Validation of coronary computed tomography angiography scores for non-invasive assessment of atherosclerotic burden through a comparison with multivessel intravascular ultrasound.

Aims: While the atherosclerotic plaque volume can be manually quantified in coronary computed tomography angiography (CTA) it is impractical for clinical routine use. Several anatomical scores have been developed as surrogates for overall atherosclerotic burden in coronary CTA and even proven to be highly predictive for future adverse events. However, they have not been validated against the gold standard for atherosclerotic burden, intra-vascular ultrasound (IVUS). In the present study we have compared several coronary CTA scores with the coronary IVUS.

Methods And Results: A total of 62 patients with diagnosed coronary disease scheduled for percutaneous intervention were prospectively enrolled. For all patients, coronary CTA and multivessel IVUS were obtained. Calcium score and 6 previously reported scores were calculated from coronary CTA imaging and compared to average IVUS-derived percent atheroma volume (PAV). On average, 3.8 ± 0.7 vessels, comprising 123.8 ± 31.3 mm in length, were imaged with IVUS per patient. All but one previously described scoring systems showed a significant association with IVUS-derived PAV. Among them, the SSS score demonstrated the strongest correlation with IVUS-PAV (r = 0.61, p < 0.001) and the greatest area under the ROC curve (C-statistic = 0.87), to predict a high PAV.

Conclusions: Most frequently used coronary CTA scores have a good correlation with global coronary atherosclerotic burden measured by multivessel IVUS derived atheroma volume. Among them, the SSS score shows the best performance being a good non-invasive alternative to IVUS for global coronary atherosclerotic burden assessment.