In vivo assessment of bifurcation optimal viewing angles and bifurcation angles by three-dimensional (3D) quantitative coronary angiography

Abstract

Evaluation and stenting of coronary bifurcation lesions may benefit from optimal angiographic views. The anatomy-defined bifurcation optimal viewing angle (ABOVA) is characterized by having an orthogonal view of the bifurcation, such that overlap and foreshortening at the ostium are minimized. However, due to the mechanical constraints of the X-ray systems, certain deep angles cannot be reached by the C-arm. Therefore, second best or, so-called obtainable bifurcation optimal viewing angle (OBOVA) has to be used as an alternative. This study assessed the distributions of ABOVA and OBOVA using 3D quantitative coronary angiography in a typical patient population. In addition, the bifurcation angles in four main coronary bifurcations were assessed and compared. Patients with obstructive coronary bifurcation disease were included in this multicenter registry. A novel and validated 3D QCA software package was applied to reconstruct the bifurcations and to calculate the bifurcation angles in 3D. A list of optimal viewing angle candidates including ABOVA was also automatically proposed by the software. In a next step, the operator selected the best viewing angle as OBOVA, while applying a novel overlap prediction approach to assure no overlap between the target bifurcation and other major coronary arteries. A total of 194 bifurcations from 181 patients were assessed. The ABOVA could not be reached in 56.7% of the cases; being 40 (81.6%), 40 (78.4%), 9 (17.6%), and 21 (48.8%) cases for LM/LAD/LCx, LAD/Diagonal, LCx/OM, and PDA/PLA, respectively. Both ABOVA and OBOVA distributed sparsely with large ranges of variance: LM/LAD/LCx, 5 ± 33 RAO, 47 ± 35 Caudal versus 4 ± 39 LAO, 35 ± 16 Caudal; LAD/Diagonal, 4 ± 38 RAO, 50 ± 14 Cranial versus 14 ± 28 LAO, 33 ± 5 Cranial; LCx/OM, 21 ± 32 LAO, 27 ± 17 Caudal versus 18 ± 31 LAO, 25 ± 13 Caudal; PDA/PLA, 34 ± 21 LAO, 36 ± 21 Cranial versus 28 ± 25 LAO, 29 ± 15 Cranial. LM/LAD/LCx had the smallest proximal bifurcation angle (128° ± 24°) and the largest distal bifurcation angle (80° ± 21°), as compared with LAD/Diagonal (151° ± 13º and 48° ± 16º), LCx/OM (146° ± 18º and 57° ± 16°), and PDA/PLA (145° ± 19° and 59° ± 17°). In conclusion, large variabilities in optimal viewing angles existed for all main coronary bifurcations. The anatomy-defined bifurcation optimal viewing angle could not be reached in vivo in roughly half of the cases due to the mechanical constraints of the current X-ray systems. Obtainable bifurcation optimal viewing angle should be provided as an alternative or second best. The bifurcation angles in the left main bifurcation demonstrated the largest variabilities.

Visual estimation versus different quantitative coronary angiography methods to assess lesion severity in bifurcation lesions

“…However, a head‐to‐head study comparing 2D with 3D bifurcation software in this phantom model is lacking. The potential benefits of 3D over 2D bifurcation software is difficult to demonstrate in this model for the following reasons: (1) in the phantom model, stenoses are shaped concentric, while advantage of 3D are expected to be more pronounced when stenoses are elliptically shaped; (2) the phantom model is constructed in a horizontal plane, while in‐vivo the coronary arteries are curved around the heart, which would result in an expected benefit of 3D QCA over 2D QCA in terms of less foreshortening of the curved arteries; (3) in the bifurcation model the most optimal view, perpendicular to the bifurcation, is easily to obtain, while it has been shown in‐vivo that the optimal viewing angle for bifurcation lesions cannot be obtained in almost half of the cases, hampering accurate 2D bifurcation QCA assessment while this optimal view can be reconstructed with 3D bifurcation QCA software .…”

Advances in three-dimensional coronary imaging and computational fluid dynamics

“…Their findings were again confirmed by Bourantas et al [19], who showed stronger correlation between 3D-QCA and intravascular ultrasound (IVUS) in lumen dimensions (r = 0.8) than 2D assessed %DS (r = 0.34). Ultimately, the greatest advantage of 3D-QCA may be that it offers improved assessment of the absolute lumen dimensions including length, diameter, tortuosity, and optimal views [20,21] and not just %DS.…”

Fast and Accurate Pressure-Drop Prediction in Straightened Atherosclerotic Coronary Arteries

“…With an accurate reconstruction of the geometry of the coronary artery and appropriate boundary conditions, CFD can compute the entire flow field (e.g., 13 ). But while software packages can obtain the 3D geometry of the coronary arteries directly, 6,26 CFD remains time consuming with conventional technology. To use WSS for decision support during an intervention, CFD must be performed within a limited time frame.…”