Coronary computed tomography angiography assessment of relationship between right coronary artery-aorta angle and the development of coronary artery disease

Abstract

Whilst a correlation has been established between wide left main coronary artery bifurcation[left anterior descending-left circumflex (LAD-LCx)] angle (>80°) and the development of coronary artery disease (CAD), this retrospective, causal-comparative pilot study aimed to explore whether a relationship exists between right coronary artery (RCA)-aorta angle and CAD. Thirty normal cases were identified via radiology reports and selected as the control group with coronary computed tomography angiography (CCTA) scans performed on a 320-slice computed tomography (CT) scanner. Thirty CAD cases were selected with invasive coronary angiography performed to confirm the degree of stenosis, and CCTA performed on dual source and 320-slice CT scanners. An independent sample t-test was used to compare the differences in coronary angles between the normal and CAD group, and analysis of variance (ANOVA) was used to assess for significant differences between coronary angles in normal and CAD subgroups. Coronary angle measurements were conducted by two independent assessors with high intraclass correlation (r=0.971-0.998, P<0.001). RCA-aorta angle measurements were significantly larger in the normal group [87.47°, 95% confidence interval (CI): 79.31° to 95.78°] compared to the CAD group (76.82°, 95% CI: 67.82° to 85.61°, P=0.05). No significant difference was found between RCA-aorta angle and degree of coronary stenosis (P=0.75). This study suggests a relationship between narrow RCA-aorta angle and CAD.

Investigation of the Relationship between Right Coronary Artery–Aorta Angle and Coronary Artery Disease and Associated Risk Factors

“…The results of this study suggest a relationship between narrow RCA-aorta angles and CAD (Figure 5), supporting the preliminary findings of our recent study [18]. There is currently very little literature available discussing possible relationships between the RCA-aorta angle and CAD.…”

“…If the RCA follows an immediately inferior path, an axial-acquired RCA-aorta measurement will be larger than the true angle size. Consequently, this method generally results in a consistently overestimated RCA-aorta angle (Figure 3), and it was concluded that this angle may be better assessed using MPRs [18]. Hence, the RCA-aorta angle was measured via MPR images in this study, by manipulating obliqued planes to identify and measure the smallest observable RCA-aorta angle.…”

“…Two-dimensional (2D) axial and multiplanar reformation (MPR) images were used to perform LAD-LCx angle measurements, as the accuracy of these methods is comparable to using three-dimensional (3D) views [4]. However, our recent study determined using axials alone to be a reliable, yet highly inaccurate method of measuring the RCA-aorta angle, as the accuracy of this approach is dependent on RCA trajectory [18]. If the RCA follows an immediately inferior path, an axial-acquired RCA-aorta measurement will be larger than the true angle size.…”

“…This motivated us to explore the relationships between the right coronary artery-aorta (RCA-aorta) angle and CAD. The findings of a pilot study by Geerlings-Batt and Sun indicated a possible association between the RCA-aorta angle and CAD [18]. However, their sample was small, consisting of 30 normal and 30 CAD cases, with the authors suggesting their method be replicated as part of a larger study to validate their preliminary findings.…”

“…This motivated us to explore the relationships between the right coronary arteryaorta (RCA-aorta) angle and CAD. The findings of a pilot study by Geerlings-Batt and Sun indicated a possible association between the RCA-aorta angle and CAD [18]. However, their sample was small, consisting of 30 normal and 30 CAD cases, with the authors The LAD-LCx angle has been studied from both causal-comparative and CFD perspectives, with evidence showing the associations between the LAD-LCx angle and CAD [13][14][15][16][17].…”