Diagnostic accuracy of coronary artery calcium score for excluding obstructive coronary artery disease

Abstract

Background: Studies in western populations have shown that zero coronary artery calcium score (CACS) is associated with a very low prevalence of obstructive coronary artery disease (CAD), even in patients presenting with chest pain. However, no data are available about the relationship between CACS and coronary artery plaques among Indian subjects. Methods: A total of 380 subjects undergoing comprehensive health check, including computed tomography coronary angiography (CTCA), at a tertiary care center in North India were included. The distribution of CACS was correlated with the coronary plaque burden and with the clinical and laboratory investigation findings. Results: The mean age of the subjects was 52.8 ± 10.0 years, and 71.8% were men. The median CACS value in the study population was 0 (interquartile range 0–4.3). Two-third of all the subjects had zero CACS and 91 (23.9%) had CACS between 1 and 99. Nonobstructive and obstructive (>50% stenosis) plaques were found in 106 (27.9%) and 24 (6.3%) subjects, respectively. Only 5.9% of the subjects with zero CACS had any coronary plaque and only 1.2% had obstructive plaques, yielding zero CACS 98.8% negative predictive value for excluding obstructive disease. Conclusion: This study shows that similar to the western populations, in Indian subjects also, zero CACS is associated with a very low prevalence of obstructive CAD and has excellent negative predictive value for ruling it out. Further large studies in diverse patient subgroups, including those with stable or unstable chest pain, are required to validate these findings.