Electron-beam computerized tomography correlates with coronary angiogram in chronic kidney disease patients

Abstract

Background/aim: Electron-beam computerized tomography (EBCT) is able to noninvasively quantify coronary artery calcification (CAC). Chronic kidney disease (CKD) patients frequently have CAC, and clinicians are puzzled regarding the clinical significance of this finding and the diagnostic accuracy of coronary EBCT in CKD. The aim of this study was to determine the correlation in CKD patients between CAC measured by EBCT and 50% stenosis determined by coronary angiography (CA), the gold standard to identify atherosclerotic lesions.

Method: We recruited 37 patients with CKD from a single institution and compared their coronary EBCT and CA results using standard statistical analysis.

Results: Patients with at least one vessel with > or = 50% stenosis by CA had higher mean CAC scores [2,407.9 +/- (SD) 3,165.3 vs. 227 +/- 443.4; p < 0.001] and higher median CAC scores (1,052 vs. 25.8; p < 0.001) as compared with those having no stenosis > or = 50%. The sensitivity was 85.7%, and the specificity 82.6% using 50% stenosis as the definition for coronary artery disease and using a CAC score of 400 as a cutoff value for the EBCT results. The area under the receiver operating characteristic curve was 0.84. The diagnostic accuracy (proportion of correct results) was 83.8%. The negative predictive value was 90.5%. The receiver operating characteristic curve suggests that the optimal cutoff value for CAC scores in our cohort is 315.9, increasing the area under the receiver operating characteristic curve to 0.91. The total coronary artery stenosis was significantly associated with the CAC score (p = 0.01).

Conclusions: EBCT has a very good predictive value for obstructive coronary artery disease. EBCT could be used as a screening tool in CKD patients with a low-to-intermediate risk for coronary artery disease.