Inter-observer agreement of the Coronary Artery Disease Reporting and Data System (CAD-RADS TM ) in patients with stable chest pain.

Purpose: To assess inter-observer variability of the Coronary Artery Disease - Reporting and Data System (CAD-RADS) for classifying the degree of coronary artery stenosis in patients with stable chest pain.

Material and methods: A prospective study was conducted upon 96 patients with coronary artery disease, who underwent coronary computed tomography angiography (CTA). The images were classified using the CAD-RAD system according to the degree of stenosis, the presence of a modifier: graft (G), stent (S), vulnerable plaque (V), or non-diagnostic (n) and the associated coronary anomalies, and non-coronary cardiac and extra-cardiac findings. Image analysis was performed by two reviewers. Inter-observer agreement was assessed.

Results: There was excellent inter-observer agreement for CAD-RADS ( k = 0.862), at 88.5%. There was excellent agreement for CAD-RADS 0 ( k = 1.0), CAD-RADS 1 ( k = 0.92), CAD-RADS 3 ( k = 0.808), CAD-RADS 4 ( k = 0.826), and CAD-RADS 5 ( k = 0.833) and good agreement for CAD-RADS 2 ( k = 0.76). There was excellent agreement for modifier G ( k = 1.0) and modifier S ( k = 1.0), good agreement for modifier N ( k = 0.79), and moderate agreement for modifier V ( k = 0.59). There was excellent agreement for associated coronary artery anomalies ( k = 0.845), non-coronary cardiac findings ( k = 0.857), and extra-cardiac findings ( k = 0.81).

Conclusions: There is inter-observer agreement of CAD-RADS in categorising the degree of coronary arteries stenosis, and the modifier of the system and associated cardiac and extra-cardiac findings.