Quantification of epicardial fat: Which method can predict significant coronary artery disease?

Pericardial Fat, Socioeconomic Status, and Biological Responses to Acute Mental Stress

OBJECTIVE

Central adiposity is associated with impaired biological responses to mental stress, and socioeconomic status (SES) might moderate this relationship. However, evidence for associations between pericardial fat, a fat depot implicated in the pathogenesis of cardiovascular disease (CVD), with cardiovascular and inflammatory responses to mental stress is lacking, and moderation by SES is unknown.

METHODS

The sample was 473 healthy men and women (mean age = 62.8 years) from the Whitehall II study. Cardiovascular and inflammatory responses to laboratory-induced mental stress, consisting of a 5-minute Stroop task and 5-minute mirror tracing task, were assessed. Pericardial fat volume was measured using electron bean computed tomography and adjusted for body surface area. SES was defined by grade of employment within the British civil service (higher/intermediate/lower).

RESULTS

Pericardial fat was associated with lower heart rate variability, raised heart rate, plasma interleukin-6, fibrinogen, and C-reactive protein at baseline. Furthermore, greater pericardial fat was associated with lower systolic blood pressure reactivity to mental stress, independent of sociodemographics, smoking status, waist-to-hip ratio, and baseline systolic blood pressure. There were no interactions between pericardial fat and SES for any outcome.

CONCLUSIONS

Greater pericardial fat was associated with numerous cardiovascular and inflammatory factors implicated in CVD. It was also related to reduced systolic blood pressure reactivity to acute mental stress, independent of central adiposity and baseline systolic blood pressure. This association did not vary by SES. Reduced systolic blood pressure reactivity to mental stress might contribute to the association between greater pericardial fat and CVD.

Cut-off point of CT-assessed epicardial adipose tissue volume for predicting worse clinical burden of SARS-CoV-2 pneumonia

Objective

To identify a cut-off value of epicardial adipose tissue (EAT) volume quantified by CT associated with a worse clinical outcome in patients with SARS-CoV-2 pneumonia.

Materials and methods

In this retrospective study, sixty patients with a diagnosis of laboratory-confirmed COVID-19 pneumonia and a chest CT exam on admission were enrolled. Based on a total severity score (range 0–20), patients were divided into two groups: ordinary group (total severity score < 7) and severe/critical group (total severity score > 7). Clinical results and EAT volume were compared between the two groups.

Results

The severe/critical patients, compared to the ordinary ones, were older (66.83 ± 11.72 vs 58.57 ± 16.86 years; p = 0.031), had higher body mass index (27.77 ± 2.11 vs 25.07 ± 2.80 kg/m²; p < 0.001) and higher prevalence of comorbidities. EAT volume was higher in severe/critical group, compared with the ordinary group (151.40 ± 66.22 cm³ vs 92.35 ± 44.46 cm³, p < 0.001). In severe/critical group, 19 (73%) patients were admitted in intensive care unit (ICU), compared with 6 (20%) patients in the ordinary group (p < 0.001). The area under the ROC curve (AUC) is equal to 0.781 (p < 0.001) (95% CI: 0.662–0.900). The cut-off found, in correspondence with the highest value of the Youden Index, is 97 cm³: the sensitivity is equal to 83.3%, while the specificity is equal to 70% for predicting a worse outcome. The risk (odds ratio) of belonging to the severe/critical group in this population due to EAT ≥ 97 cm³ is 11.667 (95% CI: 3.384–40.220; p < 0.001).

Conclusion

An EAT volume of 97 cm³ has good sensitivity and specificity to predict a greater extent of pulmonary involvement and therefore a worse clinical outcome in patients with SARS-CoV-2 pneumonia.

Quantification of epi- and pericardial adipose tissue deposits between males and females during cardiac CT may potentially help categorize coronary artery disease risk with thoracic circumference

INTRODUCTION

This study aims to investigate the association between epi- and pericardial adipose tissue deposits around the heart against patient body habitus when using cardiac computed tomography (CT).

METHODS

Ninety-two consecutive patients with suspected coronary artery disease underwent coronary CT angiography with quantitative cardiac and adipose tissue volume measurements. Body mass index (BMI), body surface area (BSA), thoracic circumference, anteroposterior diameter, cardiac and adipose tissue volumes were compared between genders by employing Pearson's correlation and results were considered statistically significant if p ≤ 0.05.

RESULTS

Statistically significant differences between genders were observed with males having a greater height (males 1.72 ± 0.11), BMI (30.76 ± 7.87 kg/m²), BSA (2.06 ± 0.21 m²), thoracic circumference (1022.12 ± 97.90 mm²), and pericardial adipose tissue volume (46.72 ± 36.62 mm³) (p < 0.05). For men, for Group 1 (BMI ≤ 27) each of the measured volumes showed moderate correlation between pericardial adipose tissue and AP chest-diameter (r = 0.429, p <0.05), whereas in Group 2 (27 < BMI ≤ 31.1), coronary artery volume had a strong association with the AP chest-diameter (r = 0.453, p < 0.05).

CONCLUSION

BMI and thoracic circumference are closely related to variable epi- and pericardial adipose tissue volumes in both males and females during cardiac CT.

IMPLICATIONS FOR PRACTICE

Quantification of epi- and pericardial adipose tissue deposits between males and females during cardiac CT may help further categorise coronary artery disease risk when including BMI and thoracic circumference for males and females.

Relation of cardiac adipose tissue to coronary calcification and myocardial microvascular function in type 1 and type 2 diabetes

Background

Cardiac adipose tissue may have local paracrine effects on epicardial arteries and the underlying myocardium, promoting calcification and affecting myocardial microcirculation. We explored whether the total amount of cardiac adipose tissue was associated with coronary artery calcium score (CAC) and myocardial flow reserve in persons with type 1 or type 2 diabetes and healthy controls.

Methods

We studied three groups: (1) 30 controls, (2) 60 persons with type 1 diabetes and (3) 60 persons with type 2 diabetes. The three groups were matched for sex and age. The three groups derived from retrospective analysis of two clinical studies. All underwent cardiac ⁸²Rb positron emission tomography/computed tomography (PET/CT) scanning. Cardiac adipose tissue volume (the sum of epicardial and pericardial fat), CAC, and myocardial flow reserve (ratio of pharmacological stress flow and rest flow) were evaluated using semiautomatic software. We applied linear regression to assess the association between cardiac adipose tissue, CAC and myocardial flow reserve.

Results

Mean (SD) cardiac adipose tissue volume was 99 (61) mL in the control group, 106 (78) mL in the type 1 diabetes group and 228 (97) mL in the type 2 diabetes group. Cardiac adipose tissue was positively associated with body mass index in all three groups (p ≤ 0.02). In the controls, cardiac adipose tissue was positively associated with CAC score (p = 0.008) and negatively associated with myocardial flow reserve (p = 0.005). However, cardiac adipose tissue was not associated with CAC or myocardial flow reserve in the groups including persons with type 1 or type 2 diabetes (p ≥ 0.50).

Conclusions

In contrast to what was found in healthy controls, we could not establish a relation between cardiac adipose tissue and coronary calcification or myocardial microvascular function in person with type 1 or type 2 diabetes. The role of cardiac adipose tissue in cardiovascular disease in diabetes remains unclear.

Epicardial adipose tissue and its association with cardiovascular risk factors and mitral annular calcium deposits

Introduction

Epicardial fat is a variety of visceral adipose tissue that secretes pro-inflammatory cytokines that can lead to progression of atherosclerosis. Previous studies have shown a correlation between cardiovascular risk factors and severity of mitral annular calcification. The aim of our study was to assess the correlation between epicardial fat thickness and mitral annular calcification.

Methods

This study recruited 188 patients who were considered for coronary angiography and underwent echocardiography within 24 hours of admission. Epicardial fat thickness was measured in the parasternal long axis view at the end-systole. Mitral annular calcification was visualized in the parasternal short-axis view and was grade as none, mild, moderate, and severe. Furthermore, left atrial diameter, severity of mitral regurgitation, left ventricular ejection fraction, and early diastolic velocities (E wave) determined by transmitral pulsed Doppler, the early mitral annular velocities measured by tissue Doppler (e'), and E/e' were obtained.

Results

Patients with an epicardial fat thickness ≥7 mm had higher prevalence of hypertension and higher SYNTAX score (p value = 0.002 and 0.0014, respectively). Also, mitral annular calcification was both more prevalent and more extensive (p value = 0.007 and <0.001, respectively) and left atrial diameter was larger in these patients compared with patients with epicardial fat thickness <7 mm (p value = 0.001).

Conclusions

Our study showed significant association between increased epicardial fat thickness and calcium deposits in the mitral valve annulus that is a degenerative process associated with cardiovascular risk factors.

Correlation of epicardial fat quantification with severity of coronary artery disease: A study in Indian population

Objective

We studied the correlation of quantified epicardial fat with severity of coronary artery disease in patients [suspected cases of coronary artery disease (CAD)] referred for computed tomography (CT) coronary angiography and established cutoffs for epicardial fat volume (EFV) for the presence of CAD and obstructive CAD.

Methods

A prospective cum retrospective cross-sectional observational study was carried out on 950 Indian subjects (suspected cases of CAD) who were referred for coronary CT in the year 2013–2016. EFV was quantified using semiautomatic technique on multidetector coronary CT angiography. The presence of atherosclerotic plaques and degree of stenosis was assessed on coronary CT angiography scans. The correlation between quantified EFV and degree of stenosis was assessed. Multivariate analysis was also performed.

Results

A higher quantity of epicardial fat is found in patients with increasing severity of coronary artery stenosis. The EFV cutoff for the presence of CAD and obstructive CAD are 49.75 and 67.69 mL with area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 0.68, 81%, 45.9%,58.24%, 72.2%, and 62.84% and 0.709, 64.9%, 66.4%, 35.84%, 86.55%, and 66%, respectively. EFV correlates with age, weight, and body mass index (BMI). Multivariate analysis revealed EFV to be an independent risk factor for the presence of CAD.

Conclusions

Higher quantities of EFV are found in patients with greater degree of coronary artery stenosis. EFV correlates with age, weight, and BMI. EFV is an independent risk factor for CAD.

Relation of body composition indexes to cardiovascular disease risk factors in young adults

BACKGROUND

To evaluate the relationship of body composition indexes with altered metabolic analytical parameters that show higher risk of cardiovascular disease in young adults.

MATERIAL AND METHODS

A cross-sectional study. Sample of 1351 young adults, different body composition parameters were obtained such as Waist Circumference (WC), Hip Circumference (HC), Body Mass Index (BMI), Body Fat% (BF%), Waist-to-height Ratio (WHtR), and Waist-Hip Ratio (WHR), conicity index (C-Index), body surface area (BSA), abdominal volume index (AVI) and deep abdominal adipose-tissue (AT). Areas under receiver operating characteristic curves (AUCs) and odds ratios for the parameters were analyzed and their optimal cut-offs. Separately a MANOVA was applied to altered metabolic analytical parameters and two body composition indexes (BMI and BSA) and their interaction.

RESULTS

BMI correlate significantly with metabolic analytical parameters (FPG r=0.08, TCh r=0.14, TGL r=0.23, HDL-C r=-0.23, LDL-C r=0.2, UA r=0.22, All P<0.01), BSA correlate with all (All P<0.001) except FPG. BMI and BSA correlate significantly with all metabolic analytical parameters (All P<0.001). The BMI individually predicts the changes of the six metabolic analytical parameters as a set [Wilk's λ=0.89, F(18,1570)=3.4, P<0.0001], but not BSA [Wilk's λ=0.98, F(6,555)=1.4, P=0.18], the interaction between these two indexes (BMI and BSA altered in the same individual) significantly predicts changes of the six metabolic analytical parameters of cardiovascular disease risk [Wilk's λ=0.97, F(6,555)=2.3, P=0.03].

CONCLUSIONS

BMI and BSA correlate with cardiovascular disease risk factor. They are superior to WC, WHtR, WHR, BF%, C-index, AVI and AT.