Comparison of the Left Main Coronary Bifurcating Angle among Patients with Normal, Non-significantly and Significantly Stenosed Left Coronary Arteries

Abstract

We evaluated the correlation of the left main coronary bifurcating angle (LCBA) with the severity of coronary atherosclerosis, risk factors of coronary artery disease (CAD) and the feasibility of measuring the LBCA using the axial plane. Coronary Computed tomography angiographies (CTAs) of 313 patients between Nov. 2006 and Oct. 2013 were reviewed and separated into three groups. Group I (211 patients) had significant stenosis (≥50%) of the left anterior descending coronary artery (LAD) and/or left circumflex coronary artery (LCX). Group II (62 subjects) had atherosclerosis without significant stenosis. Group III (40 subjects) had unremarkable coronary CTAs. Both Group I and II patients received conventional catheter angiography to confirm the severities of coronary stenoses. Significant differences were found among the groups with respect to risk factors, such as male gender, hypertension and body mass index. Axial plane measurement was feasible in most patients (82.1%), without significant differences among the groups. The mean LCBA was 84.7° among all patients, and significantly differed among groups I, II and III (87.34°, 81.16° and 75.53°, P < 0.001). The LCBA of group I was significantly higher than group III (P < 0.001) in univariate analysis, but insignificant in multivariate analysis (P = 0.064).During the past decade, coronary computed tomography angiography (coronary CTA) has been accepted as a highly reliable and less invasive modality for CAD diagnosis owing to its high spatial and temporal resolution and excellent diagnostic accuracy [1][2][3][4][5] . Coronary CTA allows the visualization of coronary artery anatomy and the associated atherosclerotic plaques 6-8 . This is represented in the ability of coronary CTA to identify the coronary anatomy as well as the location, distribution, characteristics and composition of plaques in the coronary arteries 6,7,9 .The evaluation of the left main coronary bifurcation angle (LCBA) has gained increasing clinical concern and research interest because the angulation of the LCBA has been shown to have a hemodynamic effect on shear stress, flow turbulence formation and the consequent development of plaques at the bifurcating regions; thus, measurements of the bifurcation angles will provide an insight into demonstrating the relationship among the plaques, CAD and coronary angles 4-6, 8, 10-17 . In previous studies, a wider bifurcation angle has been hypothesized as related to higher turbulence and low shear stress, which might induce plaque proliferation at the bifurcated regions, whereas a narrow angle might be more prone to present laminar flow and less likely to induce plaque formation 4-6, 8, 10-18 . Despite the evidence of a direct correlation between the LCBA and the formation of plaques 4 , to the best of the authors' knowledge, this is the first study to investigate the correlation between the LCBA

Measurement of coronary bifurcation angle with coronary CT angiography: A phantom study

“…The MPR view contains three perpendicular planes and corresponding 3D oblique plane that allows a radiologist to move in a precise manner and find the exact location of the bifurcation; while the manual rotation in VRT to find the best orthogonal view of the bifurcation angle via 'eye-balling' is a subjective decision by the radiologist. Further, Juan et al reported that 2D axial images are also reliable in measuring the left bifurcation angle when compared to invasive coronary angiography [24]. Their results support our findings of using 2D reconstructions for clinical measurements of bifurcation angles.…”

“…Cui et al further confirmed the clinical value of using bifurcation angle for prediction of significant coronary stenosis [23]. Juan et al in their recent study reported the feasibility of using 2D axial images for measurement of left bifurcation angle [24]. However, accuracy of these measurement methods has not been fully determined.…”

An investigation of correlation between left coronary bifurcation angle and hemodynamic changes in coronary stenosis by coronary computed tomography angiography-derived computational fluid dynamics

“…Use of left coronary bifurcation angle as another criterion in diagnosing CAD has been increasingly reported in the literature with improved diagnostic accuracy when compared to conventional CCTA (16)(17)(18)(19)(20)(21). A cut-off value of 80° is recommended by these studies to decide the significance of coronary stenosis.…”

“…Another approach to overcome this limitation is to measure the left coronary bifurcation angle and determine the significance of CAD. Diagnostic value of CCTA with use of left bifurcation angle has been shown in a number of studies with improved diagnostic performance reported when compared to the coronary lumen assessment (16)(17)(18)(19)(20)(21).…”

Analysis of the total lumen of circumflex branch of l eft coronary artery in norm and in myocardial infarction

“…Дана характеристика особенностям взаимоотношений артериального и венозного русел сердца [2,3]. однако работы, в которых представлены результаты сравнительного анализа ангиоархитектоники сердца в норме и при патологии, единичны [4,5].…”