Feasibility of an Automated Quantitative Computed Tomography Angiography–Derived Risk Score for Risk Stratification of Patients With Suspected Coronary Artery Disease

Abstract

Coronary computed tomography angiography (CTA) has important prognostic value. Additionally, quantitative CTA (QCT) provides a more detailed accurate assessment of coronary artery disease (CAD) on CTA. Potentially, a risk score incorporating all quantitative stenosis parameters allows accurate risk stratification. Therefore, the purpose of this study was to determine if an automatic quantitative assessment of CAD using QCT combined into a CTA risk score allows risk stratification of patients. In 300 patients, QCT was performed to automatically detect and quantify all lesions in the coronary tree. Using QCT, a novel CTA risk score was calculated based on plaque extent, severity, composition, and location on a segment basis. During follow-up, the composite end point of all-cause mortality, revascularization, and nonfatal infarction was recorded. In total, 10% of patients experienced an event during a median follow-up of 2.14 years. The CTA risk score was significantly higher in patients with an event (12.5 [interquartile range 8.6 to 16.4] vs 1.7 [interquartile range 0 to 8.4], p <0.001). In 127 patients with obstructive CAD (≥50% stenosis), 27 events were recorded, all in patients with a high CTA risk score. In conclusion, the present study demonstrated that a fully automatic QCT analysis of CAD is feasible and can be applied for risk stratification of patients with suspected CAD. Furthermore, a novel CTA risk score incorporating location, severity, and composition of coronary lesion was developed. This score may improve risk stratification but needs to be confirmed in larger studies.