Percutaneous interventions in unprotected left main lesions: novel three-dimensional imaging and quantitative analysis before and after intervention

Impact of coronary bifurcation angle on the pathogenesis of atherosclerosis and clinical outcome of coronary bifurcation intervention-A scoping review

BACKGROUND

A coronary bifurcation stenting is still a challenging issue due to frequent restenosis and stent thrombosis even with drug-eluting stents. The bifurcation angle (BA) between a main vessel and a side branch is one of the crucial determinants of coronary flow and shear stress that affect the plaque distribution. Previous bench and clinical studies have evaluated the impact of the BA between the proximal main vessel and the side branch (Angle A) and the BA between the distal main vessel and the side branch (Angle B) on the clinical outcomes of bifurcation stenting. However, the impact has not yet been fully elucidated due to a lack of statistical power or different manner of the assessment of BA.

OBJECTIVES

To analyze the published studies on coronary artery BA, the modalities used for assessment, and the impact of BA on interventions and attempt to define the pre-procedural protocols.

DATA SOURCES

A scoping review was performed using the Joanna Briggs Institute Methodology. A total of 52 relevant references were selected from PubMed, Cochrane Library, and CINAHL databases and categorized into three topic areas.

RESULTS AND CONCLUSIONS

A wider Angle A is associated with the increased likelihood of carina shift and a wider Angle B, with that of side branch occlusion. A wider Angle B promotes stent malapposition and deformation in the side branch ostium and has been reported as an independent predictor of major adverse cardiac events after bifurcation stenting; however, improvement of the drug-eluting stent, refinement of the stenting technique, and accurate 3-dimensional assessment may attenuate the adverse clinical impact of a wider BA.

IMPLICATIONS OF KEY FINDINGS

Assessment of the BA is necessary to predict the effect of bifurcation intervention procedure on the stent configuration and coronary flow at the bifurcated vessels. This will help to optimize stent selection and the stenting technique.

Comparison between two-dimensional and three-dimensional quantitative coronary angiography for the prediction of functional severity in true bifurcation lesions: Insights from the randomized DK-CRUSH II, III, and IV trials

OBJECTIVE

This study investigated the diagnostic accuracy of three-dimensional quantitative coronary angiography (3D-QCA) compared with conventional 2D-QCA for predicting functional severity assessed by fractional flow reserve (FFR) for true bifurcation lesions.

METHODS

Based on pooled data from the randomized DK-CRUSH II, III, and IV trials, we evaluated the patients with true bifurcation lesions who underwent coronary angiography together with functional evaluations using FFR in both the main vessel and the side branch. Off-line 2D- and 3D-QCA analyses were conducted using dedicated bifurcation QCA analysis software. Measurements of minimum lumen diameter (MLD), percentage diameter stenosis (% DS), and minimum lumen area (MLA) were compared between 2D- and 3D-QCA, and we evaluated their predictive values of functionally significant FFR.

RESULTS

Ninety patients were eligible for enrollment in the present study. In the main vessel, MLA measured by 3D-QCA was the most accurate predictor of FFR <0.75 (C statistic 0.85, P < 0.001), while MLD measured by 2D-QCA was a similarly accurate predictor (C statistic 0.85, P < 0.001). In the side branch, the best metrics for predicting FFR <0.75 were % DS measured by 2D-QCA with a C statistic value of 0.91 (P < 0.001) and MLA measured by 3D-QCA with a C statistic value of 0.81 (P < 0.001). However, both 2D- and 3D-QCA metrics exhibited low accuracies for predicting FFR <0.75 in intermediate bifurcation lesions.

CONCLUSIONS

3D-QCA analysis for true bifurcation lesions did not improve the predictive accuracy of functionally significant FFR compared with 2D-QCA analysis. In lesions with intermediate stenosis, the diagnostic performance of both 2D- and 3D-QCA-derived measurements in differentiating functional severity is limited.

Prediction of Coronary Atherosclerotic Ostial Lesion with a Damping of the Pressure Tracing during Diagnostic Coronary Angiography

PURPOSE

When performing coronary angiography (CAG), diagnostic catheter intubation to the ostium can cause damping of the pressure tracing. The aim of this study was to determine the predictors of atherosclerotic ostial stenosis in patients showing pressure damping during CAG.

MATERIALS AND METHODS

In total, 2926 patients who underwent diagnostic CAG were screened in this study. Pressure damping was defined as an abrupt decline of the coronary blood pressure with a blunted pulse pressure after engagement of the diagnostic catheter. According to CAG and intravascular ultrasound (IVUS), we divided damped ostia into two groups: atherosclerotic ostial lesion group (true lesion group) and non-atherosclerotic ostium group (false lesion group). Clinical and angiographic characteristics were compared between the two groups.

RESULTS

The overall incidence of pressure damping was 2.3% (68 patients and 76 ostia). Among the pressure damped ostia, 40.8% (31 of 76 ostia) were true atherosclerotic ostial lesions (true lesion group). The true lesion group had more frequent left main ostial damping and more percutaneous coronary interventions (PCIs) performed on non-ostial lesions, compared to the false lesion group. On multivariate logistic regression analysis, left main ostial damping [hazard ratio (HR) 4.11, 95% confidence interval (CI) 1.24-13.67, p=0.021] and PCI on non-ostial lesion (HR 5.34, 95% CI 1.34-21.27, p=0.018) emerged as independent predictors for true atherosclerotic ostial lesions in patients with pressure damping.

CONCLUSION

Left main ostial damping and the presence of a non-ostial atherosclerotic lesion may suggest a significant true atherosclerotic lesion in the coronary ostium.

A simple framework to generate 3D patient-specific model of coronary artery bifurcation from single-plane angiographic images

Although computer-based simulations, such as structural finite element analysis, have proven their usefulness to support procedural planning of coronary stenting, the link between the clinical practice and these engineering techniques is still limited to research test-cases. A key point to further promote such an interaction is to generate in a fast and effective manner the computational grids from the medical images. Hence, the present study proposes a simple framework to generate 3D meshes of coronary bifurcations from a pair of planar angiographic images obtained by X-ray angiography, which is the gold standard technique for the diagnosis of coronary artery stenosis.