We wanted to investigate the effect of sublingual nitroglycerin (NTG) on improving the image quality and diagnostic accuracy of coronary computed tomographic angiography (CTA) for detecting atherosclerosis and significant stenosis.

We retrospectively assessed the data of 81 patients who underwent coronary CTA. Forty three patients underwent coronary CTA without medication (the non-administrated group), while 38 patients were given 0.6 mg NTG sublingually before coronary CTA (the administrated group). Image quality was assessed using a five-point grading scale. We evaluated the diagnostic performance of coronary CTA for assessing atherosclerosis and significant stenosis (> or = 50%) in the 42 patients who underwent invasive coronary angiography.

The mean image-quality grades were 4.09±0.72 and 4.50±0.60 in the non-administrated and administrated groups, respectively (p=0.008). On the per-artery analysis, the accuracy percentages for detecting coronary CTA were 65 and 88% for atherosclerosis and 82 and 80% for significant stenosis in the non-administrated and administrated groups, respectively. On the per-patient analysis, the positive predictive values for coronary CTA were 80% and 100% for atherosclerosis and 77% and 88% for significant stenosis in the non-administrated and administrated groups, respectively.

Coronary CTA with NTG administration improved the image quality. The accuracy of coronary CTA for detecting atherosclerosis was higher in the administrated group than in the non-administrated group.