Calcification remodeling index assessed by cardiac CT predicts severe coronary stenosis in lesions with moderate to severe calcification

Objectives: To assess the diagnostic performance of the calcification remodeling index (RI) as assessed by coronary computed tomography angiography (coronary CTA) to predict the presence of severe coronary stenosis in atherosclerotic coronary lesions with moderate to severe calcification. Methods: Patients who underwent coronary CTA and invasive coronary angiography (ICA) within one month and had moderately to severely calcified lesions as revealed by coronary CTA, were retrospectively included. The calcification RI was calculated as the ratio of the cross-sectional lumen area (with inclusion of calcium area) of the most severely calcified site to the proximal reference lumen area. Other parameters, such as the calcium volume, regional Agatston score, calcification length, involved calcium arc quadrants and CTA-assessed diameter stenosis, were also recorded. A multivariate model was used to identify the variables that predict the presence of severe coronary stenosis (diameter stenosis >= 70%) as determined by ICA. Results: 422 patients with 629 lesions were finally included in the study. Lesions with severe stenoses as determined by ICA tended to have larger calcium volumes, regional Agatston scores, CTA-assessed diameter stenoses, longer calcium length, more involved calcium arc quadrants and a significantly smaller calcification remodeling index. ROC curve analysis determined the best cutoff value of the calcification RI as 0.94 (AUC = 0.816, p < 0.001), which yielded highest diagnostic accuracy (83.3%, 524/629) to identify severe coronary stenosis. Among all parameters, calcification RI <= 0.94 is the strongest independent predictor (odds ratio: 17.5, p < 0.001) of severe coronary stenosis. Conclusions: With an optimalcut-off value of 0.94, calcification RI is the strongest independent predictor of severe coronary stenosis in calcified coronary atherosclerotic lesions. (C) 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.