ABC | Volume 110, Nº5, May 2018

Original Article Gabriel et al Diagnosis of coronary artery disease Arq Bras Cardiol. 2018; 110(5):420-427 Figure 1 – Noncalcified plaque with zero calcium score. Thirty-eight-year old woman; A and B) multiplanar reconstructions showing considerable lumen reduction in anterior descending artery (DA); C) Tridimensional reconstruction showing impairment in DA (yellow arrow). Table 2 – Distribution of clinical characteristics of patients with zero calcium score with and without atherosclerotic plaque in four diagnostic imaging centers in Sao Paulo and Aracaju, Brazil, from 2001 to 2016 Variable n † With plaque n = 34 Without plaque n = 333 p Age* (years) 367 52 ± 10.7 53.9 ± 10.5 0.31 Weight (Kg) 367 71.6 ± 12.9 73.7 ± 15.2 0.42 Body mass index (Kg/m 2 ) 316 25.9 ± 3.3 27.5 ± 4.4 0.046 Female 233/367 18 (52.9) 215 (64.6) 0.180 Smoking 51/366 8 (24.2) 43 (12.9) 0.073 Non-obese 55/316 29 (90.6) 210 (73.9) 0.037 Diabetes mellitus 55/367 6 (17.6) 49 (14.7) 0.648 Dyslipidemia 180/365 16 (47.1) 164 (49.5) 0.782 Systemic arterial hypertension 211/367 20 (58.8) 191 (57.4) 0.712 Alcohol consumption 135/367 19 (55.9) 116 (34.8) 0.015 Family history 187/364 18 (52.9) 169 (51.2) 0.848 ( * ): Values as mean ± standard deviation; other values expressed as simple frequency (%); p-value obtained by the chi-square test for associations; ( † ): “n” different from total population due to missing data in the records. Also, studies involving patients with chest pain in the emergency department have shown frequencies of atherosclerotic plaques with zero CE of up to 39%, 11-13 although this is a different population from those attending outpatient services. It is of note, however, that our sample population was composed of patients referred to CCTA from their assistant physicians. As reported in international studies, we also found that the presence of atherosclerotic plaque cannot be ruled out in patients with zero CS. In our study, only the variables alcohol consumption and absence of obesity were associated with higher risk of atherosclerotic plaque, in contrast to classical risk factors for CAD (diabetes mellitus, systemic arterial hypertension and dyslipidemia). Interestingly, higher BMI was associated with absence of atherosclerotic lesion. Previous studies have suggested obesity as a protective factor for CAD, the so-called obesity paradox. 14 Nevertheless, such paradox is not concerned to abdominal obesity, which has been associated with CAD and considered more pathological than subcutaneous fat accumulation. 14-16 In our study, we did not measure abdominal circumference, which may have influenced the consistency of results. Besides, obese patients included in many studies that indicated obesity as a protective factor were younger, which may be a source of bias. 17 Alcohol consumption has also yielded diverging results. While some studies have indicated alcohol consumption as a risk factor for CAD, others have pointed out its beneficial effects, such as studies performed with wine and its component resveratrol. 18-20 Resveratrol is known for its antioxidant and anti-inflammatory effects, in addition to promote the synthesis of HDL in the liver and inhibit LDL production, thereby preventing LDL oxidation and reducing the risk of cardiovascular diseases. 21 In this regard, further studies that specify the type of beverage consumed and not only whether the subjects consumed or not alcohol are needed. 423