Prevalence of Occult Coronary Heart Disease in Asymptomatic Subjects as Detected on Coronary Computer Tomography Angiography

Background: Current cardiovascular guidelines do not support routine screening for coronary heart disease (CHD). Despite this however screening programs utilizing coronary computed tomography angiography (CCTA) exist based on the rationale that there is potential for an effective screening program given CHD remains the largest cause of death worldwide. The aim of this study was to estimate the prevalence of occult CHD in asymptomatic subjects as detected by CCTA in a tertiary Australian referral centre. Methods: Retrospective data was collected from all CCTA performed on asymptomatic subjects between January 2011 and June 2015. The outcome of interest was obstructive CHD by CCTA, which was defined by either moderate (50 69% stenosis) and/or severe (≥70% stenosis) in at least one epicardial coronary artery. Results: Four hundred and eleven subjects were included in the study. The mean age was 58 ± 9 years. Two hundred and sixty four asymptomatic subjects (64%) had some degree of CHD detected on CCTA. Obstructive CHD was detected in 75 (18%) subjects. Males were more likely to have obstructive CHD than females (20% versus 12%, p=0.035). Subjects above the age of 55 years were more likely to have obstructive CHD (24% versus 10%, p<0.001). Fourteen (3%) subjects were found to have severe CHD. Conclusions: Approximately one fifth of asymptomatic middle-aged subjects presenting to a tertiary Australian referral centre had obstructive CHD detected on screening CCTA. Males and those over the age of 55 years were more likely to have obstructive CHD. CCTA may be a potential screening tool for detecting occult CHD in an asymptomatic, middle-aged male population but requires further investigation.