Coronary CT Angiography CAD-RADS versus Coronary Artery Calcium Score in Patients with Acute Chest Pain

Background The Coronary Artery Disease Reporting and Data System (CAD-RADS) was established in 2016 to standardize the reporting of coronary artery disease at coronary CT angiography (CCTA). Purpose To assess the prognostic value of CAD-RADS at CCTA for major adverse cardiovascular events (MACEs) in patients presenting to the emergency department with chest pain. Materials and Methods This multicenter retrospective observational cohort study was conducted at four qualifying university teaching hospitals. Patients presenting to the emergency department with acute chest pain underwent CCTA between January 2010 and December 2017. Multivariable Cox regression analysis was used to evaluate risk factors for MACEs, including clinical factors, coronary artery calcium score (CACS), and CAD-RADS categories. The prognostic value compared with clinical risk factors and CACS was also assessed. Results A total of 1492 patients were evaluated (mean age, 58 years ± 14 years [standard deviation]; 759 men). During a median follow-up period of 31.5 months, 103 of the 1492 patients (7%) experienced MACEs. Multivariable Cox regression analysis showed that a moderate to severe CACS was associated with MACEs after adjusting for clinical risk factors (hazard ratio [HR] range, 2.3-4.4; P value range, <.001 to <.01). CAD-RADS categories from 3 to 4 or 5 (HR range, 3.2-8.5; P < .001) and high-risk plaques (HR = 3.6, P < .001) were also associated with MACEs. The C statistics revealed that the CAD-RADS score improved risk stratification more than that using clinical risk factors alone or combined with CACS (C-index, 0.85 vs 0.63 [P < .001] and 0.76 [P < .01], respectively). Conclusion The Coronary Artery Disease Reporting and Data System classification had an incremental prognostic value compared with the coronary artery calcium score in the prediction of major adverse cardiovascular events in patients presenting to the emergency department with acute chest pain. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Vliegenthart in this issue.