Human epicardial adipose tissue is a source of inflammatory mediators

Epicardial fat tissue can predict subclinical left ventricular dysfunction in patients with erectile dysfunction

BACKGROUND

Erectile dysfunction (ED) is an early form of atherosclerosis and subclinical myocardial dysfunction. Epicardial fat tissue (EFT) is associated with impaired left ventricular (LV) function, even in the absence of cardiovascular disease. The aim of this study was to investigate the association between EFT and LV systolic function in patients with erectile ED by speckle tracking echocardiography (2D-STE) method.

METHODS

A total of 129 consecutive patients with ED were compared with 145 age- and sex-matched control subjects. ED was evaluated using the International Index of Erectile Function questionnaire. Thickness of EFT was measured by TTE. Global LV longitudinal strain (LV-GLS) and global LV circumferential strain (LV-GCS) were measured by 2D-STE method.

RESULTS

The EFT thickness was significantly higher in the patients with ED (p <.01). LV-GLS and LV-GCS were revealed to be more deterioration in the ED group compared to controls (-18.2 ± 2.7 vs. (-21.1 ± 3.9, p<.001; -19.5 ± 4.1 vs. -21.9 ± 3.9, p<.001, respectively). It has been shown that EFT thickness is an independent predictor of LV dysfunction.

CONCLUSIONS

These results indicate that EFT thickness is associated with subclinical LV systolic dysfunction in patients with ED.

Epicardial adipose tissue may predict new-onset atrial fibrillation in patients with ST-segment elevation myocardial infarction

AIMS

In this study, we aimed to determine the relationship between EAT thickness in patients with STEMI who underwent primary percutaneous coronary intervention (pPCI) and the development of new-onset atrial fibrillation during hospital follow-up.

MATERIAL AND METHODS

Four hundred and thirteen consecutive patients [284 men (69%) and 129 women (31%)] with a mean age of 59 ± 11 years diagnosed with STEMI were included in this study. Atrial fibrillation developed in 52 (12.5%) patients during in-hospital follow-up and the remaining 361 patients were determined as the control group. There was no difference between the two groups in terms of age and sex. EAT thickness was measured using transthoracic echocardiography. Multiple regression analysis was performed to determine the independent predictors of atrial fibrillation.

RESULTS

EAT thickness was higher in the group with atrial fibrillation than in the control group (P < 0.001). The SYNTAX risk score was higher in the atrial fibrillation group (P < 0.001). A positive correlation was observed between EAT thickness and SYNTAX score (r = 0.523, P < 0.001). In the logistic regression analysis, EAT was detected to be an independent predictor for the development of atrial fibrillation (odds ratio: 4.135, 95% confidence interval 1.245-8.176, P < 0.001).

CONCLUSION

EAT thickness is an important marker of atrial fibrillation development in STEMI patients in the post-pPCI period. We think that EAT thickness can be used as a cardioembolic risk factor in STEMI patients.

Liraglutide reduces cardiac adipose tissue in type 2 diabetes: A secondary analysis of the LIRAFLAME randomized placebo-controlled trial

AIM

To test the hypothesis that treatment with liraglutide can reduce cardiac adipose tissue.

MATERIALS AND METHODS

LIRAFLAME is a randomized placebo-controlled, double-blind, parallel clinical study. Participants with type 2 diabetes were randomized to treatment with liraglutide 1.8 mg/d or placebo for 26 weeks. Computed tomography was performed at baseline and at end of treatment to evaluate the cardiac adipose tissue volume, quantified automatically. We report the results of a secondary endpoint evaluating changes in cardiac adipose tissue.

RESULTS

A total of 102 participants were randomly assigned to liraglutide (n = 51) or placebo (n = 51). At baseline, the mean (SD) cardiac adipose tissue volume was comparable between the liraglutide and the placebo group (232.6 [112.8] vs. 227.0 [103.2] mL; P = 0.80). The mean change in body weight was -3.7 (-4.8, -2.6) kg in the liraglutide and -0.18 (-0.76, 0.40) kg in the placebo group. From baseline to end of treatment the mean cardiac adipose tissue change was -11.5 (95% confidence interval -17.6, -5.4) mL in the liraglutide (P < 0.001) and -0.01 (-5.3, 5.3) mL in the placebo (P = 1.00) groups. The reduction in cardiac adipose tissue was significantly greater in the liraglutide compared to the placebo group (mean difference -11.4 [-19.4, -3.3] mL; P = 0.006), but significance was lost after adjustment for changes in body mass index (P = 0.46).

CONCLUSION

Treatment with liraglutide for 26 weeks was associated with a reduction in cardiac adipose tissue compared to placebo. The reduction was not independent of weight loss, suggesting that this is not a drug-specific effect.

ABCA1 and ABCG1 DNA methylation in epicardial adipose tissue of patients with coronary artery disease

BACKGROUND

Recent studies have focused on the potential role of epicardial adipose tissue (EAT) in the development of coronary artery disease (CAD). ABCA1 and ABCG1 transporters regulate cell cholesterol content and reverse cholesterol transport. We aimed to determine whether DNA methylation and mRNA levels of the ABCA1 and ABCG1 genes in EAT and subcutaneous adipose tissue (SAT) were associated with CAD.

METHODS

Paired EAT and SAT samples were collected from 82 patients undergoing elective cardiac surgery either for coronary artery bypass grafting (CAD group, N = 66) or valve surgery (NCAD group, N = 16). ABCA1 and ABCG1 mRNA levels in EAT and SAT samples were analyzed using real time polymerase chain reaction, ABCA1 protein levels in EAT samples were assessed by western blotting. ABCA1 and ABCG1 DNA methylation analysis was performed in 24 samples from the CAD group and 9 samples from the NCAD group via pyrosequencing.

RESULTS

DNA methylation levels in the ABCA1 promoter and ABCG1 cg27243685 and cg06500161 CpG sites were higher in EAT samples from patients with CAD compared with NCAD (21.92% vs 10.81%, p = 0.003; 71.51% vs 68.42%, p = 0.024; 46.11% vs 37.79%, p = 0.016, respectively). In patients with CAD, ABCA1 and ABCG1 DNA methylation levels were higher in EAT than in SAT samples (p < 0.05). ABCA1 mRNA levels in EAT samples were reduced in the subgroup of patients with CAD and concomitant carotid artery disease or peripheral artery disease compared with the NCAD group (p = 0.024). ABCA1 protein levels in EAT samples tended to be lower in CAD patients than in the NCAD group (p = 0.053). DNA methylation levels at the ABCG1 cg27243685 site positively correlated with plasma triglyceride concentration (r = 0.510, p = 0.008), body mass index (r = 0.556, p = 0.013) and waist-to-hip ratio (r = 0.504, p = 0.012) in SAT samples.

CONCLUSION

CAD is associated with ABCA1 and ABCG1 DNA hypermethylation in EAT. CAD with concomitant carotid artery disease or peripheral artery disease is accompanied by decreased ABCA1 gene expression in EAT. DNA methylation levels at the ABCG1 cg27243685 locus in SAT are associated with hypertriglyceridemia and obesity.

Lesion-Specific Peri-Coronary Fat Attenuation Index Is Associated With Functional Myocardial Ischemia Defined by Abnormal Fractional Flow Reserve

Background: The association between abnormal invasive fractional flow reserve (FFR) and the fat attenuation index (FAI) of lesion-specific peri-coronary adipose tissue (PCAT) is unclear.

Method: Data of patients who underwent coronary computed tomography angiography (CTA) and subsequent invasive coronary angiography (ICA) and FFR measurement within 1 week were retrospectively included. Lesion-specific FAI (FAI_lesion), lesion-free FAI (FAI_normal), epicardial adipose tissue (EAT) volume and attenuation was collected, along with stenosis severity and plaque characteristics. Lesions with FFR <0.8 were considered functionally significant. The association between FFR and each parameter was analyzed by logistic regression or receiver operating characteristic curve.

Result: A total of 227 patients from seven centers were included. EAT volume or attenuation, traditional risk factors, and FAI_normal (with vs. without ischemia: −82 ± 11 HU vs. −81 ± 11 HU, p = 0.65) were not significantly different in patients with or without abnormal FFR. In contrast, lesions causing functional ischemia presented more severe stenosis, greater plaque volume, and higher FAI_lesion (with vs. without ischemia: −71 ± 8 HU vs. −76 ± 9 HU, p < 0.01). Additionally, the CTA-assessed stenosis severity (OR 1.06, 95%CI 1.04–1.08, p < 0.01) and FAI_lesion (OR 1.08, 95%CI 1.04–1.12, p < 0.01) were determined to be independent factors that could predict ischemia. The combination model of these two CTA parameters exhibited a diagnostic value similar to the invasive coronary angiography (ICA)-assessed stenosis severity (AUC: 0.820 vs. 0.839, p = 0.39).

Conclusion: It was FAI_lesion, not general EAT parameters, that was independently associated with abnormal FFR and the diagnostic performance of CTA-assessed stenosis severity for functional ischemia was significantly improved in combination with FAI_lesion.

Imaging techniques for the assessment of adverse cardiac remodeling in metabolic syndrome

Metabolic syndrome (MetS) includes different metabolic conditions (i.e. abdominal obesity, impaired glucose tolerance, hypertriglyceridemia, decreased HDL cholesterol, and/or hypertension) that concour in the development of cardiovascular disease and diabetes. MetS individuals often show adverse cardiac remodeling and myocardial dysfunction even in the absence of overt coronary artery disease or valvular affliction. Diastolic impairment and hypertrophy are hallmarks of MetS-related cardiac remodeling and represent the leading cause of heart failure with preserved ejection fraction (HFpEF). Altered cardiomyocyte function, increased neurohormonal tone, interstitial fibrosis, coronary microvascular dysfunction, and a myriad of metabolic abnormalities have all been implicated in the development and progression of adverse cardiac remodeling related to MetS. However, despite the enormous amount of literature produced on this argument, HF remains a leading cause of morbidity and mortality in such population. The early detection of initial adverse cardiac remodeling would enable the optimal implementation of effective therapies aiming at preventing the progression of the disease to the symptomatic phase. Beyond conventional imaging techniques, such as echocardiography, cardiac tomography, and magnetic resonance, novel post-processing tools and techniques provide information on the biological processes that underlie metabolic heart disease. In this review, we summarize the pathophysiology of MetS-related cardiac remodeling and illustrate the relevance of state-of-the-art multimodality cardiac imaging to identify and quantify the degree of myocardial involvement, prognosticate long-term clinical outcome, and potentially guide therapeutic strategies.

Relationship Between Coronary Atheroma, Epicardial Adipose Tissue Inflammation, and Adipocyte Differentiation Across the Human Myocardial Bridge

Background Inflammation in epicardial adipose tissue (EAT) may contribute to coronary atherosclerosis. Myocardial bridge is a congenital anomaly in which the left anterior descending coronary artery takes a "tunneled" course under a bridge of myocardium: while atherosclerosis develops in the proximal left anterior descending coronary artery, the bridged portion is spared, highlighting the possibility that geographic separation from inflamed EAT is protective. We tested the hypothesis that inflammation in EAT was related to atherosclerosis by comparing EAT from proximal and bridge depots in individuals with myocardial bridge and varying degrees of atherosclerotic plaque. Methods and Results Maximal plaque burden was quantified by intravascular ultrasound, and inflammation was quantified by pericoronary EAT signal attenuation (pericoronary adipose tissue attenuation) from cardiac computed tomography scans. EAT overlying the proximal left anterior descending coronary artery and myocardial bridge was harvested for measurement of mRNA and microRNA (miRNA) using custom chips by Nanostring; inflammatory cytokines were measured in tissue culture supernatants. Pericoronary adipose tissue attenuation was increased, indicating inflammation, in proximal versus bridge EAT, in proportion to atherosclerotic plaque. Individuals with moderate-high versus low plaque burden exhibited greater expression of inflammation and hypoxia genes, and lower expression of adipogenesis genes. Comparison of gene expression in proximal versus bridge depots revealed differences only in participants with moderate-high plaque: inflammation was higher in proximal and adipogenesis lower in bridge EAT. Secreted inflammatory cytokines tended to be higher in proximal EAT. Hypoxia-inducible factor 1a was highly associated with inflammatory gene expression. Seven miRNAs were differentially expressed by depot: 3192-5P, 518D-3P, and 532-5P were upregulated in proximal EAT, whereas miR 630, 575, 16-5P, and 320E were upregulated in bridge EAT. miR 630 correlated directly with plaque burden and inversely with adipogenesis genes. miR 3192-5P, 518D-3P, and 532-5P correlated inversely with hypoxia/oxidative stress, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PCG1a), adipogenesis, and angiogenesis genes. Conclusions Inflammation is specifically elevated in EAT overlying atherosclerotic plaque, suggesting that EAT inflammation is caused by atherogenic molecular signals, including hypoxia-inducible factor 1a and/or miRNAs in an "inside-to-out" relationship. Adipogenesis was suppressed in the bridge EAT, but only in the presence of atherosclerotic plaque, supporting cross talk between the vasculature and EAT. miR 630 in EAT, expressed differentially according to burden of atherosclerotic plaque, and 3 other miRNAs appear to inhibit key genes related to adipogenesis, angiogenesis, hypoxia/oxidative stress, and thermogenesis in EAT, highlighting a role for miRNA in mediating cross talk between the coronary vasculature and EAT.

Association between single-slice and whole heart measurements of epicardial and pericardial fat in cardiac MRI

BACKGROUND

Epicardial (ECF) and pericardial fat (PCF) are important prognostic markers for various cardiac diseases. However, volumetry of the fat compartments is time-consuming.

PURPOSE

To investigate whether total volume of ECF and PCF can be estimated by axial single-slice measurements and in a four-chamber view.

MATERIAL AND METHODS

A total of 113 individuals (79 patients and 34 healthy) were included in this retrospective magnetic resonance imaging (MRI) study. The total volume of ECF and PCF was determined using a 3D-Dixon sequence. Additionally, the area of ECF and PCF was obtained in single axial layers at five anatomical landmarks (left coronary artery, right coronary artery, right pulmonary artery, mitral valve, coronary sinus) of the Dixon sequence and in a four-chamber view of a standard cine sequence. Pearson's correlation coefficient was calculated between the total volume and each single-slice measurement.

RESULTS

Axial single-slice measurements of ECF and PCF correlated strongly with the total fat volumes at all landmarks (ECF: r  =  0.85-0.94, P < 0.001; PCF: r  =  0.89-0.94, P < 0.001). The best correlation was found at the level of the left coronary artery for ECF and PCF (r  =  0.94, P < 0.001). Correlation between single-slice measurement in the four-chamber view and the total ECF and PCF volume was lower (r  =  0.75 and r  =  0.8, respectively, P < 0.001).

CONCLUSION

Single-slice measurements allow an estimation of ECF and PCF volume. This time-efficient analysis allows studies of larger patient cohorts and the opportunistic determination of ECF/PCF from routine examinations.

Physical Exercise Potentially Targets Epicardial Adipose Tissue to Reduce Cardiovascular Disease Risk in Patients with Metabolic Diseases: Oxidative Stress and Inflammation Emerge as Major Therapeutic Targets

Excess epicardial adiposity, within a state of obesity and metabolic syndrome, is emerging as an important risk factor for the development of cardiovascular diseases (CVDs). Accordingly, increased epicardial fat thickness (EFT) implicates the exacerbation of pathological mechanisms involving oxidative stress and inflammation within the heart, which may accelerate the development of CVDs. This explains increased interest in targeting EFT reduction to attenuate the detrimental effects of oxidative stress and inflammation within the setting of metabolic syndrome. Here, we critically discuss clinical and preclinical evidence on the impact of physical exercise on EFT in correlation with reduced CVD risk within a setting of metabolic disease. This review also brings a unique perspective on the implications of oxidative stress and inflammation as major pathological consequences that link increased EFT to accelerated CVD risk in conditions of metabolic disease.

Ischemic heart disease: Cellular and molecular immune contributions of the pericardium

Ischemic heart disease promotes complex inflammatory and remodeling pathways which contribute to the development of chronic heart failure. Although blood-derived and local cardiac mediators have traditionally been linked with these processes, the pericardial space has more recently been noted as alternative contributor to the injury response in the heart. The pericardial space contains fluid rich in physiologically active mediators, and immunologically active adipose tissue, which are altered during myocardial infarction. Key immune cells in the pericardial fluid and adipose tissue have been identified which act as mediators for cell recruitment and function after myocardial infarction have been identified in experimental models. Here, we provide an overview of the current understanding of the inflammatory mechanisms of the pericardial space and their role in post-myocardial infarction remodeling and the potential for the use of the pericardial space as a delivery vehicle for treatments to modulate heart healing.

Relationship of Nonalcoholic Fatty Liver Disease and Heart Failure With Preserved Ejection Fraction

Although there is an established bidirectional relationship between heart failure with reduced ejection fraction and liver disease, the association between heart failure with preserved ejection fraction (HFpEF) and liver diseases, such as nonalcoholic fatty liver disease (NAFLD), has not been well explored. In this paper, the authors provide an in-depth review of the relationship between HFpEF and NAFLD and propose 3 NAFLD-related HFpEF phenotypes (obstructive HFpEF, metabolic HFpEF, and advanced liver fibrosis HFpEF). The authors also discuss diagnostic challenges related to the concurrent presence of NAFLD and HFpEF and offer several treatment options for NAFLD-related HFpEF phenotypes. The authors propose that NAFLD-related HFpEF should be recognized as a distinct HFpEF phenotype.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Modulation of Cardiac Arrhythmogenesis by Epicardial Adipose Tissue: JACC State-of-the-Art Review

Obesity is a significant risk factor for arrhythmic cardiovascular death. Interactions between epicardial adipose tissue (EAT) and myocytes are thought to play a key role in the development of arrhythmias. In this review, the authors investigate the influence of EAT on arrhythmogenesis. First, they summarize electrocardiographic evidence showing the association between increased EAT volume and atrial and ventricular conduction delay. Second, they detail the structural cross talk between EAT and the heart and its arrhythmogenicity. Adipose tissue infiltration within the myocardium constitutes an anatomical obstacle to cardiac excitation. It causes activation delay and increases the risk of arrhythmias. Intercellular electrical coupling between cardiomyocytes and EAT can further slow conduction and increase the risk of block, favoring re-entry and arrhythmias. Finally, EAT secretes multiple substances that influence cardiomyocyte electrophysiology either by modulating ion currents and electrical coupling or by stimulating fibrosis. Thus, structural and paracrine cross talk between EAT and cardiomyocytes facilitates arrhythmias.

Atherosclerosis Pathways are Activated in Pericoronary Adipose Tissue of Patients with Coronary Artery Disease

PURPOSE

Perivascular release of inflammatory mediators may accelerate coronary lesion formation and contribute to plaque instability. Accordingly, we compared gene expression in pericoronary adipose tissue (PCAT) in patients with advanced coronary artery disease (CAD) and non-CAD controls.

PATIENTS AND METHODS

PCAT samples were collected during coronary bypass grafting from CAD patients (n = 21) and controls undergoing valve replacement surgery, with CAD excluded by coronary angiography (n = 19). Gene expression was measured by GeneChip™ Human Transcriptome Array 2.0. Obtained list of 1348 transcripts (2.0%) that passed the filter criteria was further analyzed by Ingenuity Pathway Analysis software, identifying 735 unique differentially expressed genes (DEGs).

RESULTS

Among the CAD patients, 416 (30.9%) transcripts were upregulated, and 932 (69.1%) were downregulated, compared to controls. The top upregulated genes were involved in inflammation and atherosclerosis (chemokines, interleukin-6, selectin E and low-density lipoprotein cholesterol (LDL-C) receptor), whereas the downregulated genes were involved in cardiac ischaemia and remodelling, platelet function and mitochondrial function (miR-3671, miR-4524a, multimerin, biglycan, tissue factor pathway inhibitor (TFPI), glucuronidases, miR-548, collagen type I, III, IV). Among the top upstream regulators, we identified molecules that have proinflammatory and atherosclerotic features (High Mobility Group Box 2 (HMGB2), platelet-derived growth platelet (PDGF) and evolutionarily conserved signaling intermediate in Toll pathways (ESCIT)). The activated pathway related to DEGs consisted of molecules with well-established role in the pathogenesis of atherosclerosis (TFPI, plasminogen activator, plasminogen activator, urokinase receptor (PLAUR), thrombomodulin). Moreover, we showed that 22 of the altered genes form a pro-atherogenic network.

CONCLUSION

Altered gene expression in PCAT of CAD patients, with genes upregulation and activation of pathway involved in inflammation and atherosclerosis, may be involved in CAD development and progression.

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

BACKGROUND

Patients with psoriasis have elevated risk of coronary artery disease.

OBJECTIVE

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

METHODS

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

RESULTS

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

LIMITATIONS

A single-center convenience sample may not be representative.

CONCLUSION

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

FABP4 and omentin-1 gene expression in epicardial adipose tissue from coronary artery disease patients

Omentin-1 and fatty acid-binding protein 4 (FABP4) are adipose tissue adipokines linked to obesity-associated cardiovascular complications. The aim of this study was to investigate epicardial adipose tissue (EAT) omentin-1 and FABP4 gene expression in obese and non-obese patients with coronary artery disease (CAD). Omentin-1 and FABP4 mRNA levels in EAT and paired subcutaneous adipose tissue (SAT) as well as adipokine serum concentrations were assessed in 77 individuals (61 with CAD; 16 without CAD (NCAD)). EAT FABP4 mRNA level was decreased in obese CAD patients when compared to obese NCAD individuals (p=0.001). SAT FABP4 mRNA level was decreased in CAD patients compared to NCAD individuals without respect to their obesity status (p=0.001). Omentin-1 mRNA level in EAT and SAT did not differ between the CAD and NCAD groups. These findings suggest that omentin-1 gene expression in adipose tissue is not changed during CAD; downregulated FABP4 gene expression in SAT is associated with CAD while EAT FABP4 gene expression is decreased only in obesity-related CAD.

Right Heart Morphology and Its Association With Excessive and Deficient Cardiac Visceral Adipose Tissue

Visceral adipose tissue is an independent risk factor for the development of atherosclerotic coronary disease, arterial hypertension, diabetes and metabolic syndrome. Right heart morphology often involves the presence of adipose tissue, which can be quantified by non-invasive imaging methods. The last decade brought a wealth of new insights into the function and morphology of adipose tissue, with great emphasis on its role in the pathogenesis of heart disease. Cardiac adipose tissue is involved in thermogenesis, mechanical protection of the heart and energy storage. However, it can also be an endocrine organ that synthesises numerous pro-inflammatory and anti-inflammatory cytokines, the effect of which is accomplished by paracrine and vasocrine mechanisms. Visceral adipose tissue has several compartments that differ in their embryological origin and vascularisation. Deficiency of cardiac adipose tissue, often due to chronic pathological conditions such as oncological diseases or chronic infectious diseases, predicts increased mortality and morbidity. To date, knowledge about the influence of visceral adipose tissue on cardiac morphology is limited, especially the effect on the morphology of the right heart in a state of excess or deficient visceral adipose tissue.

Is there an increased cardiovascular risk in patients with prolactinoma? A challenging question

PURPOSE

Epicardial adipose tissue thickness (EATT) is considered to be a surrogate for visceral fat and a novel cardiovascular risk indicator. Hyperprolactinemia has been shown to be associated with increased cardiovascular risk. The aim was to evaluate the association between EATT, carotid intima media thickness (CIMT), and cardiac functions in patients with prolactinoma.

METHODS

Patients with the diagnosis of prolactinoma were included. The control group consisted of healthy age matched individuals with normal prolactin levels. Prolactin, fasting blood glucose (FBG), insulin, hemoglobin A1c (HbA1c), alanine aminotransferase (ALT), total cholesterol, triglycerides, and high (HDL) and low density lipoprotein (LDL) cholesterol were measured. EATT, CIMT, cardiac systolic, and diastolic functions were determined using echocardiography.

RESULTS

We evaluated 67 patients with prolactinoma (aged 40.7 ± 11.9 years, F/M: 51/16) and 57 controls (aged 42.5 ± 7.4 years, F/M: 36/21). Of the 67 patients, 24 had normal prolactin levels. FBG level was higher in prolactinoma patients than in controls. Patients and controls had similar HbA1c, HOMA-IR, ALT, total, HDL, LDL cholesterol, and triglycerides levels, and similar cardiac systolic and diastolic functions. Prolactinoma patients had greater EATT (3.0 ± 0.5 mm vs. 2.6 ± 0.4 mm, p < 0.001) and CIMT (0.57 ± 0.08 mm vs. 0.52 ± 0.04 mm, p = 0.03) than controls. EATT was correlated with body mass index, FBG, HbA1c, and triglyceride levels.

CONCLUSIONS

EATT and CIMT were greater in patients with prolactinoma, although they had normal cardiac systolic and diastolic functions.

The impact of epicardial adipose tissue in patients with acute myocardial infarction

AIMS

Epicardial adipose tissue (EAT) has been linked to impaired reperfusion success after percutaneous coronary intervention (PCI). Whether EAT predicts myocardial damage in the early phase after acute myocardial infarction (MI) is unclear. Therefore, we investigated whether EAT in patients with acute MI is associated with more microvascular obstruction (MVO), greater ST-deviation, larger infarct size and reduced myocardial salvage index (MSI).

METHODS AND RESULTS

This retrospective analysis of a prospective observational study including patients with acute MI (n = 54) undergoing PCI and 12 healthy matched controls. EAT, infarct size and MSI were analyzed with cardiac magnetic resonance imaging, conducted 3-5 days and 12 weeks after MI. Patients with acute MI showed higher EAT volume than healthy controls (46 [25.;75. percentile: 37;59] vs. 24 [15;29] ml, p < 0.001). The high EAT group (above median) showed significantly more MVO (2.22 [0.00;5.38] vs. 0.0 [0.00;2.18] %, p = 0.004), greater ST-deviation (0.38 [0.22;0.55] vs. 0.15 [0.03;0.20] mV×10-1, p = 0.008), larger infarct size at 12 weeks (23 [17;29] vs. 10 [4;16] %, p < 0.001) and lower MSI (40 [37;54] vs. 66 [49;88] %, p < 0.001) after PCI than the low EAT group. After accounting for demographic characteristics, body-mass index, heart volume, infarct location, TIMI-flow grade as well as apnea-hypopnea index, EAT was associated with infarct size at 12 weeks (B = 0.38 [0.11;0.64], p = 0.006), but not with MSI.

CONCLUSIONS

Patients with acute MI showed higher volume of EAT than healthy individuals. High EAT was linked to more MVO and greater ST-deviation. EAT was associated with infarct size, but not with MSI.

Atrial Cardiomyopathy: Pathophysiology and Clinical Consequences

Around the world there are 33.5 million patients suffering from atrial fibrillation (AF) with an annual increase of 5 million cases. Most AF patients have an established form of an atrial cardiomyopathy. The concept of atrial cardiomyopathy was introduced in 2016. Thus, therapy of underlying diseases and atrial tissue changes appear as a cornerstone of AF therapy. Furthermore, therapy or prevention of atrial endocardial changes has the potential to reduce atrial thrombogenesis and thereby cerebral stroke. The present manuscript will summarize the underlying pathophysiology and remodeling processes observed in the development of an atrial cardiomyopathy, thrombogenesis, and atrial fibrillation. In particular, the impact of oxidative stress, inflammation, diabetes, and obesity will be addressed.

Epicardial Fat Expansion in Diabetic and Obese Patients With Heart Failure and Preserved Ejection Fraction-A Specific HFpEF Phenotype

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with diverse etiologies and pathophysiological factors. Obesity and type 2 diabetes mellitus (T2DM), conditions that coexist frequently, induce a cluster of metabolic and non-metabolic signaling derangements which are in favor to induce inflammation, fibrosis, myocyte stiffness, all hallmarks of HFpEF. In contrast to other HFpEF risk factors, obesity and T2DM are often associated with the generation of enlarged epicardial adipose tissue (EAT). EAT acts as an endocrine tissue that may exacerbate myocardial inflammation and fibrosis via various paracrine and vasocrine signals. In addition, an abnormally large EAT poses mechanical stress on the heart via pericardial restrain. HFpEF patients with enlarged EAT may belong to a unique phenotype that can benefit from specific EAT-targeted interventions, including life-style modifications and pharmacologically via statins and fat modifying anti-diabetics drugs; like metformin, sodium-glucose cotransporter 2 inhibitors, or glucagon-like peptide-1 receptor agonists, respectively.

Assessment of Coronary Inflammation by Pericoronary Fat Attenuation Index in Clinically Suspected Myocarditis with Infarct-Like Presentation

Background: The pathophysiology of angina-like symptoms in myocarditis is still unclear. Perivascular fat attenuation index (pFAI) by coronary computed tomography angiography (CCTA) is a non-invasive marker of coronary inflammation (CI) in atherosclerosis. We explored the presence of CI in clinically suspected myocarditis with infarct-like presentation. Methods: We retrospectively included 15 consecutive patients (67% male, age 30 ± 10 years) with clinically suspected infarct-like myocarditis who underwent CCTA to rule out coronary artery disease. Right coronary artery (RCA) pFAI mean value was compared with that of healthy volunteers. Results: Mean RCA pFAI value was −92.8 ± 8.4 HU, similar to that of healthy volunteers (−95.2 ± 6.0, p = 0.8). We found no correlation between RCA pFAI mean values and peak Troponin I (r = −0.43, p = 0.11) and C-reactive protein at diagnosis (r = −0.25, p = 0.42). Patients with higher pFAI values showed higher biventricular end-systolic volumes (ESV) (p = 0.038 for left and p = 0.024 for right ventricle) and lower right ventricular ejection fraction (RVEF) (p = 0.038) on cardiovascular magnetic resonance. Conclusions: In clinically suspected myocarditis with infarct-like presentation, RCA pFAI values are lower than those validated in atherosclerosis. The correlation between higher pFAI values, higher biventricular ESV and lower RVEF, may suggest a role of pFAI in predicting non-atherosclerotic CI (i.e., infective/immune-mediated “endothelialitis”).

Heme-oxygenase and lipid mediators in obesity and associated cardiometabolic diseases: Therapeutic implications

Obesity-mediated metabolic syndrome remains the leading cause of death worldwide. Among many potential targets for pharmacological intervention, a promising strategy involves the heme oxygenase (HO) system, specifically its inducible form, HO-1. This review collects and updates much of the current knowledge relevant to pharmacology and clinical medicine concerning HO-1 in metabolic diseases and its effect on lipid metabolism. HO-1 has pleotropic effects that collectively reduce inflammation, while increasing vasodilation and insulin and leptin sensitivity. Recent reports indicate that HO-1 with its antioxidants via the effect of bilirubin increases formation of biologically active lipid metabolites such as epoxyeicosatrienoic acid (EET), omega-3 and other polyunsaturated fatty acids (PUFAs). Similarly, HO-1and bilirubin are potential therapeutic targets in the treatment of fat-induced liver diseases. HO-1-mediated upregulation of EET is capable not only of reversing endothelial dysfunction and hypertension, but also of reversing cardiac remodeling, a hallmark of the metabolic syndrome. This process involves browning of white fat tissue (i.e. formation of healthy adipocytes) and reduced lipotoxicity, which otherwise will be toxic to the heart. More importantly, this review examines the activity of EET in biological systems and a series of pathways that explain its mechanism of action and discusses how these might be exploited for potential therapeutic use. We also discuss the link between cardiac ectopic fat deposition and cardiac function in humans, which is similar to that described in obese mice and is regulated by HO-1-EET-PGC1α signaling, a potent negative regulator of the inflammatory adipokine NOV.

Optimization of change in epicardial fat thickness for obese patients who lost weight via the bariatric surgery method using central composite and Box-Behnken experimental designs

Background

The aim of this study was to detect the optimal values for Age, Body Mass Index (BMI) and HOMA-IR of obese patients prior to surgery that results in a maximal decrease of visceral fat mass 6 months after bariatric surgery.

Method

In this study, 3³ experimental set-ups were designed. This study was approved by Baskent University Medical and Health Sciences Research Board (Approval number: KA16/281). The study data consisted of 40 obese patients who lost weight through the bariatric surgery between February 2015 and December 2016. The values of BMI, Age and HOMA for the obese patients who lost weight through the bariatric surgery were evaluated in three categories and at three levels; the response variable was determined as the Change in Epicardial Fat Thickness (ΔEFT).

Results

As a result of CCD analysis, the optimum ΔEFT = 2.571 was determined when Age = 30.52, BMI = 45.30, and HOMA = 34.62. As a result of the BBD analysis, the optimum ΔEFT = 3.756 was determined, when Age = 38.36, BMI = 63.18, and HOMA = 14.95. The optimum ΔEFT was modeled with Contour and Response Surface plots.

Conclusion

Based on the two surface response models used in our study, the maximal decrease of visceral fat mass as assessed by measuring echography images of epicardial fat thickness can be obtained by bariatric surgery of persons who are between 31 and 38 year old, have a BMI between 45 and 63 kg/m2 and have a HOMA-IR 34 between 15 and 35. Central Composite Design and a Box-Behnken Design of suitable patient data predicted 35 optimal settings of independent variables for the maximal clinical response of an intervention.

Obesity and diabetes are major risk factors for epicardial adipose tissue inflammation

BACKGROUND

Epicardial adipose tissue (EAT) directly overlies the myocardium, with changes in its morphology and volume associated with myriad cardiovascular and metabolic diseases. However, EAT’s immune structure and cellular characterization remain incompletely described. We aimed to define the immune phenotype of EAT in humans and compare such profiles across lean, obese, and diabetic patients.

METHODS

We recruited 152 patients undergoing open-chest coronary artery bypass grafting (CABG), valve repair/replacement (VR) surgery, or combined CABG/VR. Patients’ clinical and biochemical data and EAT, subcutaneous adipose tissue (SAT), and preoperative blood samples were collected. Immune cell profiling was evaluated by flow cytometry and complemented by gene expression studies of immune mediators. Bulk RNA-Seq was performed in EAT across metabolic profiles to assess whole-transcriptome changes observed in lean, obese, and diabetic groups.

RESULTS

Flow cytometry analysis demonstrated EAT was highly enriched in adaptive immune (T and B) cells. Although overweight/obese and diabetic patients had similar EAT cellular profiles to lean control patients, the EAT exhibited significantly (P ≤ 0.01) raised expression of immune mediators, including IL-1, IL-6, TNF-α, and IFN-γ. These changes were not observed in SAT or blood. Neither underlying coronary artery disease nor the presence of hypertension significantly altered the immune profiles observed. Bulk RNA-Seq demonstrated significant alterations in metabolic and inflammatory pathways in the EAT of overweight/obese patients compared with lean controls.

CONCLUSION

Adaptive immune cells are the predominant immune cell constituent in human EAT and SAT. The presence of underlying cardiometabolic conditions, specifically obesity and diabetes, rather than cardiac disease phenotype appears to alter the inflammatory profile of EAT. Obese states markedly alter EAT metabolic and inflammatory signaling genes, underlining the impact of obesity on the EAT transcriptome profile.

FUNDING

Barts Charity MGU0413, Abbott, Medical Research Council MR/T008059/1, and British Heart Foundation FS/13/49/30421 and PG/16/79/32419.

Machine learning to predict the long-term risk of myocardial infarction and cardiac death based on clinical risk, coronary calcium, and epicardial adipose tissue: a prospective study

AIMS

Our aim was to evaluate the performance of machine learning (ML), integrating clinical parameters with coronary artery calcium (CAC), and automated epicardial adipose tissue (EAT) quantification, for the prediction of long-term risk of myocardial infarction (MI) and cardiac death in asymptomatic subjects.

METHODS AND RESULTS

Our study included 1912 asymptomatic subjects [1117 (58.4%) male, age: 55.8 ± 9.1 years] from the prospective EISNER trial with long-term follow-up after CAC scoring. EAT volume and density were quantified using a fully automated deep learning method. ML extreme gradient boosting was trained using clinical co-variates, plasma lipid panel measurements, risk factors, CAC, aortic calcium, and automated EAT measures, and validated using repeated 10-fold cross validation. During mean follow-up of 14.5 ± 2 years, 76 events of MI and/or cardiac death occurred. ML obtained a significantly higher AUC than atherosclerotic cardiovascular disease (ASCVD) risk and CAC score for predicting events (ML: 0.82; ASCVD: 0.77; CAC: 0.77, P < 0.05 for all). Subjects with a higher ML score (by Youden's index) had high hazard of suffering events (HR: 10.38, P < 0.001); the relationships persisted in multivariable analysis including ASCVD-risk and CAC measures (HR: 2.94, P = 0.005). Age, ASCVD-risk, and CAC were prognostically important for both genders. Systolic blood pressure was more important than cholesterol in women, and the opposite in men.

CONCLUSIONS

In this prospective study, machine learning used to integrate clinical and quantitative imaging-based variables significantly improves prediction of MI and cardiac death compared with standard clinical risk assessment. Following further validation, such a personalized paradigm could potentially be used to improve cardiovascular risk assessment.

Impact of glucose variability on coronary plaque vulnerability in patients with dysglycemia: A whole coronary analysis with multislice computed tomography

BACKGROUND

Dysglycemia is associated with an increased risk of acute coronary syndrome caused by the disruption of vulnerable plaques. The relationship between glycemic variability (GV), which is a component of impaired glucose metabolism, and coronary plaque vulnerability has not been fully elucidated. This study investigated the impact of GV on whole coronary plaque vulnerability using multislice computed tomography (MSCT).

METHODS

We analyzed 88 patients with dysglycemia who underwent 24 h blood glucose monitoring and MSCT. The mean amplitude of glycemic excursion (MAGE) was calculated as an index of the GV. We defined a CT-derived vulnerable plaque as a plaque with a remodeling index > 1.10 and a mean CT density < 30 HU. We calculated the percentage of low-attenuation plaque (% LAP) as the ratio of the low-attenuation component (CT density < 30HU) volume to the total vessel volume.

RESULTS

Vulnerable plaques were detected in 27 patients (31%). Patients with vulnerable plaques had higher MAGE (110.0 ± 40.7 vs. 71.7 ± 21.7, p < 0.01) than patients without vulnerable plaques. A univariate logistic regression analysis showed that vulnerable plaques were associated with the MAGE [odds ratio (OR) 1.04, 95% confidence interval (CI), 1.02-1.07, p < 0.01]. In a multivariate model, the MAGE (OR 1.05, 95% CI 1.02-1.07) remained a significant predictor of vulnerable plaque presence. Patients with multivessel-vulnerable plaques had higher MAGE values than those with single-vessel involvement or no vulnerable plaques (132.3 ± 39.4 vs. 102.2 ± 39.7, vs. 71.7 ± 21.7, p < 0.01). The regression analysis showed a positive correlation between MAGE levels and the % LAP (r = 0.55, p < 0.01). In a multiple linear regression analysis, the MAGE was independently associated with the % LAP (β = 0.42, p < 0.01).

CONCLUSIONS

Increased GV is associated with the presence and extent of vulnerable plaques.

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.

COVID-19 and Obesity: Role of Ectopic Visceral and Epicardial Adipose Tissues in Myocardial Injury

In March 2020, the WHO declared coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a global pandemic. Obesity was soon identified as a risk factor for poor prognosis, with an increased risk of intensive care admissions and mechanical ventilation, but also of adverse cardiovascular events. Obesity is associated with adipose tissue, chronic low-grade inflammation, and immune dysregulation with hypertrophy and hyperplasia of adipocytes and overexpression of pro-inflammatory cytokines. However, to implement appropriate therapeutic strategies, exact mechanisms must be clarified. The role of white visceral adipose tissue, increased in individuals with obesity, seems important, as a viral reservoir for SARS-CoV-2 via angiotensin-converting enzyme 2 (ACE2) receptors. After infection of host cells, the activation of pro-inflammatory cytokines creates a setting conducive to the "cytokine storm" and macrophage activation syndrome associated with progression to acute respiratory distress syndrome. In obesity, systemic viral spread, entry, and prolonged viral shedding in already inflamed adipose tissue may spur immune responses and subsequent amplification of a cytokine cascade, causing worse outcomes. More precisely, visceral adipose tissue, more than subcutaneous fat, could predict intensive care admission; and lower density of epicardial adipose tissue (EAT) could be associated with worse outcome. EAT, an ectopic adipose tissue that surrounds the myocardium, could fuel COVID-19-induced cardiac injury and myocarditis, and extensive pneumopathy, by strong expression of inflammatory mediators that could diffuse paracrinally through the vascular wall. The purpose of this review is to ascertain what mechanisms may be involved in unfavorable prognosis among COVID-19 patients with obesity, especially cardiovascular events, emphasizing the harmful role of excess ectopic adipose tissue, particularly EAT.

CXCL16 may be a predisposing factor to atherosclerosis: An animal study

Atherosclerosis (AS) is a chronic inflammatory process initiated when lipoprotein is retained in the arterial wall. Leukocyte recruitment accelerates this process. CXC chemokine ligand 16 (CXCL16) acts as a chemokine to attract immune cells and also facilitates the phagocytosis process of modified low‑density lipoprotein. Whether CXCL16 promotes or inhibits the pathological process of AS remains to be elucidated. To clarify this, CXCL16 gene was introduced into C57BL/6J wild‑type mice to establish a stable CXCL16 overexpression mouse model. The initial changes of AS in mice were induced by high‑fat diet (HFD). To study how the interaction of HFD and CXCL16 affected fatty acid metabolism and deposition, body weight and plasma lipid profile were assessed. Soluble CXCL16, matrix metalloproteinase‑9, monocyte chemoattractant protein‑1 and intercellular adhesion molecule‑1 were detected by immunohistochemistry and ELISA to identify how CXCL16 affects AS lesion formation. The present study suggested that overexpression of CXCL16 combined with HFD lead to atherogenesis by upregulating the aforementioned inflammatory related genes at a protein level. The present study was the first, to the best of the authors' knowledge, to build a CXCL16 homozygous transgenic mice model to study how overexpressed CXCL16 is associated with AS for intervening in the occurrence and development of AS.

Relationship of Pericardial Fat Tissue With Cardiovascular Risk Factors in Patients Without Cardiovascular Diseases

Background: Obesity and related cardiovascular diseases (CVDs) are important public health problems. The role of visceral ectopic fat remains contested. We studied the relationship between pericardial fat tissue (PFT) volume and CVD risk factors. Methods: We examined 320 patients (average age 63.8 ± 19.9 years) without manifested CVD. Anthropometric indicators were measured, and body mass index (BMI) was calculated. The total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were assessed. Cardiovascular (CV) risk was calculated using the SCORE system. All patients underwent chest computed tomography with detection of PFT volume using specialized semiautomatic software. Results: Among study participants with normal body mass, the PFT volume was 1.95 cm³ [2.1; 3.9], while it was 3.0 cm³ [2.0; 3.7] in overweight patients and 3.6 cm³ [2.7; 4.7] in obese patients (P < 0.001). Patients with hypertension (HTN) also had significantly higher PFT volumes compared with individuals without HTN: 3.1 cm³ [2.3; 4.15] versus 1.8 cm³ [1.0; 2.5] (P < 0.001). Patients with higher CV risk had significantly higher PFT volume, categorized as follows: 1.6 cm³ [1.0; 2.4], low risk; 2.24 cm³ [2.0; 3.1], moderate risk; 3.1 cm³ [2.4; 3.7], high risk; and 3.9 cm³ [3.0; 5.1], very high risk, respectively (P < 0.001). Results of multiple regression demonstrated that waist circumference and HDL-C were significantly associated with PFT volume. Another model revealed a significant association of BMI and PFT volume with the level of CV risk. Conclusions: This study demonstrates the association of PFT volume with the major diagnostic criteria of obesity, HTN, lipid disorders, and CV risk measured by the SCORE system.

Epicardial adipose tissue modulates arrhythmogenesis in right ventricle outflow tract cardiomyocytes

AIMS

Ventricular arrhythmia (VA) frequently occurs in fatty infiltrative cardiomyopathy or epicardial adipose tissue (EAT) abundant hearts. Right ventricular outflow tract (RVOT), commonly covered with EAT, is vital for VA genesis. This study explored whether EAT contributes to RVOT arrhythmogenesis.

METHODS AND RESULTS

Conventional microelectrodes and whole-cell patch clamp were used to record electrical activity and ionic currents in rabbit RVOT tissue preparation or isolated single cardiomyocytes with or without (control) connected EAT. Epicardial adipose tissue-connected (N = 6) RVOT had more portions of fibrosis than did control (N = 5) RVOT (160.3 ± 23.2 vs. 91.9 ± 13.4 μm2/mm2, P < 0.05). Epicardial adipose tissue-connected RVOT cardiomyocytes (n = 18) had lower negative resting membrane potential (-68 ± 1 vs. -73 ± 2 mV, P < 0.05); smaller action potential (AP) amplitude (108 ± 4 vs. 135 ± 6 mV, P < 0.005); and longer 90%, 50%, and 20% of AP duration repolarization (361 ± 18 vs. 309 ± 9 ms, P < 0.05; 310 ± 17 vs. 256 ± 13 ms, P < 0.05; and 182 ± 19 vs. 114 ± 24 ms, P < 0.05, respectively) than did control (n = 13) RVOT cardiomyocytes. Moreover, compared with control RVOT cardiomyocytes, EAT-connected RVOT cardiomyocytes had larger transient outward potassium currents, similar delayed rectifier potassium currents, smaller L-type calcium currents, and inward rectifier potassium currents. After ajmaline (10 μM, a sodium channel blocker) superfusion, high VA inducibility was observed through rapid pacing in EAT-connected RVOT but not in control RVOT.

CONCLUSIONS

Epicardial adipose tissue exerts distinctive electrophysiological effects on RVOT with a propensity towards VA induction, which might play a role in lipotoxicity pathogenesis-related ventricular arrhythmogenesis.

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

OBJECTIVES

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

Increased Pericardial Adipose Tissue in Smokers

BACKGROUND

Pericardial adipose tissue (PAT), a visceral fat depot directly located to the heart, is associated with atherosclerotic and inflammatory processes. The extent of PAT is related to the prevalence of coronary heart disease and might be used for cardiovascular risk prediction. This study aimed to determine the effect of smoking on the extent of PAT.

METHODS

We retrospectively examined 1217 asymptomatic patients (490 females, age 58.3 ± 8.3 years, smoker n = 573, non-smoker n = 644) with a multislice CT scanner and determined the PAT volume. Coronary risk factors were determined at inclusion, and a multivariate analysis was performed to evaluate the influence of smoking on PAT independent from accompanying risk factors.

RESULTS

The mean PAT volume was 215 ± 107 mL in all patients. The PAT volume in smokers was significantly higher compared to PAT volume in non-smokers (231 ± 104 mL vs. 201 ± 99 mL, p = 0.03). Patients without cardiovascular risk factors showed a significantly lower PAT volume (153 ± 155 mL, p < 0.05) compared to patients with more than 1 risk factor. Odds ratio was 2.92 [2.31, 3.61; p < 0.001] for elevated PAT in smokers.

CONCLUSION

PAT as an individual marker of atherosclerotic activity and inflammatory burden was elevated in smokers. The finding was independent from metabolic risk factors and might therefore illustrate the increased inflammatory activity in smokers in comparison to non-smokers.

Myocardial Glucose Metabolism Is Increased in Newly Diagnosed Lung Adenocarcinoma

BACKGROUND

Cardiac metabolism alterations may be involved in abnormalities of cancer patients' cardiovascular system. This study aimed to explore whether left ventricular myocardial glucose metabolism is altered and its related factors in newly diagnosed patients with lung adenocarcinoma (LAD) who underwent fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT).

METHODS

From our 18F-FDG PET/CT imaging database, 171 patients with newly diagnosed LAD and 43 nononcologic subjects with matched age and sex were retrospectively analyzed. The included patients underwent conventional 18F-FDG PET/CT imaging with a >12-h fasting before 18F-FDG administration. The standardized uptake values (SUVs) of the left ventricular (LV) myocardium, arterial wall, epicardial adipose tissue (EAT), spleen, and bone marrow were separately measured. Laboratory parameters and echocardiographic results were collected as well. LAD patients were divided into 2 groups based on the 95th percentile of LV maximal SUV (SUVmax) obtained from the 43 nononcologic subjects. Univariate analysis and multiple logistic regression analysis were used to identify significant factors.

RESULTS

Higher LV SUVmax was found (3.8 [2.4, 7.7] vs. 3.0 [2.0, 5.4], p = 0.052) in LAD than that in nononcologic patients, whereas no significant differences of 18F-FDG uptake were found in the arterial wall, EAT, spleen, or bone marrow between LAD patients and controls. The maximum diameter (Dmax) of the LAD lesion, SUVmax of spleen, and SUVmax of EAT were related to LV SUVmax in LAD.

CONCLUSIONS

Myocardial glucose metabolism is increased in patients with newly diagnosed LAD. Dmax of LAD lesion, spleen activity, and EAT activity contribute to the increased LV activity in LAD.

Development of artificial intelligence in epicardial and pericoronary adipose tissue imaging: a systematic review

Background

Artificial intelligence (AI) technology has been increasingly developed and studied in cardiac imaging. This systematic review summarizes the latest progress of image segmentation, quantification, and the clinical application of AI in evaluating cardiac adipose tissue.

Methods

We exhaustively searched PubMed and the Web of Science for publications prior to 30 April 2021. The search included eligible studies that used AI for image analysis of epicardial adipose tissue (EAT) or pericoronary adipose tissue (PCAT). The risk of bias and concerns regarding applicability were assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.

Results

Of the 140 initially identified citation records, 19 high-quality studies were eligible for this systematic review, including 15 (79%) on the image segmentation and quantification of EAT or PCAT and 4 (21%) on the clinical application of EAT or PCAT in cardiovascular diseases. All 19 included studies were rated as low risk of bias in terms of flow and timing, reference standards, and the index test and as having low concern of applicability in terms of reference standards and patient selection, but 16 (84%) studies did not conduct external validation.

Conclusion

AI technology can provide accurate and quicker methods to segment and quantify EAT and PCAT images and shows potential value in the diagnosis and risk prediction of cardiovascular diseases. AI is expected to expand the value of cardiac adipose tissue imaging.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41824-021-00107-0.

Incidence of new-onset atrial fibrillation in COVID-19 is associated with increased epicardial adipose tissue

PURPOSE

Coronary artery calcium (CAC) and epicardial adipose tissue (EAT) can predict AF in the general population. We aimed to determine if CAC and EAT measured by computed tomographic (CT) scanning can predict new-onset AF in patients admitted with COVID-19 disease.

METHODS

We performed a retrospective, post hoc analysis of all patients admitted to Montefiore Medical Center with a confirmed COVID-19 diagnosis from March 1st to June 23rd, 2020, who had a non-contrast CT of the chest within 5 years prior to admission. We determined ordinal CAC scores and quantified the EAT volume and examined their relationship with inpatient mortality.

RESULTS

A total of 379 patients were analyzed. There were 16 events of new-onset AF (4.22%). Patients who developed AF during the index admission were more likely to be male (75 vs 47%, p < 0.001) and had higher EAT (129.5 [76.3-197.3] vs 91.0 [60.0-129.0] ml, p = 0.049). There were no differences on age (68 [56-71] vs 68 [58-76] years; p = 0.712), BMI (28.5 [25.3-30.8] vs 26.9 [23.1-31.8] kg/m²; p = 0.283), ordinal CAC score (3 [1-6] vs 2 [0-4]; p = 0.482), or prevalence of diabetes (56.3 vs 60.1%; p = 0.761), hypertension (75.0 vs 87.3%, p = 0.153), or coronary artery disease (50.0 vs 39.4%, p = 0.396). Patients with new-onset AF had worse clinical outcomes (death/intubation/vasopressors) (87.5 vs 44.1%; p = 0.001).

CONCLUSION

Increased EAT measured by non-contrast chest CT identifies patients hospitalized with COVID-19 at higher risk of developing new-onset AF. Patients with new-onset AF have worse clinical outcomes.

Impact of the distribution of epicardial and visceral adipose tissue on left ventricular diastolic function

Although epicardial adipose tissue (EAT) and abdominal visceral adipose tissue (VAT) can contribute to left ventricular diastolic dysfunction (LVDD), the impact of these distribution has not been fully understood. A total of 235 patients who underwent cardiac computed tomography angiography and Doppler echocardiography was included in this study. We evaluated the association of indexed EAT volume and VAT area with septal and lateral early diastolic mitral annular velocity (e'). The VAT area index was significantly associated with septal and lateral e' velocity after adjusted for conventional cardiovascular risk factors and obstructive coronary artery disease (β-estimate; - 0.015 and - 0.019, both p = 0.01). The natural logarithmic EAT volume index (ln EAT volume index) also showed a significant association with septal and lateral e' (β-estimate; - 1.72 and - 0.99, both p < 0.01). The significant association of ln EAT volume index with septal and lateral e' was observed even after adjusting for VAT area index (β-estimate; - 0.79 and - 1.52, both p < 0.03). In the subgroup analysis, there were significant association of ln EAT volume index with both septal and lateral e' in the lower VAT group (β-estimate; - 1.40 and - 1.53, both p < 0.03) and with lateral e' in the higher VAT group (β-estimate - 1.64, p = 0.006). In contrast, ln EAT volume index was not associated with septal e' in the higher VAT group (p = 0.98). EAT accumulation was significantly associated with LVDD independently of obstructive coronary artery disease and abdominal VAT. The impact of EAT on LVDD may vary depending on the amount of abdominal VAT.

Epicardial Adipose Tissue: The Genetics Behind an Emerging Cardiovascular Risk Marker

Evidence points epicardial adipose tissue (EAT) as an emerging cardiovascular risk marker. Whether genetic polymorphisms linked with atherosclerosis are associated with higher EAT is still unknown. We aim to assess the role of genetic burden of atherosclerosis and its association to EAT in a cohort of asymptomatic individuals without coronary disease. A total of 996 participants were prospectively enrolled in a single Portuguese center. EAT volume was measured by Cardiac Computed Tomography and participants were distributed into 2 groups, above and below median EAT. SNPs were genotyped and linked to their respective pathophysiological axes. A multiplicative genetic risk score (mGRS) was constructed, representing the genetic burden of the studied SNPs. To evaluate the association between genetics and EAT, we compared both groups by global mGRS, mGRS by functional axes, and SNPs individually. Individuals above-median EAT were older, had a higher body mass index (BMI) and higher prevalence of hypertension, metabolic syndrome, diabetes, and dyslipidemia. They presented higher GRS, that remained an independent predictor of higher EAT volumes. The group with more EAT consistently presented higher polymorphic burden across numerous pathways. After adjustment, age, BMI, and mGRS of each functional axis emerged as independently related to higher EAT volumes. Amongst the 33 SNPs, MTHFR677 polymorphism emerged as the only significant and independent predictor of higher EAT volumes. Patients with higher polymorphism burden for atherosclerosis present higher EAT volumes. We present the first study in a Portuguese population, evaluating the genetic profile of EAT through GWAS and GRS, casting further insight into this complicated matter.

Role of Perivascular Adipose Tissue and Exercise on Arterial Function with Obesity

Adipose tissue and arterial dysfunction are common in the obese state. Perivascular adipose tissue (PVAT) plays an important role in mediating arterial health, and with obesity, the PVAT dysfunction negatively affects arterial health. Exercise training exerts direct and beneficial effects on PVAT, providing an additional and novel pathway by which exercise can improve arterial health in diseased populations.

Regional Heterogeneity of Perivascular Adipose Tissue: Morphology, Origin, and Secretome

Perivascular adipose tissue (PVAT) is a unique fat depot with local and systemic impacts. PVATs are anatomically, developmentally, and functionally different from classical adipose tissues and they are also different from each other. PVAT adipocytes originate from different progenitors and precursors. They can produce and secrete a wide range of autocrine and paracrine factors, many of which are vasoactive modulators. In the context of obesity-associated low-grade inflammation, these phenotypic and functional differences become more evident. In this review, we focus on the recent findings of PVAT’s heterogeneity by comparing commonly studied adipose tissues around the thoracic aorta (tPVAT), abdominal aorta (aPVAT), and mesenteric artery (mPVAT). Distinct origins and developmental trajectory of PVAT adipocyte potentially contribute to regional heterogeneity. Regional differences also exist in ways how PVAT communicates with its neighboring vasculature by producing specific adipokines, vascular tone regulators, and extracellular vesicles in a given microenvironment. These insights may inspire new therapeutic strategies targeting the PVAT.

Contribution of Adipose Tissue to the Chronic Immune Activation and Inflammation Associated With HIV Infection and Its Treatment

White adipose tissue (AT) contributes significantly to inflammation – especially in the context of obesity. Several of AT’s intrinsic features favor its key role in local and systemic inflammation: (i) large distribution throughout the body, (ii) major endocrine activity, and (iii) presence of metabolic and immune cells in close proximity. In obesity, the concomitant pro-inflammatory signals produced by immune cells, adipocytes and adipose stem cells help to drive local inflammation in a vicious circle. Although the secretion of adipokines by AT is a prime contributor to systemic inflammation, the lipotoxicity associated with AT dysfunction might also be involved and could affect distant organs. In HIV-infected patients, the AT is targeted by both HIV infection and antiretroviral therapy (ART). During the primary phase of infection, the virus targets AT directly (by infecting AT CD4 T cells) and indirectly (via viral protein release, inflammatory signals, and gut disruption). The initiation of ART drastically changes the picture: ART reduces viral load, restores (at least partially) the CD4 T cell count, and dampens inflammatory processes on the whole-body level but also within the AT. However, ART induces AT dysfunction and metabolic side effects, which are highly dependent on the individual molecules and the combination used. First generation thymidine reverse transcriptase inhibitors predominantly target mitochondrial DNA and induce oxidative stress and adipocyte death. Protease inhibitors predominantly affect metabolic pathways (affecting adipogenesis and adipocyte homeostasis) resulting in insulin resistance. Recently marketed integrase strand transfer inhibitors induce both adipocyte adipogenesis, hypertrophy and fibrosis. It is challenging to distinguish between the respective effects of viral persistence, persistent immune defects and ART toxicity on the inflammatory profile present in ART-controlled HIV-infected patients. The host metabolic status, the size of the pre-established viral reservoir, the quality of the immune restoration, and the natural ageing with associated comorbidities may mitigate and/or reinforce the contribution of antiretrovirals (ARVs) toxicity to the development of low-grade inflammation in HIV-infected patients. Protecting AT functions appears highly relevant in ART-controlled HIV-infected patients. It requires lifestyle habits improvement in the absence of effective anti-inflammatory treatment. Besides, reducing ART toxicities remains a crucial therapeutic goal.

Obesity and Heart Failure with Preserved Ejection Fraction

Obese heart failure with preserved ejection fraction (HFpEF) is a distinct HFpEF phenotype. Sodium retention, high circulating neurohormone levels, alterations in energy substrate metabolism, group 3 pulmonary hypertension, pericardial restraint, and systemic inflammation are central pathophysiologic mechanisms. Confirming the diagnosis may be challenging and high suspicion is required. Reduction of visceral adipose tissue, via caloric restriction and/or bariatric surgery, may improve outcomes in obese HFpEF patients. Furthermore, mineralocorticoid receptor inhibition, neprilysin inhibition, and sodium-glucose cotransporter 2 inhibition can ameliorate the effects of adiposity on the cardiovascular system, allowing for promising new treatment targets for the obese HFpEF phenotype.

The association between epicardial adipose tissue and non-alcoholic fatty liver disease: A systematic review of existing human studies

The prevalence of non-alcoholic fatty liver disease (NAFLD) has significantly risen all around the world. Although visceral fat mass has been identified as an independent risk factor for NAFLD, the association of other ectopic fat depots, such as Epicardial adipose tissue (EAT), with the disease has not been fully elucidated. The aim of the current study was to systematically review all available human studies conducted on the associations between EAT and NAFLD. All human studies published in English, which examined the association between the thickness or the volume of EAT and the incidence of NAFLD were systematically searched on PubMed, Scopus, and Google Scholar search engines, from inception up to April 2021. Eighteen studies that met inclusion criteria were included in the final review. A total of 86 studies were found through searching the databases. After excluding duplicates, seventy six remained studies were scanned by title and abstract, out of which, 58 were excluded. Finally, eighteen articles (thirteen cross-sectional studies and five case-control studies) published between 2008 and 2021, were included in the review. According to the results of the reviewed articles, EAT was associated with the presence and progression of NAFLD. Furthermore, NAFLD patients with thicker EAT may need a more intensive hepatic follow-up. However, we suggest further investigation to find out the underlying mechanisms describing the observed association.

Alternative sites of echocardiographic epicardial fat assessment and coronary artery disease

AIMS

Increasing evidence points towards the use of epicardial fat (EF) as a reliable biomarker of coronary artery disease extent and severity. We aim to assess the different locations of echocardiographic EF thickness measurement and their relation with the presence, extent, and severity of coronary artery disease (CAD) in patients admitted with acute coronary syndromes (ACS).

METHODS

Prospective cohort study including patients admitted for ACS. EF was assessed by transthoracic echocardiography and compared with coronary angiography findings. Spearmen correlation analysis was used to search for EF correlations. Receiver-operating characteristic curve analysis was performed to assess the predictive value of the different sites of measurement of EF thickness for the presence of CAD. To evaluate other potential variables independently associated with CAD, we performed multivariate analysis employing logistic regression.

RESULTS

196 patients were included. Significant CAD was diagnosed in 83.7% of patients. In all views, EF thickness was greater in patients with CAD (p < 0.001). We found a moderate correlation between EF thickness and CAD extent and severity. EF thickness measured at RV basal level showed a good performance in predicting significant CAD in patients with ACS (AUC = 0.885, 95% CI 0.80-0.97, p < 0.001). For a value of mean RV basal region EF thickness ≥ 12.57 mm, sensitivity was 85% and specificity was 80.8%.

CONCLUSION

In patients admitted with ACS, echocardiographic EF thickness predicted the presence of CAD, as well as its extent and severity. We found EF thickness measured at the RV basal region to be the best predictor of significant CAD.

Pericardial Fat and the Risk of Heart Failure

BACKGROUND

Obesity is a well-established risk factor for heart failure (HF). However, implications of pericardial fat on incident HF is unclear.

OBJECTIVES

This study sought to examine the association between pericardial fat volume (PFV) and newly diagnosed HF.

METHODS

This study ascertained PFV using cardiac computed tomography in 6,785 participants (3,584 women and 3,201 men) without pre-existing cardiovascular disease from the MESA (Multi-Ethnic Study of Atherosclerosis). Cox proportional hazards regression was used to evaluate PFV as continuous and dichotomous variable, maximizing the J-statistic: (Sensitivity + Specificity - 1).

RESULTS

In 90,686 person-years (median: 15.7 years; interquartile range: 11.7 to 16.5 years), 385 participants (5.7%; 164 women and 221 men) developed newly diagnosed HF. PFV was lower in women than in men (69 ± 33 cm3 vs. 92 ± 47 cm3; p < 0.001). In multivariable analyses, every 1-SD (42 cm3) increase in PFV was associated with a higher risk of HF in women (hazard ratio [HR]: 1.44; 95% confidence interval [CI]: 1.21 to 1.71; p < 0.001) than in men (HR: 1.13; 95% CI: 1.01 to 1.27; p = 0.03) (interaction p = 0.01). High PFV (≥70 cm3 in women; ≥120 cm3 in men) conferred a 2-fold greater risk of HF in women (HR: 2.06; 95% CI: 1.48 to 2.87; p < 0.001) and a 53% higher risk in men (HR: 1.53; 95% CI: 1.13 to 2.07; p = 0.006). In sex-stratified analyses, greater risk of HF remained robust with additional adjustment for anthropometric indicators of obesity (p ≤ 0.008), abdominal subcutaneous or visceral fat (p ≤ 0.03) or biomarkers of inflammation and hemodynamic stress (p < 0.001) and was similar among Whites, Blacks, Hispanics, and Chinese (interaction p = 0.24). Elevated PFV predominantly augmented the risk of HF with preserved ejection fraction (p < 0.001) rather than reduced ejection fraction (p = 0.31).

CONCLUSIONS

In this large, community-based, ethnically diverse, prospective cohort study, pericardial fat was associated with an increased risk of HF, particularly HF with preserved ejection fraction, in women and men.

Prevention of Pathological Atrial Remodeling and Atrial Fibrillation: JACC State-of-the-Art Review

Atrial enlargement in response to pathological stimuli (e.g., hypertension, mitral valve disease) and physiological stimuli (exercise, pregnancy) can be comparable in magnitude, but the diseased enlarged atria is associated with complications such as atrial fibrillation (AF), whereas physiological atrial enlargement is not. Pathological atrial enlargement and AF is also observed in a small percentage of athletes undergoing extreme/intense endurance sport and pregnant women with preeclampsia. Differences between physiological and pathological atrial enlargement and underlying mechanisms are poorly understood. This review describes human and animal studies characterizing atrial enlargement under physiological and pathological conditions and highlights key knowledge gaps and clinical challenges, including: 1) the limited ability of atria to reverse remodel; and 2) distinguishing physiological and pathological enlargement via imaging/biomarkers. Finally, this review discusses how targeting distinct molecular mechanisms underlying physiological and pathological atrial enlargement could provide new therapeutic and diagnostic strategies for preventing or reversing atrial enlargement and AF.

Fetal epicardial fat thickness in fetal growth restriction; effects on fetal heart function and relationship with the severity of disease

OBJECTIVE

To investigate fetal epicardial fat thickness (EFT) value in fetal growth restriction (FGR) and its relationship with clinical parameters, fetal modified myocardial index (Mod-MPI), and the Doppler parameters.

MATERIAL METHODS

Eighty-five pregnant women, with 30 diagnosed with FGR and 55 healthy pregnant women as control group participated in this prospective case-control study. FGR group was divided into 2 subgroups as early (n = 9) and late FGR (n = 21) groups. Demographic data were taken from the medical records. Amnion fluid value, fetal biometric measurements, and Doppler parameters were obtained. Fetal EFT and fetal Mod-MPI were measured by using the echocardiographic methods. The correlation tests were performed to assess the association between EFT and clinical and ultrasonographic parameters. p < .05 was interpreted as statistically significant.

RESULTS

EFT value was found statistically lower in the early and late FGR groups than the control group (p = .003). Higher umbilical artery pulsatility index (PI) and lower cerebroplacental ratio (CPR) values were found in the early and late FGR (p < .001, p = .001). The optimal EFT cutoff level to predict FGR disease was measured as 1.25 with 63.3% specificity and 77.4% sensitivity. Lower ejection time (ET) and higher Mod-MPI and isovolumetric contraction time (ICT) values were found in the group FGR with absent UAEDF than in the group FGR with no absent UAEDF (p = .001, p < .000, p < .000, respectively). Correlation tests showed statistically negative and weak correlations among EFT, umbilical artery PI, and mean Ut A-PI (p = .019, p = .019). Positive correlations were found in regard to gestational age, EFW, and EFT (p = .002, p < .000).

CONCLUSION

Our study showed that the measurement of EFT may contribute to predicting the diagnosis of FGR. Moreover, lower EFT values can be related to the severity of FGR. Future randomized control studies are needed to understand the effects and pathways of fetal EFT on fetal cardiac function.