Research Article: Quantification of left coronary bifurcation angles and plaques by coronary computed tomography angiography for prediction of significant coronary stenosis: A preliminary study with dual-source CT

Date Published: March 27, 2017

Publisher: Public Library of Science

Author(s): Yue Cui, Wenjuan Zeng, Jie Yu, Jing Lu, Yuannan Hu, Nan Diao, Bo Liang, Ping Han, Heshui Shi, Salvatore De Rosa.

http://doi.org/10.1371/journal.pone.0174352

Abstract

To evaluate the diagnostic performance of left coronary bifurcation angles and plaque characteristics for prediction of coronary stenosis by dual-source CT.

106 patients suspected of coronary artery disease undergoing both coronary computed tomography angiography (CCTA) and invasive coronary angiography (CAG) within three months were included. Left coronary bifurcation angles including the angles between the left anterior descending artery and left circumflex artery (LAD-LCx), left main coronary artery and left anterior descending artery (LM-LAD), left main coronary artery and left circumflex artery (LM-LCx) were measured on CT images. CCTA plaque parameters were calculated by plaque analysis software. Coronary stenosis ≥ 50% by CAG was defined as significant.

106 patients with 318 left coronary bifurcation angles and 126 vessels were analyzed. The bifurcation angle of LAD-LCx was significantly larger in left coronary stenosis ≥ 50% than stenosis < 50%, and significantly wider in the non-calcified plaque group than calcified. Multivariable analyses showed the bifurcation angle of LAD-LCx was an independent predictor for significant left coronary stenosis (OR = 1.423, P = 0.002). In ROC curve analysis, LAD-LCx predicted significant left coronary stenosis with a sensitivity of 66.7%, specificity of 78.4%, positive predictive value of 85.2% and negative predictive value of 55.8%. The lipid plaque volume improved the diagnostic performance of CCTA diameter stenosis (AUC: 0.854 vs. 0.900, P = 0.045) in significant coronary stenosis. The bifurcation angle of LAD-LCx could predict significant left coronary stenosis. Wider LAD-LCx is related to non-calcified lesions. Lipid plaque volume could improve the diagnostic performance of CCTA for coronary stenosis prediction.

Partial Text

Coronary artery disease (CAD) is the leading cause for death in developed and developing countries [1]. The most common reason of CAD is atherosclerosis. The intravascular ultrasound (IVUS) is recommended as the reference standard to quantify atherosclerosis plaques [2]. However, IVUS is an invasive examination with expensive costs and high risks for the routinely clinical application. Coronary computed tomography angiography (CCTA) is a reliable non-invasive imaging modality that is widely used for the diagnosis of coronary stenosis with high sensitivity and negative predictive value [3, 4]. Additionally, CCTA can measure coronary bifurcation angles with high accuracy [5]. The three-dimensional (3D) geometry construction of coronary artery bifurcations could have an effect on the hemodynamic flow patterns and play an important role in the plaque formation, distribution and composition [6, 7]. By analyzing the hemodynamic of various left coronary bifurcation angle in simulated and realistic models, Chaichana et al. found that wider bifurcation angles might induce low wall shear stress, which may lead to the development and progression of CAD [6–8]. In addition, CCTA allows visualization and quantification of plaque characteristics [9, 10]. Coronary high-risk plaque features, including low attenuation non-calcified plaque, positive remodeling, napkin-ring sign and spotty calcium, may be associated with acute coronary syndrome (ACS), adverse cardiovascular events and ischemia [11, 12]. CCTA has the capability to evaluate and quantify the potentially high-risk plaques without extra imaging, which could improve image-guided prevention, interventions and therapy [11, 12]. However, the diagnostic performance of quantification of left coronary bifurcation angles and plaque characteristics by CCTA for prediction of significant coronary stenosis has been less extensively studied. The aim of this study was to evaluate the diagnostic performance of left coronary bifurcation angles and the CCTA plaque parameters for the prediction of significant coronary stenosis using invasive coronary angiography (CAG) as the reference standard and explore the potential risk factors for development of atherosclerosis. We hypothesized that the left coronary bifurcation angle of LAD-LCx and quantitative plaque analysis represent a more accurate method for diagnosis of significant coronary stenosis.

In the present study, we demonstrated a direct relationship between left coronary bifurcation angles and left coronary stenosis severity. The results showed that wider bifurcation angle of LAD-LCx was associated with significant left coronary stenosis, greater plaque burden, and non-calcified plaques. It also confirmed that the bifurcation angle of LAD-LCx and lipid plaque volume were independent predictors for significant coronary stenosis and lipid plaque volume could improve the diagnostic performance of CCTA diameter stenosis for the prediction of obstructive CAD.

This study evaluated the diagnostic performance of left coronary bifurcation angles and plaque characteristics for prediction of coronary stenosis. Results showed that the bifurcation angle of LAD-LCx may predict significant left coronary stenosis. Wider bifurcation angle of LAD-LCx was related to larger plaque burden and non-calcified lesions. The addition of lipid plaque volume to diameter stenosis on CCTA increased the diagnostic performance for the determination of obstructive CAD.

 

Source:

http://doi.org/10.1371/journal.pone.0174352

 

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