Understanding the Coronary Bifurcation Stenting

Drug-Coated Balloon-Based Treatment of Left Main True Bifurcation Lesion

BACKGROUND

There is a paucity of data regarding drug-coated balloon (DCB) treatment in the context of left main (LM) true bifurcation lesions.

AIMS

The aim of this study was to evaluate the safety and efficacy of DCB-based treatment for unprotected LM true bifurcation lesions.

METHODS

A total of 39 patients with LM true bifurcation lesion (Medina: 1,1,1/0,1,1/1,0,1) who were successfully treated with DCB alone or in combination with drug-eluting stent (DES) were retrospectively enrolled into the DCB-based group. They were compared with 39 propensity-matched patients who were treated with second-generation DES from the COBIS III registry (n = 2648). Major adverse cardiovascular events (MACE) were defined as cardiac death, myocardial infarction, stent or target lesion thrombosis, and target lesion revascularization at the 2-year follow-up.

RESULTS

Baseline clinical characteristics were similar between the groups, except for the prevalence of in-stent restenosis (ISR) lesions (41.0% in DCB-based group vs. 17.9% in DES-only group, p = 0.047). In the DCB-based group, 59.0% of the patients (n = 23) underwent DCB-only treatment. There were no cases of abrupt vessel closure requiring treatment following DCB application. The MACE were comparable between both groups (12.8% in DCB-based group vs. 17.9% in DES-only group, p = 0.861) after 2 years.

CONCLUSIONS

In patients with unprotected LM true bifurcation lesions, DCB-based treatment demonstrated comparable clinical outcomes at the 2-year follow-up when compared to DES-only treatment. DCB-based treatment could be considered a safe and effective alternative to DES for carefully selected patients who have achieved satisfactory predilation results (Impact of DCB Treatment in De Novo Coronary Lesion; NCT04619277).

Differential Prognosis of True Bifurcation Lesions According to Left Main Versus Non-Left Main Location and Treatment Strategy

BACKGROUND

Although true bifurcation lesions are associated with a high risk of procedural complications, the differential prognostic implications of percutaneous coronary intervention for true bifurcations according to lesion location are unclear. This study aimed to identify whether clinical outcomes of true bifurcation lesions differed between left main coronary artery (LM) and non-LM bifurcations and to determine the optimal treatment strategy for subtypes of bifurcation lesions in the current-generation drug-eluting stent era.

METHODS

The ULTRA-BIFURCAT (Combined Insights From the Unified COBIS III, RAIN, and ULTRA Registries) was created by merging 3 bifurcation-dedicated registries from Korea and Italy. For this, 6548 patients treated with bifurcation lesions were stratified by lesion location and subtype. The primary end point was major adverse cardiac events (MACEs; composite of all-cause death, myocardial infarction, target lesion revascularization, and stent thrombosis) at 800 days.

RESULTS

In patients with an LM bifurcation, those with a true bifurcation had a significantly higher risk of a MACE than those with a nontrue bifurcation (20.2% versus 13.4%, adjusted hazard ratio [HR], 1.44 [95% CI, 1.11-1.86]; P=0.006). Conversely, there was no significant difference in the risk of a MACE according to true versus nontrue bifurcation in patients with non-LM bifurcation lesions (9.0% versus 8.8%; adjusted HR, 1.02 [95% CI, 0.82-1.27]; P=0.849). For LM true bifurcations, MACE rates were comparable between 1-stent and 2-stent strategies, whereas for LM nontrue bifurcations, the 2-stent strategy was associated with a significantly higher risk of MACEs than the 1-stent strategy. No significant differences in the risk of MACEs were observed in non-LM bifurcation lesions according to lesion subtype or treatment strategy.

CONCLUSIONS

Clinical outcomes were worse for LM true bifurcation lesions than non-LM true bifurcation lesions. A provisional 1-stent strategy should be the preferred approach for treating LM nontrue bifurcation lesions.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03068494, NCT03544294, and NCT05205148.

Shepherd's Crook Curve: A Novel Technique for Angulated Side Branch Access in Bifurcation Angioplasty

Coronary intervention involving the region of bifurcation remains a challenging issue for the cardiologist as well as a complication. A number of factors including the angulation of side branch with the main branch determines the success. Though provisional strategy remains the best option in bifurcation intervention, at times a two-stent strategy cannot be avoided. We report a case in which percutaneous coronary intervention was performed on the left anterior descending artery (LAD) at its bifurcation with a major diagonal branch (> 2.5 mm). The ostium of the diagonal was diseased, and the branch took off from the LAD at an unfavorable angle (> 120°). We describe the use of the "shepherd's crook wire curve" approach, a modification of the reverse wire technique, which allowed us to successfully wire, dilate, and protect the diagonal and so named to reflect its resemblance to the shape of a shepherd's crook.

Immediate, Short-Term, Intermediate, and Long-Term Clinical Outcomes of True Bifurcation Stenting

INTRODUCTION

Coronary artery bifurcation lesion is an epicardial stenosis that, when compared to non-bifurcation lesions, poses a greater risk of adverse events and can compromise prognosis. This study aims to investigate the clinical efficacy of different stenting techniques, particularly in terms of their immediate, short-term, intermediate, and long-term outcomes in patients with true bifurcation lesions.

METHODOLOGY

This retrospective observational cohort study was conducted in a tertiary cardiac hospital in Islamabad, from February 1, 2015, to February 28, 2021. A total of 172 patients who met the inclusion criteria and underwent percutaneous coronary intervention were selected using a consecutive sampling technique. Follow-up was maintained for three years to assess procedural outcomes.

RESULTS

Of the 172 participants, the majority were males (69%) and only 4% were above 75 years of age. A significant relation between major adverse cardiac events (MACEs) with acute coronary syndrome (ACS) and previous percutaneous coronary intervention (PCI) (p < 0.000) was observed. Procedural success was good in all patients using the drug-eluting stent. The MAC rate was 6.9% and the final kissing balloon inflation, stenting technique, and bifurcation involvement were significantly associated with MACE occurrence (p < 0.01), and mortality was reported in two patients (1.16%). MACEs were associated with mortality; previous PCI and hypertension increased the risk of mortality.

CONCLUSION

The two-stent strategy can be used with good long-term outcomes and low complication rates.

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.

3D reconstruction of coronary artery bifurcations from intravascular ultrasound and angiography

Coronary bifurcation lesions represent a challenging anatomical subset, and the understanding of their 3D anatomy and plaque composition appears to play a key role in devising the optimal stenting strategy. This study proposes a new approach for the 3D reconstruction of coronary bifurcations and plaque materials by combining intravascular ultrasound (IVUS) and angiography. Three patient-specific silicone bifurcation models were 3D reconstructed and compared to micro-computed tomography (µCT) as the gold standard to test the accuracy and reproducibility of the proposed methodology. The clinical feasibility of the method was investigated in three diseased patient-specific bifurcations of varying anatomical complexity. The IVUS-based 3D reconstructed bifurcation models showed high agreement with the µCT reference models, with r2 values ranging from 0.88 to 0.99. The methodology successfully 3D reconstructed all the patient bifurcations, including plaque materials, in less than 60 min. Our proposed method is a simple, time-efficient, and user-friendly tool for accurate 3D reconstruction of coronary artery bifurcations. It can provide valuable information about bifurcation anatomy and plaque burden in the clinical setting, assisting in bifurcation stent planning and education.

OCT Guidance in Bifurcation Percutaneous Coronary Intervention

Coronary bifurcation is defined by the European Bifurcation Consensus as a coronary artery stenosis adjacent to the origin of a significant side branch. Its anatomy is composed of 3 different segments: proximal main vessel, distal main vessel and side branch. Coronary artery bifurcation lesions are encountered in approximately 15-20% of all percutaneous coronary interventions and constitute a complex subgroup of lesions characterized by lower procedural success rates and higher rates of adverse outcomes. In recent years, a growing focus in the European and Japanese bifurcation club meetings has been the emerging role of intravascular imaging, in guiding successful bifurcation percutaneous coronary interventions (PCI). In this review we will present the main ways optical coherence tomography (OCT) can be used to improve outcomes during bifurcation PCI.

Drug-Eluting Stents: Technical and Clinical Progress

Drug-eluting stents (DES) demonstrated superior efficacy when compared to bare metal stents and plain-old balloon angioplasty and are nowadays used in almost all percutaneous revascularization procedures. The design of the stent platforms is constantly improving to maximize its efficacy and safety. Constant development of DES includes adoption of new materials used for scaffold production, new design types, improved overexpansion abilities, new polymers coating and, finally, improved antiproliferative agents. Especially nowadays, with the immense number of available DES platforms, it is crucial to understand how different aspects of stents impact the effect of their implantation, as subtle differences between various stent platforms could impact the most important issue-clinical outcomes. This review discusses the current status of coronary stents and the impact of stent material, strut design and coating techniques on cardiovascular outcomes.

Long-Term Clinical Outcomes and Its Predictors Between the 1- and 2-Stent Strategy in Coronary Bifurcation Lesions - A Baseline Clinical and Lesion Characteristic-Matched Analysis

BACKGROUND

Differences in the impact of the 1- or 2-stent strategy in similar coronary bifurcation lesion conditions are not well understood. This study investigated the clinical outcomes and its predictors between 1 or 2 stents in propensity score-matched (PSM) complex bifurcation lesions.

METHODS AND RESULTS

We analyzed the data of patients with bifurcation lesions, obtained from a multicenter registry of 2,648 patients (median follow up, 53 months). The patients were treated by second generation drug-eluting stents (DESs). The primary outcome was target lesion failure (TLF), composite of cardiac death, target vessel myocardial infarction (TVMI), and ischemia-driven target lesion revascularization (TLR). PSM was performed to balance baseline clinical and angiographic discrepancies between 1 and 2 stents. After PSM (N=333 from each group), the 2-stent group had more TLRs (hazard ratio [HR] 3.14, 95% confidence interval [CI] 1.42-6.97, P=0.005) and fewer hard endpoints (composite of cardiac death and TVMI; HR 0.44, 95% CI 0.19-1.01, P=0.054), which resulted in a similar TLF rate (HR 1.40, 95% CI 0.83-2.37, P=0.209) compared to the 1-stent group. Compared with 1-stent, the 2-stent technique was more frequently associated with less TLF in the presence of main vessel (pinteraction=0.008) and side branch calcification (pinteraction=0.010).

CONCLUSIONS

The 2-stent strategy should be considered to reduce hard clinical endpoints in complex bifurcation lesions, particularly those with calcifications.

Fundamentals of percutaneous coronary bifurcation interventions

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

Customizable Angioplasty Balloon-Forming Machine: Towards Precision Medicine in Coronary Bifurcation Lesion Interventions

The ability to customize the size and shape of angioplasty balloons may be useful in many clinical and research applications of coronary and endovascular intervention. Fully customizable balloons are outside the reach of most researchers due to their prohibitive cost. A small-scale balloon-forming machine was developed to produce fully customizable balloons. This study describes the creation of this customizable balloon-forming machine and identifies the key components of manufacturing a patient-specific balloon. Using a standard balloon-shaped mold created with a novel application of 3D stereolithography-printed resin, 104 PET balloon formation tests were conducted. A statistical study was conducted in which molding temperature and inflation air pressure were independent variables ranging from 100 to 130 °C and from 3.7 to 6.8 atm, respectively. The criteria for balloon-forming success were defined; pressure and temperature combined were found to have a significant impact on the success (p = 0.011), with 120 °C and 4.76 atm resulting in the highest chance for success based on a regression model.

Effect of Wire Jailing at Side Branch in 1-Stent Strategy for Coronary Bifurcation Lesions

OBJECTIVES

This study aimed to determine whether side branch (SB) wire jailing before main vessel (MV) stenting could prevent SB occlusion after the 1-stent strategy for bifurcation percutaneous coronary intervention.

BACKGROUND

The benefits of SB wire jailing in the 1-stent strategy remain unclear.

METHODS

From the COBIS (Coronary Bifurcation Stenting) III registry, 1,890 patients with bifurcation lesions who underwent the 1-stent strategy using second-generation drug-eluting stents were identified and classified into 2 groups according to the use of SB wire jailing: wire jailing (n = 819) and non-wire jailing (n = 1,071). The incidence of SB occlusion (Thrombolysis In Myocardial Infarction flow grade <3) and target lesion failure (cardiac death, myocardial infarction, or target lesion revascularization) was compared.

RESULTS

The incidence of final SB occlusion was not significantly different between wire jailing (1.8%) vs non-wire jailing (2.9%; P = 0.182). However, wire jailing at the SB was a significant protective factor for SB occlusion after MV stenting on multivariate analysis and was significantly associated with a lower incidence of SB occlusion in patients with significant stenoses (≥60%) at the SB (5.1% vs 11.3%; odds ratio: 0.42; 95% CI: 0.19-0.89; P = 0.028) or MV (3.1% vs 6.2%; odds ratio: 0.49; 95% CI: 0.24-0.95; P = 0.039). During follow-up (median 52 months), the incidence of target lesion failure was not significantly different between wire jailing and non-wire jailing (7.6% vs 6.3%; P = 0.343).

CONCLUSIONS

During bifurcation percutaneous coronary intervention with the 1-stent strategy, wire jailing at the SB was associated with a lower rate of final SB occlusion following MV stenting in patients with severe stenoses at the SB or MV but not with overall bifurcation lesions. Long-term clinical outcomes were comparable between the 2 groups.

Design and Performance Evaluation of a Novel Vascular Robotic System for Complex Percutaneous Coronary Interventions

The robotic-assisted percutaneous coronary intervention is an emerging technology with great potential to solve the shortcomings of existing treatments. However, the current robotic systems can not manipulate two guidewires or ballons/stents simultaneously for coronary bifurcation lesions. This paper presents VasCure, a novel bio-inspired vascular robotic system, to deliver two guidewires and stents into the main branch and side branch of bifurcation lesions in sequence. The system is designed in master-slave architecture to reduce occupational hazards of radiation exposure and orthopedic injury to interventional surgeons. The slave delivery device has one active roller and two passive rollers to manipulate two interventional devices. The performance of the VasCure was verified by in vitro and in vivo animal experiments. In vitro results showed the robotic system has good accuracy to deliver guidewires and the maximum error is 0.38mm. In an animal experiment, the interventional surgeon delivered two guidewires and balloons to the left circumflex branch and the left anterior descending branch of the pig, which confirmed the feasibility of the vascular robotic system.

Comparison of 2-Stenting Strategies Depending on Sequence or Technique for Bifurcation Lesions in the Second-Generation Drug-Eluting Stent Era - Analysis From the COBIS (Coronary Bifurcation Stenting) III Registry

BACKGROUND

It has not been determined which specific 2-stenting strategy is the best for bifurcation lesions. Our aim was to investigate the clinical outcomes of various 2-stenting strategies in the era of 2nd-generation drug-eluting stents (2G-DES).

METHODS AND RESULTS

We analyzed 454 patients who finally underwent 2-stenting for a bifurcation lesion, from among 2,648 patients enrolled in the COBIS III registry. The primary outcome was target lesion failure (TLF). Patients were analyzed according to stenting sequence (provisional [main vessel stenting first] vs. systemic [side branch stenting first]) and stenting technique (crush vs. T vs. culotte vs. kissing/V stenting). Overall, 4.4 years' TLF after 2-stenting treatment for bifurcation lesion was excellent: TLF 11.2% and stent thrombosis 1.3%. There was no difference in TLF according to 2-stenting strategy (11.1% vs. 10.5%, P=0.990 for provisional and systemic sequence; 8.6% vs. 14.4% vs. 12.9% vs. 12.2%, P=0.326 for crush, T, culotte, kissing/V technique, respectively). Only left main (LM) disease and a shorter duration of dual antiplatelet therapy (DAPT) were associated with TLF. The distribution of DAPT duration differed between patients with and without TLF, and the time-point of intersection was 2.5 years. Also, the side branch was the most common site of restenosis.

CONCLUSIONS

The stenting sequence or technique did not affect clinical outcomes, but LM disease and shorter DAPT were associated with TLF, in patients with bifurcation lesions undergoing 2-stenting with 2G-DES.

Ten-Year Trends in Coronary Bifurcation Percutaneous Coronary Intervention: Prognostic Effects of Patient and Lesion Characteristics, Devices, and Techniques

Background

Despite advances in devices and techniques, coronary bifurcation lesion remains a challenging lesion subset in the field of percutaneous coronary intervention (PCI). We evaluate 10‐year trends in bifurcation PCI and their effects on patient outcomes.

Methods and Results

We analyzed 10‐year trends in patient/lesion characteristics, devices, PCI strategy, stent optimization techniques, and clinical outcomes using data from 5498 patients who underwent bifurcation PCI from 2004 to 2015. Clinical outcomes 2 years after the index procedure were evaluated in terms of target vessel failure (a composite of cardiac death, myocardial infarction, and target vessel revascularization) and a patient‐oriented composite outcome (a composite of all‐cause death, myocardial infarction, and any revascularization). During the 10‐year study period, patient and lesion complexity, such as multivessel disease, diabetes mellitus, chronic kidney disease, and left main bifurcation, increased continuously (all P<0.001). The risk of target vessel failure or patient‐oriented composite outcome decreased continuously from 2004 to 2015 (target vessel failure: from 12.3% to 6.9%, log‐rank P<0.001; patient‐oriented composite outcome: from 13.6% to 9.3%, log‐rank P<0.001). The use of a second‐generation drug‐eluting stent and decreased target vessel failure risk in true bifurcation lesions were the major contributors to improved patient prognosis (interaction P values were <0.001 and 0.013, respectively).

Conclusions

During the past decade of bifurcation PCI, patient and lesion characteristics, devices, PCI techniques, and patient prognosis have all significantly changed. Despite increased patient and lesion complexity, clinical outcomes after bifurcation PCI have improved, mainly because of better devices and more widespread adoption of procedural optimization techniques and appropriate treatment strategies.

Registration

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01642992 and NCT03068494.

Nano-crush technique in narrow angle (<70˚) bifurcation - bench test, computed tomographic reconstruction, fluid dynamics, and clinical outcomes

BACKGROUND

Bifurcation stenting techniques are still refining and under testing. Nano-crush is a novel technique which allow minimum protrusion of side branch struts at the ostium. To demonstrate the efficacy of Nano-crush technique in narrow-angle bifurcation (<70˚) using bench test model, 3D reconstruction of the stent structure, computational fluid dynamics study and a clinical follow-up.

METHODS

This was a retrospective observational single-centre study which included 40 patients who underwent angioplasty using Nano-crush technique for de-novo complex coronary bifurcation lesions with narrow bifurcation angle(<70˚) between April-2016 to March-2019. The in-vitro bench test and computational fluid dynamics analysis were performed using a bifurcation model designed. The clinical primary endpoint was major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, and target lesion revascularization (TLR) at one-year angiographic follow-up.

RESULTS

The reconstructed results of in-vitro bench test showed minimum length of stent struts moving away from the rounded side branch ostium. The mean age of patients was 62.8 ± 7.98 years (32 male) and presented 100% procedural success. The mean bifurcation angle was 47.3˚ ± 9.2˚. The MACE was reported in 4 (10%) patients which included 1 (2.5%) death and 3 (7.5%) TLR at the mean follow-up of 35.54 ± 12.31 months. No significant correlation between occurrence of MACE and gender, age, comorbidities and bifurcation angle was reported.

CONCLUSIONS

The Nano-crush technique demonstrated least metal load around carina and abnormal flow dynamics in narrow angle (<70˚) bifurcation lesions and also reported favorable long-term clinical outcomes.

Drug coated balloons for coronary artery bifurcation lesions: A systematic review and focused meta-analysis

OBJECTIVES

We sought to systematically review the evidence supporting the role of drug coated balloons (DCBs) in the treatment of coronary bifurcation lesions.

BACKGROUND

DCBs are emerging as an attractive alternative treatment strategy for treating coronary bifurcations due to simplifying the approach and reducing rates of stent related complications. We systematically reviewed the evidence for DCB use in coronary bifurcations and conducted a focused meta-analysis on late lumen loss in the side branch comparing DCB and plain old balloon angioplasty (POBA).

METHODS

This study was conducted in line with the PRISMA statement. All studies (including both RCTs and observational studies, excluding case reports) using DCB as part of a bifurcation strategy were included in this review. A literature search identified a total of ten studies for inclusion. A focused meta-analysis was undertaken for the use of DCB in side-branch compared with POBA. Mean late lumen loss was used with a random effects model due to heterogeneity.

RESULTS

DCB was found to be superior to POBA for side branch treatment in bifurcations (p = 0.01). There are four studies that investigated the use of DCB for main branch treatment in a bifurcation, with evidence supporting its safety in main branches of bifurcation lesions, while prospective observational studies have demonstrated favourable target lesion revascularisation rates.

CONCLUSION

Although there is a lack of robust RCTs comparing DCBs with current generation DES, DCBs appear safe in main branch bifurcation lesions with improved side branch late lumen loss when compared with DES or POBA.

Assessment of single and double coronary bifurcation stenting techniques using multimodal imaging and 3D modeling in reanimated swine hearts using Visible Heart® methodologies

Stent implantation in bifurcated coronary lesions is technically challenging so that procedural refinements are continuously investigated. Novel procedure modeling and intracoronary imaging techniques may offer critical insights on stent deformations and stent-wall interactions during bifurcation stenting procedures. Thus, we assessed coronary bifurcation stenting techniques using multimodal imaging and 3D modeling in reanimated swine hearts. Harvested swine hearts were reanimated using Visible Heart® methodologies and (under standard fluoroscopic guidance) used to test 1-stent (provisional and inverted provisional) and 2-stent (culotte, TAP and DK-crush) techniques on bifurcations within various coronary vessels using commercially available devices. Intracoronary angioscopy and frequency-domain optical-coherence-tomography (OCT) were obtained during the procedures. 3D OCT reconstruction and micro-computed tomography 3D modeling (post heart fixations) were used to assess stent deformations and stent-wall interactions. We conducted multiple stenting procedures and collected unique endoscopic and OCT images (and subsequent computational models from micro-CT) to assess stent deformations and device/wall interactions during different steps of bifurcation stenting procedures. Endoscopy, micro-CT and virtual reality processing documented that different 1- and 2-stent techniques, practiced according to experts’ recommended steps, achieve optimal post-intervention stent conformation. As compared with intra-procedural endoscopy, software-generated 3D OCT images accurately depicted stent deformations during 1-stent techniques. On the opposite, during more complex 2-stent techniques, some defects were appreciated at 3D OCT reconstruction despite optimal 2D OCT images. This study provided unique insights regarding both stent deformations occurring in the course of bifurcation stenting and the efficacy of OCT to visualize them.

Association of Side-Branch Treatment and Patient Factors in Left Anterior Descending Artery True Bifurcation Lesions: Analysis from the GRAND-DES Pooled Registry

Methods

Patients undergoing PCI to left anterior descending (LAD) bifurcation lesions with contemporary DES were analyzed from a nationwide registry. Baseline risk was assessed using the Age, Creatinine, and Ejection Fraction (ACEF) score. Target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, and target lesion revascularization, was assessed at 3 years.

Results

Among 1,089 patients with LAD bifurcation lesions, 548 (50.3%) patients underwent SB treatment. The SB treatment group showed a nonsignificant, but numerically lower rate of 3-year TLF (6.6% vs. 9.2%, HR 0.75, 95%CI 0.44–1.28, p = 0.29). In patients with low pretreatment risk (ACEF<1.22), SB treatment was associated with a lower rate of 3-year TLF (HR 0.43, 95%CI 0.19–0.96, p = 0.04), while no significant difference was observed in patients with high risk (ACEF≥1.22). The difference in the low risk group was mostly driven by target lesion revascularization (HR 0.24, 95%CI 0.08–0.75, p = 0.01).

Conclusions

SB treatment for LAD bifurcation lesions showed favorable long-term outcomes compared with main-branch-only intervention, especially in patients with low pretreatment risk.

3D reconstruction of coronary artery bifurcations from coronary angiography and optical coherence tomography: feasibility, validation, and reproducibility

The three-dimensional (3D) representation of the bifurcation anatomy and disease burden is essential for better understanding of the anatomical complexity of bifurcation disease and planning of stenting strategies. We propose a novel methodology for 3D reconstruction of coronary artery bifurcations based on the integration of angiography, which provides the backbone of the bifurcation, with optical coherence tomography (OCT), which provides the vessel shape. Our methodology introduces several technical novelties to tackle the OCT frame misalignment, correct positioning of the OCT frames at the carina, lumen surface reconstruction, and merging of bifurcation lumens. The accuracy and reproducibility of the methodology were tested in n = 5 patient-specific silicone bifurcations compared to contrast-enhanced micro-computed tomography (µCT), which was used as reference. The feasibility and time-efficiency of the method were explored in n = 7 diseased patient bifurcations of varying anatomical complexity. The OCT-based reconstructed bifurcation models were found to have remarkably high agreement compared to the µCT reference models, yielding r² values between 0.91 and 0.98 for the normalized lumen areas, and mean differences of 0.005 for lumen shape and 0.004 degrees for bifurcation angles. Likewise, the reproducibility of our methodology was remarkably high. Our methodology successfully reconstructed all the patient bifurcations yielding favorable processing times (average lumen reconstruction time < 60 min). Overall, our method is an easily applicable, time-efficient, and user-friendly tool that allows accurate and reproducible 3D reconstruction of coronary bifurcations. Our technique can be used in the clinical setting to provide information about the bifurcation anatomy and plaque burden, thereby enabling planning, education, and decision making on bifurcation stenting.

Critical aspects of balloon position during final proximal optimization technique (POT) in coronary bifurcation stenting

OBJECTIVES

In a coronary bifurcation bench model, to determine the effects of side branch (SB) wire crossing position and balloon position on the stent scaffolding after the final proximal optimization technique (POT).

BACKGROUND

POT performed as a final step after SB dilatation or kissing balloon inflation (KBI) has been widely advocated despite limited evidence.

METHODS

Thirty-one stent implantations in bifurcation phantoms were performed using a one-stent provisional technique with (KBI) (n = 13), with POT-side-POT technique (n = 12) or with the two-stent culotte technique (n = 6). SB wiring was performed through either a proximal or a distal stent cell and confirmed by optical coherence tomography. Final POT was performed with the balloon positioned either across or proximal to the SB takeoff. The area of the opened stent cell in front of the SB was assessed by 3D reconstructed microcomputation tomography scans performed before and after Final POT.

RESULTS

In cases with metallic carina, final POT across the SB takeoff caused SB rejailing. Regardless of stent technique and wire position, a Final POT across the SB takeoff reduced the SB cell opening area by 43% [32%;58%] (n = 15). The largest reduction (54-70%) was found after the POT-side-POT technique in procedures with a proximal wiring. Final POT performed proximal to the SB takeoff caused limited or no SB cell opening area reduction (4% [0.6%;6%] [n = 16]).

CONCLUSION

Final POT with balloon positioned across the SB takeoff in a narrow angle bifurcation reduces largest stent cell area in front of the SB ostium and may cause SB rejailing in cases with metallic carina.

Relationship between neointimal strut bridge and jailed side-branch ostial area

BACKGROUND

Our study analyzed the relationship between the neointimal strut bridge and jailed side-branch (SB) ostial area in patients with coronary heart disease (CHD) who had a single drug-eluting stent (DES) crossover of the left anterior descending coronary artery (LAD)/diagonal branch (D) bifurcation.

PATIENTS AND METHODS

A total of 64 CHD patients with an LAD/D bifurcation treated by optical coherence tomography (OCT)-guided single-DES implantation and followed up at 1 year after primary percutaneous intervention (pPCI) were enrolled in our study. According to the two-dimensional OCT results, patients were divided into a non-neointimal bridge group (n = 44) and a neointimal bridge group (n = 20). Basic clinical, angiographic, 2D and 3D OCT, and DES results were analyzed.

RESULTS

The blood lipid levels of the two groups after the 1‑year follow-up were lower than the levels 1 year earlier (p < 0.05). There was a notable decrease in the SB ostial minimum lumen diameter and area directly after pPCI vs. before pPCI in both groups. The diameter stenosis directly after pPCI showed a clear increase compared with the pre-pPCI value in both groups (p < 0.05 or p < 0.01, respectively). The strut distance of the neointimal bridges in the neointimal bridge group was greater than in the non-neointimal bridge group (p < 0.05). A clearly short strut distance of the neointimal bridge was observed compared with the strut distance of the non-neointimal bridge in the neointimal bridge group (p < 0.05). A larger neointimal bridge area and a smaller SB ostial area were found in the neointimal bridge group compared with the non-neointimal bridge group (p < 0.05 or p < 0.01, respectively).

CONCLUSION

A short strut distance facilitated formation of a neointimal bridge, which significantly influenced the SB ostial area after single crossover stenting of the SB orifice at the 1‑year follow-up.