Epicardial Fat Volume Research Articles

Evolutional change in epicardial fat and its correlation with myocardial diffuse fibrosis in heart failure patients

The aim of this study was to characterize the characteristics of epicardial fat (EAT) in different stage heart failure (HF) patients and its relationship between cardiac fibrosis. EAT is visceral adipose tissue that possesses inflammatory properties. Inflammation and obesity are associated with cardiac fibrosis, but the relationship between cardiac fibrosis and EAT is unknown. EAT volume was measured using cardiac magnetic resonance imaging (CMR) in 180 subjects: 58 patients with systolic HF, 63 patients with HF and preserved ejection fraction, and 59 patients without HF. CMR derived myocardial extracellular volume (ECV) was used for fibrosis quantification. Patients with systolic HF had significantly more EAT compared with patients with HF and preserved ejection fraction or the control group (patients without HF) (indexed EAT volume [mL/m2], 27.0 [22.7-31.6] vs 25.6 [21.4-31.2] and 24.2 [21.0-27.6], P<.05). The adjusted EAT amount was associated with ECV completely independent of age, hypertension, diabetes, etiology of HF, left ventricular ejection fraction, CMR-late gadolinium enhancement (LGE), left ventricular mass index, and left ventricular end-diastolic volume index (correlation coefficient: 0.49; 95% confidence interval: 0.12-0.86, P<.01). Increased CMR ECV was more associated with EAT in those with advanced age, male sex, LGE on magnetic resonance imaging-LGE images, and less left ventricular end-diastolic volume index. EAT volume is highly associated with CMR ECV independent of traditional risk factors and left ventricular mass or volume. Whether EAT plays a role in the long-term prognosis of HF requires future investigation.

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OBJECTIVES/SPECIFIC AIMS: The goal is to understand the underlying mechanism of epicaridial fat biology and its response to cardiometabolic disease by using quantitative multi-echo Dixon (mDixon) of water and lipid sequence, T2* blood-oxygen-level-dependent (BOLD) sequence of iron content, and data analysis methods to determine the quantity of brown Versus white fat. To accomplish this goal, we propose to define the histological, genetic, and metabolite state of epicardial fat and to confirm the relationship between fat phenotype and magnetic resonance (MR) characteristics. We will then investigate whether MR is more effective in identifying patients with lower cardiovascular disease risk than computed tomography (CT). METHODS/STUDY POPULATION: We will recruit 100 patients undergoing open-heart surgery and will quantify mDixon (proton density fat fraction), BOLD (T2*), and T2/T1 maps of epicardial, extrapericardial, and subcutaneous fat before their surgery. We will then (a) validate MR findings by direct depot-specific tissue analysis for lipid content, histological, and genetic markers of inflammation and brown and white fat, (b) develop plasma and fat depot specific metabolite profiling of cardiovascular disease risk and correlate with imaging characteristics. We will categorize cardiovascular risk score (Cardiovascular Health Status) of our 100 patients on quartiles. We will then build models where the categorized cardiovascular risk score are regressed on MR measures (epicardial fat fraction, T2*, and T2/T1 maps) and CT measures (epicardial fat volume and coronary calcium score). RESULTS/ANTICIPATED RESULTS: We anticipate to learn about epicardial fat biology and the role of inflammation in cardiometabolic disease. We will validate proton density fat fraction, T2* and T2 map against histology of epicardial fat for lipid content, established markers of brown and white fat and inflammation, respectively, to help us translate imaging technique to clinical practice. In respect to our second aim we anticipate that MR identifies patients at lower cardiovascular risk quartile than CT. DISCUSSION/SIGNIFICANCE OF IMPACT: Interest in epicardial fat as a visceral fat of the heart and coronary arteries is rapidly growing as the scientific based evidence indicates that the anatomic specificity is an important contributor to the cardiovascular diseases. The transformation of epicardial fat from a cardioprotective phenotype to a pro-inflammatory, atherosclerosis-promoting state triggers inflammation that is coincident with the expansion of epicardial fat volume detected by anatomic imaging. This study will impact the management of patients at risk for cardiovascular disease because it will demonstrate that quantification of epicardial fat status by MR identifies fat tissue changes validated by histology at lower cardiovascular disease risk quartile than CT.

Increased Epicardial Fat Volume Is Independently Associated with the Presence and Severity of Systemic Sclerosis

The study aimed to determine if intrathoracic fat volumes are associated with the presence and severity of systemic sclerosis (SSc), defined by the presence of pulmonary arterial hypertension (PAH). A total of 265 patients were included in the study, 202 of whom had SSc (134 had SSc with no PAH and 68 had SSc-associated PAH) and who underwent high-resolution computed tomography, and 63 controls who underwent coronary computed tomography angiography with calcium scoring. Intrathoracic and epicardial (EFV) fat volumes were quantified by manual tracing of the mediastinum and the pericardium, the difference of which represents the extrapericardial fat volume. Associations between these three fat volumes and the presence and severity of SSc, adjusted for cardiovascular risk factors and interstitial lung disease, were evaluated by logistic regression analysis. Of the 202 patients with SSc, the mean age was 55 years (ranged from 20 to 86), and 79% (159 of 202) were women. Adjusted EFV (odds ratio [OR]: 1.065; 95% confidence interval [CI]: 1.046-1.084, P = < 0.0001), extrapericardial fat volume (OR: 1.028, 95% CI: 1.017-1.038, P = < 0.0001), and intrathoracic fat volume (OR: 1.033, 95% CI: 1.023-1.043, P = 0.001) were associated with the presence of SSc. Only EFV was associated with SSc severity (adjusted OR: 1.010, 95% CI: 1.003-1.018, P = 0.007). Increased epicardial fat volume is associated with the presence and severity of SSc, independent of cardiovascular risk factors and interstitial lung disease.

Cardiac computed tomography-derived epicardial fat volume and attenuation independently distinguish patients with and without myocardial infarction

Background and objectiveEpicardial adipose tissue (EAT) volume is associated with coronary plaque burden and adverse events. We aimed to determine, whether CT-derived EAT attenuation in addition to EAT volume distinguishes patients with and without myocardial infarction.Methods and resultsIn 94 patients with confirmed or suspected coronary artery disease (aged 66.9±14.7years, 61%male) undergoing cardiac CT imaging as part of clinical workup, EAT volume was retrospectively quantified from non-contrast cardiac CT by delineation of the pericardium in axial images. Mean attenuation of all pixels from EAT volume was calculated. Patients with type-I myocardial infarction (n = 28) had higher EAT volume (132.9 ± 111.9ml vs. 109.7 ± 94.6ml, p = 0.07) and CT-attenuation (-86.8 ± 5.8HU vs. -89.0 ± 3.7HU, p = 0.03) than patients without type-I myocardial infarction, while EAT volume and attenuation were only modestly inversely correlated (r = -0.24, p = 0.02). EAT volume increased per standard deviation of age (18.2 [6.2–30.2] ml, p = 0.003), BMI (29.3 [18.4–40.2] ml, p<0.0001), and with presence of diabetes (44.5 [16.7–72.3] ml, p = 0.0002), while attenuation was higher in patients with lipid-lowering therapy (2.34 [0.08–4.61] HU, p = 0.04). In a model containing volume and attenuation, both measures of EAT were independently associated with the occurrence of type-I myocardial infarction (OR [95% CI]: 1.79 [1.10–2.94], p = 0.02 for volume, 2.04 [1.18–3.53], p = 0.01 for attenuation). Effect sizes remained stable for EAT attenuation after adjustment for risk factors (1.44 [0.77–2.68], p = 0.26 for volume; 1.93 [1.11–3.39], p = 0.02 for attenuation).ConclusionCT-derived EAT attenuation, in addition to volume, distinguishes patients with vs. without myocardial infarction and is increased in patients with lipid-lowering therapy. Our results suggest that assessment of EAT attenuation could render complementary information to EAT volume regarding coronary risk burden.

The association of epicardial fat volume with coronary characteristics and clinical outcome.

Recent studies have demonstrated the relationship between epicardial fat volume (EFV) and coronary atherosclerosis, but their association is modest at best. Our purpose is to elucidate the association of epicardial fat with coronary characteristics and clinical outcome. We performed coronary computed tomographic angiography in 651 patients and divided them into three groups according to tertiles of EFV; low-tertile (n = 215), 36-123 ml; middle-tertile (n = 218), 124-165 ml; high-tertile (n = 218), 166-489 ml. The prevalence of coronary calcium score (CCS) >0 (71.6, 73.4, and 83.9% in low-, middle-, and high-tertile group, respectively) and CCS >100 (39.1, 39.9, and 59.2% in each group) was significantly higher in patients with high-tertile EFV compared to the other two groups (p = 0.0047 and p < 0.0001, respectively). The prevalence of CCS >400 was 17.2, 25.7, and 33.1% in each group, which increased stepwise as EFV increased. The significant stenosis (36.2 vs. 27.0%, p = 0.0383), total coronary occlusion (5.5 vs. 0.9%, p = 0.0156), and high-risk plaque (11.0 vs. 5.6%, p = 0.0368) were more prevalent in patients with high-tertile EFV compared to those with low-tertile EFV. The combined rate of cardiac death and myocardial infarction was 0.9, 2.3, and 6.4% in each patient group, respectively, which was significantly higher in patients with high-tertile EFV compared to those with low-tertile EFV (p = 0.0004). The prevalence of coronary artery calcium, significant stenosis, and high-risk plaque increased sharply in patients with high EFV, which was associated with higher rate of cardiac death and myocardial infarction. Thus, high EFV was associated with advanced coronary atherosclerosis and poor prognosis.

Epicardial fat volume in women with chest pain and no obstructive coronary artery disease – the ipower study

Epicardial fat volume in women with chest pain and no obstructive coronary artery disease – the ipower study

Quantitative analysis of epicardial fat volume: effects of scanning protocol and reproducibility of measurements in non-contrast cardiac CT vs. coronary CT angiography.

Several studies have focused on the role of epicardial fat in the pathogenesis of cardiovascular disease (CVD). The main purpose of the study was to evaluate a computerized method for the quantitative analysis of epicardial fat volume (EFV) by non-contrast cardiac CT (NCT) for coronary calcium scan and coronary CT angiography (coronary CTA). Thirty patients (61±12.5 years, 73% male, body mass index (BMI) =25.9±6.3 kg/m2) referred to our Institution for suspected coronary artery disease (CAD) underwent NCT and coronary CTA. Epicardial boundaries were traced by 2 experienced operators (operator 1, operators 2) on 3 and 6 short-axis (SA) slices. EFV was computed with a semi-automatic method using an in-house developed software based on spherical harmonic representation of the epicardial surface. In order to analyze the inter-observer variability both the Coefficient of Repeatability (CR) and Intra Class Correlation (ICC) were computed. The total EFV was 103.62±50.97 and 94.96±67.91 cc in NCT and coronary CTA with non-significant difference (P=0.292). CR error was 10.22 cc for operator 1 and 11.31 cc for operator 2 in NCT and 7.99 cc for operator 1 and 7.75 cc for operator 2 in coronary CTA. To analyze the inter-observer variability CR and ICC were computed. CR was 8.17 and 8.39 cc with NCT and 7.07 and 7.21 cc with CTA for 6 and 3 SA slices respectively. ICC values >0.99 were obtained in all cases. The right ventricular EFV was 67.23±31.4 and 57.41±34.3 cc for NCT and coronary CTA respectively; the corresponding values for left ventricular EFV were 38.01±19.1 and 35.27±25.9 cc. Both NCT and coronary CTA can be used with low intra- and inter-observer variability for computer-assisted measurements of EFV. Cardiac CT may allow a fast and reliable computation of EFV in clinical setting.

Interrelations of Epicardial Fat Volume, Left Ventricular T1-Relaxation Times and Myocardial Strain in Hypertensive Patients: A Cardiac Magnetic Resonance Study.

This cardiac magnetic resonance study was performed to assess myocardial fibrosis by evaluating T1-relaxation time (T1), to measure left ventricular (LV) strain, and to determine epicardial fat volume (EFV) in hypertensive patients with no history of cardiovascular (CV) events and to relate the results to the presence of coronary atherosclerotic artery disease (CAD) in these patients. A total of 123 subjects were examined at 1.5 T. Of them, 98 were hypertensive patients (58 men; mean age, 62.9±10.7 y; body mass index, 29.0±5.6 kg/m) and 25 were controls without CV risk factors or disease (13 men; 60.1±10.7 y; 28.1±5.4 kg/m). All patients had a well-treated blood pressure. In the hypertensive group, 56 patients had no CAD, whereas 42 patients had CAD. T1 was assessed by a modified Look-Locker inversion recovery sequence. Longitudinal and circumferential peak systolic strain (LS; CS) was determined with dedicated cardiac magnetic resonance software (feature tracking). EFV (normalized to the body surface area) was assessed by a 3D Dixon sequence. T1 (ms) and EFV (mL/m) were higher and CS and LS (%) were lower in hypertensive patients compared with those in nonhypertensive controls (P<0.05), independent of the presence of CAD (controls: T1=967.2±16.9, LS=-25.2±4.6, CS=-28.7±5.0, EFV=58.2±21.1; hypertensive patients overall: T1=991.3±45.5, LS=-21.0±4.5, CS=-25.0±5.9, EFV=71.1±25.3; hypertensive patients without CAD: T1=991.6±48.4, LS=-21.0±4.7, CS=-24.6±6.3, EFV=71.3±26.6; hypertensive patients with CAD: T1=986.7±39.2, LS=-21.1±4.3, CS=-25.5±5.4, EFV=70.9±23.6). There were no significant differences between hypertensive patients with and those without CAD and between patients grouped according to the number of vessels affected (0-vessel disease, 1-vessel disease, 2-vessel disease, or 3-vessel disease). Hypertension is associated with signs of myocardial fibrosis and an impaired LV contractility despite a normal LV ejection fraction, as well as with an increased EFV. However, CAD, in the absence of previous pathologies with consecutive myocardial ischemic damage, did not additionally affect these parameters.

Relationship of Echocardiographic Epicardial Fat Thickness and Epicardial Fat Volume by Computed Tomography with Coronary Artery Calcification: Data from the CAESAR Study

No study has assessed the association between echocardiographic epicardial fat thickness (EFT) and computed tomography (CT)-based epicardial fat volume (EFV) and coronary artery calcification. The aim of this study is to evaluate the association between EFT and EFV and coronary artery calcification. Among the 2,299 individuals enrolled in the CArdiometabolic risk, Epicardial fat, and Subclinical Atherosclerosis Registry (CAESAR) study, 2,276 (1,851 men; mean age 45±8.9years) who underwent echocardiographic EFT and CT-based EFV measurements and obtained a coronary artery calcium score (CACS) were included in this study. The overall prevalence of CAC >0 was 19.3%. EFT was significantly correlated with EFV (r=0.374, p <0.001) but the k statistic showed only slight agreement (k=0.146, p <0.001). Multivariate regression analyses adjusted for age, sex, body mass index, waist circumference, systolic blood pressure, daily alcohol intake, smoking status, and vigorous exercise and glucose, blood urea nitrogen, uric acid, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high-sensitivity C reactive protein, and hemoglobinA1c levels revealed that an increase in the absolute values of EFT and EFV was significantly associated with the presence of coronary artery calcium (ORs [95% CIs], 2.023 [1.282-3.193] and 1.785 [1.173-2.716], respectively) and CACS (standardized β values=0.082 and 0.061, p=0.001 and 0.042, respectively). These results show that EFT and EFV are associated with coronary artery calcification in Korean adults despite the relatively weak correlation between EFT and EFV.

Cardiac magnetic resonance based evaluation of aortic stiffness and epicardial fat volume in patients with hypertension, diabetes mellitus, and myocardial infarction.

Background Aortic stiffness and epicardial fat relate to cardiovascular risk. Their relationship with each other and their role with hypertension, diabetes mellitus (DM), and myocardial infarction (MI) can be evaluated by cardiac magnetic resonance (CMR). Purpose To explore an association between aortic stiffness and epicardial as well as paracardial fat volume (EFV and ParaFV, respectively) in hypertensive patients and to relate the results to the presence of DM and MI. Material and Methods A total of 156 hypertensive and 20 non-hypertensive participants were examined at 1.5 Tesla. A 2D-velocity-encoded sequence was acquired to assess aortic pulse wave velocity (PWV in m/s) as a measure of aortic stiffness. A 3D-Dixon sequence was used to determine EFV and ParaFV. Results PWV correlated with EFV (R = 0.474; P < 0.001), but not with ParaFV. Fat volumes (in mL/m2) and PWV were lower in non-hypertensive controls compared to hypertensive patients. EFV and PWV were significantly higher in diabetic hypertensive patients without MI (n = 19; PWV: 10.4 ± 2.9; EFV: 92.5 ± 19.3) compared to hypertension-only patients (n = 84 [no DM or MI]; EFV: 64.8 ± 25.1, PWV: 9.0 ± 2.6; P < 0.05). Logistic regression analysis showed a significant association between the presence of a MI and a higher EFV ( P < 0.05), but not with PWV ( P = 0.060) or ParaFV ( P = 0.375). Conclusion A relationship between aortic stiffness and EFV was found in hypertensive patients. Both were increased in the presence of DM; however, only EFV was increased in the presence of MI. This may relate to the PWV lowering effect of the antihypertensive medication used by hypertensive patients and underscores the benefit of EFV assessment in this regard.

Luseogliflozin reduces epicardial fat accumulation in patients with type 2 diabetes: a pilot study

BackgroundAccumulation of epicardial fat (EF) is associated with increased cardio-metabolic risks and coronary events, independently of traditional cardiovascular risk factors. Therefore, the reduction of EF volume (EFV) may be associated with reduced cardio-metabolic risks and future cardiovascular events. Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce body fat including visceral fat and cardiovascular events in patients with type 2 diabetes. However, it has still been unknown whether SGLT2 inhibitors can reduce EFV.MethodsType 2 diabetic patients with HbA1c 6.5–9.0% and body mass index (BMI, kg/m2) ≥25.0 were enrolled in this single arm pilot study. Participants were administered luseogliflozin 2.5 mg daily and the dosage was tolerated to be increased up to 5.0 mg daily. EFV [median (interquartile range), cm3] was measured by magnetic resonance imaging. Primary endpoint was the decrease in EFV at 12 weeks. Visceral fat area (VFA, cm2) and liver attenuation index (LAI) measured by the abdominal computed tomography, and skeletal muscle index (SMI) and body fat (%) measured by the whole body dual-energy X-ray absorptiometry were also determined at baseline and at 12 weeks.ResultsNineteen patients (mean age: 55 ± 12 years; 26% female) completed this study. Luseogliflozin treatment significantly reduced EFV at 12 weeks [117 (96–136) to 111 (88–134), p = 0.048]. The body weight, BMI, systolic and diastolic blood pressure, HbA1c, fasting plasma glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), triglycerides, SMI, and body fat were significantly reduced by luseogliflozin at 12 weeks. The reduction of EFV was significantly correlated with the reduction of C-reactive protein (r = 0.493, p = 0.019). Neither VFA nor LAI were significantly reduced by the luseogliflozin treatment. No severe adverse events were observed.ConclusionsOur data suggest that luseogliflozin could reduce the EFV in parallel with the improvement of systemic micro-inflammation and the reduction of body weight in Japanese patients with type 2 diabetes. The reduction of muscle mass after the administration of SGLT2 inhibitors may require a particular attention.Trial registration umin.ac.jp, UMIN000019072

Intrathoracic Fat Measurements Using Multidetector Computed Tomography (MDCT): Feasibility and Reproducibility.

Intrathoracic fat volume, more specifically, epicardial fat volume, is an emerging imaging biomarker of adverse cardiovascular events. The purpose of this work is to show the feasibility and reproducibility of intrathoracic fat volume measurement applied to contrast-enhanced multidetector computed tomography images. A retrospective cohort study of 62 subjects free of cardiovascular disease (55% females, age = 49 ± 11 years) conducted from 2008 to 2011 formed the study group. Intrathoracic fat volume was defined as all fat voxels measuring −50 to −250 Hounsfield Unit within the intrathoracic cavity from the level of the pulmonary artery bifurcation to the heart apex. The intrathoracic fat was separated into epicardial and extrapericardial fat by tracing the pericardium. The measurements were obtained by 2 readers and compared for interrater reproducibility. The fat volume measurements for the study group were 141 ± 72 cm3 for intrathoracic fat, 58 ± 27 cm3 for epicardial fat, and 84 ± 50 cm3 for extrapericardial fat. There was no statistically significant difference in intrathoracic fat volume measurements between the 2 readers, with correlation coefficients of 0.88 (P = .55) for intrathoracic fat volume and −0.12 (P = .33) for epicardial fat volume. Voxel-based measurement of intrathoracic fat, including the separation into epicardial and extrapericardial fat, is feasible and highly reproducible from multidetector computed tomography scans.

Association between epicardial fat volume and coronary artery calcification in patients with chronic kidney disease

Objective: To evaluate whether epicardial fat volume (EFV) is related to coronary artery calcification in patients with chronic kidney disease(CKD). Method: Multi-slice computed tomography was performed in 30 healthy subjects and 120 patients with CKD. Cross-sectional tomographic cardiac slices from base to apex were traced semi-automatically using a Volume Viewer of AW4.3 off-line workstation, and EFV was measured by assigning Hounsfield units ranging from -250 to -30 HU to fat.The coronary artery calcification score was assessed by CaScoring software. High density lipoprotein cholesterol(HDL-C), low density lipoprotein cholesterol(LDL-C) and collecting the body mass index (BMI), dialysis route, history of diabetes and coronary artery disease were used to analyze the relationship between EFV and other risk factors in patients with CKD. Results: There were 60.8%(73/120) male (mean age 62.8 years) and 39.2%(47/120) female (mean age 66.6 years) in the patients cohort, 73.3%(88/120) patients had coronary artery disease, 55.8%(67/120) had diabetes, 21 patients were on peritoneal dialysis and 9 on hemodialysis. EFV was apparently higher in stage 4-5 D CKD group compared with the control group((140.03±54.71), (145.01±64.56)and (141.45±62.04) cm(3) vs.(92.42±39.56)cm(3), P=0.007, 0.015 and 0.001), was similar between CKD3 and control group, and EFV was significantly higher in peritoneal dialysis group than in hemodialysis group and in coronary artery disease group compared with no coronary artery disease group((140.67±70.31) cm(3) vs.(105.22±61.49) cm(3), P=0.002). EFV was obviously higher in diabetes group than no diabetes group((148.41±65.78) cm(3) vs.(110.53±62.37) cm(3), P=0.007). CACS was apparently increased in stage 3-5 CKD group compared with the control group(140.0 vs.4.3, P<0.001). (3)When the patients were divided into four groups according to the eGFR, EFV was positively associated with CACS(r(s)=0.539, P=0.004) in control group, and the association become more robust in patients with CKD5(r(s)=0.841, P<0.000 1). EFV was related to age(r=0.662, P=0.005), BMI(r=0.648, P=0.009)and HDL-C(r=-0.433, P=0.024), but not related to eGFR and LDL-C. EFV was related to CACS(r=0.427, R(2)=0.182 3, P<0.001). CACS was positively correlated to age and BMI (all P<0.05)and negatively correlated with eGFR(P<0.05). Conclusions: Measurement of EFV may provide another useful noninvasive indicator of coronary artery calcification in CKD patients.

Machine learning in the prediction of cardiac epicardial and mediastinal fat volumes

We propose a methodology to predict the cardiac epicardial and mediastinal fat volumes in computed tomography images using regression algorithms. The obtained results indicate that it is feasible to predict these fats with a high degree of correlation, thus alleviating the requirement for manual or automatic segmentation of both fat volumes. Instead, segmenting just one of them suffices, while the volume of the other may be predicted fairly precisely. The correlation coefficient obtained by the Rotation Forest algorithm using MLP Regressor for predicting the mediastinal fat based on the epicardial fat was 0.9876, with a relative absolute error of 14.4% and a root relative squared error of 15.7%. The best correlation coefficient obtained in the prediction of the epicardial fat based on the mediastinal was 0.9683 with a relative absolute error of 19.6% and a relative squared error of 24.9%. Moreover, we analysed the feasibility of using linear regressors, which provide an intuitive interpretation of the underlying approximations. In this case, the obtained correlation coefficient was 0.9534 for predicting the mediastinal fat based on the epicardial, with a relative absolute error of 31.6% and a root relative squared error of 30.1%. On the prediction of the epicardial fat based on the mediastinal fat, the correlation coefficient was 0.8531, with a relative absolute error of 50.43% and a root relative squared error of 52.06%. In summary, it is possible to speed up general medical analyses and some segmentation and quantification methods that are currently employed in the state-of-the-art by using this prediction approach, which consequently reduces costs and therefore enables preventive treatments that may lead to a reduction of health problems.

Is epicardial fat depot associated with atrial fibrillation? A systematic review and meta-analysis.

Atrial fibrillation (AF) is the leading rhythm disorder in western countries. A direct relationship between left atrium (LA) enlargement and electromechanical remodelling has been established. A causative link between epicardial fat (EF), visceral adipose tissue deposited around the heart, and AF has been hypothesized. Several reports suggested the association between EF and the presence of AF. The aim of this study was to verify the relationship between AF and EF depot, performing a meta-analysis of observational case series studies. Studies were identified by searching electronic databases by two independent investigators using 'atrial fibrillation' and 'epicardial fat' as keywords. Comparisons between healthy participants and AF cases were performed using a random effect meta-analysis estimating standardized mean difference among comparison groups. Meta regression was used to address the effect given by potential biological and technical confounders. Through a search result of 502 articles, only 7 were selected to conduct the present study. The comparison between all AF with respect to healthy participants resulted in a 32.0 ml of EF difference (95% confidence interval (CI) = 21.5, 42.5) showing that EF volume is higher in AF cases. A statistical significant difference of EF was observed when comparing both persistent and paroxysmal AF subtypes with respect to healthy participants (EF difference 48.0 ml (95% CI = 25.2, 70.8) and 15.7 ml (95% CI = 10.1, 21.4) for persistent and paroxysmal, respectively). A significant EF difference resulted also when comparing persistent to paroxysmal AF subtypes (29.6 ml (95% CI = 12.7, 46.5)). The present work expands the strength of previously reported association between EF amount and atrial arrhythmia.

Prognostic implications of epicardial fat volume quantification in acute pericarditis.

The pathophysiology of acute pericarditis remains largely unknown, and biomarkers are needed to identify patients susceptible to complications. As adipose tissue has a pivotal role in cardiovascular disease pathogenesis, we hypothesized that quantification of epicardial fat volume (EFV) provides prognostic information in patients with acute pericarditis. Fifty (n = 50) patients with first diagnosis of acute pericarditis were enrolled in this study. Patients underwent a cardiac computerized tomography (CT) scan to quantify EFV on a dedicated workstation. Patients were followed up in hospital for atrial fibrillation (AF) development and up to 18 months for the composite clinical endpoint of development of constrictive, recurrent or incessant pericarditis or poor response to nonsteroidal anti-inflammatory drugs. Patients presenting with chest pain had lower EFV vs. patients without chest pain (167·2 ± 21·7 vs. 105·1 ± 11·1 cm3 , respectively, P < 0·01); EFV (but not body mass index) was strongly positively correlated with pericardial effusion size (r = 0·395, P = 0·007) and associated with in-hospital AF. At follow-up, patients that reached the composite clinical endpoint had lower EFV (P < 0·05). After adjustment for age, EFV was associated with lower odds ratio for the composite clinical endpoint point of poor response to NSAIDs or the development of constrictive, recurrent or incessant pericarditis during follow-up (per 20 cm3 increase in EFV: OR = 0·802 [0·656-0·981], P < 0·05). We report for the first time a significant association of EFV with the clinical features and the outcome of patients with acute pericarditis. Measurement of EFV by CT may have important prognostic implications in these patients.

Impact of obesity and epicardial fat on early left atrial dysfunction assessed by cardiac MRI strain analysis.

BackgroundDiastolic dysfunction is a major cause of morbidity in obese individuals. We aimed to assess the ability of magnetic resonance imaging (MRI) derived left atrial (LA) strain to detect early diastolic dysfunction in individuals with obesity and type 2 diabetes, and to explore the association between cardiac adipose tissue and LA function.MethodsTwenty patients with obesity and T2D (55 ± 8 years) and nineteen healthy controls (48 ± 13 years) were imaged using cine steady state free precession and 2-point Dixon cardiovascular magnetic resonance. LA function was quantified using a feature tracking technique with definition of phasic longitudinal strain and strain rates, as well as radial motion fraction and radial velocities.ResultsSystolic left ventricular size and function were similar between the obesity and type 2 diabetes and control groups by MRI. All patients except four had normal diastolic assessment by echocardiography. In contrast, measures of LA function using magnetic resonance feature tracking were uniformly altered in the obesity and type 2 diabetes group only. Although there was no significant difference in intra-myocardial fat fraction, Dixon 3D epicardial fat volume(EFV) was significantly elevated in the obesity and type 2 diabetes versus control group (135 ± 31 vs. 90 ± 30 mL/m2, p < 0.001). There were significant correlations between LA functional indices and both BMI and EFV (p ≤ 0.007).ConclusionsLA MRI-strain may be a sensitive tool for the detection of early diastolic dysfunction in individuals with obesity and type 2 diabetes and correlated with BMI and epicardial fat supporting a possible association between adiposity and LA strain. Trials Registration Australian New Zealand Clinical Trials Registry No. ACTRN12613001069741

Rapid Fire Abstract: Cardiac imaging with computed tomography and radionuclide techniques: usefulness in miscellaneous patient subsets347A novel CT calcium-based approach for predicting mitral stenosis348Value of 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography in the diagnosis of native, prosthetic and device related infective endocarditis349Pulmonary veins anatomy variants assessment using CT in patients with atrial fibrillation350Aortic valve area using cardiac CT to improve the

Rapid Fire Abstract: Cardiac imaging with computed tomography and radionuclide techniques: usefulness in miscellaneous patient subsets347A novel CT calcium-based approach for predicting mitral stenosis348Value of 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography in the diagnosis of native, prosthetic and device related infective endocarditis349Pulmonary veins anatomy variants assessment using CT in patients with atrial fibrillation350Aortic valve area using cardiac CT to improve the

Associations of Epicardial, Abdominal, and Overall Adiposity With Atrial Fibrillation.

Although adiposity is increasingly recognized as a risk factor for atrial fibrillation (AF), the importance of epicardial fat compared with other adipose tissue depots remains uncertain. We sought to characterize and compare the associations of AF with epicardial fat and measures of abdominal and overall adiposity. We conducted a meta-analysis of 63 observational studies including 352 275 individuals, comparing AF risk for 1-SD increases in epicardial fat, waist circumference, waist/hip ratio, and body mass index. A 1-SD higher epicardial fat volume was associated with a 2.6-fold higher odds of AF (odds ratio, 2.61; 95% confidence interval [CI], 1.89-3.60), 2.1-fold higher odds of paroxysmal AF (odds ratio, 2.14; 95% CI, 1.45-3.16) and, 5.4-fold higher odds of persistent AF (odds ratio, 5.43; 95% CI, 3.24-9.12) compared with sinus rhythm. Likewise, a 1-SD higher epicardial fat volume was associated with 2.2-fold higher odds of persistent compared with paroxysmal AF (odds ratio, 2.19; 95% CI, 1.66-2.88). Similar associations existed for postablation, postoperative, and postcardioversion AF. In contrast, associations of abdominal and overall adiposity with AF were less extreme, with relative risks per 1-SD higher values of 1.32 (95% CI, 1.25-1.41) for waist circumference, 1.11 (95% CI, 1.08-1.14) for waist/hip ratio, and 1.22 (95% CI, 1.17-1.27) for body mass index. Strong and graded associations were observed between increasing epicardial fat and AF. Moreover, the strength of associations of AF with epicardial fat is greater than for measures of abdominal or overall adiposity. Further studies are needed to assess the mechanisms and clinical relevance of epicardial fat.

Abstract 13819: Delayed Enhancement Cardiac Magnetic Resonance Imaging Predicts Response to Cardiac Resynchronization Therapy

Introduction: Primary predictors of cardiac resynchronization therapy (CRT) are based on conduction system characteristics, such as QRS duration and morphology. The ability of MRI to predict CRT response is less understood. Methods: We studied 83 patients who received cardiac MRI with gadolinium delayed enhancement (DE) prior to CRT. Patients had preCRT EF ≤ 40%, preCRT QRS ≥ 120ms, and paired ~1 year postCRT echocardiograms. MRIs were read without knowledge of patient characteristics or CRT outcomes and echocardiograms were read in a core-lab blinded to MRI results. Results: Patients were classified as having no DE (n=27), only septal midwall DE (n=20), or scar / DE (transmural, subendocardial, or subepicardial) (n=36). Prior to CRT, those with septal midwall DE (25 ± 7) had lower EFs than those with scar / DE (31 ± 6, p=0&lt;0.01), but not statistically different from those without DE (29 ± 6). Those without DE had better (p&lt;0.001) EF (14.2 ± 10 units) and LVESV improvements (-42 ± 21%) following CRT than those with midwall DE (EF: 2.1 ± 9 units; LVESV: -3 ± 35%) or those with scar / DE (EF: 1.4 ± 8 units; LVESV: -5 ± 25%). There was no difference in CRT response between non-ischemics with septal midwall DE and patients with scar / DE. In univariate regression models LBBB tended (p=0.12) to predict a beneficial EF response to CRT while presence of midwall DE was highly significant (p&lt;0.001) for predicting a lack of response in the 47 patients without scar. In a multivariate model including many baseline characteristics, septal midwall DE provided predictive value (p&lt;0.001) for EF response whereas the common predictors of gender (p=0.693) and LBBB (p=0.913) did not. Conclusions: DE cardiac MRI is a good predictor of response to CRT. The absence of any DE predicts a significant improvement in EF and LV volumes. In the idiopathic non-ischemic population the presence of septal midwall DE was a better negative predictor of response than more traditional characteristics of LBBB and gender. In addition, the presence of transmural, subendocardial, or subepicardial scar also predicted lack of improvement in LV function and volumes with CRT. The information obtained from DE MRI could help determine which patients would be best helped by CRT.