CAD-RADS may underestimate coronary plaque progression as detected by serial CT angiography

Figures

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  Figure 1. Flow chart of the study. CT, computed tomography; CTA, computed tomography angiography.

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  Figure 2. Representative case of plaque progression. A 51-year-old male patient underwent serial CTA scanning due to stable chest pain. In 2013, the patient had one affected coronary segment (mid-LAD) with plaque. The figure shows the LAD with a non-calcified plaque leading to mild stenosis (CAD-RADS 2, SSS 2, SIS 1). We detected coronary plaque progression on the proximal and distal LAD segment of LAD 6 years later, including de novo calcified plaque development. The total segment involvement and segment stenosis scores were both higher on follow-up (SSS 4 and SIS 3), however, based on the worst stenosis CAD-RADS score of 2 was assigned. CAD-RADS, Coronary Artery Disease—Reporting and Data System; LAD, left anterior descending artery; LCX, Left circumflex artery; SIS, segment involvement score; SSS, segment stenosis score.

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  Figure 3. Sankey diagram depicting coronary plaque progression based on SSS and CAD-RADS. Patient-based progression of coronary atherosclerosis using SSS and CAD-RADS severity is depicted on the Sankey diagram. This type of flow diagram depicts the number of patients with progression during follow-up, where the width of the arrow is proportional to the flow rate (number of patients). No progression was found in 54 patients’ SSS and in 82 patients’ CAD-RADS during the follow-up period (marked with light blue). The number of patients with increase in SSS and CAD-RADS are depicted at 1, 2, and ≥3 years based on serial CTA imaging (orange). CAD-RADS substantially underestimates changes in disease severity and extent of CAD. During the follow-up period we could identify three patients with SSS increase at 1 year (rapid progression of CAD), whereas most patients progressed later at 3 or more years. CAD-RADS, Coronary Artery Disease—Reporting and Data System; SSS, segment stenosis score.

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  Figure 4. Sankey diagram depicting coronary plaque progression based on SSS among those with no progression in CAD-RADS classification for lesion severity. A total of 82 patients in our study did not progress based on CAD-RADS severity, although a large proportion of patients demonstrated coronary plaque progression based on SSS. Increasing number of patients developed higher stenosis scores during follow-up period: 2 patients had higher SSS at 1 year, 9 patients had higher SSS at 2 years, and 17 patients had higher SSS at 3 years or more. Four patients had substantial increase in SSS (three or more) despite no changes in CAD-RADS classification. SSS, segment stenosis score.