Prevalence and extent of coronary artery disease among patients with a zero calcium score

Abstract

Background and objective: Coronary artery calcium is a specific indicator of and an independent risk factor for atherosclerosis. However, calcium scoring may miss non calcified plaques, which were indicated to be of clinical importance. This study aimed to identify the presence of non calcified plaques in patients with zero coronary artery calcium score who have been examined with computed tomography coronary angiography and find out any association between the presence of non-calcified plaques and risk factors and presenting symptoms in those patients.Methods: In this retrospective study, we analyzed the computed tomography images of 9826 consecutive patients attending the cardiac center in Erbil, Iraq, between January 2016 and September 2020. Of these patients, we included 2805 patients with a zero coronary artery calcium score in the study. Coronary calcium-scoring scans were followed by computed tomography coronary angiography (256 MSCT Philips ICT). The coronary artery calcium scores were calculated, and the presence of non calcified plaques and significant stenosis (>50% of vessel diameter) were evaluated.Results: Of the 2805 patients with a zero coronary artery calcium score, 896 (31.9%) had atherosclerotic plaques; 143 patients (5.1%) had significant coronary stenosis. Among coronary risk factors, diabetes mellitus (OR = 2.1; 95% CI 1.4-3.3), hypertension (OR = 1.3; 95% CI 1.07-1.58)), male sex (OR = 1.9; 95% CI 1.5-2.3) and old age (OR was 3.2 for the age group 35-44 years reaching 27.7 in the age group ≥ 75 years) were significantly correlated with the presence of atherosclerosis and obstructive coronary artery disease.Conclusion: Although coronary artery calcium scoring is a safe and reliable test to exclude obstructive coronary artery disease, the absence of coronary artery calcium does not absolutely exclude the presence of atherosclerosis. Computed tomography coronary angiography is mandatory for determining the atheroma burden from zero coronary artery calcium score plaques.