IJCS | Volume 33, Nº1, January / February 2019

58 of metabolically healthy but obese (MHO) individuals, with hormonal and insulin resistance profile not compatible with increased adiposity has become a matter of discussion. 7,8 Previous studies have investigated the incidence of cardiovascular disease in MHO, with controversial results. 9,10 Also, although data derived from intermediate markers of disease (e.g. the carotid intima media thickness) can evaluate the association of these parameters with the presence of CAD inMHO individuals, there are few data available about the association between body mass index (BMI) and coronary artery calcium score as determinant of subclinical atherosclerosis. Coronary artery calcium score was shown to be superior than other methods for the evaluation of subclinical atherosclerosis in cardiovascular event prediction. 11 Therefore, the aimof the present studywas to evaluate whether obesity alone is correlated with the presence of CAD, evaluated by coronary computed tomography angiography (CCTA). Methods Patients and study design We reviewed the database and patients medical records in a tertiary hospital in Sao Paulo (Brazil). The sample was composed of 1,814 patients consecutively referred for cardiac/coronary computed tomography angiography between August 2010 and July 2012. The study was approved by the ethics committee of the Pontifical Catholic University of Paraná (approval number 1524216) andwas in accordancewith theHelsinki Declaration. The studywas registered in Plataforma Brasil (registration number 55363016.6.0000.0020) and informed consent to participate in this study was waived. All data were collected and registered in specific spreadsheets by trained investigators, and then manually transferred to a database of the CCTA division. Epidemiological and clinical data Data contained in the patient admission questionnaire were collected by direct interview and/or from medical records. Variables included demographic and anthropometric data, indication for CCTA, risk factors for CAD – hypertension, diabetes, dyslipidemia, smoking, family history of CAD – parameters of CCTA acquisition and results of the test. Computed tomography angiography, a contrast computed tomography, is clinically used for evaluation of coronary stenosis/obstruction. The test allows the calculation of the coronary artery calcium, which consists in a non-invasive imaging method to identify atherosclerosis in asymptomatic individuals. Definitions of obese and metabolically healthy but obese patients Patients with a BMI greater than 30 kg/m 2 were considered obese, and MHO patients were identified based on the absence of the following criteria – 1) hypertriglyceridemia (triglycerides > 150 mg/dL) or pharmacological treatment for this condition; 2) low HDL-cholesterol (HDL < 40 mg/dL) or pharmacological treatment for this condition; 3) hypertension, defined as blood pressure ≥ 130/85 mmHg or pharmacological treatment for this condition; 4) altered fasting glucose (glucose ≥ 100 mg/dL) or diagnosis of diabetes, or pharmacological treatment for this condition. Coronary computed tomography angiography 1. Acquisition parameters and protocol Two computed tomography scanners were used for the tests - Siemens Somatom Sensation 64 and Siemens Somaton Definition Flash (Siemens Healthcare, Forchheim, Germany), following respective protocols. Patients with blood pressure higher than 100 mmHg received5mgsublingual nitratesprior to the test,whereasa beta-blocker (metoprolol 150mg in patients with BMI ≥ 30 kg/m 2 , and 75mg in thosewith BMI ≤ 30 kg/m 2 ) was orally administered to patients with a heart rate higher than 80 bpm on the test day. In addition, if necessary, intravenous metoprolol (maximum 20 mg) was used during CCTA to achieve target heart rate (≤ 65 bpm). Patients with no history of angioplasty or surgical revascularization underwent computed tomography scanning synchronized with electrocardiography before contrast injection for quantification of coronary artery calcium (Agatston units). Subsequently, contrast was injected at high flow rates (maximum of 6 mL/s - Henetix 350 mg/mL, Guerbet, Rio de Janeiro, Brazil), with concomitant acquisition of CCTA. The following parameters were obtained for analysis: 1) tube voltage of 100-140 kV; 2) adjusted tube current (estimated by the tomography device according to chest attenuation of each patient); 3) collimation 2 x 128 x 0.6 mm or 64 x 0.6 mm, according to the scanner specifications. The tests on both Pereira et al. Obesity and coronary artery disease Int J Cardiovasc Sci. 2020;33(1):57-64 Original Article