Feasibility, reproducibility and characteristics of coronary bifurcation type assessment by three-dimensional optical coherence tomography

Three-dimensional optical coherence tomography for guidance of percutaneous coronary intervention for coronary bifurcation disease: a review of current clinical applications

Percutaneous coronary intervention (PCI) for coronary bifurcation disease remains one of the most challenging situations in interventional cardiology in terms of procedural success rates and long-term cardiac events. Optical coherence tomography (OCT), with a higher signal-to-noise ratio and the ability to distinguish plaque components, can display the true condition of bifurcation lesions without overlapping or shortening and achieve detailed visualization of vascular structures, which is superior to those of other imaging modalities. Three-dimensional (3D) reconstruction of OCT images (3D-OCT) helps to gain a more informed understanding of the geometry and morphology of bifurcation lesions and provide additive information on plaque distribution. Following stent implantation, 3D-OCT can also guide the re-crossing of guide wires through stent struts jailing the side branch (SB) ostium and more clearly display the jailing strut configuration, as well as the ideal position of the guidewire recrossing point and stent struct link connection, to confirm the optimal guidewire position and understand interactions between stents and vessel walls, which may improve clinical results after PCI. The present review provides an up-to-date overview of the clinical use of 3D-OCT for accurate assessment of bifurcation anatomy, guiding the optimal guidewire rewiring into SB during bifurcation stenting, and evaluation of post-PCI results, offering novel information about atherosclerotic disease or stenting process.

Validation of the Cut-Plane Method for Accurate Measurement of Side-Branch Ostium Area in Coronary Bifurcation Lesions: A 3D-OCT Analysis

Objective

This study aimed to validate the effectiveness, accuracy, and feasibility of the cut-plane method for measuring the side branch (SB) ostium area in three-dimensional optical coherence tomography (3D-OCT) pullbacks performed in the main branch (MB).

Methods

A total of 109 sets of OCT pullbacks from the MB and SB of coronary artery bifurcation lesions were analyzed using Vivolight OCT software. Measurements of the SB ostium area from the MB and SB pullbacks were analyzed. Measurements of the SB ostium area from the actual SB pullback were used as a reference. 3D cut-plane analysis was used to estimate the correlations and mean errors with the reference measurements.

Results

Thirty-four sets of OCT images from the C7XR system and 75 sets from the CornarisTM system were analyzed using Vivolight software. There was a strong correlation between the reference measurements of the SB ostium area and the measurements obtained through 3D cut-plane analysis in the overall dataset (r = 0.925). This correlation was observed consistently with both the C7XR system (r = 0.955) and CornarisTM system (r = 0.900). Similar results were found in subset analyses of true and nontrue bifurcations (r = 0.936; r = 0.898, respectively) and in left main (LM) or non-LM bifurcation subsets (r = 0.932; r = 0.873, respectively).

Conclusions

There were strong correlations between measurements of the SB ostium area by 3D-OCT and the reference measurements, and thus may be a reliable and accurate alternative to direct OCT pullback examinations of the SB.

Risk Assessment of Side Branch Compromise After Coronary Bifurcation Stenting - A Substudy of the 3D-OCT Bifurcation Registry

BACKGROUND

Side branch (SB) occlusion during bifurcation stenting is a serious complication. This study aimed to predict SB compromise (SBC) using optical coherence tomography (OCT).

METHODS AND RESULTS

Among the 168 patients who enrolled in the 3D-OCT Bifurcation Registry, 111 bifurcation lesions were analyzed to develop an OCT risk score for predicting SBC. SBC was defined as worsening of angiographic SB ostial stenosis (≥90%) immediately after stenting. On the basis of OCT before stenting, geometric parameters (SB diameter [SBd], length from proximal branching point to carina tip [BP-CT length], and distance of the polygon of confluence [dPOC]) and 3-dimensional bifurcation types (parallel or perpendicular) were evaluated. SBC occurred in 36 (32%) lesions. The parallel-type bifurcation was significantly more frequent in lesions with SBC. The receiver operating characteristic curve indicated SBd ≤1.77 mm (area under the curve [AUC]=0.73, sensitivity 64%, specificity 75%), BP-CT length ≤1.8 mm (AUC=0.83, sensitivity 86%, specificity 68%), and dPOC ≤3.96 mm (AUC=0.68, sensitivity 63%, specificity 69%) as the best cut-off values for predicting SBC. To create the OCT risk score, we assigned 1 point to each of these factors. As the score increased, the frequency of SBC increased significantly (Score 0, 0%; Score 1, 8.7%; Score 2, 28%; Score 3, 58%; Score 4, 85%; P<0.0001).

CONCLUSIONS

Prediction of SBC using OCT is feasible with high probability.

Artificial Intelligence for the Interventional Cardiologist: Powering and Enabling OCT Image Interpretation

Intravascular optical coherence tomography (IVOCT) is a form of intra-coronary imaging that uses near-infrared light to generate high-resolution, cross-sectional, and 3D volumetric images of the vessel. Given its high spatial resolution, IVOCT is well-placed to characterise coronary plaques and aid with decision-making during percutaneous coronary intervention. IVOCT requires significant interpretation skills, which themselves require extensive education and training for effective utilisation, and this would appear to be the biggest barrier to its widespread adoption. Various artificial intelligence-based tools have been utilised in the most contemporary clinical IVOCT systems to facilitate better human interaction, interpretation and decision-making. The purpose of this article is to review the existing and future technological developments in IVOCT and demonstrate how they could aid the operator.