Epicardial adipose tissue thickness is a predictor for plaque vulnerability in patients with significant coronary artery disease

Epicardial Adipose Tissue: a Potential Therapeutic Target for Cardiovascular Diseases

With increased ageing of the population, cardiovascular disease (CVD) has become the most important factor endangering human health worldwide. Although the treatment of CVD has become increasingly advanced, there are still a considerable number of patients with conditions that have not improved. According to the latest clinical guidelines of the European Cardiovascular Association, obesity has become an independent risk factor for CVD. Adipose tissue includes visceral adipose tissue and subcutaneous adipose tissue. Many previous studies have focused on subcutaneous adipose tissue, but visceral adipose tissue has been rarely studied. However, as a type of visceral adipose tissue, epicardial adipose tissue (EAT) has attracted the attention of researchers because of its unique anatomical and physiological characteristics. This review will systematically describe the physiological characteristics and evaluation methods of EAT and emphasize the important role and treatment measures of EAT in CVD.

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

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

Cardiac Computed Tomography Evaluation of Association of Left Ventricle Disfunction and Epicardial Adipose Tissue Density in Patients with Low to Intermediate Cardiovascular Risk

Background and objectives: Epicardial adipose tissue density (EAD) has been associated with coronary arteries calcium score, a higher load of coronary artery disease (CAD) and plaque vulnerability. This effect can be related to endocrine and paracrine effect of molecules produced by epicardial adipose tissue (EAT), that may influence myocardial contractility. Using coronary computed tomography angiography (CCT) the evaluation of EAD is possible in basal scans. The aim of the study is to investigate possible associations between EAD and cardiac function. Material and Methods: 93 consecutive patients undergoing CCT without and with contrast medium for known or suspected coronary CAD were evaluated. EAD was measured on basal scans, at the level of the coronary ostia, the lateral free wall of the left ventricle, at the level of the cardiac apex, and at the origin of the posterior interventricular artery. Cardiac function was evaluated in post-contrast CT scans in order to calculate ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV). Results: A statistically significant positive correlation between EAD and ejection fraction (r = 0.29, p-value < 0.01) was found. Additionally, a statistically significant negative correlation between EAD and ESV (r = -0.25, p-value < 0.01) was present. Conclusion: EAD could be considered a new risk factor associated with reduced cardiac function. The evaluation of this parameter with cardiac CT in patients with low to intermediate cardiovascular risk is possible.

Evaluation of pericoronary adipose tissue attenuation on CT

Pericoronary adipose tissue (PCAT) is the fat deposit surrounding coronary arteries. Although PCAT is part of the larger epicardial adipose tissue (EAT) depot, it has different pathophysiological features and roles in the atherosclerosis process. While EAT evaluation has been studied for years, PCAT evaluation is a relatively new concept. PCAT, especially the mean attenuation derived from CT images may be used to evaluate the inflammatory status of coronary arteries non-invasively. The most commonly used measure, PCAT_MA, is the mean attenuation of adipose tissue of 3 mm thickness around the proximal right coronary artery with a length of 40 mm. PCAT_MA can be analyzed on a per-lesion, per-vessel or per-patient basis. Apart from PCAT_MA, other measures for PCAT have been studied, such as thickness, and volume. Studies have shown associations between PCAT_MA and anatomical and functional severity of coronary artery disease. PCAT_MA is associated with plaque components and high-risk plaque features, and can discriminate patients with flow obstructing stenosis and myocardial infarction. Whether PCAT_MA has value on an individual patient basis remains to be determined. Furthermore, CT imaging settings, such as kV levels and clinical factors such as age and sex affect PCAT_MA measurements, which complicate implementation in clinical practice. For PCAT_MA to be widely implemented, a standardized methodology is needed. This review gives an overview of reported PCAT methodologies used in current literature and the potential use cases in clinical practice.

Epicardial Adipose Tissue Thickness Is Related to Plaque Composition in Coronary Artery Disease

(1) Background: Currently, limited data are available regarding the relationship between epicardial fat and plaque composition. The aim of this study was to assess the relationship between visceral fat surrounding the heart and the lipid core burden in patients with coronary artery diseases; (2) Methods: Overall, 331 patients undergoing coronary angiography with combined near-infrared spectroscopy and intravascular ultrasound imaging were evaluated for epicardial adipose tissue (EAT) thickness using transthoracic echocardiography. Patients were divided into thick EAT and thin EAT groups according to the median value; (3) Results: There was a positive correlation between EAT thickness and maxLCBI4mm, and maxLCBI4mm was significantly higher in the thick EAT group compared to the thin EAT group (437 vs. 293, p < 0.001). EAT thickness was an independent predictor of maxLCBI4mm ≥ 400 along with age, low-density lipoprotein-cholesterol level, acute coronary syndrome presentation, and plaque burden in a multiple linear regression model. Receiver operating characteristic curve analysis showed that EAT thickness was a predictor for maxLCBI4mm ≥ 400; (4) Conclusions: In the present study, EAT thickness is related to the lipid core burden assessed by NIRS-IVUS in patients with CAD which suggests that EAT may affect the stability of the plaques in coronary arteries.

Echocardiographic epicardial fat thickness and immature granulocyte are novel inflammatory predictors of acute ischemic stroke: a prospective study

BACKGROUND

Acute ischemic stroke (AIS) is the most common type of stroke. Inflammation is the primary factor in the pathogenesis of atherosclerosis. Use of immature granulocytes (IGs) has been recommended as a new indicator of systemic inflammation. However, data on the association between echocardiographic epicardial fat tissue thickness (EFT) and IGs in patients with AIS are limited.

OBJECTIVE

To evaluate the association between the presences of IGs, epicardial fat tissue and AIS.

DESIGN AND SETTING

Prospective study in a tertiary-care university hospital in Antalya, Turkey.

METHODS

Our study included 53 AIS patients and 41 healthy controls with age and gender compatibility. Blood samples and transthoracic echocardiography of all participants were compared.

RESULTS

IG levels were significantly higher in patients with AIS than in controls (0.62 ± 0.36 versus 0.28 ± 0.02, P < 0.001). The mean EFT was 3.74 ± 0.61 mm in the control group and 6.33 ± 1.47 mm in the AIS patient group. EFT was significantly greater in AIS patients than in controls (P < 0.001). For the optimum cut-off value for IG (0.95), the area under the curve (AUC) was determined to be 0.840; sensitivity was determined to be 81.1% and specificity, 92.5%. For the optimum cut-off value for EFT (4.95 mm), the AUC was determined to be 0.953; sensitivity was determined to be 90.6% and specificity, 90%.

CONCLUSIONS

IG and echocardiographic EFT are clinical markers that can be used to predict AIS risk.

Epicardial Adipose Tissue Volume Is Associated with High Risk Plaque Profiles in Suspect CAD Patients

OBJECTIVE

To explore the association between EAT volume and plaque precise composition and high risk plaque detected by coronary computed tomography angiography (CCTA).

METHODS

101 patients with suspected coronary artery disease (CAD) underwent CCTA examination from March to July 2019 were enrolled, including 70 cases acute coronary syndrome (ACS) and 31 cases stable angina pectoris (SAP). Based on CCTA image, atherosclerotic plaque precise compositions were analyzed using dedicated quantitative software. High risk plaque was defined as plaque with more than 2 high risk features (spotty calcium, positive remolding, low attenuation plaque, napkin-ring sign) on CCTA image. The association between EAT volume and plaque composition was assessed as well as the different of correlation between ACS and SAP was analyzed. Multivariable logistic regression analysis was used to explore whether EAT volume was independent risk factors of high risk plaque (HRP).

RESULTS

EAT volume in the ACS group was significantly higher than that of the SAP group (143.7 ± 49.8 cm3 vs. 123.3 ± 39.2 cm3, P = 0.046). EAT volume demonstrated a significant positive correlation with total plaque burden (r = 0.298, P = 0.003), noncalcified plaque burden (r = 0.245, P = 0.013), lipid plaque burden (r = 0.250, P = 0.012), and homocysteine (r = 0.413, P ≤ 0.001). In ACS, EAT volume was positively correlated with total plaque burden (r = 0.309, P = 0.009), noncalcified plaque burden (r = 0.242, P = 0.044), and lipid plaque burden (r = 0.240, P = 0.045); however, no correlation was observed in SAP. Patients with HRP have larger EAT volume than those without HRP (169 ± 6.2 cm3 vs. 130.6 ± 5.3 cm3, P = 0.002). After adjustment by traditional risk factors and coronary artery calcium score (CACS), EAT volume was an independent risk predictor of presence of HRP (OR: 1.018 (95% CI: 1.006-1.030), P = 0.004).

CONCLUSIONS

With the increasing EAT volume, more dangerous plaque composition burdens increase significantly. EAT volume is a risk predictor of HRP independent of convention cardiovascular risk factors and CACS, which supports the potential impact of EAT on progression of coronary atherosclerotic plaque.

The Napkin-Ring Sign – the Story Behind Invasive Coronary Angiography

Coronary artery disease (CAD) represents one of the leading causes of morbidity and mortality across Europe. Most of the patients do not experience any warning sign before the coronary event develops, therefore screening this group of patients is essential to prevent major cardiac events. Coronary computed tomography angiography (CCTA) offers a noninvasive approach of the coronary arteries, providing information not only on the presence and severity of the coronary stenosis, but is also able to characterize the structure of the coronary wall. CCTA allows complex evaluation of the extension of CAD, and by assessing the structure of the atherosclerotic plaque, it can identify its degree of vulnerability. The napkin-ring sign (NRS) represents a ring-like attenuation of the non-calcified portion of the coronary lesion and has a high specificity (96–100%) for the identification of thin cap fibroatheroma (TCFA) or culprit lesion in acute coronary syndromes (ACS). It is also an independent predictor for ACS events and the strongest predictor for future ACS. Modern CCTA can provide submillimeter isotropic spatial resolution. Thus, CT attenuation-based tissue interpretation enables the assessment of total coronary plaque burden and individual plaque components, with a similar accuracy as intravascular ultrasoud-based investigations. This review aims to present the important role of CCTA as a potent screening tool for patients with CAD, and the current evidences in the detection and quantification of vulnerable plaques.

Association of plaque calcification pattern and attenuation with instability features and coronary stenosis and calcification grade

BACKGROUND AND AIMS

Coronary computed tomography (CT) allows calculating coronary artery calcium score (CACS). However, other CT features might be more strongly related to plaque vulnerability and risk of future coronary events. This study investigated the association of plaque calcification pattern and attenuation with plaque instability features, coronary artery disease (CAD) grade and CACS.

METHODS

One-hundred patients with coronary stenosis associated with calcified plaques were considered for this analysis. CACS, CAD grade, calcification pattern and attenuation, features of plaque instability, and epicardial adipose tissue (EAT) thickness and attenuation were assessed with non-contrast and contrast-enhanced CT angiography.

RESULTS

Of 373 calcified plaques, 131 were responsible for the highest degree of coronary stenosis (1.31 ± 0.53 per patient). Participants were stratified according to the features of the highest-grade lesion(s) into patients with large (35%), spotty (52%) or mixed (13%) calcification pattern and tertiles of plaque calcification attenuation (using the mean value for multiple lesions). Patients with large calcification pattern or higher plaque calcification attenuation had higher stenosis and CACS grade (and EAT attenuation), but lower plaque instability score, whereas those with spotty calcification pattern or lower plaque calcification attenuation had lower stenosis and CACS grade (and EAT attenuation), but higher plaque instability score. Among the instability features, low attenuation and napkin-ring sign, but not positive remodeling, were associated with a spotty pattern and a lower calcification attenuation.

CONCLUSIONS

Both the pattern and attenuation of calcification should be considered, in addition to CACS, for risk stratification of heavily calcified high-risk patients with non-critical coronary stenosis.

From CT to artificial intelligence for complex assessment of plaque-associated risk

The recent technological developments in the field of cardiac imaging have established coronary computed tomography angiography (CCTA) as a first-line diagnostic tool in patients with suspected coronary artery disease (CAD). CCTA offers robust information on the overall coronary circulation and luminal stenosis, also providing the ability to assess the composition, morphology, and vulnerability of atherosclerotic plaques. In addition, the perivascular adipose tissue (PVAT) has recently emerged as a marker of increased cardiovascular risk. The addition of PVAT quantification to standard CCTA imaging may provide the ability to extract information on local inflammation, for an individualized approach in coronary risk stratification. The development of image post-processing tools over the past several years allowed CCTA to provide a significant amount of data that can be incorporated into machine learning (ML) applications. ML algorithms that use radiomic features extracted from CCTA are still at an early stage. However, the recent development of artificial intelligence will probably bring major changes in the way we integrate clinical, biological, and imaging information, for a complex risk stratification and individualized therapeutic decision making in patients with CAD. This review aims to present the current evidence on the complex role of CCTA in the detection and quantification of vulnerable plaques and the associated coronary inflammation, also describing the most recent developments in the radiomics-based machine learning approach for complex assessment of plaque-associated risk.

Epicardial fat thickness correlates with coronary in-stent restenosis in patients with acute myocardial infarction

OBJECTIVE

To determine the relation between epicardial fat thickness and coronary in-stent restenosis in patients with acute myocardial infarction and percutaneous coronary intervention.

METHODS

A prospective study was conducted, which included 129 patients (67.3% male, mean age 62.9±10 years) with ST segment elevation acute myocardial infarction undergoing primary percutaneous coronary intervention with bare metal stent. Patients were divided in two groups according to the presence (n=21) or not (n=108) of in-stent restenosis during one year follow-up.

RESULTS

Epicardial fat was significantly thicker in patients with coronary in-stent restenosis (5.51±1.6 vs 4.14±2.0mm, p=0.006). A proportionally and significantly thicker epicardial fat was found according to the increase in coronary disease severity (3.3±0.9mm vs 4.3±1.8mm vs 4.7±2.3mm vs 6.7±2.2mm, for type A, B1, B2 and C lesions, respectively, p=0.001) and number of vessels (3.07±1.2mm vs 4.92±1.8mm vs 5.43±2.2mm, for one, two and three vessels disease, respectively, p<0.0001). Epicardial fat thickness ≥4.7mm had 75.0% sensibility and 69.0% specificity for predicting restenosis (AUC=0.737).

CONCLUSIONS

Echocardiographic evaluation of epicardial fat thickness could identify those patients with acute myocardial infarction with greater probabilities of in-stent restenosis after percutaneous coronary intervention.

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.

Echocardiographic measurements of epicardial adipose tissue and comparative ability to predict adverse cardiovascular outcomes in patients with coronary artery disease

The present study aimed to compare echocardiography measurements of epicardial adipose tissue (EAT) thickness and other risk factors regarding their ability to predict adverse cardiovascular outcomes in patients with coronary artery disease (CAD). Outcomes of 107 patients (86 males, 21 females, mean age 63.6 years old) submitted to diagnostic echocardiography and coronary angiography were prospectively analyzed. EAT (measures over the right ventricle, interventricular groove and complete bulk of EAT) and left ventricle ejection fraction (LVEF) were performed by echocardiography. Coronary complexity was evaluated by Syntax score. Primary endpoints were major adverse cardiovascular events (MACE’s), composite of cardiovascular death, myocardial infarction, unstable angina, intra-stent re-stenosis and episodes of decompensate heart failure requiring hospital attention during a mean follow up of 15.94 ± 3.6 months. Mean EAT thickness was 4.6 ± 1.9 mm; and correlated with Syntax score and body mass index; negatively correlated with LVEF. Twenty-three cases of MACE's were recorded during follow up, who showed higher EAT. Diagnostic ability of EAT to discriminate MACE's was comparable to LVEF (AUROC > 0.5); but higher than Syntax score. Quartile comparison of EAT revealed that measurement of the complete bulk of EAT provided a better discrimination range for MACE's, and higher, more significant adjusted risk (cutoff 4.6 mm, RR = 3.91; 95% CI 1.01–15.08; p = 0.04) than the other risk factors. We concluded that echocardiographic measurement of EAT showed higher predicting ability for MACE’s than the other markers tested, in patients with CAD. Whether location for echocardiographic measurement of EAT impacts the diagnostic performance of this method deserves further study.

Association of Epicardial Adipose Tissue and High-Risk Plaque Characteristics: A Systematic Review and Meta-Analysis

Background

Epicardial adipose tissue (EAT) is hypothesized to alter atherosclerotic plaque composition, with potential development of high‐risk plaque (HRP). EAT can be measured by volumetric assessment (EAT‐v) or linear thickness (EAT‐t). We performed a systematic review and random‐effects meta‐analysis to assess the association of EAT with HRP and whether this association is dependent on the measurement method used.

Methods and Results

Electronic databases were systematically searched up to October 2016. Studies reporting HRP by computed tomography or intracoronary imaging and studies measuring EAT‐v or EAT‐t were included. Odds ratios were extracted from multivariable models reporting the association of EAT with HRP and described as pooled estimates with 95% confidence intervals (CIs). Analysis was stratified by EAT measurement method. Nine studies (n=3772 patients) were included with 7 measuring EAT‐v and 2 measuring EAT‐t. Increasing EAT was significantly associated with the presence of HRP (odds ratio: 1.26 [95% CI, 1.11–1.43]; P<0.001). Patients with HRP had higher EAT‐v than those without (weighted mean difference: 28.3 mL [95% CI, 18.8–37.8 mL]; P<0.001). EAT‐v was associated with HRP (odds ratio: 1.19 [95% CI, 1.06–1.33]; P<0.001); however, EAT‐t was not (odds ratio: 3.09 [95% CI, 0.56–17]; P=0.2). Estimates remained significant when adjusted for small‐study effect bias (odds ratio: 1.13 [95% CI, 1.03–1.28]; P=0.04).

Conclusions

Increasing EAT is associated with the presence of HRP, and patients with HRP have higher quantified EAT‐v. The association of EAT‐v with HRP is significant compared with EAT‐t; however, a larger scale study is still required, and further evaluation is needed to assess whether EAT may be a potential therapeutic target for novel pharmaceutical agents.

Clinical Trial Registration

URL: https://www.crd.york.ac.uk/. Unique identifier: CRD42017055473.

Original research. The Assessment of Epicardial Adipose Tissue in Acute Coronary Syndrome Patients. A Systematic Review

Background: This systematic review seeks to evaluate the role of epicardial adipose tissue (EAT), quantified either by thickness, assessed by transthoracic echocardiography, or by volume, assessed by cardiac computed tomography (CT), in the follow-up of patients with acute coronary syndromes (ACS). Method: One-hundred forty-four articles were screened, from which 56 were reviewed in full-text. From those, 47 studies were excluded for the following reasons: they did not meet the inclusion criteria; they were either reviews or meta-analyses; the study cohorts included only stable coronary artery disease patients; they did not state a clear and concise study design, endpoints, or follow-up. The final draft included nine studies for systematic evaluation. Results: Of the 2,306 patients included in the review, 170 underwent cardiac CT while the remaining 2,136 underwent transthoracic echocardiography for the measurement of EAT. The analysis found that the EAT thickness was significantly associated with major adverse cardiovascular events (MACE) rates during hospitalization (OR: -1.3, 95% CI: 1.05-1.62, p = 0.020) and at three years (HR: 1.524, 95% CI: 1.0-2.2, p = 0.038). The included studies found that EAT was correlated with the following clinical and angiographic risk scores for ACS: GRACE (r = 0.438, p <0.001), TIMI risk score (r = 0.363, p = 0.001), SYNTAX score (r = 0.690, p <0.0001; r = 0.610, p <0.01), and Gensini score (r = 0.438, p = 0.001). There was an inverse correlation between ST-segment resolution of <70% after revascularization and EAT (r = −0.414, p = 0.01), and the myocardial blush grade (r = −0.549, p <0.001). The EF aggregation ranged between 2.65 mm and 4.7 mm within the included studies. Conclusions: EAT, evaluated either by echocardiography or cardiac CT, correlates with the severity of coronary lesions, with the clinical and angiographic risk scores for acute coronary syndromes, with indicators for coronary reperfusion, and with short- and long-term MACE rates. Further studies are required to fully elucidate the role of this extensively studied but still novel cardiovascular biomarker as part of a risk prediction tool.

Perivascular adipose tissue as a regulator of vascular disease pathogenesis: identifying novel therapeutic targets

Adipose tissue (AT) is an active endocrine organ with the ability to dynamically secrete a wide range of adipocytokines. Importantly, its secretory profile is altered in various cardiovascular disease states. AT surrounding vessels, or perivascular AT (PVAT), is recognized in particular as an important local regulator of vascular function and dysfunction. Specifically, PVAT has the ability to sense vascular paracrine signals and respond by secreting a variety of vasoactive adipocytokines. Due to the crucial role of PVAT in regulating many aspects of vascular biology, it may constitute a novel therapeutic target for the prevention and treatment of vascular disease pathogenesis. Signalling pathways in PVAT, such as those using adiponectin, H₂ S, glucagon-like peptide 1 or pro-inflammatory cytokines, are among the potential novel pharmacological therapeutic targets of PVAT.

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Echocardiographic epicardial fat thickness is a predictor for target vessel revascularization in patients with ST-elevation myocardial infarction

Background

The amount of epicardial adipose tissue (EAT) has been demonstrated to correlate with the severity of coronary artery disease (CAD) and the CAD activity.

The aim of this study is to assess the impact of EAT on long term clinical outcomes in patients with ST elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI).

Methods

We analyzed the data and clinical outcomes of 761 patients (614 males, 57 ± 12 year-old) with STEMI who underwent successful primary PCI from 2003 to 2009. All patients were divided into two groups: thick EAT group, EAT ≥ 3.5 mm and thin EAT group, EAT < 3.5 mm. The primary end points were all-cause death, recurrent MI, target vessel revascularization (TVR) and major cardiac adverse events (MACEs), composite of all-cause death, recurrent MI and TVR, within 5 years.

Results

Median and mean EAT of 761 patients were 3.3 mm and 3.6 ± 1.7 mm, respectively. Mean follow up period was 46 ± 18 months. MACE-free survival rate in the thick EAT group was significantly lower than in the thin EAT group (log-rank P = 0.001). The event-free survival rate of all-cause death of the thick EAT group was significantly lower than that of the thin EAT group (log-rank P = 0.005). The TVR-free survival rate in the thick EAT group was significantly lower than in the thin EAT group (log-rank P = 0.007). The event-free survival rate of recurrent MI were not significantly different between the groups (log-rank P = 0.206). In the Cox’s proportional hazard model, the adjusted hazard ratio of thick EAT thickness for TVR was 1.868 (95% confidence interval 1.181–2.953, P = 0.008).

Conclusion

This study demonstrates that the EAT thickness is related with long term clinical outcome in patients with STEMI. The EAT thickness might provide additional information for future clinical outcome, especially TVR.

Relationship between indexed epicardial fat volume and coronary plaque volume assessed by cardiac multidetector CT

We explored whether baseline indexed epicardial fat volume (EFVi) and serial changes in EFVi were associated with increase in coronary plaque volume as assessed by multidetector computed tomography.We retrospectively reviewed 87 patients with coronary artery plaque, identified during either baseline or follow-up cardiac computed tomography (CT) examinations. Each plaque volume was measured in volumetric units using a semiautomatic software tool. EFVi was quantified by calculating the total volume of epicardial tissue of CT density -190 to -30 HU, indexed to the body surface area. Clinical cardiovascular risk factors were extracted by medical record review at the time of the cardiac CT examinations. The relationship between EFVi and coronary plaque volume was explored by regression analysis.Although the EFVi did not change significantly from baseline to the time of the follow-up CT (65.7 ± 21.8 vs 66.0 ± 21.8 cm/m, P = 0.620), the plaque volumes were increased significantly on the follow-up CT scans. The annual change in EFVi was not accompanied by a parallel change in coronary plaque volume (P = 0.096-0.500). On univariate analysis, smoking, hypercholesterolemia, 10-year coronary heart disease risk, obesity, and baseline EFVi predicted rapid increases in lipid-rich and fibrous plaque volumes. On multivariate analysis, baseline EFVi (odds ratio = 1.029, P = 0.016) was an independent predictor of a rapid increase in lipid-rich plaque volume.EFVi was shown to be an independent predictor of a rapid increase in lipid-rich plaque volume. However, changes in EFVi were not associated with parallel changes in coronary plaque volume.

Measurement of epicardial fat thickness by transthoracic echocardiography for predicting high-risk coronary artery plaques

Epicardial adipose tissue (EAT) volume is reported to be associated with coronary plaques. We evaluated whether non-invasive measurement of EAT thickness by echocardiography can predict high-risk coronary plaque characteristics determined independently by coronary computed tomography (CT) angiography. We enrolled 406 patients (mean age 63 years, 57 % male) referred for 64-slice CT. EAT was measured on the right ventricle free wall from a parasternal long-axis view at the end of systole. High-risk coronary plaques were defined as low-density plaques (<30 Hounsfield units) with positive remodeling (remodeling index >1.05). Patients were divided into thin or thick EAT groups using a cutoff value derived from receiver operator characteristic curve analysis for discriminating high-risk plaques. The receiver operator characteristic cutoff value was 5.8 mm with a sensitivity of 83 % and specificity of 64 % (area under the curve 0.77, 95 % confidence interval 0.70-0.83, p < 0.01). Compared with the thin EAT group, the thick EAT group had a high prevalence of low-density plaques (4 vs. 24 %, p < 0.01), positive remodeling (39 vs. 60 %, p < 0.01), and high-risk plaques (3 vs. 17 %, p < 0.01). Multiple logistic analysis revealed that thick EAT was a significant predictor of high-risk plaques (odds ratio 7.98, 95 % confidence interval 2.77-22.98, p < 0.01) after adjustment for covariates, including conventional risk factors, visceral adipose tissue area, and medications. The measurement of EAT thickness by echocardiography may provide a non-invasive option for predicting high-risk coronary plaques.

Evaluation of epicardial adipose tissue in familial partial lipodystrophy

BACKGROUND

Dunnigan type Familial Partial Lipodystrophy (FPLD) is characterized by loss of subcutaneous fat from the limbs and excessive accumulation on the visceral adipose tissue (VAT). Affected individuals have insulin resistance (IR), diabetes, dyslipidemia and early cardiovascular (CV) events, due to their imbalanced distribution of total body fat (TBF). Epicardial adipose tissue (EAT) is correlated with VAT. Hence, EAT could be a new index of cardiac and visceral adiposity with great potential as a marker of CV risk in FPLD.

OBJECTIVE

Compare EAT in FPLD patients versus healthy controls. Moreover, we aimed to verify if EFT is related to anthropometrical (ATPM) and Dual-Energy X-ray Absorptiometry (DEXA) measures, as well as laboratory blood findings. We postulated that FPLD patients have enlarged EAT.

METHODS

This is an observational, cross-sectional study. Six patients with a confirmed mutation in the LMNA gene for FPLD were enrolled in the study. Six sex, age and BMI-matched healthy controls were also selected. EFT was measured by transthoracic echocardiography (ECHO). All participants had body fat distribution evaluated by ATPM and by DEXA measures. Fasting blood samples were obtained for biochemical profiles and also for leptin measurements.

RESULTS

Median EFT was significantly higher in the FPLD group than in matched controls (6.0 ± 3.6 mm vs. 0.0 ± 2.04 mm; p = 0.0306). Additionally, FPLD patients had lower leptin values. There was no significant correlation between EAT and ATPM and DEXA measurements, nor laboratory findings.

CONCLUSIONS

This study demonstrates, for the first time, that EAT measured by ECHO is increased in FPLD patients, compared to healthy controls. However, it failed to prove a significant relation neither between EAT and DEXA, ATPM or laboratory variables analyzed.

Epicardial adipose tissue thickness is associated with myocardial infarction and impaired coronary perfusion

Objective:

Epicardial adipose tissue (EAT) is associated with the presence, severity and extent of atherosclerotic coronary artery disease (CAD) in addition to subclinical atherosclerosis. We investigated if EAT thickness is related to acute myocardial infarction in patients with CAD. We also searched for the association between EAT thickness and objective coronary flow and myocardial perfusion parameters such as Thrombolysis in Myocardial Infarction Frame count (TFC) and myocardial blush grade (MBG).

Methods:

Two-hundred consecutive patients with stable angina pectoris or acute coronary syndrome who were admitted to Ufuk University Faculty of Medicine, Dr Ridvan Ege Hospital cardiology department were included in this observational, cross-sectional study. EAT thickness was evaluated by conventional transthoracic echocardiography. Coronary angiography was performed to determine the coronary involvement and perfusion.

Results:

Mean EAT thicknesses were 5.4±1.9 mm, 6.3±1.8 mm, and 8.5±1.4 mm in the stable angina pectoris (SAP), unstable angina pectoris (USAP) and acute myocardial infarction groups, respectively (p<0.001). With increasing EAT thickness, TFC increases whereas mean MBG values decrease (for EAT thickness <5 mm, 5-7 mm, >7 mm; mean TFC: 21.6±2.2, 25.3±3.3 and 35.2±7.7; and MBG values: 2.98±0.14, 2.83±0.57 and 1.7±1.16, respectively; both p<0.001). Cut-off EAT value to predict AMI was identified as 7.8 mm (ROC analysis AUC: 0.876; p<0.001, 95% CI: 0.822-0.927). Sensitivity and specificity of EAT cut-off value 7.8 mm to predict AMI were 81.8% and 82.5% respectively.

Conclusion:

Increased EAT is associated with AMI and it may prove beneficial for choosing patients who would need more aggressive approach in terms of risk reduction using echocardiography which is a relatively cheap and readily available tool as a follow-up parameter.

Epicardial fat and vascular risk: a narrative review

PURPOSE OF REVIEW

We comment on the associations between epicardial adiposity and cardiovascular disease (CVD) and associated risk factors. The effects of lifestyle measures and CVD drugs on cardiac adipose tissue are also discussed.

RECENT FINDINGS

Epicardial adipose tissue exerts cardioprotective properties; however, in cases of pathological enlargement, epicardial fat can lead to myocardial inflammation and dysfunction as well as left ventricular hypertrophy and coronary artery disease (CAD) due to paracrine actions that include increased production of reactive oxygen species, atherogenic and inflammatory cytokines. Cardiac adiposity is associated with CAD, obesity, type 2 diabetes, metabolic syndrome, nonalcoholic fatty liver disease, and chronic kidney disease, as well as with CVD risk factors such as lipids, hypertension, obesity markers, and carotid atherosclerosis.

SUMMARY

Due to its anatomical and functional proximity to the coronary circulation, epicardial adipose tissue may represent an even more direct CVD risk marker than central adiposity. Lifestyle measures and certain drugs may affect its thickness, although there are limited data currently available. The clinical implications of epicardial fat in daily practice remain to be established in future studies.

Visceral adipose tissue as a source of inflammation and promoter of atherosclerosis

The current epidemic of obesity with the associated increasing incidence of insulin resistance, diabetes mellitus and atherosclerosis affecting a large proportion of the North American and Western populations, has generated a strong interest in the potential role of visceral adipose tissue in the development of atherosclerosis and its complications. The intra-abdominal and epicardial space are two compartments that contain visceral adipose tissue with a similar embryological origin. These visceral fats are highly inflamed in obese patients, patients with the metabolic syndrome and in those with established coronary artery disease; additionally they are capable of secreting large quantities of pro-inflammatory cytokines and free fatty acids. There is accumulating evidence to support a direct involvement of these regional adipose tissue deposits in the development of atherosclerosis and its complicating events, as will be reviewed in this article.