Quantitative and Qualitative Coronary Plaque Assessment Using Computed Tomography Coronary Angiography: A Comparison...

To compare computed tomography coronary angiography (CTCA) with intravascular ultrasound (IVUS) in quantitative and qualitative plaque assessment.

Patients who underwent IVUS and CTCA within 3 months for suspected coronary artery disease were retrospectively studied. Plaque volumes on CTCA were quantified manually and with automated-software and were compared to IVUS. High-risk plaque features were compared between CTCA and IVUS.

There were 769 slices in 32 vessels (27 patients). Manual plaque quantification on CTCA was comparable to IVUS per slice (mean difference of 0.06±0.07, p=0.44; Bland-Altman 95% limits of agreement -2.19-2.08 mm³, bias of -0.06mm³) and per vessel (3.1mm³ ± -2.85mm³, p=0.92). In contrast, there was significant difference between automated-software and IVUS per slice (2.3±0.09mm³, p<0.001; 95% LoA -6.78 to 2.25mm^3, bias of -2.2mm³) and per vessel (33.04±10.3 mm³, p<0.01). The sensitivity, specificity, positive and negative predictive value of CTCA to detect plaques that had features of echo-attenuation on IVUS was 93.3%, 99.6%, 93.3% and 99.6% respectively. The association of ≥2 high-risk plaque features on CTCA with echo attenuation (EA) plaque features on IVUS was excellent (86.7%, 99.6%, 92.9% and 99.2%). In comparison, the association of high-risk plaque features on CTCA and plaques with echo-lucency on IVUS was only modest.

Plaque volume quantification by manual CTCA method is accurate when compared to IVUS. The presence of at least two high-risk plaque features on CTCA is associated with plaque features of echo attenuation on IVUS.