Aim: To find out the severity of coronary plaques on computed tomography coronary angiography (CTCA) in patients with zero calcium score.

Methodology: Prospective descriptive study of 245 selected patients, who had a zero coronary calcium score and underwent CT coronary angiography on 128 slice Toshiba’s Multidetector CT scanner (MDCT), from Dec 2012 to January 2018 at a hospital in Peshawar. Images were assessed on Vitrea workstation for calculation of plaque burden and vessel analysis was done using automated and manual select vessel option. The presence of plaques and extent of stenosis were evaluated. Retrospective interpretation of prospectively acquired data was done using and SPSS.

Results: 130 patients (53%) had atherosclerotic disease; 23 (9.3% of total patients) had significant (>50%) coronary stenosis, out of which 10 patients had >70% stenosis. 107 (43.6% of total patients) had non-significant (<50%) coronary stenosis. 115 (46.9%) patients had normal coronary arteries.

Conclusion: In patients with zero calcium score, atherosclerosis was seen in 53% patients and 9.3% had significant coronary artery disease. Hence, zero calcium score does not absolutely exclude the coronary artery disease.

Keywords: Calcium score, coronary computed tomography angiography, non-calcified plaque