ABC | Volume 110, Nº5, May 2018

Original Article Gabriel et al Diagnosis of coronary artery disease Arq Bras Cardiol. 2018; 110(5):420-427 Table 1 – Clinical characteristics of patients with zero calcium score in diagnostic imaging centers in Sao Paulo and Aracaju, Brazil, from 2001 to 2016 Variable n † % Mean age (years) * 367 53.7 ± 10.5 Female sex 233/367 63.5 Systemic arterial hypertension 211/367 57.5 Dyslipidemia 180/367 49.3 Diabetes mellitus 55/367 15.0 Body mass index (kg/m²) 316 27.3 ± 4.4 Obesity 77/316 24.4 Family history of CAD 187/364 51.4 Alcohol consumption 135/367 36.8 Smoking 51/366 13.9 Atypical chest pain † 138/342 40.4 Typical chest pain † 85/341 24.9 CAD: coronary artery disease; ( * ): Values in mean ± standard deviation; other values expressed as simple frequency (%); ( † ): “n” different from total population due to missing data in the records Of 367 patients, 211 (57.7%) patients were hypertensive, 180 (49.3%) dyslipidemic and 55 (15.0%) diabetic. Mean age was 53.7 (±10.5) years and 63.5% were women. Clinical data of patients with zero CS according to the presence or absence of atherosclerotic plaque at CCTA are described in Table 1. Frequency of atherosclerotic plaque in coronary arteries was 9.3% (34/367); 95%CI 6.3 – 12.3. In this group, mean age was 52 ± 10 years and 18 (52.9%) were women (Table 2). A detailed analysis revealed the presence of obstructive lesions (larger than 50% of vessel lumen) in 47% (16/34) of cases, distributed as follows: a) in one segment – 12 patients; b) in two segments – 3 patients; and c) in more than two segments – 1 patient (Figure 1). In the subgroup of patients with nonobstructive lesions (18/34), 15 and 3 patients, respectively, had one and three coronary segments affected (Table 3). The most affected artery was the anterior descending, 16 (35.56%) in its proximal segment, 10 (22.22%) in the middle segment, and 2 (4.44%) in the distal one. It is worth mentioning that analysis of atheroma in the CCTA with contrast phase revealed that 3/34 (8.8%) patients had plaques with some degree of calcification that were not detected by the CS (Figure 2). Clinical features of patients with zero CS, classified by the presence or absence of atherosclerotic plaques in coronary arteries In patients with coronary artery plaque, most patients were obese(90.6% vs .73.9%;BMI:25.9±3.3k/m 2 vs .27.5±4.4k/m 2 ; p = 0.046) and alcohol drinkers (55.9% vs . 34.8%) (Table 2). The other variables were not different between the groups. Non-adjusted odds ratio of the factors associated with the presence of atherosclerotic plaque in patients with zero CS were 2.3 (95%CI = 1.1 – 4.8; p = 0.018) for alcohol consumption and 3.4 (95%CI = 1.0 – 11.5; p = 0.049) for absence of obesity (Table 4). Finally, analysis of contingency table for adjusted odds ratio confirmed higher OR values for alcohol drinkers (OR = 3.4; 95%CI = 1.1 – 5.19; p = 0.018) and non-obese patients (OR = 3.4; 95%CI = 1.0 – 11.7; p = 0.047) (Table 5). Discussion The main finding of the present study was the considerable presence (9.3%) of obstructive (≥50%) coronary atherosclerotic plaques in patients with zero CS. Clinical features found to be associated with the presence of plaques were alcohol consumption and absence of obesity, in contrast to other risk factors usually associated with CAD, such as: diabetes mellitus, systemic arterial hypertension and dyslipidemia. 8 Data on the literature have shown variable prevalence of atherosclerotic plaque in individuals with zero CS. In a study conducted in Isfahan (Iran), 385 patients with zero CS were studied, and 16 of them (4.1%) had atherosclerotic plaque at CCTA. 5 In another study involving symptomatic and asymptomatic patients showed that only symptomatic subjects with zero CS had atherosclerotic plaque (8.4%). 9 According to the CONFIRM study, in patients with zero CS, 13% had nonobstructive atherosclerotic lesions, and 3.5% had obstructive lesion greater than 50%. 4 A multicentric cohort study in which Brazil participates (a CORE64 sub‑study) confirmed that a zero CS does not exclude the need for revascularization. With a sample of 291 patients (72 with zero CS), 19% had stenosis ≥50%, and 13% of them required revascularization. 10 422