The Association between Coronary Artery Calcification on MDCT and Angiographic Coronary Artery Stenosis

ABSTRACT

BACKGROUND AND OBJECTIVES: The assessment of CT-derived coronary artery calcification (CAC) has been used as a surrogate measurement for coronary atherosclerosis. However, the blooming artifact caused by CAC on MDCT is the potential limitation when evaluating the coronary artery stenosis. The aim of this study was to classify the morphologic characteristics of CAC on MDCT and to test whether this new classification predicts the stenotic severity on coronary angiography. SUBJECTS AND METHODS: A total of 73 CAC lesions were observed on 64 slice MDCT in the 56 enrolled patients (MF=3323, mean age 66+/-9.3 years) who underwent coronary angiography. The morphologic types of CAC on 64-slice MDCT were classified into four groups [degree of stenosis (S), shape of the calcification (M), length of the calcification (L) and the number of calcified vessels (N)] with using a scoring system, and this morphologic classification was compared with the angiographic severity of coronary stenosis. RESULTS: Diffuse (L3), elongated (M2) and multi-vessel (N2) calcified lesions were significantly associated with angiographic coronary artery stenosis (p=0.03, p=0.019 and p=0.002, respectively) On the multivariate regression analysis, multivessel CAC was the only independent predictor for significant coronary artery stenosis [p=0.019, beta=3.77, CI 1.23-11.5 (95%)]. The type of stenosis (luminal narrowing > or =50%) accompanying CAC on MDCT was not correlated with the angiographically determined stenosis (p=0.13). A total morphologic score less than 4 had a negative predictive value of 78% for predicting significant coronary artery stenosis. CONCLUSION: Our results suggest that the diffuse and multi-vessel CAC on MDCT can predict the coronary artery stenosis; however, the stenosis severity of the lesion accompanying CAC on MDCT might not coincide with the angiographic severity. Therefore, the morphologic classification with this scoring system should be considered for use when evaluating lesion with CAC on MDCT.