Bifurcation Lesions

Coronary Drug-Coated Balloons: A Comprehensive Review of Clinical Applications and Controversies

Drug-coated balloons have emerged as a promising therapeutic option in the treatment of cardiovascular disease. This review article provides an overview of the concept of drug-coated balloons and their clinical applications in both de novo and treated coronary artery disease. A summary of key clinical trials and registry studies evaluating drug-coated balloons is presented for reference. Overall, this article aims to provide clinicians and researchers with a comprehensive understanding of the current state of drug-coated balloon technology and its implications in clinical practice.

Optical Coherence Tomography Predictors of SIde Branch REstenosis after unprotected Left Main bifurcation angioplasty using double kissing crush technique (OP-SIBRE LM Study)

BACKGROUND

Among the two stent strategies, contemporary evidence favors double kissing crush technique (DKC) for complex unprotected distal left main bifurcation (UdLMB) lesions. However one of the major challenges to these lesions is side branch (SB) restenosis.

AIMS

Our aim was to identify optical coherence tomographic (OCT) characteristics that may predict SB restenosis (SBR) after UdLMB angioplasty using DKC technique.

METHODS

This was a single-center, retrospective study that included 60 patients with complex UdLMB disease, who underwent OCT-guided angioplasty using DKC technique. Angiographic follow-up was performed in all patients at 1 year to identify patients with SBR. Patients with SBR group were compared with patients without SBR (NSBR group) for OCT parameters during index procedure.

RESULTS

Twelve (20%) patients developed SBR at 1-year follow-up. The SBR group had longer SB lesion (18.8 ± 3.2 vs. 15.3 ± 3.7 mm, p = 0.004) and neo-metallic carinal length (2.1 vs. 0.1 mm, p < 0.001) when compared to the NSBR group. Longer neo-metallic carinal length was associated with the absence of the dumbbell sign, presence of hanging stent struts across the SB ostium on OCT of final MB pullback. On multivariate regression analysis, SB distal reference diameter (DRD) and SB stent expansion were identified as independent predictors of SBR with SB-DRD of ≤2.8 mm (area under curve-0.73, sensitivity-83.3%, and specificity-62.5%) and SB stent expansion of ≤89% (area under curve-0.88, sensitivity-83.3%, and specificity- 81.2%) as the best cut off values to predict SBR.

CONCLUSIONS

SB DRD and SB stent expansion are the OCT predictors of future SBR after UdLMB angioplasty using DKC technique.

Novel application of drug-coated balloons in coronary heart disease: A narrative review

The incidence of coronary heart disease (CAD) has soared over the years, and coronary intervention has become an increasingly important therapeutic approach. The past decade has witnessed unprecedented developments in therapeutic medical instruments. Given that drug-coated balloons bring many benefits, they are indicated for an increasing number of conditions. In this article, we review the results of current clinical trials about drug-coated balloons and summarize their safety and clinical progression in different coronary artery diseases, laying the groundwork for basic research, and clinical therapeutics of this patient population.

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.

Bioresorbable scaffolds for treatment of coronary bifurcation lesions: Critical appraisal and future perspectives

Bioresorbable vascular scaffolds have been recently introduced as a novel paradigm for coronary artery disease treatment allowing temporary vessel support and drug delivery without indefinite coronary caging, potentially reducing the long-term limitation of metallic stents. The scientific community has rapidly embraced this concept and bioresorbable devices have been introduced in clinical practice. However, despite the fact that bifurcation lesions represent a large and challenging subset in the field of interventional cardiology, this subgroup of lesions have been avoided in the initial experience with bioresorbable scaffolds and clear recommendations on methodological approaches are lacking. In the present report, we describe the various techniques for bifurcation treatment with bioresorbable scaffolds and the theoretical advantages and disadvantages of this technology in different scenarios, with a glimpse to challenging subsets and possible complications. Therefore, we aim to provide experience based insights and practical guidance for bioresorbable scaffold implantation in bifurcation lesions. © 2016 Wiley Periodicals, Inc.

Impact of the complexity of bifurcation lesions treated with drug-eluting stents: the DEFINITION study (Definitions and impact of complEx biFurcation lesIons on clinical outcomes after percutaNeous coronary IntervenTIOn using drug-eluting steNts)

OBJECTIVES

The present study established criteria to differentiate simple from complex bifurcation lesions and compared 1-year outcomes stratified by lesion complexity after provisional stenting (PS) and 2-stent techniques using drug-eluting stents.

BACKGROUND

Currently, no criterion can distinguish between simple and complex coronary bifurcation lesions. Comparisons of PS and 2-stent strategies stratified by lesion complexity have also not been reported previously.

METHODS

Criteria of bifurcation complexity in 1,500 patients were externally tested in another 3,660 true bifurcation lesions after placement of drug-eluting stents. The primary endpoint was the occurrence of a major adverse cardiac event (MACE) at 12 months. The secondary endpoint was the rate of stent thrombosis (ST).

RESULTS

Complex (n = 1,108) bifurcation lesions were associated with a higher 1-year rate of MACE (16.8%) compared with simple (n = 2,552) bifurcation lesions (8.9%) (p < 0.001). The in-hospital ST and 1-year target lesion revascularization rates after 2-stent techniques in the simple group (1.0% and 5.6%, respectively) were significantly different from those after PS (0.2% [p = 0.007] and 3.2% [p = 0.009], respectively); however, 1-year MACE rates were not significantly different between the 2 groups. For complex bifurcation lesions, 2-stent techniques had lower rates of 1-year cardiac death (2.8%) and in-hospital MACE (5.0%) compared with PS (5.3%, p = 0.047; 8.4%, p = 0.031).

CONCLUSIONS

Complex bifurcation lesions had higher rates of 1-year MACE and ST. The 2-stent and PS techniques were overall equivalent in 1-year MACE. However, 2-stent techniques for complex lesions elicited a lower rate of cardiac death and in-hospital MACE but higher rates of in-hospital ST and revascularization at 1 year for simple lesions.

The utility of stent enhancement to guide percutaneous coronary intervention for bifurcation lesions

AIMS

Percutaneous coronary intervention (PCI) of bifurcation lesions is complex and is technically very demanding. Coronary angiography is considered the gold standard method to guide PCI but has several limitations. The purpose of this study was to determine the utility of stent enhancement with StentBoost® (StB), a novel fluoroscopic imaging technique, and its potential role during bifurcation PCI.

METHODS AND RESULTS

This prospective study included 97 patients who underwent bifurcation PCI (98 bifurcations), using StB. Bifurcation lesions were classified according to the modified Medina classification. StB was performed in all patients to obtain improved stent visualisation and to detect optimal release and deployment. Therefore, three groups were formed, according to the quality of image: optimal visualisation, suboptimal visualisation and poor visualisation. Most of the bifurcation disease involved the main vessel (99%) and in 80 patients (81.6%) there was side branch involvement. Most bifurcations had both main vessel and side branch lesions (Medina 1,1,1) (70 patients, 71.4%). StB image quality was good in 79.6% of the cases (optimal visualisation of the stent and guidewire), was suboptimal in 19.4%, and poor in 1% (overlapping of structures or devices). In three cases, StB enabled the identification of the guidewire and angioplasty balloon passing outside stent borders during rewiring of the side branch.

CONCLUSIONS

Imaging techniques have a primary role during bifurcation PCI. StentBoost is a simple and quick method that offers several advantages, enabling improved stent visualisation, appropriate rewiring of the side branch, adequate stent expansion and optimal apposition of the struts to the wall.

Incidence, correlates, and significance of abnormal cardiac enzyme rises in patients treated with surgical or percutaneous based revascularisation: a substudy from the Synergy between Percutaneous Coronary Interventions with Taxus and Cardiac Surgery (SYNTAX) Trial

AIMS

The aim of the present investigation was to determine the long-term prognostic association of post-procedural cardiac enzyme elevation within the randomised Synergy between Percutaneous Coronary Intervention (PCI) with TAXUS and Cardiac Surgery (SYNTAX) Trial.

METHODS

1800 patients with unprotected left main or de novo three-vessel coronary artery disease were randomised to undergo coronary artery bypass graft (CABG) surgery or PCI. Per protocol patients underwent post-procedural blood sampling with creatine kinase (CK), and the cardiac specific MB iso-enzyme (CK-MB) only if the preceding CK ratio was ≥ 2 × the upper limit of normal (ULN). An independent chemistry laboratory evaluated all collected blood samples.

RESULTS

Post-procedural CK sampling was available in 1629 of 1800 patients (90.5%). As per protocol, CK-MB analyses were undertaken in 474 of 491 patients (96.5%) in the CABG arm, and 53 of 61 patients (86.9%) in the PCI arm. Within the CABG arm, despite the limitations of incomplete data, a post-procedural CK-MB ratio <3/≥3 ULN separated 4-year mortality into low- and high-risk groups (2.3% vs. 9.5%, p=0.03). Additionally, in the CABG arm, a post-procedural CK-MB ratio ≥3 ULN was associated with an increased frequency of a high SYNTAX Score (≥33) tertile (high [≥33] SYNTAX Score: 39.5%, intermediate [23-32] SYNTAX Score 31.0%, low [≤22] SYNTAX Score 29.5%, p=0.02). Within the PCI arm, a post-procedural CK ratio of <2 or ≥2 ULN separated 4-year mortality into low- and high-risk groups (10.8% vs. 23.3%, p=0.001). Notably, there was an early (within 6 months) and late (after 2 years) peak in mortality in patients with a post-PCI CK ratio of ≥2 ULN. Lack of pre-procedural thienopyridine, carotid artery disease, type 1 diabetes, and presence of coronary bifurcations were independent correlates of a CK ratio ≥2 ULN post-PCI.

CONCLUSION

Cardiac enzyme elevations post-CABG or post-PCI are associated with an adverse long-term mortality; the causes of which are multifactorial.

Personal Experience with Bioresorbable Scaffolds in Bifurcations

Bioresorbable scaffolds represent a promising new technology in the field of percutaneous coronary interventions. The concept of the eventual resorption of the scaffold pertains to multiple theoretical advantages that may hold true particularly in bifurcation lesions - no permanent caging of the coronary artery, avoidance of acquired device malapposition and delayed hypersensitivity reactions, no permanent metallic stent protrusion in the main branch, etc. The worldwide experience with the use of bioresorbable scaffolds is limited. In our experience of selected bifurcation lesions, a provisional approach using one-scaffold has excellent results. Two-scaffold techniques appeared feasible. Our data support the exploration of the use of bioresorbable scaffolds in more challenging coronary substrates like bifurcations. Prospective registries and ideally randomised trials should assess whether the theoretical benefits of bioresorbable vascular scaffolds (BVS) in bifurcation lesions can produce sustainable good clinical outcomes.

Clinical outcomes after zotarolimus and everolimus drug eluting stent implantation in coronary artery bifurcation lesions: insights from the RESOLUTE All Comers Trial

OBJECTIVE

We investigated clinical outcomes after treatment of coronary bifurcation lesions with second generation drug eluting stents (DES).

DESIGN

Post hoc analysis of a randomised, multicentre, non-inferiority trial.

SETTING

Multicentre study.

PATIENTS

All comers study with minimal exclusion criteria.

INTERVENTIONS

Patients were treated with either zotarolimus or everolimus eluting stents. The patient population was divided according to treatment of bifurcation or non-bifurcation lesions and clinical outcomes were compared between groups.

MAIN OUTCOMES MEASURES

Clinical outcomes within 2-year follow-up.

RESULTS

A total of 2265 patients were included in the present analysis. Two-year follow-up data were available in 2223 patients: 1838 patients in the non-bifurcation group and 385 patients in the bifurcation group. At 2-year follow-up the bifurcation and the non-bifurcation lesion groups showed no significant differences in terms of cardiac death (2.3 vs 2.1, p=0.273), target lesion failure (9.7% vs 13.8%, p=0.255), major adverse cardiac events (11.5% vs 15.1%, p=0.305), target lesion revascularisation (4.7% vs 6.0%, p=0.569), and definite or probable stent thrombosis (1.6% vs 1.8%, p=0.419).

CONCLUSIONS

The use of second generation DES for the treatment of coronary bifurcation lesions was associated with similar long term mortality and clinical outcomes compared with non-bifurcation lesions.

Is there a higher risk of stent thrombosis in bifurcation lesion or is it related to the technique?

Bifurcation lesions and bifurcation stenting have been reported to be risk factors of stent thrombosis (ST). ST is a complex process that may be the culmination of device, patient, lesion and procedural factors. The strategy of provisional SB stenting is widely accepted for suitable bifurcation lesions, and is accompanied by low rates of ST. However, it is not applicable to all patients, and in these clinical scenarios (approx. 10%), there is no consensus on the best option for elective stenting with two stents regarding the incidence of ST. Excessive metal scaffolding, such as in the classical crush technique, should be avoided. Further accumulation of long-term data from larger clinical registries and randomised studies will be needed to elucidate the best technique regarding the avoidance of ST in bifurcation treatment. Dedicated bifurcation stents tailored for each type of lesion could resolve this issue, especially the excess of metal protruding in the vessel lumen or crushed onto the wall. However, they need to be tested in upcoming and ongoing trials. Stent thrombosis (ST) is the sudden occlusion of a stented coronary artery due to thrombus formation. Despite major improvements of antiplatelet therapy, thrombotic events remain the primary cause of death after percutaneous coronary interventions (PCI). The clinical consequences of ST are frequently catastrophic and include death in 20% to 48% or major myocardial infarction (MI) in 60% to 70% of the cases. In the drug-eluting stent era, ST and especially very late ST remains a concern of coronary intervention. Bifurcation lesions and bifurcation stenting have been reported to be the risk factors for ST. ST is a complex process that may be a culmination of device, patient, lesion, and procedural factors. The exact cause of the higher risk of ST in bifurcation lesions is unknown although pathologic studies have suggested that the arterial branch points are predisposed to development of atherosclerotic plaque, thrombus, and inflammation because they are foci of low shear stress.

Flow and atherosclerosis in coronary bifurcations

Coronary bifurcations are among the most frequent sites affected by atherosclerosis. In these regions, complex haemodynamic conditions prevail and local flow disturbances dictate the localisation and progression of atheroma. Endothelial shear stress (ESS) is the main flow-related factor affecting the distribution of atherosclerosis in a bifurcation. Plaques are more prevalent in low ESS areas, such as the lateral walls of the main vessel and side branches, while they are less common in the flow divider or carina, which is characterised by high ESS. However, the carina is not free of atheroma and is affected in up to one third of cases, but never in isolation. Lesions in the carina are likely to develop at a later stage of atherosclerosis, as result of circumferential expansion of plaques from the lateral wall. Pulsatile flow augments the local atherogenic environment by inducing low and oscillatory ESS. The geometrical configuration is also important as increased curvature and wide angles between the side branches of the bifurcation intensify flow perturbations, and highly curved segments show low ESS in the inner aspect of curvatures. Further research on the flow conditions which determine the initiation and progression of atherosclerosis in bifurcations will allow for more efficient prevention and management strategies.

Treating coil migration in combination therapy involving stenting and coiling for a wide-necked renal aneurysm

A man with a wide-necked renal artery aneurysm underwent combination therapy involving stenting and coiling to embolize it. However, a large section of one of the coils had migrated outside the stent implanted across the orifice of the aneurysm. After repositioning the migrated coil inside the stent, the implantation of another stent together with sandwiching of the coil between two stents repaired the prolapsed coil. This report describes precautions that should be taken during combination therapy involving stenting and coiling to embolize a wide-necked aneurysm.