Relation of aortic calcification, wall thickness, and distensibility with severity of coronary artery disease: evaluation with coronary CT angiography

Background: Three known risk factors for aortic atherosclerosis predict the severity of coronary artery disease (CAD): aortic calcification (AC), aortic wall thickness (AWT), and aortic distensibility (AD). Purpose: To determine the relationship of AC, AWT, and AD with the severity of CAD. Material and Methods: A total of 104 patients who underwent both coronary CT angiography (CCTA) and invasive coronary angiography were enrolled. The severity of CAD was assessed by three methods: the segment involvement score (SIS), the segment stenosis score (SSS), and the modified Gensini score (mG). We quantified AC using the Agatston method on low-dose ungated chest CT (LDCT). We measured AWT at the thickest portion of the descending thoracic aorta on CCTA. AD was calculated as the difference between the maximum and minimum areas of the ascending aorta and the pulse pressure. The relationships between the severity of CAD and the three aortic factors were assessed. Results: The AC and AWT of the thoracic aorta were significantly higher in the occlusive CAD (OCAD) group (1984.21 +/- 2986.10 vs. 733.00 +/- 1648.71, P = 0.01; 4.13 +/- 1.48 vs. 3.40 +/- 1.01, P = 0.22). Patients with OCAD had more than one epicardial coronary artery with >50% luminal stenosis. The AC (r = 0.453 with SIS; r = 0.454 with SSS; r = 0.427 with mG) and the AWT (r = 0.279 with SIS; r = 0.324 with SSS; r = 0.304 with mG) were significantly correlated with all three methods, and the AD was negatively correlated with the SIS (r = - 0.221, P < 0.05, respectively) in the unadjusted model. After adjustment for cardiovascular risk factors, only the correlations between AC and all three methods assessing CAD remained significant. Conclusion: There are significant relationships between AC, AWT and AD and severity of CAD. In particular, AC measured on LDCT is the most consistent predictor of severity of CAD.