Hemodynamic impact of changes in bifurcation geometry after single-stent cross-over technique assessed by intravascular ultrasound and fractional flow reserve

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.

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.

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.

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.

Stenting techniques for coronary bifurcation lesions: Evidence from a network meta-analysis of randomized clinical trials

OBJECTIVES

We conducted a systematic review and network meta-analysis of available randomized clinical trials (RCTs) to compare cardiovascular outcomes involving stenting techniques in coronary bifurcation lesions.

BACKGROUND

Although provisional stenting of the main branch and balloon angioplasty of the side branch is considered the standard approach, the use of two stents is often pursued with a wide variety of bifurcation stenting techniques available.

METHODS

We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and Clinicaltrials.gov from inception to December 2018. We performed a frequentist network meta-analysis to estimate relative risks (RR) of death, major adverse cardiovascular events (MACE), target vessel revascularization (TVR), target lesion revascularization (TLR), and stent thrombosis (ST) among different two stent bifurcation techniques.

RESULTS

We identified 14 studies, yielding data on 4,285 patients. Double Kissing (DK) Crush and Mini-crush were associated with significant reductions in MACE, TVR, and TLR when compared with the Provisional stenting (RR 0.31-0.55 [all p < .01] and RR 0.42-0.45 [all p < .02], respectively) and with the remaining bifurcation techniques (RR 0.44-0.55 [all p < .05] for DK Crush and RR 0.37-0.45 [all p < .05] for Mini-crush). In addition, Culotte and Crush were associated with an increased risk for ST compared to Provisional stenting (RR 3.25-4.27 [both p < .05]) and to DK crush (RR 3.02-3.99 [both p < .05]).

CONCLUSIONS

DK crush and mini-crush were found to be associated with fewer events and complications compared to the other techniques reviewed, including the Provisional approach. Further, Culotte and Crush were associated with an increased risk of stent thrombosis when compared to the Provisional approach.

Side branch fractional flow reserve after provisional stenting of calcified bifurcation lesions: The ORBID-FFR study

OBJECTIVES

We examined the incidence of side branch (SB) compromise after provisional stenting of calcified bifurcation lesions treated with rotational atherectomy (RA) or cutting balloon angioplasty (CBA) and the utility of optical coherence tomography (OCT) to detect functionally significant SB stenoses.

BACKGROUND

The comparative impact of RA versus CBA on SB compromise and functional significance remains poorly characterized.

METHODS

Seventy-one consecutive patients with 71 calcified bifurcation lesions with angiographically intermediate SB stenoses were randomized to RA (n = 35) or CBA (n = 36). The primary endpoint was SB compromise defined as SB diameter stenosis ≥70%, SB dissection or thrombolysis in myocardial infarction flow grade < 3 after provisional stenting. Secondary endpoints included SB FFR in noncompromised SBs and its correlation with SB ostium area (SBOA) assessed by three-dimensional OCT.

RESULTS

SB compromise after provisional stenting was observed in 7 (20.0%) lesions that underwent RA and in 9 (25.0%) lesions treated with CBA (p = .62). Mean SB FFR was 0.83 ± 0.08 and was similar between the study arms. Functionally significant SB stenosis (FFR ≤ 0.80) was detected in 17(30.9%) angiographically noncompromised SBs. SBOA after stenting was an independent predictor of FFR ≤ 0.80 (OR 0.002, 95% CI: 0.00-0.15, p = .002). The optimal cutoff value for SBOA to predict functionally significant SB stenosis was 0.76 mm² (sensitivity 82%, specificity 89% and area under the curve 0.92, 95% CI: 0.84-0.99).

CONCLUSIONS

The rates of SB compromise and functionally significant stenosis after provisional stenting of calcified bifurcation lesions were similar between two lesion preparation strategies. OCT SBOA can detect SB branches with FFR ≤ 0.80 with high sensitivity and specificity.

Noncalcified plaque burden quantified from coronary computed tomography angiography improves prediction of side branch occlusion after main vessel stenting in bifurcation lesions: results from the CT-PRECISION registry

OBJECTIVES

To assess the incremental value of quantitative plaque features measured from computed tomography angiography (CTA) for predicting side branch (SB) occlusion in coronary bifurcation intervention.

METHODS

We included 340 patients with 377 bifurcation lesions in the post hoc analysis of the CT-PRECISION registry. Each bifurcation was divided into three segments: the proximal main vessel (MV), the distal MV, and the SB. Segments with evidence of coronary plaque were analyzed using semi-automated software allowing for quantitative analysis of coronary plaque morphology and stenosis. Coronary plaque measurements included calcified and noncalcified plaque volumes, and corresponding burdens (respective plaque volumes × 100%/vessel volume), remodeling index, and stenosis.

RESULTS

SB occlusion occurred in 28 of 377 bifurcation lesions (7.5%). The presence of visually identified plaque in the SB segment, but not in the proximal and distal MV segments, was the only qualitative parameter that predicted SB occlusion with an area under the curve (AUC) of 0.792. Among quantitative plaque parameters calculated for the SB segment, the addition of noncalcified plaque burden (AUC 0.840, p = 0.003) and low-density plaque burden (AUC 0.836, p = 0.012) yielded significant improvements in predicting SB occlusion. Using receiver operating characteristic curve analysis, optimal cut-offs for noncalcified plaque burden and low-density plaque burden were > 33.6% (86% sensitivity and 78% specificity) and > 0.9% (89% sensitivity and 73% specificity), respectively.

CONCLUSIONS

CTA-derived noncalcified plaque burden, when added to the visually identified SB plaque, significantly improves the prediction of SB occlusion in coronary bifurcation intervention.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03709836 registered on October 17, 2018.

Randomised comparison of provisional side branch stenting versus a two-stent strategy for treatment of true coronary bifurcation lesions involving a large side branch: the Nordic-Baltic Bifurcation Study IV

Background

It is still uncertain whether coronary bifurcations with lesions involving a large side branch (SB) should be treated by stenting the main vessel and provisional stenting of the SB (simple) or by routine two-stent techniques (complex). We aimed to compare clinical outcome after treatment of lesions in large bifurcations by simple or complex stent implantation.

Methods

The study was a randomised, superiority trial. Enrolment required a SB≥2.75 mm, ≥50% diameter stenosis in both vessels, and allowed SB lesion length up to 15 mm. The primary endpoint was a composite of cardiac death, non-procedural myocardial infarction and target lesion revascularisation at 6 months. Two-year clinical follow-up was included in this primary reporting due to lower than expected event rates.

Results

A total of 450 patients were assigned to simple stenting (n=221) or complex stenting (n=229) in 14 Nordic and Baltic centres. Two-year follow-up was available in 218 (98.6%) and 228 (99.5%) patients, respectively. The primary endpoint of major adverse cardiac events (MACE) at 6 months was 5.5% vs 2.2% (risk differences 3.2%, 95% CI -0.2 to 6.8, p=0.07) and at 2 years 12.9% vs 8.4% (HR 0.63, 95% CI 0.35 to 1.13, p=0.12) after simple versus complex treatment. In the subgroup treated by newer generation drug-eluting stents, MACE was 12.0% vs 5.6% (HR 0.45, 95% CI 0.17 to 1.17, p=0.10) after simple versus complex treatment.

Conclusion

In the treatment of bifurcation lesions involving a large SB with ostial stenosis, routine two-stent techniques did not improve outcome significantly compared with treatment by the simpler main vessel stenting technique after 2 years.

Trial registration number

NCT01496638.

The Relation Between Optical Coherence Tomography-Detected Layered Pattern and Acute Side Branch Occlusion after Provisional Stenting of Coronary Bifurcation Lesions

BACKGROUND/PURPOSE

Layered pattern (presumed to be healed plaque after a thrombotic event) can be observed by optical coherence tomography (OCT). We sought to assess the ability of OCT-detected plaque composition to predict acute side branch (SB) occlusion after provisional bifurcation stenting.

METHODS

This is a retrospective observational study using pre-intervention OCT in the main vessel to predict Thrombolysis in Myocardial Infarction (TIMI) flow grade ≤1 in a SB (diameter ≥ 1.5 mm) after provisional bifurcation stenting. OCT-detected layered pattern was defined as plaque with a superficial layer that had a different optical intensity and a clear demarcation from underlying tissue.

RESULTS

Overall, 207 patients with stable coronary disease were included. SB occlusion occurred in 26/207 (12.6%) bifurcation lesions. Operators decided not to perform additional treatment, and TIMI flow did not improve to ≥2 in cases with SB occlusion. The prevalence of OCT-detected layered pattern was more common in lesions with versus without SB occlusion (88.5% versus 33.7%, p < 0.0001); OCT-detected layered pattern was more often located on the same side of the SB (73.9% versus 21.3%, p < 0.0001) circumferentially compared to lesions without SB occlusion. Multivariable analysis showed that OCT-detected layered pattern was an independent predictor of SB occlusion (odds ratio 18.8, 95% confidence interval 5.1-68.8, p < 0.0001) along with true bifurcation lesion and wider angiographic bifurcation angle.

CONCLUSIONS

The presence of an OCT-detected layered pattern near its ostium was a strong predictor of SB occlusion after provisional bifurcation stenting.

Elliptical stretch as a cause of side branch ostial compromise after main vessel stenting in coronary bifurcations: New insights from numerical analysis

BACKGROUND

The side branch (SB) compromise after main vessel (MV) stenting remains a significant problem in coronary bifurcation treatment. Currently the two major hypotheses for the mechanism of SB compromise are carina shift from MV into the SB and plaque shift into the ostium of side vessel. It is proposed herein, SB ostial deformation leading to reshaping of the ostium from circle to ellipse is a third possible mechanism. In the current study, the theoretical effects and correlation of ostial deformation with fractional flow reserve (FFR) is explored.

METHODS

Based on angiographic measurements and theoretical analysis formulas, three different SB ostial areas using circular ostial shape assumption and elliptical ostial shape assumption were calculated. Three different types of ostial areas with FFR values after MV stenting in 49 patients from the FIESTA registry were compared and analyzed.

RESULTS

It was found that there is significant overestimation of stenosis severity when estimated by the circle formula, than with the ellipse formula - ASc vs. ASds with 25% ± 13%, p < 0.001, ASc vs. ASmld with 9% ± 10%, p < 0.001. The elliptical shape assumptions provide more accurate ostial area stenosis, which correlates better with FFR. This finding is more significant in less severe stenosis (< 70% area stenosis) than in a more severe one.

CONCLUSIONS

A third possible mechanism of SB compromise after MV stenting of coronary bifurcation stenosis is elliptical ostial deformation at the ostium of SBs. The ostial area, calculated based on elliptical assumption correlates better with FFR, than area stenosis calculated with the traditional circular formula.

Intracoronary electrocardiogram to guide percutaneous interventions in coronary bifurcations - a proof of concept: the FIESTA (Ffr vs. IcEcgSTA) study

AIMS

The aim of this study was to determine the accuracy of the intracoronary electrocardiogram (icECG) to detect ischaemia during bifurcation lesion percutaneous coronary intervention (PCI) with fractional flow reserve (FFR) as a reference.

METHODS AND RESULTS

Patients with significant bifurcation lesions defined as FFR ≤0.80 were included. FFR and icECG were performed in the main vessel (MV) and side branch (SB) before and after provisional stenting. icECG was recorded with an uninsulated proximal wire end connected to a unipolar lead. The diagnostic accuracy of the icECG for the detection of ischaemia in the SB after MV stenting was determined with FFR as a reference. Overall, 37 patients were included. Seventeen bifurcations had an SB FFR ≤0.80 after MV stenting and 20 patients had an ST-segment elevation on the icECG. There was significant correlation between SB FFR and ST-segment elevation on the icECG (r=-0.533, p<0.001). The diagnostic accuracy of icECG ST-elevation to detect functionally significant SB stenosis revealed an AUC of 0.71 (95% CI: 0.64-0.80) with a sensitivity of 88% and specificity of 75% with a positive predictive value of 75% and negative predictive value of 88%. Neither SB FFR nor icECG correlated with SB percent diameter stenosis after MV stenting.

CONCLUSIONS

Intracoronary ECG has a good ability to predict functionally significant stenosis at the SB after MV stenting during bifurcation PCI. This method provides a novel strategy to assess the significance of an SB lesion without the need of a pressure wire.

Endovascular stent-induced alterations in host artery mechanical environments and their roles in stent restenosis and late thrombosis

Cardiovascular stent restenosis remains a major challenge in interventional treatment of cardiovascular occlusive disease. Although the changes in arterial mechanical environment due to stent implantation are the main causes of the initiation of restenosis and thrombosis, the mechanisms that cause this initiation are still not fully understood. In this article, we reviewed the studies on the issue of stent-induced alterations in arterial mechanical environment and discussed their roles in stent restenosis and late thrombosis from three aspects: (i) the interaction of the stent with host blood vessel, involve the response of vascular wall, the mechanism of mechanical signal transmission, the process of re-endothelialization and late thrombosis; (ii) the changes of hemodynamics in the lumen of the vascular segment and (iii) the changes of mechanical microenvironment within the vascular segment wall due to stent implantation. This review has summarized and analyzed current work in order to better solve the two main problems after stent implantation, namely in stent restenosis and late thrombosis, meanwhile propose the deficiencies of current work for future reference.

Understanding the Coronary Bifurcation Stenting

Coronary bifurcation stenting is still complex and associated with a high risk of stent thrombosis and restenosis even with contemporary techniques. Although provisional approach has been proved to be the standard strategy of treatment, There is still lack of evidences for multiple steps of the procedure. For so many years we have been focused on the optimization of side branch (SB), but the clinical outcome is mostly dependent on the main vessel (MV) stenting. The optimal expansion of MV stent without the compromise of SB is the ultimate goal to achieve in the coronary bifurcation stenting. Understanding the anatomy and physiology of coronary bifurcation lesion should be the most important step to this goal. The relationship of vessel diameter between branches and the anatomical and functional significance of plaque shift and carina shift are two most important concepts to understand. They are the science behind the predictors of SB occlusion, and the rationale of proximal optimization technique and final kissing ballooning. This specific review will be devoted to review those concepts as well as clinical evidences to support them.

Clinical Outcome of Double Kissing Crush Versus Provisional Stenting of Coronary Artery Bifurcation Lesions: The 5-Year Follow-Up Results From a Randomized and Multicenter DKCRUSH-II Study (Randomized Study on Double Kissing Crush Technique Versus Provisional Stenting Technique for Coronary Artery Bifurcation Lesions)

BACKGROUND

Provisional stenting is effective for anatomic simple bifurcation lesions. Double kissing crush stenting reduces the 1-year rate of target lesion revascularization. This study aimed to investigate the 5-year clinical results of the DKCRUSH-II study (Randomized Study on Double Kissing Crush Technique Versus Provisional Stenting Technique for Coronary Artery Bifurcation Lesions).

METHODS AND RESULTS

A total of 370 patients with coronary bifurcation lesions who were randomly assigned to either the double kissing crush or provisional stenting group in the DKCRUSH-II study were followed for 5 years. The primary end point was the occurrence of a major adverse cardiac event at 5 years. Patients were classified by simple and complex bifurcation lesions according to the DEFINITION criteria (Definitions and Impact of Complex Bifurcation Lesions on Clinical Outcomes After Percutaneous Coronary Intervention Using Drug-Eluting Stents). At 5 years, the major adverse cardiac event rate (23.8%) in the provisional stenting group was insignificantly different to that of the double kissing group (15.7%; P=0.051). However, the difference in the target lesion revascularization rate between 2 groups was sustained through the 5-year follow-up (16.2% versus 8.6%; P=0.027). The definite and probable stent thrombosis rate was 2.7% in each group (P=1.0). Complex bifurcation was associated with a higher rate of target lesion revascularization (21.6%) at 5 years compared with 11.1% in patients with a simple bifurcation (P=0.037), with an extremely high rate in the provisional stenting group (36.8% versus 12.5%, P=0.005) mainly because of final kissing balloon inflation (19.4% versus 5.2%; P=0.036).

CONCLUSIONS

The double kissing crush stenting technique for coronary bifurcation lesions is associated with a lower rate of target lesion revascularization. The optimal stenting approach based on the lesions' complexity may improve the revascularization for patients with complex bifurcations.

CLINICAL TRIAL REGISTRATION

URL: http://www.chictr.org. Unique identifier: ChiCTR-TRC-0000015.

Optical coherence tomography to guide percutaneous treatment of coronary bifurcation disease

INTRODUCTION

Cardiovascular disease remains the most common cause of death worldwide. Enormous progress in the technology and applicability of percutaneous techniques to treat obstructive coronary heart disease has been made, and the number of percutaneous coronary interventions (PCI) is increasing. Coronary bifurcations are involved in a substantial number of PCIs and despite recent advances, bifurcation PCI remains a challenge in terms of immediate success and long-term outcome. Angiography has a limited capacity for showing important features of the 3 dimensional coronary vessel anatomy, position of stent struts and exact wire positions and is therefore suboptimal for guiding bifurcation PCI. Intracoronary optical coherence tomography (OCT) provides high resolution and the information gained during PCI is unprecedented compared with angiography guidance and intravascular ultrasound. Areas covered: This review will provide an overview of the use of OCT to guide bifurcation-PCI. Expert commentary: OCT is a promising guide for bifurcation-PCI at each individual step: from planning the strategy (provisional versus two-stent strategy), to guidance during PCI, and finally checking the interventional result. Until dedicated randomized trails are complete, we recommend OCT guidance for interventions in complex coronary bifurcation disease and for imaging when unexpected procedural events occur.

Coronary fractional flow reserve measurements of a stenosed side branch: a computational study investigating the influence of the bifurcation angle

Background

Coronary hemodynamics and physiology specific for bifurcation lesions was not well understood. To investigate the influence of the bifurcation angle on the intracoronary hemodynamics of side branch (SB) lesions computational fluid dynamics simulations were performed.

Methods

A parametric model representing a left anterior descending—first diagonal coronary bifurcation lesion was created according to the literature. Diameters obeyed fractal branching laws. Proximal and distal main branch (DMB) stenoses were both set at 60 %. We varied the distal bifurcation angles (40°, 55°, and 70°), the flow splits to the DMB and SB (55 %:45 %, 65 %:35 %, and 75 %:25 %), and the SB stenoses (40, 60, and 80 %), resulting in 27 simulations. Fractional flow reserve, defined as the ratio between the mean distal stenosis and mean aortic pressure during maximal hyperemia, was calculated for the DMB and SB (FFR_SB) for all simulations.

Results

The largest differences in FFR_SB comparing the largest and smallest bifurcation angles were 0.02 (in cases with 40 % SB stenosis, irrespective of the assumed flow split) and 0.05 (in cases with 60 % SB stenosis, flow split 55 %:45 %). When the SB stenosis was 80 %, the difference in FFR_SB between the largest and smallest bifurcation angle was 0.33 (flow split 55 %:45 %). By describing the ΔP_SB−Q_SB relationship using a quadratic curve for cases with 80 % SB stenosis, we found that the curve was steeper (i.e. higher flow resistance) when bifurcation angle increases (ΔP = 0.451*Q + 0.010*Q² and ΔP = 0.687*Q + 0.017*Q² for 40° and 70° bifurcation angle, respectively). Our analyses revealed complex hemodynamics in all cases with evident counter-rotating helical flow structures. Larger bifurcation angles resulted in more pronounced helical flow structures (i.e. higher helicity intensity), when 60 or 80 % SB stenoses were present. A good correlation (R² = 0.80) between the SB pressure drop and helicity intensity was also found.

Conclusions

Our analyses showed that, in bifurcation lesions with 60 % MB stenosis and 80 % SB stenosis, SB pressure drop is higher for larger bifurcation angles suggesting higher flow resistance (i.e. curves describing the ΔP_SB−Q_SB relationship being steeper). When the SB stenosis is mild (40 %) or moderate (60 %), SB resistance is minimally influenced by the bifurcation angle, with differences not being clinically meaningful. Our findings also highlighted the complex interplay between anatomy, pressure drops, and blood flow helicity in bifurcations.

Plaque morphology predictors of side branch occlusion after provisional stenting in coronary bifurcation lesion: Results of optical coherence tomography bifurcation study (ORBID)

OBJECTIVES

The aim of this study was to identify the predictors of side branch (SB) ostial stenosis developed after provisional stenting of the main vessel (MV) using optical coherence tomography (OCT).

BACKGROUND

Provisional stenting remains the main approach to treatment of bifurcation lesions; however, it may result in the narrowing of SB ostium. There is little information about underlying plaque morphology of the MV lesion and its potential impact on the SB after provisional stenting.

METHODS

Patients with stable coronary disease with angiographic MV lesion not involving SB were included in a prospective single center study. The primary outcome was significant SB ostium stenosis (SBOS), defined as residual stenosis of >50% after MV stenting.

RESULTS

Thirty bifurcation lesions in 30 patients were analyzed in the study. Poststenting significant SBOS was observed in 30% of patients. The MV lesions with SBOS > 50% were characterized by a higher prevalence of lipid rich plaques (100 vs. 64%, p = 0.040) and spotty calcifications (60 vs. 0%, p = 0.005). Maximal lipid arcs were greater (257° vs. 132°, p = 0.001) and lipid volume index was higher (1380 vs. 574, p = 0.012) in the SBOS >50% group. Multivariate logistic regression analysis identified maximal lipid arc (odds ratio (OR): 1.014, p = 0.038) and the presence of lipid plaque contralateral to SB ostium (OR: 8.14, p = 0.046) before stenting as independent predictors of significant SBOS after PCI.

CONCLUSIONS

High lipid content of the MV lesion and a contralateral location of lipid in the bifurcation area may contribute to SBOS after provisional stenting. © 2016 Wiley Periodicals, Inc.

Practical based approach to left main bifurcation stenting

Despite the recent developments that have been made in the field of percutaneous left main (LM) intervention, the treatment of distal LM bifurcation remains challenging. The provisional one-stent approach for LM bifurcation has shown more favorable outcomes than the two-stent technique, making the former the preferred strategy in most types of LM bifurcation stenosis. However, elective two-stent techniques, none of which has been proven superior to the others, are still used in patients with severely diseased large side branches to avoid acute hemodynamic compromise. Selecting the proper bifurcation treatment strategy using meticulous intravascular ultrasound evaluation for side branch ostium is crucial for reducing the risk of side branch occlusion and for improving patient outcomes. In addition, unnecessary complex intervention can be avoided by measuring fractional flow reserve in angiographically isolated side branches. Most importantly, good long-term clinical outcomes are more related to the successful procedure itself than to the type of stenting technique, emphasizing the greater importance of optimizing the chosen technique than the choice of method.

The story of plaque shift and carina shift

Side branch (SB) occlusion is one of the most serious complications of main vessel (MV) stenting. Although plaque shift has been considered the major mechanism of SB occlusion, recent studies have suggested carina shift to be the more important cause. Considering the recent pressure wire as well as intravascular ultrasonography studies, the relationship between carina shift and plaque shift in SB occlusion can be described as follows. The anatomical compromise of the SB after MV stenting is not as functionally significant as it appears, because it is mostly explained by carina shift, which is not the major cause of functional compromise. Superimposition of plaque shift over carina shift appears to be the mechanism of haemodynamically significant SB stenosis. Plaque is shifted mostly from the proximal MV, which explains why the plaque burden of the proximal MV is a significant risk factor of SB functional compromise or occlusion.

Three-Dimensional Optical Coherence Tomographic Analysis of Eccentric Morphology of the Jailed Side-Branch Ostium in Coronary Bifurcation Lesions

BACKGROUND

The severity of angiographic diameter stenosis of the jailed side-branch ostium is usually overestimated over the 3-D optical coherence tomography (OCT)-measured actual stenosis. Using 3-D OCT, morphologic changes in the jailed side-branch ostium were evaluated before and after a single stent crossover at coronary bifurcation lesions.

METHODS

In 109 patients who received a single stent crossover at coronary bifurcation lesions, the minimal lumen area (MLA) before and after intervention and the eccentricity of the jailed side-branch ostium were measured with 3-D OCT. The eccentricity index was defined as the ratio of maximal diameter/minimal diameter of the jailed side-branch ostium. When the eccentricity index was < 1.5, the shape of the jailed side-branch ostium was defined as circular. The MLA of the jailed side-branch ostium was also calculated from the quantitative coronary angiography (QCA) minimal lumen diameter assuming a circular lumen.

RESULTS

The 3-D OCT-measured MLA of the jailed side-branch ostium decreased from 2.91 ± 1.65 mm(2) before intervention to 2.37 ± 1.48 mm(2) after intervention (P < 0.01). The QCA-derived MLA also decreased from 2.35 ± 1.71 mm(2) before intervention to 1.68 ± 1.56 mm(2) after intervention (P < 0.01). However, the 3-D OCT-measured MLA was significantly larger than the QCA-derived MLA (P < 0.01). The shape of the jailed side-branch ostium changed from circular to elliptical after the stent implantation (eccentricity index: 1.40 ± 0.33 before intervention; 1.71 ± 0.60 after intervention; P < 0.01).

CONCLUSIONS

Compared with QCA measurements, 3-D OCT analysis could be useful to guide decisions regarding additional intervention after stent implantation across coronary bifurcation lesions.

Randomized Comparison of FFR-Guided and Angiography-Guided Provisional Stenting of True Coronary Bifurcation Lesions: The DKCRUSH-VI Trial (Double Kissing Crush Versus Provisional Stenting Technique for Treatment of Coronary Bifurcation Lesions VI)

OBJECTIVES

This study sought to compare the outcomes of fractional flow reserve (FFR)-guided and angiography (Angio)-guided provisional side-branch (SB) stenting for true coronary bifurcation lesions.

BACKGROUND

Angio-guided provisional SB stenting after stenting of the main vessel provides favorable outcomes for the majority of coronary bifurcation lesions. Whether an FFR-guided provisional stenting approach is superior has not been studied.

METHODS

A total of 320 patients with single Medina 1,1,1 and 0,1,1 coronary bifurcation lesions undergoing stenting with a provisional SB approach were randomly assigned 1:1 to Angio-guided and FFR-guided groups. SB stenting was performed for Thrombolysis In Myocardial Infarction flow grade<3, ostial SB stenosis>70%, or greater than type A dissection after main vessel stenting in the Angio-guided group and for SB-FFR<0.80 in the FFR-guided group. The primary endpoint was the 1-year composite rate of major adverse cardiac events (cardiac death, myocardial infarction, and clinically driven target vessel revascularization).

RESULTS

Comparing the Angio-guided and FFR-guided groups, treatment of the SB (balloon or stenting) was performed in 63.1% and 56.3% of lesions respectively (p=0.07); stenting of the SB was attempted in 38.1% and 25.9%, respectively (p=0.01); and, when attempted, stenting was successful in 83.6% and 73.3% of SBs, respectively (p=0.01). The 1-year composite major adverse cardiac event rate was 18.1% in both groups (hazard ratio: 0.91, 95% confidence interval: 0.48 to 1.88; p=1.00). The 1-year target vessel revascularization and stent thrombosis rates were 6.9% and 5.6% (p=0.82) and 1.3% and 0.6% (p=0.56) in the Angio-guided and FFR-guided groups, respectively.

CONCLUSIONS

In this multicenter, randomized trial, angiographic and FFR guidance of provisional SB stenting of true coronary bifurcation lesions provided similar 1-year clinical outcomes. (Randomized Study on DK Crush Technique Versus Provisional Stenting Technique for Coronary Artery Bifurcation Lesions; ChiCTR-TRC-07000015).

Impact of final kissing balloon inflation after simple stent implantation for the treatment of non-left main true coronary bifurcation lesions in patients with acute coronary syndrome

OBJECTIVES

We sought to evaluate the impact of final kissing balloon inflation (FKBI) after simple stent implantation for the treatment of non-left main true coronary bifurcation lesions in patients with acute coronary syndrome (ACS).

BACKGROUND

Whether FKBI should be mandatory after simple stent implantation for the treatment of coronary bifurcation lesion is controversial. Besides, ACS patients who have undergone bifurcation percutaneous coronary intervention with simple stent implantation may experience worse prognosis compared to stable angina pectoris patients.

METHODS

Two hundred and fifty one eligible patients (67.7% male, mean age 61.7 ± 10.4 years) were enrolled. The study population was divided into two groups according to the performance of FKBI. The primary end points were major adverse cardiac event (MACE); target lesion revascularization (TLR), non-fatal myocardial infarction (MI) and cardiac death during the follow-up period.

RESULTS

Over a mean follow-up period of 3.0 ± 1.9 years, there were 29 MACEs (10 TLR, 6 non-fatal MI, and 13 cardiac deaths), representing an event rate of 11.6%. Kaplan-Meier survival analysis revealed that FBKI group had favorable outcome compared to non-FKBI group with regard to hard events (p = 0.010) as well as composite MACEs (p = 0.008). In multivariable analysis, FKBI was a significant predictor of composite MACEs [hazard ratio 0.398 (95% confidence interval 0.190-0.836, p = 0.015)] and hard events [hazard ratio 0.325 (95% confidence interval 0.130-0.811, p = 0.016)].

CONCLUSIONS

In terms of prognosis, performing FKBI after simple stent implantation for the treatment of non-left main true coronary bifurcation lesions may be mandatory in ACS patients.

Percutaneous coronary intervention for coronary bifurcation disease: consensus from the first 10 years of the European Bifurcation Club meetings

The European Bifurcation Club (EBC) is an independent, non-political and informal "think tank" of scientists with a particular interest in clinical, technical and fundamental aspects of the management of coronary artery bifurcation disease. Bifurcations account for 15-20% of all percutaneous coronary interventions (PCI) and remain one of the most challenging lesions in interventional cardiology in terms of procedural success rate as well as long-term cardiac events. The optimal management is, despite a fast growing scientific literature, still the subject of considerable debate, one of the main concerns being the potential increased risk of late stent thrombosis associated with treatment complexity. The EBC was initiated in 2004 and aims to facilitate an exchange of ideas on management of bifurcation disease. The EBC hosts an annual, compact meeting dedicated to bifurcations which brings together physicians, engineers, biologists, physicists, epidemiologists and statisticians for detailed discussions. Every meeting is finalised with a consensus statement which reflects the unique opportunity of combining the opinion of interventional cardiologists with the opinion of a large variety of other scientists on bifurcation management. This year the EBC celebrates its 10-year anniversary. This consensus document represents the summary of the consensus from the last ten years of the annual EBC meetings.