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 2 – Presence of calcification in zero calcium score. Female patient, 67 years old; Black arrow - Partially calcified plate in anterior descending ostium (AD), not detected by calcium score, followed by noncalcified plaques in proximal and middle thirds (white arrows) Table 3 – Distribution of atherosclerotic lesions at coronary computed tomography angiography in patients with zero calcium score Variable One vessel affected Two vessels affected Two or more vessels affected Total n = 34 Obstructive lesion > 50% 12 (75%) 3 (18.7%) 1 (6.3%) 16 (47.0%) Nonobstructive lesion 15 (83.3%) 3 (16.6%) 0 18 (53%) Limitations Some inherent limitations deserve to be mentioned – first, as previously described, patients were referred to CCTA with CS from their assistant physicians, and the possibility of a selection bias cannot be excluded; second, coronary risk stratification of patients was not performed before their inclusion and data on risk factors were obtained by questionnaires; third, sample was collected in four different centers and, although the tests were performed following similar protocols, some characteristics are particular of each service which may have cause a bias in the analysis; fourth, since we studied patients with clinical indication for CCTA, our sample differed fromasymptomatic patientswithout positive ischemic test, who would be referred to CS alone, and in whomcoronary calcificationwould predict cardiovascular events. Conclusions The frequency of atherosclerotic plaque in patients with zero CS was relatively high, indicating that in patients with clinical indication for CCTA, the absence of coronary calcification does not exclude atherosclerotic plaque or obstructive lesion, especially in obese and alcohol drinkers. Author contributions Conception and design of the research: Gabriel FS, Gonçalves LFG, Pinto IMF, Oliveira JLM; Acquisition of data: Gabriel FS, Gonçalves LFG, Santana SMM, Matos CJO, Conceição FMS, Souto MJS; Analysis and interpretation of the data: Gabriel FS, Gonçalves LFG, Melo EV, Sousa ACS, Oliveira JLM; Statistical analysis: Gabriel FS, Melo EV; Writing of the manuscript: Gabriel FS, Gonçalves LFG, Sousa ACS, Pinto IMF, Oliveira JLM; Critical revision of the manuscript for intellectual content: Gabriel FS, Gonçalves LFG, Melo EV, Sousa ACS, Pinto IMF, Santana SMM, Matos CJO, Conceição FMS, Oliveira JLM, Souto MJS. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. 424