFrEF, 163 with HFpEF, and 108 non-HF controls). We also evaluated cardiac structure and diastolic and systolic function by echocardiography and CMRI. Patients with HFpEF had significantly more intramyocardial fat than HFrEF patients or non-HF controls [intramyocardial fat content (%), 1.56 (1.26, 1.89) vs. 0.75 (0.50, 0.87) and 1.0 (0.79, 1.15), P < 0.05]. Intramyocardial fat amount (%) was higher in HFpEF women than in men [1.91% (1.17%, 2.32%) vs. 1.22 (0.87%, 2.02%), P = 0.01]. When estimated by CMRI (left ventricular peak filling rate), echocardiographic E/e' level, or left atrial volume index, intramyocardial fat correlated with LV diastolic dysfunction parameters in HFpEF patients, and this was independent of age, co-morbidities, body mass index, gender, and myocardial fibrosis (standardized coefficient: β = -0.34, P = 0.03; β = 0.29, P = 0.025; and β = 0.25, P = 0.02, respectively).

CONCLUSIONS

Patients with HFpEF had significantly more intramyocardial fat than HFrEF patients or non-HF controls. Independent of risk factors or gender, intramyocardial fat correlated with LV diastolic dysfunction parameters in HFpEF patients.

Epicardial adipose tissue volume in patients with coronary artery disease or non-ischaemic dilated cardiomyopathy: evaluation with cardiac magnetic resonance imaging

AIM

To compare the amount of epicardial adipose tissue (EAT) in patients with coronary artery disease (CAD) or non-ischaemic dilated cardiomyopathy (NIDCM) with that in patients with negative cardiac magnetic resonance imaging (CMR).

MATERIALS AND METHODS

One hundred and fifty patients (median age 57 years, interquartile range [IQR] 46-66 years) who underwent CMR were evaluated retrospectively: 50 with CAD, 50 with NIDCM, and 50 with negative CMR. For each patient, the EAT mass index (EATMI) to body surface area, end-diastolic volume index (EDVI), end-systolic volume index (ESVI), stroke volume (SV), ejection fraction (EF) for both ventricles, and left ventricle (LV) mass index were estimated. Intra and inter-reader reproducibility was tested in a random subset of 30 patients, 10 for each group. Mann-Whitney U test, Kruskal-Wallis test, Spearman's correlation, and Bland-Altman statistics were used.

RESULTS

The EATMI in CAD patients (median 15.7 g/m², IQR 8.3-25.7) or in NIDCM patients (15.9 g/m², 11.5-18.1) was significantly higher than that in negative CMR patients (9.1 g/m², 6-12; p<0.001 both). No significant difference was found between CAD and NIDCM patients (p=1.000). A correlation between EATMI and LV mass index was found in NIDCM patients (r=0.455, p=0.002). Intra- and inter-reader reproducibility were up to 80% and 72%, respectively.

CONCLUSION

Patients with NIDCM or CAD exhibited an increased EATMI in comparison to negative CMR patients. CMR can be used to estimate EAT with good reproducibility.

Epicardial adipose tissue and cardiovascular diseases

Obesity is a heterogeneous disease with different degrees of cardiovascular (CV) and metabolic manifestations. Certain ectopic fat depots may contribute to obesity-related CV risk and may explain part of the risk differential observed in metabolically healthy obese and the so called "obesity paradox". The growing interest towards the potential impact of epicardial adipose tissue (EAT) in cardiovascular (CV) risk has led to deepen its biological function. Genetic, epigenetic and environmental factors may drive the shift towards a dysfunctional EAT characterized by a pro-inflammatory and pro-fibrotic phenotype. Due to the close anatomic proximity to coronary arteries, a thicker and dysfunctional EAT actively contribute to development and progression of coronary atherosclerosis. Beside classical paracrine transmission, EAT may directly release mediators into the vasa vasorum of the coronary arterial wall, a mechanism referred to as "vasocrine". Similarly, the pro-inflammatory and pro-fibrotic secretome characterizing dysfunctional EAT may impair cardiac structure and function, thus being implicated in the pathogenesis of diastolic heart failure and atrial fibrillation. The development of 3D imaging techniques have paved the way for clarifying the causative role of EAT in CV pathophysiology, the use of EAT volume/thickness in CV risk stratification and potential cardio-protective effects of EAT reduction. The aim of this narrative review is to update current knowledge on the pathophysiological functions of EAT, focusing on basic mechanisms and potential clinical implications.