A growing amount of evidence suggests that regional fat distribution plays an important part in the development of an unfavorable metabolic and cardiovascular risk profile. Epicardial fat is a metabolically active organ that generates various bioactive molecules, which might significantly affect cardiac function. This small, visceral fat depot is now recognized as a rich source of free fatty acids and a number of bioactive molecules, such as adiponectin, resistin and inflammatory cytokines, which could affect the coronary artery response. The observed increases in concentrations of inflammatory factors in patients who have undergone coronary artery bypass grafting remain to be confirmed in healthy individuals. Furthermore, epicardial adipose mass might reflect intra-abdominal visceral fat. Therefore, we propose that echocardiographic assessment of this tissue could serve as a reliable marker of visceral adiposity. Epicardial adipose tissue is also clinically related to left ventricular mass and other features of the metabolic syndrome, such as concentrations of LDL cholesterol, fasting insulin and adiponectin, and arterial blood pressure. Echocardiographic assessment of epicardial fat could be a simple and practical tool for cardiovascular risk stratification in clinical practice and research. In this paper, we briefly review the rapidly emerging evidence pointing to a specific role of epicardial adipose tissue both as a cardiac risk marker and as a potentially active player in the development of cardiac pathology.

Metabolic syndrome is related to multiple cardiovascular risk factors. Visceral adipose tissue (VAT) plays a key role in metabolic syndrome. Easy detection of VAT could be an important tool to increase knowledge of metabolic syndrome. The objective of this study was to study the relationship of echocardiographic epicardial adipose tissue to anthropometric and clinical parameters of metabolic syndrome. We selected 72 consecutive subjects, 46.5 ؎ 17. M ETABOLIC SYNDROME IS related to multiple cardiovascular risk factors (1-3). There are no wellaccepted criteria for the diagnosis of metabolic syndrome. Nevertheless, it is identified by the presence of three or more metabolic alterations, such as abdominal obesity, hypertension, impaired fasting glucose or glucose intolerance, high levels of triglycerides, low levels of high-density lipoprotein cholesterol, and insulin resistance (4). Plasma adiponectin and C-reactive protein (CRP) have also been proposed to be related to central adiposity and cardiovascular risk (5-7).Visceral obesity seems to play a key role in the development of all features of metabolic syndrome (8 -15). Hence, detection of visceral adipose tissue (VAT), the fat deposited around the internal organs, might be important for risk stratification of metabolic syndrome. Nevertheless, it is difficult to obtain an accurate measurement and characterization of VAT. Several methods are applied as surrogates for estimation of VAT. Anthropometric measurements are the most used, but are frequently imprecise. However, waist circumference is widely accepted as a good predictor of intraabdominal fat mass (16, 17). Imaging techniques are certainly more precise and reliable than anthropometric measurements. Magnetic resonance imaging (MRI), the gold standard technique, estimates VAT accurately, but unfortunately it is costly (18). Recently, we have proposed and validated a new method to estimate VAT by echocardiographic epicardial adipose tissue measurement (19). Epicardial adipose tissue is a true visceral fat deposited around the heart with characteristics of a high insulin-resistant tissue. Epicardial adipose tissue measurement could be an important tool to increase knowledge of metabolic syndrome on epidemiological basis.The aim of this work was to study the relationship of echocardiographic epicardial adipose tissue to anthropometric, metabolic, and cardiac parameters of metabolic syndrome. Subjects and Methods SubjectsWe selected 72 consecutive subjects (Caucasian; 36 females and 36 males), 46.5 Ϯ 17.4 yr of age, with a body mass index (BMI) between 22 and 47 kg/m 2 (median, 34). Echocardiographic measurements were performed in all subjects during routine examinations. Metabolic syndrome was identified by the presence of three or more of the following parameters: BMI greater than 30 kg/m 2 , predominant truncal/abdominal fat distribution (value of waist circumference Ͼ88 cm in women and Ͼ102 cm in men), impaired fasting glucose (fasting glucose Ͼ110 mg/ dl), hypertension (systolic arterial blood pressure Ͼ13...

Research Methods and Procedures:We selected 60 healthy subjects (29 women, 31 men, 49.5 Ϯ 16.2 years) with a wide range of body mass indexes. Each subject underwent transthoracic echocardiogram and magnetic resonance imaging (MRI) to measure epicardial fat thickness on the right ventricle. Measurements of epicardial adipose tissue thickness were obtained from the same echocardiographic and MRI views and points. MRI was also used to measure VAT cross-sectional areas at the level of L4 to L5. Anthropometric indexes were also measured. Results: Subjects with predominant visceral fat accumulation showed higher epicardial adipose tissue thickness than subjects with predominant peripheral fat distribution: 9.97 Ϯ 2.88 vs. 4.34 Ϯ 1.98 (p ϭ 0.005) and 7.19 Ϯ 2.74 vs. 3.43 Ϯ 1.64 (p ϭ 0.004) in men and women, respectively. Simple linear regression analysis showed an excellent correlation between epicardial adipose tissue and waist circumference (r ϭ 0.895, p ϭ 0.01) and MRI abdominal VAT (r ϭ 0.864, p ϭ 0.01). Multiple regression analysis showed that epicardial adipose tissue thickness (r 2 ϭ 0.442, p ϭ 0.02) was the strongest independent variable correlated to MRI VAT. Bland test confirmed the good agreement between the two methods. Discussion: Epicardial adipose tissue showed a strong correlation with anthropometric and imaging measurements of VAT. Hence, transthoracic echocardiography could be an easy and reliable imaging method for VAT prediction.

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