Coronary artery calcium assessment on routine non-gated chest CT as a gatekeeper for additional imaging in patients with stable chest pain

Abstract

Abstract Aims In Coronary Artery Disease (CAD), currently applied risk assessment methods often overestimate patients’ risk of obstructive CAD. To enhance and patient-tailor risk estimation, assessment of Coronary Artery Calcium (CAC) can be applied. In ∼10% of patients presenting with stable chest pain a non-gated chest computed tomography (CT) has been previously performed, suitable for CAC assessment. This study is the first to investigate the clinical value of CAC assessment on non-gated chest CT for risk assessment of obstructive CAD. Purpose This study aims to point out the clinical utility of visual CAC assessment for enhancing risk assessment and avoid unnecessary additional imaging in patients presenting with stable chest pain. Methods For this study, all patients referred for coronary CT angiography (CCTA), in whom a prior non-gated chest CT was performed, were included. To assess the extent of patients’ CAC, an ordinal score was applied. CAD was assessed on CCTA and obstructive CAD was defined as stenosis of ≥70%. Patients were stratified in to groups according to CAC severity, pre-test probability and number of risk factors. Percentages of patients with obstructive CAD were compared between the groups. Results A total of 181 patients of 30-88 years old were included. The percentage of obstructive CAD was significantly different between de CAC groups (p<0.01). The absence of CAC ruled out obstructive CAD with 100% certainty, irrespective of sex, pre-test probability, type of complaint and number of risk factors. Additionally, a mild CAC score ruled out obstructive CAD in patients with low – intermediate PTP or non-anginal complaints, with 100% certainty. Conclusion CAC assessment on non-gated chest CT can safely rule out obstructive CAD in patients presenting with stable chest pain and can therefore function as a radiation-free and cost-free gatekeeper for additional imaging.CCTA results for CAC severityDecisiontree patients with chest pain