Optimal Fluoroscopic Projections of Coronary Ostia and Bifurcations Defined by Computed Tomographic Coronary Angiography

Three-Dimensional CT for Preprocedural Planning of PCI for Ostial Right Coronary Artery Lesions: A Randomized Controlled Pilot Trial

BACKGROUND

Geographic stent-ostium mismatch is an important predictor of target lesion failure after percutaneous coronary intervention of an aorto-ostial right coronary artery lesion. Optimal visualization of the aorto-ostial plane is crucial for precise stent implantation at the level of the ostium. This study investigates whether preprocedural 3-dimensional computed tomography (3DCT), with determination of the optimal viewing angle, would allow for more precise stent implantation and reduce procedure time, contrast, and radiation dose.

METHODS

In this single-center, prospective, open-label, core-laboratory blinded trial, a total of 30 patients with an aorto-ostial right coronary artery lesion were randomly assigned to either percutaneous coronary intervention with a preprocedural 3DCT or angiography-guided percutaneous coronary intervention. The optimal working view angle was determined by 3DCT in the intervention group and by the operators' discretion in the control group. The primary end point was the percentage of patients without geographic mismatch, as determined by intravascular ultrasound.

RESULTS

3DCT-determined C-arm angles were heterogenous but, in general, more extreme left anterior oblique projections were used (P<0.0001). While stent implantation was in the optimal position in all patients randomized to the intervention group, geographic mismatch was present in 5 (33%) patients randomized to the control group (P=0.06). The mean amount of procedural contrast (P<0.0001), mean radiation (P=0.03), and median procedure time (P=0.03) were significantly lower in the intervention group. The 3DCT scan was able to predict the calcium arc (P<0.0001) and minimal lumen area by intravascular ultrasound (P=0.003).

CONCLUSIONS

Preprocedural 3DCT planning for percutaneous coronary intervention of aorto-ostial right coronary artery lesions allows for optimal stent positioning while reducing procedure time, contrast, and radiation dose.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05172323.

The impact of bifurcation angle on clinical outcomes in patients who underwent nano-crush technique: the insight from the multicenter EVOLUTE-CRUSH V study

BACKGROUND

This multicenter study aimed to retrospectively assess the relationship between bifurcation angle (BA) and major cardiovascular events (MACEs) in patients undergoing nano-crush technique (NCT) for complex bifurcation lesions (CBLs).

METHODS

A total of 122 consecutive patients [male: 85 (69.6%), mean age: 61.53 ± 9.03 years] who underwent NCT between January 2019 and January 2024 were included. The primary endpoint was a combined endpoint (MACE) including cardiac death, target vessel myocardial infarction (TVMI), or clinically driven target lesion revascularization (TLR). Patients were classified into two groups: MACE-positive and MACE-negative patients.

RESULTS

Among the study population, 22 patients (18%) had at least one MACE. The BA (46.89 ± 14.65° vs. 65.23 ± 10.40°, P = 0.001) was notably lower in the MACE-positive group than the MACE-negative group. In multivariable regression analysis, decreased BA was identified as one of the independent predictors of MACE (odds ratio = 0.908; 95% confidence interval: 0.852-0.969; P < 0.001). We divided the study cohort into two subgroups based on historical narrow and wide BAs (<70 vs. ≥70°). The incidence of MACE (25.3 vs. 6.4%, P = 0.008), clinically driven TLR (22.7 vs. 4.3%, P = 0.009), and TVMI (18.7 vs. 0%, P = 0.001) were notably higher in the BA <70° group than in the BA ≥70° group. Kaplan-Meier analysis also revealed that MACE-free survival was significantly lower in the BA <70° group than in the BA ≥70° group under mid-term follow-up (log-rank P = 0.009).

CONCLUSION

This observational multicenter study showed that the BA significantly affects mid-term outcomes in patients who underwent NCT. In addition, our findings suggest that NCT may not be a viable option in patients with narrow-angle (<70°) CBLs.

Computed Tomography Angiography in the Catheterization Laboratory: A Guide Towards Optimizing Coronary Interventions

Cardiac computed tomography (CT) has become an essential tool in the pre-procedural planning and optimization of coronary interventions. Its non-invasive nature allows for the detailed visualization of coronary anatomy, including plaque burden, vessel morphology, and the presence of stenosis, aiding in precise decision making for revascularization strategies. Clinicians can assess not only the extent of coronary artery disease but also the functional significance of lesions using techniques like fractional flow reserve (FFR-CT). By providing comprehensive insights into coronary structure and hemodynamics, cardiac CT helps guide personalized treatment plans, ensuring the more accurate selection of patients for percutaneous coronary interventions or coronary artery bypass grafting and potentially improving patient outcomes.

Multimodal Imaging of Coronary Bifurcation TAP Procedures Utilizing Visible Heart® Methodologies: EBC Recommended Steps and Bailout Procedures

In some cases it is critical to clinically perform coronary bifurcation stenting to minimize the potential risk for restenosis and/or stent thrombosis. The European Bifurcation Club (EBC) has provided guidelines for optimally performing such procedures. Yet, sometimes such procedures do not go as planned, and in some cases bailout procedures are required. Here we utilized Visible Heart® (VH) methodologies and multimodal visualizations to better understand each step for optimally performed T and small protrusion (TAP) procedures, as well as those in which complications occurred. These studies were performed within reanimated swine hearts in which endoscopes, fluoroscopy, and optical coherence tomography (OCT) could readily be used. Additionally, because these procedures were performed in reanimated hearts, one could intentionally cause complications, so to perform bailout procedures. Finally, following these procedures each specimen was micro CT scanned, and high resolution computational models (~40 microns) were reconstructed of the final outcomes.

Tricuspid Valve S-Curves and Chamber Views: Implications for Transcatheter Tricuspid and Pulmonary Valve Interventions, Part 2 of the S-Curves and Chamber Views Series

Despite the challenges associated with periprocedural imaging, transcatheter tricuspid valve interventions have shown important impact on outcomes. A comprehensive understanding of the anatomy of the right heart and surrounding structures is crucial. One way to optimize these interventions is by identifying the optimal fluoroscopic viewing angles along the S-curve of the tricuspid valve. Integration of chamber views using multimodality imaging (multislice computed tomography, fluoroscopy, and echocardiography) may increase operator confidence and reduce procedural duration, radiation exposure, contrast volume, and complication rates.

Interventional Applications for an Ostial Protection Guidewire-The WALPO Technique

Coronary atherosclerotic lesions at the ostium and proximal coronary arteries pose significant challenges in percutaneous coronary interventions (PCI), especially in the left main coronary artery (LMCA). Guide catheter-induced damage can lead to severe complications such as vessel dissection or myocardial infarction. Ostial stent placement with drug-eluting stents offers mechanical support and reduces restenosis but is technically challenging due to the anatomical complexity of the ostium. Complications like longitudinal stent deformation and hydraulic dissection from contrast media are specific concerns. The aortic free-floating wire technique, expanded in this article to Wire in Aorta for Localization and Protection of the Ostium (WALPO), provides a method for safely locating and protecting the ostium during PCI, aiming to improve the safety and efficacy of PCI at this location.

The Balloon-Assisted Double-Kissing T-Stenting Technique: Concept, In Vitro Model, and Case Examples

Background

In complex bifurcation percutaneous coronary intervention, 2-stent strategies are often required. Commonly used 2-stent techniques can lead to suboptimal results due to their complexity. We developed the balloon-assisted double-kissing T-stenting (DKT) technique, which uses balloons to optimize stent placement, delivery, and final architecture.

Methods

With the balloon-assisted DKT technique, a balloon is inflated into the main branch (MB) to identify the best position of the side-branch (SB) stent instead of relying on angiography. DKT aims at supporting the SB ostium with stent crowns instead of distorted open cell(s), by achieving a longitudinal deformation with minimal crush of the SB stent upon implantation of the MB stent. This hypothesis was tested on a bench model. We report how the technique was performed in 2 cases and provide intracoronary imaging of the results.

Results

As hypothesized, DKT resulted in a longitudinal accordion-like deformation and minimal crush effect on bench. The SB ostium was supported by stent crowns. The SB wall opposed to the carina was well covered with crowns from the MB stent after proximal optimization technique and final kissing. The technique was successfully used in 2 complex left main cases with perfect coverage of the SB ostium as assessed with intracoronary imaging.

Conclusions

The balloon-assisted DKT is a simple technique that combines strengths of double-kissing crush and culotte techniques, results in appropriate SB ostium coverage, and deserves further investigation.

Murray law-based quantitative flow ratio to assess left main bifurcation stenosis: selecting the angiographic projection matters

Murray law-based quantitative flow ratio (µQFR) assesses fractional flow reserve (FFR) in bifurcation lesions using a single angiographic view, enhancing the feasibility of analysis; however, accuracy may be compromised in suboptimal angiographic projections. FFRCT is a well-validated non-invasive method measuring FFR from coronary computed tomographic angiography (CCTA). We evaluated the feasibility of µQFR in left main (LM) bifurcations, the impact of the optimal/suboptimal fluoroscopic view with respect to CCTA, and its diagnostic concordance with FFRCT. In 300 patients with three-vessel disease, the values of FFRCT and µQFR were compared at distal LM, proximal left anterior descending artery (pLAD) and circumflex artery (pLCX). The optimal viewing angle of LM bifurcation was defined on CCTA by 3-dimensional coordinates and converted into a 2-dimensional fluoroscopic view. The best fluoroscopic projection was considered the closest angulation to the optimal viewing angle on CCTA. µQFR was successfully computed in 805 projections. In the best projections, µQFR sensitivity was 88.2% (95% CI 76.1-95.6) and 84.8% (71.1-93.7), and specificity was 96.8% (93.8-98.6) and 97.2% (94.4-98.9), in pLAD and pLCX, respectively, with regard to FFRCT. The AUC of µQFR for predicting FFRCT ≤ 0.80 tended to be improved using the best versus suboptimal projections (0.94 vs. 0.89 [p = 0.048] in pLAD; 0.94 vs. 0.88 [p = 0.075] in pLCX). Computation of µQFR in LM bifurcations using a single angiographic view showed high feasibility from post-hoc analysis of coronary angiograms obtained for clinical purposes. The fluoroscopic viewing angle influences the diagnostic performance of physiological assessment using a single angiographic view.

Management strategies for heavily calcified coronary stenoses: an EAPCI clinical consensus statement in collaboration with the EURO4C-PCR group

Since the publication of the 2015 EAPCI consensus on rotational atherectomy, the number of percutaneous coronary interventions (PCI) performed in patients with severely calcified coronary artery disease has grown substantially. This has been prompted on one side by the clinical demand for the continuous increase in life expectancy, the sustained expansion of the primary PCI networks worldwide, and the routine performance of revascularization procedures in elderly patients; on the other side, the availability of new and dedicated technologies such as orbital atherectomy and intravascular lithotripsy, as well as the optimization of the rotational atherectomy system, has increased operators' confidence in attempting more challenging PCI. This current EAPCI clinical consensus statement prepared in collaboration with the EURO4C-PCR group describes the comprehensive management of patients with heavily calcified coronary stenoses, starting with how to use non-invasive and invasive imaging to assess calcium burden and inform procedural planning. Objective and practical guidance is provided on the selection of the optimal interventional tool and technique based on the specific calcium morphology and anatomic location. Finally, the specific clinical implications of treating these patients are considered, including the prevention and management of complications and the importance of adequate training and education.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 1

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of evidence that has led to major recommendations in clinical practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region based on updated information in the field that including both wire- and image-based physiologic assessment. This is Part 1 of the whole consensus document, which describes the general concept of coronary physiology, as well as practical information on the clinical application of physiologic indices and novel image-based physiologic assessment.

Percutaneous Treatment of Left Main Disease: A Review of Current Status

Percutaneous treatment of the left main coronary artery is one of the most challenging scenarios in interventional cardiology, due to the large portion of myocardium at risk the technical complexity of treating a complex bifurcation with large branches. Our aim is to provide un updated overview of the current indications for percutaneous treatment of the left main, the different techniques and the rationale underlying the choice for provisional versus upfront two-stent strategies, intravascular imaging and physiology guidance in the management of left main disease, and the role of mechanical support devices in complex high-risk PCI.

Computed tomographic angiography in coronary artery disease

Coronary computed tomographic angiography (CCTA) is becoming the first-line investigation for establishing the presence of coronary artery disease and, with fractional flow reserve (FFRCT), its haemodynamic significance. In patients without significant epicardial obstruction, its role is either to rule out atherosclerosis or to detect subclinical plaque that should be monitored for plaque progression/regression following prevention therapy and provide risk classification. Ischaemic non-obstructive coronary arteries are also expected to be assessed by non-invasive imaging, including CCTA. In patients with significant epicardial obstruction, CCTA can assist in planning revascularisation by determining the disease complexity, vessel size, lesion length and tissue composition of the atherosclerotic plaque, as well as the best fluoroscopic viewing angle; it may also help in selecting adjunctive percutaneous devices (e.g., rotational atherectomy) and in determining the best landing zone for stents or bypass grafts.

The Role of CT-Guided Optimal Fluoroscopic Viewing Angle for Coronary Engagement After TAVR

We report the case of an 89-year-old woman with prior transcatheter aortic valve replacement who underwent successful left coronary artery engagement and left circumflex percutaneous coronary intervention using patient-specific computed tomography fluoroscopic projections. (Level of Difficulty: Advanced.).

Aortic Annulus S-Curve: Implications for Transcatheter Aortic Valve Replacement and Related Procedures, Part 1

Most transcatheter aortic valve replacement-related procedures (eg, transcatheter aortic valve replacement implantation depth, commissural alignment, coronary access, bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction, paravalvular leak closure) require an optimal fluoroscopic viewing angle located somewhere along the aortic annulus S-curve. Chamber views, coronary cusp and coronary anatomy, can be understood along the aortic annulus S-curve. A better understanding of the optimal fluoroscopic viewing angles along the S-curve may translate into increased operator confidence and improved safety and efficacy while reducing procedural time, radiation dose, contrast volume, and complication rates.

Pre-procedural planning of coronary revascularization by cardiac computed tomography: An expert consensus document of the Society of Cardiovascular Computed Tomography

Coronary CT angiography (CCTA) demonstrated high diagnostic accuracy for detecting coronary artery disease (CAD) and a key role in the management of patients with low-to-intermediate pretest likelihood of CAD. However, the clinical information provided by this noninvasive method is still regarded insufficient in patients with diffuse and complex CAD and for planning percutaneous coronary intervention (PCI) and surgical revascularization procedures. On the other hand, technology advancements have recently shown to improve CCTA diagnostic accuracy in patients with diffuse and calcific stenoses. Moreover, stress CT myocardial perfusion imaging (CT-MPI) and fractional flow reserve derived from CCTA (CT-FFR) have been introduced in clinical practice as new tools for evaluating the functional relevance of coronary stenoses, with the possibility to overcome the main CCTA drawback, i.e. anatomical assessment only. The potential value of CCTA to plan and guide interventional procedures lies in the wide range of information it can provide: a) detailed evaluation of plaque extension, volume and composition; b) prediction of procedural success of CTO PCI using scores derived from CCTA; c) identification of coronary lesions requiring additional techniques (e.g., atherectomy and lithotripsy) to improve stent implantation success by assessing calcium score and calcific plaque distribution; d) assessment of CCTA-derived Syntax Score and Syntax Score II, which allows to select the mode of revascularization (PCI or CABG) in patients with complex and multivessel CAD. The aim of this Consensus Document is to review and discuss the available data supporting the role of CCTA, CT-FFR and stress CT-MPI in the preprocedural and possibly intraprocedural planning and guidance of myocardial revascularization interventions.

Pre-procedural planning of coronary revascularization by cardiac computed tomography: An expert consensus document of the Society of Cardiovascular Computed Tomography

Coronary CT angiography (CCTA) demonstrated high diagnostic accuracy for detecting coronary artery disease (CAD) and a key role in the management of patients with low-to-intermediate pretest likelihood of CAD. However, the clinical information provided by this noninvasive method is still regarded insufficient in patients with diffuse and complex CAD and for planning percutaneous coronary intervention (PCI) and surgical revascularization procedures. On the other hand, technology advancements have recently shown to improve CCTA diagnostic accuracy in patients with diffuse and calcific stenoses. Moreover, stress CT myocardial perfusion imaging (CT-MPI) and fractional flow reserve derived from CCTA (CT-FFR) have been introduced in clinical practice as new tools for evaluating the functional relevance of coronary stenoses, with the possibility to overcome the main CCTA drawback, i.e. anatomical assessment only. The potential value of CCTA to plan and guide interventional procedures lies in the wide range of information it can provide: a) detailed evaluation of plaque extension, volume and composition; b) prediction of procedural success of CTO PCI using scores derived from CCTA; c) identification of coronary lesions requiring additional techniques (e.g., atherectomy and lithotripsy) to improve stent implantation success by assessing calcium score and calcific plaque distribution; d) assessment of CCTA-derived Syntax Score and Syntax Score II, which allows to select the mode of revascularization (PCI or CABG) in patients with complex and multivessel CAD. The aim of this Consensus Document is to review and discuss the available data supporting the role of CCTA, CT-FFR and stress CT-MPI in the preprocedural and possibly intraprocedural planning and guidance of myocardial revascularization interventions.

Cinefluoroscopy for assessment of mechanical heart valves with suspected dysfunction

Background

Mechanical heart valves (MHVs) are preferred prosthesis types in many, especially younger patients who need surgical valve replacement. Although echocardiography is most frequently performed for prosthesis assessment during follow-up, ultrasound artifacts usually preclude a precise investigation of prosthesis function. Cinefluoroscopy (CF) is a simple and effective method to analyze and quantify opening and closing of prosthesis leaflets but requires careful visualization of the valve using optimal viewing angles. Here, we investigated the quality of CF studies in clinical routine and their suitability for quantitative analysis of prosthesis function.

Methods and results

We retrospectively identified 94 patients with 118 cinefluoroscopies performed by 31 different investigators in one tertiary center from 2012 to 2021. Of 150 MHVs (98% bi-leaflet prostheses), 87 (58%) were aortic, 53 (34%) mitral, 7 (5%) tricuspid, and 5 (3%) pulmonary valve prostheses, respectively. CF studies were categorized by their suitability to quantitatively assess opening and closing angles. Visualization of valve function was “sufficient” in 23%, “suboptimal” in 46%, and “unsuitable” in 31% of the cases.

Conclusion

In clinical routine, only one-fourth of CF studies allow for a complete assessment of leaflet motion of MHVs. Although this may be in part due to the varying experience of operators, the high number of unsuitable studies suggests that optimal viewing angles may not be achievable in all patients. Further research is required to investigate standard viewing angles and anatomy after MHV implantation to improve the quality of CF studies and reduce radiation exposure of patients and operators.

Quantitative Flow Ratio Based on Murray Fractal Law: Accuracy of Single Versus Two Angiographic Views

Background

Murray bifurcation fractal law-based quantitative flow ratio (QFR), namely, μQFR, is a novel method for the fast computation of fractional flow reserve (FFR) from a single angiographic view. We aimed to compare the diagnostic accuracy of computational QFR based on single vs 2 angiographic views in patients with intermediate coronary stenosis.

Methods

The algorithm of μQFR was extended to develop a Murray law-based 3-dimensional (3D) μQFR from 2 angiographic projections. Patients with both angiographic views acquired according to the protocol-specified recommended views in the FAVOR (Functional Diagnostic Accuracy of Quantitative Flow Ratio in Online Assessment of Coronary Stenosis) II China study were included. μQFR was computed separately from the first (μQFR1) and second (μQFR2) angiographic projections, whereas the 3D-μQFR was computed based on both projections, all blinded to FFR data. Hemodynamically significant coronary stenosis was defined by wire-based FFR of ≤0.80.

Results

Altogether, 280 vessels from 262 patients had 2 protocol-specified recommended angiographic views; μQFR1, μQFR2, and 3D-μQFR were successfully computed in all these vessels. The mean FFR was 0.82 ± 0.12. The vessel-level diagnostic accuracy for μQFR1, μQFR2, and 3D-μQFR to identify hemodynamically significant stenosis was 92.1% (95% CI, 89.0%-95.3%), 92.5% (95% CI, 89.4%-95.6%), and 93.2% (95% CI, 90.3%-96.2%), respectively, with similar areas under the receiver operating characteristic curve for μQFR1 (0.96, P < .001), μQFR2 (0.95, P < .001), and 3D-μQFR (0.95, P < .001). μQFR1 and μQFR2 had excellent correlation (r = 0.95) and agreement (mean difference = 0.00 ± 0.03).

Conclusions

Computation of μQFR from a single angiographic view had comparably good diagnostic performance as 2-view 3D-μQFR in identifying hemodynamically significant coronary stenosis.

Treatment of coronary bifurcation lesions, part I: implanting the first stent in the provisional pathway. The 16th expert consensus document of the European Bifurcation Club

Stepwise layered provisional stenting (PS) is the most commonly used strategy to treat coronary bifurcation lesions (CBL). The term 'stepwise layered' emphasises the versatility of this approach that allows the adjustment of the procedure plan according to the CBL complexity, starting with stent implantation in one branch and implantation of a second stent in the other branch only when required. A series of refinements have been implemented over the years to facilitate the achievement of predictable procedural results using this approach. However, despite its simplicity and versatility, operators using this technique require full knowledge of the pitfalls of each procedural step. Part I of this 16^th European Bifurcation Club consensus paper provides a detailed step-by-step overview of the pitfalls and technical troubleshooting during the implantation of the first stent using the PS strategy for the treatment of CBL.

Coronary access after transcatheter aortic valve replacement in bicuspid versus tricuspid aortic stenosis

BACKGROUND

It is unknown whether there are differences in coronary access after transcatheter aortic valve replacement (TAVR) between bicuspid and tricuspid anatomy.

AIMS

Our aim was to investigate coronary access after TAVR using a self-expanding transcatheter heart valve (THV) in bicuspid versus tricuspid aortic valves (BAV vs TAV), based on CT simulation.

METHODS

A total of 86 type 0 BAV, 70 type 1 BAV, and 132 TAV patients were included. If the coronary ostium faced the sealed parts of the THV or the tilted-up native leaflet (NL), this was defined as THV- or NL-related challenging coronary access, respectively. If coaxial engagement was not allowed due to interference from the unwrapped frame, THV-related complex coronary access was defined.

RESULTS

The incidence of THV-related challenging coronary access was 21.2% for the left coronary artery (LCA) and 17.7% for the right coronary artery (RCA), and type 0 BAV patients encountered fewer THV-related challenging LCA access than their TAV counterparts (OR 0.42, 95% CI: 0.20-0.89). NL-related challenging coronary access was observed in 3.1% for LCA and 1.4% for RCA, and THV-related complex coronary access was identified in 5.9% for LCA and 17.0% for RCA; however, no significant differences were found among groups. The proportion of optimal fluoroscopic viewing angles suitable for guiding LCA engagement was similar among groups (64.0% vs 70.0% vs 62.1%), but those suitable for guiding RCA engagement were significantly higher in the type 0 BAV group (31.4% vs 4.3% vs 9.1%).

CONCLUSIONS

Coronary access may be challenging or complex in a significant proportion of both BAV and TAV patients after TAVR. Type 0 BAV anatomy may be more favourable for post-TAVR coronary access.

Contemporary Evidence-Based Diagnosis and Management of Severe Coronary Artery Calcification

Percutaneous treatment of heavily calcified coronary lesions remains a challenge for interventional cardiologists with increased risk of incomplete lesion preparation, suboptimal stent deployment, procedural complications, and a higher rate of acute and late stent failure. Adequate lesion preparation through calcium modification is crucial in optimising procedural outcomes. Several calcium modification devices and techniques exist, with rotational atherectomy the predominant treatment for severely calcified lesions. Novel technologies such as intravascular lithotripsy are now available and show promise as a less technical and highly effective approach for calcium modification. Emerging evidence also emphasises the value of detailed characterisation of calcification severity and distribution especially with intracoronary imaging for appropriate device selection and individualised treatment strategy. This review aims to provide an overview of the non-invasive and invasive evaluation of coronary calcification, discuss calcium modification techniques and propose an algorithm for the management of calcified coronary lesions.

Fundamentals of percutaneous coronary bifurcation interventions

Coronary bifurcation lesions (CBLs) account for 15%-20% of all percutaneous coronary interventions. The complex nature of these lesions is responsible for poorer procedural, early and late outcomes. This complex lesion subset has received great attention in the interventional cardiac community, and multiple stenting techniques have been developed. Of these, the provisional stenting technique is most often the default strategy; however, the elective double stenting (EDS) technique is preferred in certain subsets of complex CBLs. The double kissing crush technique may be the preferred EDS technique because of its efficacy and safety in comparative trials; however, this technique consists of many steps and requires training. Many new methods have recently been added to the EDS techniques to provide better stent scaffolding and to reduce early and late adverse outcomes. Intravascular imaging is necessary to determine the interventional strategy and postinterventional results. This review discusses the basic concepts, contemporary percutaneous interventional technical approaches, new methods, and controversial treatment issues of CBLs.

Coronary CT Angiography to Guide Percutaneous Coronary Intervention

Coronary CT angiography (CCTA) has emerged as a powerful noninvasive tool for characterizing the presence, extent, and severity of coronary artery disease (CAD) in patients with stable angina. Recent technological advancements in CT scanner hardware and software have augmented the rich information that can be derived from a single CCTA study. Beyond merely identifying the presence of CAD and assessing stenosis severity, CCTA now allows for the identification and characterization of plaques, lesion length, and fluoroscopic angle optimization, as well as enables the assessment of the physiologic extent of stenosis through CT-derived fractional flow reserve, and may even allow for the prediction of the response to revascularization. These and other features make CCTA capable of not only guiding invasive coronary angiography referral, but also give it the unique ability to help plan coronary intervention. This review summarizes current and future applications of CCTA in procedural planning for percutaneous coronary intervention, provides rationale for wider integration of CCTA in the workflow of the interventional cardiologist, and details how CCTA may help improve patient care and clinical outcomes. Keywords: CT Angiography © RSNA, 2022.

An adaptive optimal viewing angle determination algorithm for TEVAR operation

BACKGROUND

The determination of the right x-ray angiography viewing angle is an important issue during the treatment of thoracic endovascular aortic repair (TEVAR). An inaccurate projection angle (manually determined today by the physicians according to their personal experience) may affect the placement of the stent and cause vascular occlusion or endoleak.

METHODS

Based on the acquisition of a computed tomography angiography (CTA) image before TEVAR, an adaptive optimization algorithm is proposed to determine the optimal viewing angle of the angiogram automatically. This optimal view aims at avoiding any overlapping between the left common carotid artery and the left subclavian artery. Moreover, the proposed optimal procedure exploits the patient-specific morphology to adaptively reduce the potential foreshortening effect.

RESULTS

Experimental results conducted on thirty-five patients demonstrate that the optimal angiographic viewing angle based on the proposed method has no significant difference when compared with the expert practice (p = 0.0678).

CONCLUSION

We propose a method that utilizes the CTA image acquired before TEVAR to automatically calculate the optimal C-arm angle. This method has the potential to assist surgeons during their interventional procedure by providing a shorter procedure time, less radiation exposure, and less contrast injection.

Role of IVUS in the rectification of angiographically judged ramus intermedius and its clinical significance

Background

Due to the technical limitations of coronary artery angiography (CAG), ramus intermedius (RI) is sometimes difficult to distinguish from a high-origin obtuse marginal branch or a high-origin diagonal branch. This study sought to investigate the role of intravascular ultrasonography (IVUS) in the rectification of angiographically judged RI.

Methods

This study retrospectively analyzed 165 patients who were reported to have an RI based on CAG and underwent IVUS implementation from 02/01/2009 to 31/12/2019 in Zhongshan Hospital, Fudan University. Taking IVUS as the gold standard, we calculated the accuracy of RI identification by CAG and evaluated the impact of RI on revascularization strategy.

Results

Among the 165 patients, 89 patients (54%) were demonstrated to have an RI on IVUS (IVUS-RI), 32 patients (19%) were identified to have a high-origin diagonal branch on IVUS (IVUS-h-D), and 44 patients (27%) had an actual high-origin obtuse marginal artery on IVUS (IVUS-h-OM). Among 84 patients who underwent one-stent crossover stenting because of left main furcation lesions (48 patients in the IVUS-RI group, 12 patients in the IVUS-h-D group, and 24 in the IVUS-h-OM group), 14.6% of patients in the IVUS-RI group, 33.3% in the IVUS-h-D group and 0% in the IVUS-h-OM group had CAG-RI compromise (P = 0.02), which was defined as severe stenosis of the RI ostium (> 75%) or significant RI flow impairment (TIMI < 3).

Conclusions

Only 54% of CAG-RIs were confirmed by IVUS, which indicates the necessity of preintervention IVUS to distinguish real RIs from other branches in LM furcation lesions.

CT Angiography Followed by Invasive Angiography in Patients With Moderate or Severe Ischemia-Insights From the ISCHEMIA Trial

OBJECTIVES

This study aimed to examine the concordance of coronary computed tomographic angiography (CCTA) assessment of coronary anatomy and invasive coronary angiography (ICA) as the reference standard in patients enrolled in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches).

BACKGROUND

Performance of CCTA compared with ICA has not been assessed in patients with very high burdens of stress-induced ischemia and a high likelihood of anatomically significant coronary artery disease (CAD). A blinded CCTA was performed after enrollment to exclude patients with left main (LM) disease or no obstructive CAD before randomization to an initial conservative or invasive strategy, the latter guided by ICA and optimal revascularization.

METHODS

Rates of concordance were calculated on a per-patient basis in patients randomized to the invasive strategy. Anatomic significance was defined as ≥50% diameter stenosis (DS) for both modalities. Sensitivity analyses using a threshold of ≥70% DS for CCTA or considering only CCTA images of good-to-excellent quality were performed.

RESULTS

In 1,728 patients identified by CCTA as having no LM disease ≥50% and at least single-vessel CAD, ICA confirmed 97.1% without LM disease ≥50%, 92.2% with at least single-vessel CAD and no LM disease ≥50%, and only 4.9% without anatomically significant CAD. Results using a ≥70% DS threshold or only CCTA of good-to-excellent quality showed similar overall performance.

CONCLUSIONS

CCTA before randomization in ISCHEMIA demonstrated high concordance with subsequent ICA for identification of patients with angiographically significant disease without LM disease.

Practical utilization of cardiac computed tomography for the success in complex coronary intervention

Percutaneous coronary intervention (PCI) for complex lesions is still technically demanding and is associated with less favorable procedural parameters such as lower success rate, longer procedural time, higher contrast volume and unexpected complications. Because the conventional angiographic analysis is limited by the inability to visualize the plaque information and the occluded segment, cardiac computed tomography has evolved as an adjunct to invasive angiography to better characterize coronary lesions to improve success rates of PCI. Adding to routine image reconstructions by coronary computed tomography angiography, the thin-slab maximum intensity projection method, which is a handy reconstruction technique on an ordinary workstation, could provide easy-to-understand images to reveal the anatomical characteristics and the lumen and plaque information simultaneously, and then assist to build an in-depth strategy for PCI. Especially in the treatment of chronic total occlusion lesion, these informations have big advantages in the visualization of the morphologies of entry and exit, the occluded segment and the distribution of calcium compared to invasive coronary angiography. Despite of the additional radiation exposure, contrast use and cost for cardiac computed tomography, the precise analysis of lesion characteristics would consequently improve the procedural success and prevent the complication in complex PCI.