Identification of Coronary Artery Side Branch Supplying Myocardial Mass That May Benefit From Revascularization

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.

Percutaneous coronary intervention for bifurcation coronary lesions using optimised angiographic guidance: the 18th consensus document from the European Bifurcation Club

The 2023 European Bifurcation Club (EBC) meeting took place in Warsaw in October, and the latest evidence for the use of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) to optimise percutaneous coronary interventions (PCI) on coronary bifurcation lesions (CBLs) was a major focus. The topic generated deep discussions and general appraisal on the potential benefits of IVUS and OCT in PCI procedures. Nevertheless, despite an increasing recognition of IVUS and OCT capabilities and their recognised central role for guidance in complex CBL and left main PCI, it is expected that angiography will continue to be the primary guidance modality for CBL PCI, principally due to educational and economic barriers. Mindful of the restricted access/adoption of intracoronary imaging for CBL PCI, the EBC board decided to review and describe a series of tips and tricks which can help to optimise angiography-guided PCI for CBLs. The identified key points for achieving an optimal angiography-guided PCI include a thorough analysis of pre-PCI images (computed tomography angiography, multiple angiographic views, quantitative coronary angiography vessel estimation), a systematic application of the technical steps suggested for a given selected technique, an intraprocedural or post-PCI use of stent enhancement and a low threshold for bailout use of intravascular imaging.

Standardized angiographic projections allow evaluation of coronary artery side branches with quantitative flow ratio (QFR)

Quantitative flow ratio (QFR) is a novel, software-based noninvasive method for the quantitative evaluation of coronary physiology. QFR results correlate with invasive FFR measurements in the three main epicardial coronary arteries. However, QFR data for the evaluation of coronary side branches (SB) are scarce. The evaluation of QFR-performance of SB was retrospective and prospective. Eighty-seven patients with suspected chronic coronary syndrome, who received angiography using routine core lab projections, were retrospectively analyzed. On the second part 37 patients, who received angiography using recommended standardized coronary angiography projections, were prospectively analyzed. Quantitative analysis was performed for SB with a maximum lumen diameter proximal of ≥2 mm based on quantitative coronary angiography (QCA) by two certified experts with the software QAngio XA 3D 3.2. Using routine projections, QFR computation in 55 % of the SB were obtained (123 out of 224). Using standardized projections, 85 % of SB were computed by QFR (64 out of 75; p < 0.001 vs routine projections). The fluoroscopy time for recommended projections was not significantly different as opposed to routine projections (3.75 ± 2.2 vs. 4.58 ± 3.00 min, p = 2.6986). Using the standardized projections was associated with a higher amount of contrast medium (53.44 ± 24.23 vs. 87.95 ± 43.73 ml, p < 0.01), longer overall procedure time (23.23 ± 16.35 vs. 36.14 ± 17.21 min, p < 0.01) and a higher dose area product (1152.28 ± 576.70 vs. 2540.68 ± 1774.07 cGycm2, p < 0.01). Our study shows that the blood flow of the vast majority of coronary SB can be determined non-invasively by QFR in addition to the main epicardial coronary arteries when standardized projections are used.

Definitions and Standardized Endpoints for Treatment of Coronary Bifurcations

The Bifurcation Academic Research Consortium (Bif-ARC) project originated from the need to overcome the paucity of standardization and comparability between studies involving bifurcation coronary lesions. This document is the result of a collaborative effort between academic research organizations and the most renowned interventional cardiology societies focused on bifurcation lesions in Europe, the United States, and Asia. This consensus provides standardized definitions for bifurcation lesions; the criteria to judge the side branch relevance; the procedural, mechanistic, and clinical endpoints for every type of bifurcation study; and the follow-up methods. Considering the complexity of bifurcation lesions and their evaluation, detailed instructions and technical aspects for site and core laboratory analysis of bifurcation lesions are also reported. The recommendations included within this consensus will facilitate pooled analyses and the effective comparison of data in the future, improving the clinical relevance of trials in bifurcation lesions, and the quality of care in this subset of patients.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 2

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 clinical data that has led to major recommendations in all 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 includes both wire- and image-based physiologic assessment. This is Part 2 of the whole consensus document, which provides theoretical and practical information on physiologic indexes for specific clinical conditions and patient statuses.

Propensity-matched analysis of long-term clinical results after ostial circumflex revascularisation

BACKGROUND

Percutaneous coronary intervention (PCI) of the ostium of the left circumflex artery (LCx) is technically challenging. The aim of this study was to compare long-term clinical outcomes of ostial PCI located in the LCx versus the left anterior descending artery (LAD) in a propensity-matched population.

METHODS

Consecutive patients with a symptomatic isolated 'de novo' ostial lesion of the LCx or LAD treated with PCI were included. Patients with a stenosis of >40% in the left main (LM) were excluded. A propensity score matching was performed to compare both groups. The primary endpoint was target lesion revascularisation (TLR); other endpoints included target lesion failure and an analysis of the bifurcation angles.

RESULTS

From 2004 to 2018, 287 consecutive patients with LAD (n=240) or LCx (n=47) ostial lesions treated with PCI were analysed. After the adjustment, 47 matched pairs were obtained. The mean age was 72±12 years and 82% were male. The LM-LAD angle was significantly wider than the LM-LCx angle (128°±23° vs 108°±24°, p=0.002). At a median follow-up of 5.5 (IQR 1.5-9.3) years, the rate of TLR was significantly higher in the LCx group (15% vs 2%); with an HR of 7.5, 95% CI 2.1 to 26.4, p<0.001. Interestingly, in the LCx group, TLR-LM occurred in 43% of the TLR cases; meanwhile, no TLR-LM involvement was found in the LAD group.

CONCLUSIONS

Isolated ostial LCx PCI was associated with an increase in the rate of TLR compared with ostial LAD PCI at long-term follow-up. Larger studies evaluating the optimal percutaneous approach at this location are needed.

An Approach to Non-left Main Bifurcation Lesions: A Contemporary Review

Bifurcated anatomical locations in the arterial tree, such as coronary artery bifurcations, are prone to develop obstructive atherosclerotic lesions due to the pro-atherogenic low wall shear stress. The percutaneous treatment of bifurcation lesions is among the most challenging complex coronary interventions, including different multistep stenting strategies. Even though provisional side branch (SB) stenting is recommended as the primary approach in most cases, the debate continues between provisional SB and upfront two-stent strategies, particularly in complex bifurcations consisting of a significantly diseased SB that supplies a crucial myocardial territory. This review will highlight the importance of understanding the bifurcation philosophy and provide an individual algorithmic approach to find the optimal treatment strategy for each patient with a non-left main coronary bifurcation lesion. Considering the most recent scientific evidence, the advantages and disadvantages of each stenting technique and the role of intracoronary imaging to optimize bifurcation percutaneous coronary intervention outcomes will be discussed.

The 17th expert consensus document of the European Bifurcation Club - techniques to preserve access to the side branch during stepwise provisional stenting

Provisional stenting has become the default technique for the treatment of most coronary bifurcation lesions. However, the side branch (SB) can become compromised after main vessel (MV) stenting and restoring SB patency can be difficult in challenging anatomies. Angiographic and intracoronary imaging criteria can predict the risk of side branch closure and may encourage use of side branch protection strategies. These protective approaches provide strategies to avoid SB closure or overcome compromise following MV stenting, minimising periprocedural injury. In this article, we analyse the strategies of SB preservation discussed and developed during the most recent European Bifurcation Club (EBC) meetings.

Determinants of Seattle Angina Questionnaire in Multivessel Disease Patients Undergoing Percutaneous Coronary Intervention: Insights from a Single-Center Study

INTRODUCTION

The Seattle Angina Questionnaire (SAQ-7) quantifies the impact of angina on patient functionality and quality of life. There is scarce data on the impact of social determinants and comorbidities on SAQ-7 in patients undergoing percutaneous coronary intervention (PCI) with planned staged PCI.

METHODS

Patients completed a SAQ-7 before each PCI. Multivariable regression analysis was performed to study the impact of social determinants, comorbidities, and procedural characteristics on SAQ-7 scores at index PCI and at the time of the staged PCI.

RESULTS

531 patients were studied. Female sex, non-White race, coronary artery bypass graft history (CABG), and chronic lung disease were associated with lower baseline SAQ-7 scores. Overall, SAQ-7 increased between index procedure and staged PCI (11.9 ± 23.4). Body mass index (BMI) and the treatment of bifurcation lesions were independently associated with improvement of SAQ-7 between PCIs. Post-intervention, neither sex nor race was independently associated with changes in SAQ-7 scores.

CONCLUSION

Different disparities and comorbid factors affect SAQ-7 before and after PCI. After revascularization, sex and race were not independent predictors of SAQ-7 improvement.

[Bifurcation lesions : Are new strategies and devices needed?]

Interventional treatment of bifurcation lesions, especially true complex bifurcation lesions, continue to be a challenge for interventional cardiologists. A primary one stent strategy is always preferred for simple bifurcation lesions, whereas studies in recent years have shown that a two stent strategy may be advantageous for true bifurcations, i.e. those involving at least the distal main branch as well as the side branch. This seems to be even more pronounced when the lesion presents as complex, i.e., the side branch shows high-grade stenosis over longer stretches and the complete lesion fulfils certain criteria, e.g., severe calcification and a bifurcation angle < 45° or > 70°. According to the latest randomized trials and meta-analyses, the double kissing (DK) crush and double kissing mini-crush (DKMC) techniques in particular seem to be advantageous for these lesions; however, in recent years the established techniques have been continuously refined and further developed. The DK culotte technique and the nano-crush technique deserve special attention. Both techniques seem to further improve and simplify the existing underlying strategies; however, further studies to prove the superiority of these techniques over the established ones are still pending. Overall, the implementation of the available randomized study results, the further development of the techniques and also of the materials can continuously improve the outcome of the patients after interventional treatment of bifurcation lesions. This is also confirmed by the latest registry data, which for the first time could show equal event rates in patients after treatment of complex lesions compared to simple lesions in the clinical practice.

Left Main Disease

Traditionally, the treatment of left main coronary artery disease is recommended coronary artery bypass grafting because of its superior long-term outcomes compared with medical treatment and plain old balloon angioplasty. However, improvement of percutaneous coronary intervention technique and introduction of drug-eluting stent led to change of treatment strategy of left main coronary artery disease through cumulative data for revascularization that based on clinical evidence.

Effect of the ratio of vessel-specific volume to fractional myocardial mass on fractional flow reserve

This study aimed to examine whether the ratio of vessel-specific coronary arterial lumen volume to the fraction of myocardial mass (V_R/M_R) affects myocardial ischemia. We proposed a calculation method for V_R/M_R, and compared the ratio of total epicardial coronary arterial lumen volume to left ventricular myocardial mass (V/M) with V_R/M_R in predicting myocardial ischemia. V_R/M_R and V/M were computed using data from 205 patients with 241 stenosis vessel who underwent coronary computed tomography angiography (CTA), quantitative coronary angiography, and fractional flow reserve. The vessel-specific coronary arterial lumen volume (V_R) was obtained from CTA by segmenting the coronary arterial lumen volume, while the vessel-specific fraction of myocardial mass (M_R) was obtained by allometric scaling. The V_R/M_R was then calculated. The cut-off values of V/M (23.55 mm³/g) and V_R/M_R (12.98 mm³/g) were used to define equal groups of ischemic and non-ischemic patients, respectively. Using these cut-off values, the accuracy, specificity, sensitivity, positive predictive value, and negative predictive value of V/M were 60%, 76%, 45%, 57%, and 66%, and of V_R/M_R were 87%, 92%, 77%, 89%, and 83%, respectively. Patients have different V_R/M_R values in different stenotic coronary arteries. Clinically, V_R/M_R is a quantitative indicator of the risk of myocardial ischemia.

Clinical Outcomes of Percutaneous Coronary Intervention for Bifurcation Lesions According to Medina Classification

Background

Coronary bifurcation lesions (CBLs) are frequently encountered in clinical practice and are associated with worse outcomes after percutaneous coronary intervention. However, there are limited data around the prognostic impact of different CBL distributions.

Methods and Results

All CBL percutaneous coronary intervention procedures from the prospective e‐Ultimaster (Prospective, Single‐Arm, Multi Centre Observations Ultimaster Des Registry) multicenter international registry were analyzed according to CBL distribution as defined by the Medina classification. Cox proportional hazards models were used to compare the hazard ratio (HR) of the primary outcome, 1‐year target lesion failure (composite of cardiac death, target vessel–related myocardial infarction, and clinically driven target lesion revascularization), and its individual components between Medina subtypes using Medina 1.0.0 as the reference category. A total of 4003 CBL procedures were included. The most prevalent Medina subtypes were 1.1.1 (35.5%) and 1.1.0 (26.8%), whereas the least prevalent was 0.0.1 (3.5%). Overall, there were no significant differences in patient and procedural characteristics among Medina subtypes. Only Medina 1.1.1 and 0.0.1 subtypes were associated with increased target lesion failure (HR, 2.6 [95% CI, 1.3–5.5] and HR, 4.0 [95% CI, 1.6–9.0], respectively) at 1 year, compared with Medina 1.0.0, prompted by clinically driven target lesion revascularization (HR, 3.1 [95% CI, 1.1–8.6] and HR, 4.6 [95% CI, 1.3–16.0], respectively) as well as cardiac death in Medina 0.0.1 (HR, 4.7 [95% CI, 1.0–21.6]). No differences in secondary outcomes were observed between Medina subtypes.

Conclusions

In a large multicenter registry analysis of coronary bifurcation percutaneous coronary intervention procedures, we demonstrate prognostic differences in 1‐year outcomes between different CBL distributions, with Medina 1.1.1 and 0.0.1 subtypes associated with an increased risk of target lesion failure.

Percutaneous coronary intervention of bifurcation lesions

Bifurcation coronary artery disease is common as the development of atherosclerosis is facilitated by altered endothelial shear stress. Multiple anatomical and physiological factors need to be considered when treating bifurcation lesions. To achieve optimal results, various stenting techniques have been developed, each with benefits and limitations. In this state-of-the-art review we describe technically important characteristics of bifurcation lesions and summarise the evidence supporting contemporary bifurcation techniques.

Physiological Approach for Coronary Artery Bifurcation Disease: Position Statement by Korean, Japanese, and European Bifurcation Clubs

Coronary artery bifurcation lesions are frequently encountered in cardiac catheterization laboratories and are associated with more complex procedures and worse clinical outcomes than nonbifurcation lesions. Therefore, anatomical and physiological assessment of bifurcation lesions before, during, and after percutaneous coronary intervention is of paramount clinical importance. Physiological assessment can help interventionalists appreciate the hemodynamic significance of coronary artery disease and guide ischemia-directed revascularization. However, it is important to understand that the physiological approach for bifurcation disease is more important than simply using physiological indexes for its assessment. This joint consensus document by the Korean, Japanese, and European bifurcation clubs presents the concept of a physiological approach for coronary bifurcation lesions, as well as current knowledge, practical tips, pitfalls, and future directions of applying physiological indexes in bifurcation percutaneous coronary intervention. This document aims to guide interventionalists in performing appropriate physiology-based assessments and treatment decisions for coronary bifurcation lesions.

Definitions and Standardized Endpoints for Treatment of Coronary Bifurcations

The Bifurcation Academic Research Consortium (Bif-ARC) project originated from the need to overcome the paucity of standardization and comparability between studies involving bifurcation coronary lesions. This document is the result of a collaborative effort between academic research organizations and the most renowned interventional cardiology societies focused on bifurcation lesions in Europe, the United States, and Asia. This consensus provides standardized definitions for bifurcation lesions; the criteria to judge the side branch relevance; the procedural, mechanistic, and clinical endpoints for every type of bifurcation study; and the follow-up methods. Considering the complexity of bifurcation lesions and their evaluation, detailed instructions and technical aspects for site and core laboratory analysis of bifurcation lesions are also reported. The recommendations included within this consensus will facilitate pooled analyses and the effective comparison of data in the future, improving the clinical relevance of trials in bifurcation lesions, and the quality of care in this subset of patients.

Anatomic and Hemodynamic Plaque Characteristics for Subsequent Coronary Events

Objectives

While coronary computed tomography angiography (CCTA) enables the evaluation of anatomic and hemodynamic plaque characteristics of coronary artery disease (CAD), the clinical roles of these characteristics are not clear. We sought to evaluate the prognostic implications of CCTA-derived anatomic and hemodynamic plaque characteristics in the prediction of subsequent coronary events.

Methods

The study cohort consisted of 158 patients who underwent CCTA with suspected CAD within 6–36 months before percutaneous coronary intervention (PCI) for acute myocardial infarction (MI) or unstable angina and age-/sex-matched 62 patients without PCI as the control group. Preexisting high-risk plaque characteristics (HRPCs: low attenuation plaque, positive remodeling, napkin-ring sign, spotty calcification, minimal luminal area &lt;4 mm2, or plaque burden ≥70%) and hemodynamic parameters (per-vessel fractional flow reserve [FFRCT], per-lesion ΔFFRCT, and percent ischemic myocardial mass) were analyzed from prior CCTA. The primary outcome was a subsequent coronary event, which was defined as a composite of vessel-specific MI or revascularization for unstable angina. The prognostic impact of clinical risk factors, HRPCs, and hemodynamic parameters were compared between vessels with (160 vessels) and without subsequent coronary events (329 vessels).

Results

Vessels with a subsequent coronary event had higher number of HRPCs (2.6 ± 1.4 vs. 2.3 ± 1.4, P = 0.012), lower FFRCT (0.76 ± 0.13 vs. 0.82 ± 0.11, P &lt; 0.001), higher ΔFFRCT (0.14 ± 0.12 vs. 0.09 ± 0.08, P &lt; 0.001), and higher percent ischemic myocardial mass (29.0 ± 18.5 vs. 26.0 ± 18.4, P = 0.022) than those without a subsequent coronary event. Compared with clinical risk factors, HRPCs and hemodynamic parameters showed higher discriminant abilities for subsequent coronary events with ΔFFRCT being the most powerful predictor. HRPCs showed additive discriminant ability to clinical risk factors (c-index 0.620 vs. 0.558, P = 0.027), and hemodynamic parameters further increased discriminant ability (c-index 0.698 vs. 0.620, P = 0.001) and reclassification abilities (NRI 0.460, IDI 0.061, P &lt; 0.001 for all) for subsequent coronary events. Among vessels with negative FFRCT (&gt;0.80), adding HRPCs into clinical risk factors significantly increased discriminant and reclassification abilities for subsequent coronary events (c-index 0.687 vs. 0.576, P = 0.005; NRI 0.412, P = 0.002; IDI 0.064, P = 0.001) but not for vessels with positive FFRCT (≤0.80).

Conclusion

In predicting subsequent coronary events, both HRPCs and hemodynamic parameters by CCTA allow better prediction of subsequent coronary events than clinical risk factors. HRPCs provide more incremental predictability than clinical risk factors alone among vessels with negative FFRCT but not among vessels with positive FFRCT.

Clinical Trial Registration

PreDiction and Validation of Clinical CoursE of Coronary Artery DiSease With CT-Derived Non-INvasive HemodYnamic Phenotyping and Plaque Characterization (DESTINY Study), NCT04794868.

Five-Year Outcomes After Fractional Flow Reserve-Based Deferral of Revascularization in Chronic Coronary Syndrome: Final Results From the J-CONFIRM Registry

BACKGROUND

Little large-scale data is available about the long-term (beyond 3 years) clinical outcomes after fractional flow reserve (FFR)-based deferral of revascularization in clinical practice. We sought to assess the 5-year outcomes after deferral of revascularization based on FFR.

METHODS

The J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry) prospectively enrolled 1263 patients with 1447 lesions in whom revascularization was deferred based on FFR from 28 Japanese centers. The primary study end point was the cumulative 5-year incidence of target vessel failure (TVF), including cardiac death, target vessel-related myocardial infarction, and clinically driven target vessel revascularization.

RESULTS

Five-year follow-up was completed in 92.2% of patients. The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization (9.8%). Cardiac death and target vessel-related myocardial infarction were 1.9% and 0.95%, respectively. Cumulative 5-year incidence of TVF was similar between the FFR 0.75 to 0.80 and 0.81 to 0.85 groups even after adjustment for baseline characteristics (12.2% versus 13.0%, inverse probability-weighted hazard ratio, 0.86 [95% CI, 0.46-1.60]; P=0.63). Compared with the almost normal FFR (0.86-1.00) group, the significant (<0.75) and borderline (0.75-0.85) FFR groups showed a higher incidence of TVF at 5 years (29.9% versus 12.8% versus 8.6%, P<0.001). Independent predictors of the 5-year TVF were hemodialysis, FFR value, left main coronary artery lesion, prior percutaneous coronary intervention, and male sex.

CONCLUSIONS

The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization. Notably, cardiac death and target vessel-related myocardial infarction rarely occurred during the follow-up. Our findings highlight the long-term safety of FFR-based deferral of revascularization in patients with chronic coronary syndrome. Registration: URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000014473.

Side Branch is the Main Determinant Factor of Bifurcation Lesion Complexity: Critical Review with a Proposal Based on Single-centre Experience

Although bifurcation stenting can be often managed with a simple provisional approach, in some settings, more complex techniques are appropriate. Based on our clinical experience and on data from literature, we propose a simple algorithm that may assist in selecting cases for elective double stenting. We found that, when the side branch is of adequate dimensions and affected by significant disease (longer than 10 mm and/or with presence of ostial calcifications), double stenting is associated with a lower incidence of adverse events, compared with provisional stenting.

Bifurcation functional significance score as predictor of mortality: a validating study

Considerable progress has been made in the treatment of coronary bifurcation stenosis. Anatomical characteristics of the vessel and lesion, however, fail to give information about the functional significance of the bifurcation stenosis. To the best of our knowledge, there is no study that systematically establishes the baseline functional significance of coronary stenosis and its effect on procedural and clinical outcomes. Patients with significant angiographic bifurcation lesions defined as diameter stenosis > 50% in main vessel and/or side branch were included. FFR was performed in main vessel (MV) and side branch (SB) before and after percutaneous coronary intervention (PCI). 169 patients from Fiesta study (derivation cohort) and 555 patients from prospective bifurcation registry (clinical effect cohort) were analyzed to validate angiographic prediction score (BFSS) used to determine the potentially functional significance of coronary bifurcation stenosis. Bifurcation functional significance score (including the following parameters-SYNTAX ≥ 11, SB/MB BARI score, MV %DS ≥ 55%, main branch (MB) %DS ≥ 65%, lesion length ≥ 25 mm) with a maximum value of 11 was developed. A cut-off value of 6.0 was shown to give the best discriminatory ability-with accuracy 87% (sensitivity 77%, specificity 96%, p < 0.001). There was also a significant difference in all-cause mortality between patients with BFSS ≥ 6.0 vs. BFSS < 6.0-25.5% vs. 18.4%, log-rank p = 0.001 as well as cardiac mortality: BFSS ≥ 6.0 vs. BFSS < 6.0-17.7% vs. 14.5%, log-rank (p = 0.016). The cardiac mortality was significantly lower in patients with smaller absolute SB territory, p = 0.023. An angiographic score (BFSS) with good discriminatory ability to determine the functional significance of coronary bifurcation stenosis was developed. The value for BFSS ≥ 6.0 can be used as a discriminator to define groups with higher risk for all-cause and cardiac mortality. Also, we found that the smaller side branches pose greater mortality risk.

Percutaneous coronary intervention in side branch coronary arteries: Insights from the Japanese nationwide registry

Background

Performance of percutaneous coronary intervention (PCI) in side-branch vessels (SB-PCI) has not been fully investigated despite the technical advancement of PCI.

Methods

We investigated 257,492 patients registered in the Japanese nationwide PCI registry from January to December 2018; 199,767 (78%) underwent PCI for major vessel PCI (MV-PCI), 21,555 (8.4%) underwent SB-PCI, and 24,862 (9.6%) underwent PCI for both vessels (SB + MV-PCI). The frequencies of primary composite adverse events, defined as in-hospital mortality and procedural complications (i.e., peri-procedural myocardial infarction, tamponade, new-onset cardiogenic shock, stent thrombosis, emergent surgery, and bleeding), and PCI for restenotic lesions were investigated. Their association with institutional frequency of each PCI was also investigated.

Results

Fewer drug-eluting stents (66% vs. 86%) and more drug-coated balloons (23% vs. 9%) were used in SB-PCI than in MV-PCI (p < 0.001). Pre-procedure non-invasive testing was similarly performed in SB-PCI and MV-PCI (57% vs. 61%). The composite endpoint was observed in 0.7%, 1.9%, and 2.2% of the SB-PCI, SB + MV-PCI, and MV-PCI groups, respectively (p < 0.001). Institutional frequency of SB-PCI was inversely associated with the composite-endpoint risk for all PCI procedures (odds ratio 1.37, 95% confidence interval 1.04–1.81 in the lowest tertile, with reference to the middle tertile, p = 0.02). Frequency of PCI for restenotic lesions was also inversely associated with the institutional frequency of MV-PCI (p < 0.001).

Conclusion

SB-PCI was performed safely with a low frequency of acute complications, and higher SB-PCI frequency presented a lower risk of in-hospital adverse events, albeit with a cost of an increase in PCI for restenotic lesions.

Long-Term Follow-Up of Patients With Isolated Side Branch Coronary Artery Disease

The data with respect to stable coronary artery disease (SCAD) are mainly confined to main vessel disease. However, there is a lack of information and long-term outcomes regarding isolated side branch disease. This study aimed to evaluate long-term major adverse cardiac and cerebrovascular events (MACCEs) in patients with isolated side branch coronary artery disease (CAD). A total of 437 patients with isolated side branch SCAD were included. After a median follow-up of 38 months, the overall MACCE and all-cause mortality rates were 14.6% and 5.9%, respectively. Among angiographic features, 68.2% of patients had diagonal artery and 82.2% had ostial lesions. In 28.8% of patients, the vessel diameter was ≥2.75 mm. According to the American College of Cardiology lesion classification, 84.2% of patients had either class B or C lesions. Age, ostial lesions, glycated hemoglobin A1c, and neutrophil levels were independent predictors of MACCE. On the other hand, side branch location, vessel diameter, and lesion complexity did not affect outcomes. Clinical risk factors seem to have a greater impact on MACCE rather than lesion morphology. Therefore, the treatment of clinical risk factors is of paramount importance in these patients.

Contemporary Management of Isolated Ostial Side Branch Disease: An Evidence-based Approach to Medina 001 Bifurcations

The optimal management of bifurcation lesions has received significant interest in recent years and remains a matter of debate among the interventional cardiology community. Bifurcation lesions are encountered in approximately 21% of percutaneous coronary intervention procedures and are associated with an increased risk of major adverse cardiac events. The Medina classification has been developed in an attempt to standardise the terminology when describing bifurcation lesions. The focus of this article is on the management of the Medina 0,0,1 lesion (‘Medina 001’), an uncommon lesion encountered in <5% of all bifurcations. Technical considerations, management options and interventional techniques relating to the Medina 001 lesion are discussed. In addition, current published data supporting the various proposed interventional treatment strategies are examined in an attempt to delineate an evidence-based approach to this uncommon lesion.

Standardizing the Definition and Analysis Methodology for Complete Coronary Artery Revascularization

Guideline‐based medical therapy is the foundation of treatment for individuals with coronary artery disease. However, revascularization with either percutaneous coronary intervention or coronary artery bypass grafting may be beneficial in patients with acute coronary syndromes, refractory symptoms, or in other specific scenarios (eg, left main disease and heart failure). While the goal of percutaneous coronary intervention and coronary artery bypass grafting is to achieve complete revascularization, anatomical and ischemic definitions of complete revascularization and their methodology for assessment remain highly variable. Such lack of consensus invariably contributes to the absence of standardized approaches for invasive treatment of coronary artery disease. Herein, we propose a novel, comprehensive, yet pragmatic algorithm with both anatomical and ischemic parameters that aims to provide a systematic method to assess complete revascularization after percutaneous coronary intervention or coronary artery bypass grafting in both clinical practice and clinical trials.

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.

Asia Pacific consensus document on coronary bifurcation interventions

Coronary bifurcation intervention is common but complex. Progress in this field has been made in recent years with considerable contribution from the Asia Pacific (APAC) region. However, the standard of practice varies across the APAC region due to differences in culture, socioeconomic state and healthcare set-up. Practice may also differ from the rest of the world. Hence, a panel of experts was invited to discuss topics relevant to bifurcation intervention in order to make a concerted effort to achieve consensus that is applicable within the region and in line with available evidence.

Anatomical attributes of clinically relevant diagonal branches in patients with left anterior descending coronary artery bifurcation lesions

AIMS

This study aimed to investigate the anatomical attributes determining myocardial territory of diagonal branches and to develop prediction models for clinically relevant branches using myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA).

METHODS AND RESULTS

The amount of ischaemia and subtended myocardial mass of diagonal branches was quantified using MPI by percent ischaemic myocardium (%ischaemia) and CCTA by percent fractional myocardial mass (%FMM), respectively. In 49 patients with isolated diagonal branch disease, the mean %ischaemia by MPI was 6.8±4.0%, whereas in patients with total occlusion or severe disease of all diagonal branches it was 8.4±3.3%. %ischaemia was different according to the presence of non-diseased diagonal branches and dominant left circumflex artery (LCx). In the CCTA cohort (306 patients, 564 diagonal branches), mean %FMM was 5.9±4.4% and 86 branches (15.2%) had %FMM ≥10%. %FMM was different according to LCx dominance, number of branches, vessel size, and relative dominance between two diagonal branches. The diagnostic accuracy of prediction models for %FMM ≥10% based on logistic regression and decision tree was 0.92 (95% CI: 0.85-0.96) and 0.91 (95% CI: 0.84-0.96), respectively. There was no difference in the diagnostic performance of models with and without size criterion.

CONCLUSIONS

LCx dominance, number of branches, vessel size, and dominance among diagonal branches determined the myocardial territory of diagonal branches. Clinical application of prediction models based on these anatomical attributes can help to determine the clinically relevant diagonal branches in the cardiac catheterisation laboratory.

CLINICAL TRIAL REGISTRATION

NCT03935542

5-Year Outcomes According to FFR of Left Circumflex Coronary Artery After Left Main Crossover Stenting

OBJECTIVES

The aim of the current study was to evaluate the long-term clinical impact of fractional flow reserve (FFR) in jailed left circumflex coronary artery (LCx) after left main coronary artery (LM) simple crossover stenting.

BACKGROUND

Although the provisional side-branch intervention with FFR guidance has been validated for non-LM bifurcation lesions, the outcome of such a strategy in LM bifurcation disease is not well-known.

METHODS

Patients who underwent LM-to-left anterior descending coronary artery simple crossover stenting and who had FFR measurements in the LCx thereafter were enrolled. A low FFR was defined as ≤0.80. The clinical outcomes were assessed by the 5-year rate of target lesion failure (TLF) (a composite of cardiac death, target-vessel myocardial infarction, or target lesion revascularization).

RESULTS

In 83 patients, the mean FFR of the LCx after LM stenting was 0.87 ± 0.08, and 14 patients (16.9%) had a low FFR. There was no correlation between the FFR and angiographic % diameter stenosis in jailed LCx (R² = 0.039; p = 0.071) and there was no difference in the angiographic % diameter stenosis in the high and low FFR groups. At 5 years, the low FFR group had a significantly higher rate of TLF than the high FFR group (33.4% vs. 10.7%; hazard ratio: 4.09, 95% confidence interval: 1.15 to 14.52; p = 0.029). However, there was no difference in the clinical outcomes according to the angiographic % diameter stenosis. In a multivariate analysis, a low FFR was an independent predictor of the risk for a 5-year TLF (hazard ratio: 6.49; 95% confidence interval: 1.37 to 30.73; p = 0.018).

CONCLUSIONS

The patients with a high FFR in jailed LCx had better 5-year outcomes than those with a low FFR. The FFR measurement in jailed LCx can be helpful in selecting an adequate treatment strategy and may reduce unnecessary complex procedures.

Allometric scaling patterns among the human coronary artery tree, myocardial mass, and coronary artery flow

Human coronary artery tree is a physiological transport system for oxygen and vital materials through a hierarchical vascular network to match the energy demands of myocardium, which has the highest oxygen extraction ratio among body organs and heavily depends on the blood flow for its energy supply. Therefore, it would be reasonable to expect that the key design principle of this arterial network is to minimize energy expenditure, which can be described by allometric scaling law. We enrolled patients who underwent coronary computed tomography angiography without obstructive lesion. The cumulative arterial length (L), volume (V), and diameter (D) in relation to the artery-specific myocardial mass (M) were assessed. Flow rate (Q) was computed using quantitative flow ratio (QFR) measurement in patients who underwent invasive angiography. A total of 638 arteries from 43 patients (mean age 61 years, male gender 65%) were analyzed. A significant power-law relationship was found among L-M, V-M, D-M, V-L, D-L, and V-D, and also among Q-M, Q-L, Q-V, and Q-D in 106 arteries interrogated with QFR (p < .001, all). Our results suggest that the fundamental design principle of the human coronary arterial network may follow allometric scaling law.

One- and 3-year outcomes of percutaneous bifurcation left main revascularization with modern drug-eluting stents: a systematic review and meta-analysis

AIMS

Optimal percutaneous coronary intervention (PCI) strategy for coronary left main (LM) bifurcation lesions remains controversial. We performed systematic review and meta-analysis comparing one and 3-year clinical outcomes of 1- and 2- stent strategies using modern drug eluting stents (DESs) for revascularization of LM bifurcation disease.

METHODS

We systematically identified all investigations published between January 2015 and February 2020 comparing the use of single versus double-stent strategies for the revascularization of LM bifurcation lesions. The primary endpoint was 1- and 3-years all-cause mortality. Secondary outcomes included target lesion revascularization (TLR), target lesion failure (TLF), major adverse cardiovascular vents (MACEs) and cardiovascular (CV) mortality while the tertiary outcome was overall occurrence of stent thrombosis (ST) at 1- and 3-years.

RESULTS

No significant differences were observed between the two groups in terms of all-cause mortality rate both at 1 and 3-year follow-up. Single stent strategy was associated with a significantly lower risk of TLR (OR 0.78, 95% CI 0.62- 0.97, p = 0.03, I² = 61%) as well as of MACEs (OR 0.78, 95% CI 0.63-0.97, I² = 24%) compared to 2-stent strategy. Conversely no significant differences between the two groups were observed in terms of TLF, CV mortality and ST during the same follow-up period.

CONCLUSIONS

In patients with LM bifurcation disease, single stent strategy demonstrated lower rate of MACEs and TLR but was not superior to 2-stent strategy in terms of CV mortality, TLF and ST at 1 and 3-year follow-up.

Proximal Side Optimization: A Modification of the Double Kissing Crush Technique

Coronary bifurcations with significant lesions >10 mm in the side branch (SB) are likely to require two-stent treatment techniques. To date, double kissing Crush (DK-Crush) stenting has demonstrated higher rates of final kissing balloon inflation and better clinical outcomes. The technical iterations that lead to optimal clinical outcomes have been attributed to the first kissing balloon that repairs the distorted proximal segment and fully expands the orifice of the side stent. One potential caution, which relates to all Crush techniques, is the possibility of the guidewire crossing in an inappropriate position toward the Crushed SB stent. When this occurs, the SB stent may be further Crushed, leaving the ostium uncovered, which potentially negates the benefit of the Crush technique. In our experience, proximal side optimization (PSO) during DK-Crush stenting ensures stent size 'accommodation' to the larger vessel diameter in the proximal segment and better strut apposition to the wall, which is particularly important in the ostial segment. The benefits of this additional modification of the established DK-Crush technique are reduction or elimination of the risk of SB stent distortion, increase of the space of optimal wiring, and avoidance of guidewire advancement under the stent struts, even in unfavorable anatomies with extreme angulation. The author describes a step-by-step approach of a proposed PSO technique, which is easy to perform without any additional procedural time or costs.

The impact of the extent of side branch disease on outcomes following bifurcation stenting

OBJECTIVES

To define the impact of side branch (SB) lesion length on clinical outcomes after percutaneous coronary intervention (PCI) on bifurcation lesions.

BACKGROUND

The role of the SB lesion length remains questionable in PCI planning and its implication on clinical outcome is controversial.

METHODS

Data from the retrospective multicenter EBC-P2BiTO registry were analyzed. The primary endpoint was the occurrence of major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction excluding periprocedural, or stent thrombosis at 13 months median follow-up (IQR 11-28). By using propensity scores for inverse probability of treatment weighting (IPTW), the comparison of treatment groups was adjusted to correct for potential confounding.

RESULTS

Among 1,252 patients, SB was normal in 489 (39%), diseased in 763 (61%) cases. MACE occurred in 68 patients (5.4%). The optimal discriminant SB lesion length for MACE was ≥10 mm, with an area under the curve of 0.71 (p < .01). The incidence of MACE was higher among patients with SB lesions ≥10 mm (8%) than with normal SB (4.1%) (hazard ratio [HR], 2.8; 95% confidence interval [CI], 1.5-5.3; p = .001, IPTW-adjusted) or SB lesions <10 mm (5.1%) (HR, 1.5; 95% CI, 1.1-3.3; p = .048, IPTW-adjusted), being similar between these last two groups.

CONCLUSIONS

In bifurcation PCI, SB lesion length ≥ 10 mm identifies patients at higher risk of MACE than those with <10 mm SB lesions and those without SB disease, considering that no differences were observed among these last two groups. Careful planning is mandatory when approaching bifurcations with long SB lesions.

Histopathologic and physiologic effect of bifurcation stenting: current status and future prospects

Introduction: Coronary bifurcation lesions are involved in up to 20% of all percutaneous coronary interventions (PCI). However, bifurcation lesion intervention is associated with a high complication rate, and optimal treatment of coronary bifurcation is an ongoing debate.Areas covered: Both different stenting techniques and a variety of devices have been suggested for bifurcation treatment, including the use of conventional coronary stents, bioresorbable vascular scaffolds (BVS), drug-eluting balloons (DEB), and stents dedicated to bifurcations. This review will summarize different therapeutic approaches with their advantages and shortcomings, with special emphasis on histopathologic and physiologic effects of each treatment strategy.Expert opinion: Histopathology and clinical data have shown that a more simple treatment strategy is beneficial in bifurcation lesions, achieving superior results. Bifurcation interventions through balloon angioplasty or placement of stents can importantly alter the bifurcation's geometry and accordingly modify local flow conditions. Computational fluid dynamics (CFD) studies have shown that the outcome of bifurcation interventions is governed by local hemodynamic shear conditions. Minimizing detrimental flow conditions as much as possible should be the ultimate strategy to achieve long-term success of bifurcation interventions.

Diagnostic Value of Lesion-specific Measurement of Myocardial Blood Flow Using Hybrid PET/CT

BACKGROUND

We evaluated whether lesion-specific measurement of myocardial blood flow (MBF) and flow reserve (MFR) by hybrid imaging of myocardial perfusion positron emission tomography (PET) and coronary computed tomography (CT) can provide additional diagnostic value.

METHODS

Forty-three patients with stable angina underwent N-13 ammonia PET and coronary CT before invasive coronary angiography (CAG). The lesion-specific MBF was calculated from the average MBF of the myocardial segments downstream of a coronary stenosis using hybrid PET/CT images. The hyperemic MBF, resting MBF, and MFR were measured for the left anterior descending artery (LAD) using conventional and lesion-specific methods. The diagnostic accuracy was compared between the two methods for significant LAD stenoses (≥ 70% reference diameter on CAG).

RESULTS

There were 19 significant LAD stenoses. The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 71%, 68%, 74%, 65%, and 70% for conventional hyperemic MBF (optimal cutoff = 2.15 mL/min/g), 79%, 63%, 74%, 65%, and 70% for conventional MFR (optimal cutoff = 1.82), 83%, 74%, 80%, 78%, and 80% for lesion-specific hyperemic MBF (optimal cutoff = 1.75 mL/min/g), and 79%, 79%, 83%, 75%, and 79% for lesion-specific MFR (optimal cutoff = 1.86), respectively. The lesion-specific measurement was more accurate and had a better linear correlation with anatomical stenosis severity for both hyperemic MBF and MFR.

CONCLUSIONS

Lesion-specific measurement using hybrid PET/CT imaging showed significant improvement in the diagnostic accuracy of PET-measured hyperemic MBF and MFR.

Coronary CT Angiography-derived Fractional Flow Reserve Testing in Patients with Stable Coronary Artery Disease: Recommendations on Interpretation and Reporting

Noninvasive fractional flow reserve derived from coronary CT angiography (FFRCT) is increasingly used in patients with coronary artery disease as a gatekeeper to the catheterization laboratory. While there is emerging evidence of the clinical benefit of FFRCT in patients with moderate coronary disease as determined with coronary CT angiography, there has been less focus on interpretation, reporting, and integration of FFRCT results into routine clinical practice. Because FFRCT analysis provides a plethora of information regarding pressure and flow across the entire coronary tree, standardized criteria on interpretation and reporting of the FFRCT analysis result are of crucial importance both in context of the clinical adoption and in future research. This report represents expert opinion and recommendation on a standardized FFRCT interpretation and reporting approach. Published under a CC BY 4.0 license.

Prediction of side branch occlusions in percutaneous coronary interventions by coronary computed tomography: the CT bifurcation score as a novel tool for predicting intraprocedural side branch occlusion

AIMS

Side branch (SB) occlusion is one of the major technical hurdles in the percutaneous coronary intervention (PCI) of bifurcation lesions. Our aim was to investigate whether preprocedural coronary computed tomography angiography (CCTA) could predict intraprocedural SB occlusion.

METHODS AND RESULTS

A total of 260 bifurcation lesions were enrolled from 246 patients who underwent CCTA before elective bifurcation PCI. Quantitative plaque analysis was performed in the main vessel (MV) and SB. Intraprocedural SB occlusion occurred in 42 lesions (16%). These lesions were characterised by SB plaque, calcified plaque in the MV, low attenuation plaque in the main proximal segment or SB, and a ratio of MV to SB ostium area >4.3, which constituted a point-based CT bifurcation score. The CT bifurcation score was cross-validated, outperforming any angiographic Medina classification or RESOLVE score (c-statistics=0.749 versus 0.631 to 0.551; p<0.05 for all). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CT bifurcation score ≥1 were 90%, 42%, 23%, 96%, and 50%, respectively.

CONCLUSIONS

Comprehensive CCTA assessment was able to predict intraprocedural SB occlusion better than the current angiographic classification or scoring system. The CT bifurcation score may thus be a helpful guide for selecting the optimal bifurcation PCI strategy.

Calcific lesion preparation for coronary bifurcation stenting

Bifurcating coronary lesions are a very common challenge in interventional cardiology because of the technical complexity in their treatment, the risk of side branch occlusion and an overall worse outcome when compared to non-bifurcating lesions. The presence of calcifications represents further complexity due to the difficulty in device delivery and stent expansion as well as enhanced risk of side branch occlusion. Rotational and orbital atherectomy, scoring and cutting balloons, coronary lithoplasty are available tools which have been introduced over the last three decades to overcome such issue. Nevertheless, their application in different contexts of bifurcations presents specific caveats and the studies directed at comparing such techniques have never been expressly oriented in the subset of the bifurcating lesion. In this paper, we review these devices and their usefulness in bifurcations by analyzing consistent data from clinical trials, and we propose a practical algorithm for the treatment of severely calcified bifurcating lesions according to their anatomical features.

Percutaneous coronary intervention for obstructive bifurcation lesions: the 14th consensus document from the European Bifurcation Club

The European Bifurcation Club recommends an approach to a bifurcation stenosis which involves careful assessment, planning and a sequential provisional approach. In the minority of lesions where two stents are required, careful deployment and optimal expansion are essential to achieve a long-term result.

Outcomes of the Tryton-dedicated bifurcation stent for the treatment of true coronary bifurcations: Individual-patient-data pooled analysis

OBJECTIVES

We aimed to evaluate the safety and efficacy of the dedicated Tryton side branch (SB) stent for the treatment of true bifurcations involving large SBs.

BACKGROUND

Bifurcation lesions are associated with lower procedural success and a higher risk of adverse cardiac events. Provisional stenting (PS) is currently the default approach for the treatment of bifurcation lesions. The Tryton stent is a dedicated bifurcation stent system for the treatment of true bifurcation lesions.

METHODS

We performed an individual-patient-data pooled post-hoc analysis of the Tryton Pivotal randomized controlled trial and post-approval Confirmatory Study. Only patients with true bifurcations involving a SB ≥ 2.25 mm in diameter were included. The primary endpoint was non-inferiority of Tryton compared with PS for target vessel failure (TVF) at 1 year.

RESULTS

Of the 411 patients meeting the criteria for enrolment, 287 patients were treated with the Tryton stent and 124 with PS. Procedural success was higher in the Tryton group (95.4 versus 82.3%, P < 0.0001). TVF at 1 year was 8.1% in the Tryton group and 9.7% in the PS group, meeting the pre-specified criteria for non-inferiority established for the randomized controlled trail (p_{non-inferiority} = 0.02). At 9-month angiographic follow-up, SB diameter stenosis was significantly lower in the Tryton group (29.3 ± 21.9 versus 41.1 ± 17.5, P = 0.0008) and in-segment binary restenosis (diameter stenosis ≥ 50%) was higher in the PS group (19.0 versus 34.2%, respectively, P = 0.052).

CONCLUSIONS

In patients with true bifurcations involving a large SB, treatment with the Tryton SD Stent was clinically non-inferior to PS and showed favorable angiographic outcomes.