The Proximal Optimisation Technique for Intervention of Coronary Bifurcations

Novel Method for Restitution of a Torqued and Entrapped Kinked 7F Catheter in the Ascending Aorta

Knotting and kinking of diagnostic coronary artery catheters are potentially catastrophic complications though their occurrence is uncommon. However, abrupt kinking of 7F guide catheters in the ascending aorta becomes a quirky puzzle. This case emphasizes the importance of avoiding kinking and provides recommendations for catheter retrieval in the unlikely event of this complication. To the best of our knowledge, the technique used in our case has not been described before.

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.

Contemporary Left Main Percutaneous Coronary Intervention: A State-of-the-art Review

The majority of the left ventricular myocardium is supplied by the left main coronary artery. Atherosclerotic obstruction of the left main coronary artery therefore leads to significant myocardial jeopardy. Coronary artery bypass surgery (CABG) has been the gold standard for left main coronary artery disease in the past. However, advancements in technology have established percutaneous coronary intervention (PCI) as a standard, safe and reasonable alternative to CABG, with comparable outcomes. Contemporary PCI of left main coronary artery disease comprises careful patient selection, accurate technique guided by either intravascular ultrasound or optical coherence tomography and - if necessary - physiological assessment using fractional flow reserve. This review focuses on current evidence from registries and randomised trials comparing PCI with CABG, procedural tips and tricks, adjuvant technologies and the triumph of PCI.

Influence of different postballoon expansion procedures: A finite element analysis

BACKGROUND

Postballoon expansion is considered as an appropriate procedure for adequate stent expansion for coronary bifurcation lesions. Two postballoon expansion procedures are currently recommended: proximal optimization technique (POT)/side/POT and POT/kiss/POT. However, the effects of the two postballoon expansion treatments are different. There is a lack of biomechanical study to quantify the difference.

PURPOSE

It is recognized that biomechanical factors influence the occurrence of Major Cardiovascular Adverse Events (MACE), which includes recurrent angina pectoris, acute myocardial infarction and coronary heart disease death. The current paper evaluated the two postexpansion strategies and quantified biomechanical parameters to provide a basis for clinical decisions.

METHODS

Based on the CT angiography (CTA) data of a patient diagnosed with coronary bifurcation lesions, a personalized coronary bifurcation lesion model was constructed, and the surgical procedure after two expansions was simulated. The POT/side/POT and POT/kiss/POT expansion procedures were analyzed from the perspective of biomechanics through finite element analysis. The biomechanics factors, including the percentage of stent malapposition and stent occlusion at the side branch (SB) opening, the stent ellipse index of proximal main vessel (PMV) segment, the minimum lumen area of the stent vessel segment and the stress distribution of the vessel wall, were used to quantify clinician concerns about factors affecting patient outcomes. The factors include stent adhesion, SB open stent occlusion, poor stent deformation, patency effect of vessel stenosis, and vessel wall damage.

RESULTS

Both postexpansion procedures were successfully simulated. The malapposition rate during POT/side/POT was larger (1.2% vs. 0.42%) and stent occlusion at the SB opening from the cross-section perpendicular to the SB opening after the POT/side/POT procedure was 0.20%, compared with 0.00% after POT/kiss/POT. POT/kiss/POT produced a larger PMV segment stent ellipse index. Minimum lumen area after POT/side/POT was 5.6 mm² and after POT/kiss/POT 5.9 mm² . POT/kiss/POT produces an effect of greater vascular stress than POT/side/POT.

CONCLUSION

Numerical simulations provide a quantitative analysis to inform clinicians of the differences between preoperative planning and surgical procedures. Biomechanical analysis of the differences between the two postexpansion strategies found that the POT/kiss/POT procedure resulted in better stent fit, less occlusion of the SB open stent and better vascular patency but also resulted in poor stent deformation and caused greater vessel wall stress. The current study informs rationales for clinical understanding of postexpansion strategies.

The Cone Flare Crush Modified-T (CFCT) stenting technique for coronary artery bifurcation lesions

Background

The present study is a prospective observational single arm clinical investigation, with parallel bench test interrogation, aimed at investigating the technical feasibility, safety and clinical outcomes with the cone flare crush modified-T (CFCT) bifurcation stenting technique. Bifurcation percutaneous coronary intervention (PCI) remains an area of ongoing procedural evolution. More widely applicable and reproducible techniques are required.

Methods

From April 2018 until March 2019, 20 consecutive patients underwent bifurcation PCI using the CFCT technique with a Pt-Cr everolimus drug-eluting stent with a bioresorbable polymer. Exercise stress echocardiography was performed at 12-month follow-up. The primary outcome was a composite of cardiac related mortality, myocardial infarction, target lesion/vessel revascularization and stroke. Safety secondary endpoints included bleeding, all-cause mortality and stent thrombosis.

Results

All patients underwent a successful CFCT bifurcation procedure with no complications to 30-day follow-up. One patient met the primary endpoint requiring target lesion revascularization at 9 months for stable angina. There were no other primary or secondary outcome events in the cohort. There were no strokes, deaths, stent thrombosis or myocardial infarction during the follow-up period. The mean CCS score improved from 2.25 to 0.25 (p < 0.0001). Optical coherence tomography (OCT) and bench test findings indicated optimal side branch ostial coverage and minimal redundant strut material crowding the neo-carina.

Conclusions

The CFCT technique appears to be a safe, efficacious and feasible strategy for managing coronary artery bifurcation disease. Expanded and randomized datasets with longer term follow-up are required to further explore confirm this feasibility data. (ANZCTR ID: ACTRN12618001145291).

Optimal Site for Proximal Optimization Technique in Complex Coronary Bifurcation Stenting: A Computational Fluid Dynamics Study

BACKGROUND/PURPOSE

The optimal position of the balloon distal radio-opaque marker during the post optimization technique (POT) remains debated. We analyzed three potential different balloon positions for the final POT in two different two-stenting techniques, to compare the hemodynamic effects in terms of wall shear stress (WSS) in patients with complex left main (LM) coronary bifurcation.

METHODS/MATERIALS

We reconstructed the patient-specific coronary bifurcation anatomy using the coronary computed tomography angiography (CCTA) data of 8 consecutive patients (6 males, mean age 68.2± 18.6 years) affected by complex LM bifurcation disease. Subsequently a virtual bench test was performed in each patient using two different double stenting techniques represented by the DK and Nano crush using the reconstruction of Orsiro stents (Biotronik IC, Bulack, Switzerland).

RESULTS

A significant reduction in the mean WSS values in all the lesion's sites was observed when the final POT was performed 1 mm distally the carina cut plane in both techniques. Moreover, a significant improvement in the mean WSS values of the entire SB (e.g. LCX) was obtained performing the POT 1 mm distally to the carina cut plane. The proximal POT resulted in larger area of lower WSS values at the carina using both the Nano crush and the DK crush techniques.

CONCLUSIONS

In patients with complex LM bifurcation disease the use of a final POT performed 1 mm distally to the carina cut plane might results in more favorable WSS patterns (i.e. higher WSS values) along all stented segments and, especially, along the entire LCX lesions.

Left Main Coronary Interventions: A Practical Guide

Coronary artery bypass surgery has been the accepted treatment for left main coronary artery disease for over 50 years. Balloon angioplasty was later used then abandoned because of deaths likely due to restenosis or thrombotic occlusion. However, rapid innovations in drug-eluting stent designs leading to more biocompatible thin strut platforms with optimal drug elution profiles and further advances in modern pharmacotherapy involving potent P2Y₁₂ inhibitors combined with utilization of intracoronary imaging and physiologic assessment for procedural planning and optimization have transformed percutaneous interventions into successful alternatives to coronary artery bypass graft surgery (CABG) in selected LM anatomic territories. Herein, we provide an evidence-based practical guide on how to approach and perform LM percutaneous interventions (PCI).

An Upfront Two-Stent Strategy for True Coronary Bifurcation Lesions with A Large Side Branch in Acute Coronary Syndrome: A Two-Year Follow-Up Study

Background and Objectives: Little is known about the upfront two-stent strategy (U2SS) for true coronary bifurcation lesions (CBLs) in acute coronary syndrome (ACS). We aimed to present our two-year follow-up results on the U2SS by using different two-stent techniques for the true CBL with a large side branch (SB) in ACS patients, including unstable angina (UA), non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI), and to identify independent predictors of the presence of major adverse cardiac events (MACEs) after intervention. Materials and Methods: The study included 201 consecutive ACS patients with true CBLs who underwent percutaneous coronary intervention (PCI) using U2SS from October 2015 to March 2018. Clinical outcomes at follow-up were assessed. MACE was defined as a composite of cardiac death, non-fatal myocardial infarction, and target lesion revascularization (TLR). Results: 31.3% of the patients had an UA, 46.3% had an NSTEMI, and 22.4% had an STEMI. CBL was most frequently located in the left anterior descending (LAD)/diagonal artery (59.2%). In total, 71.1% of the patients had a Medina classification (1,1,1). Overall, 62.2% of cases were treated with mini-crush stenting. Clopidogrel was given in 23.9% of the patients; 71.1% of the patients received everolimus eluting stent (EES); and 11.9% received a sirolimus eluting stent (SES). Final kissing balloon inflation was carried out in all patients, with an unsatisfactory rate of 5%. A proximal optimization technique sequence was successfully carried out in all patients. The MACE incidence was 16.9% with a median follow-up period of 2.1 years. There were seven cardiac deaths (3.5%). The TLR rate was 13.4% (n = 27), with PCI treatment in 16 patients, and coronary artery bypass grafting treatment in 11 patients. After multivariate penalized logistic regression analysis (Firth logistic regression), clopidogrel use (odds ratio (OR): 2.19; 95% confidence interval (CI): 0.41–2.51; p = 0.007) and SES use (OR: 1.86; 95% CI: 0.31–2.64; p = 0.014) were independent predictors of the presence of MACE. Conclusion: U2SS is feasible and safe for the true CBLs with large and diseased SB in ACS patients, and is related to a relatively low incidence of MACE. Clopidogrel use and SES use may predict the MACE development in ACS patients treated using U2SS.

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.

Percutaneous Coronary Intervention for Coronary Bifurcation Lesions: Latest Evidence

PURPOSE OF REVIEW

This paper provides a synopsis of the best evidence to guide bifurcation percutaneous coronary intervention (PCI), with a focus on recent studies. This is with the aim of guiding the interventional cardiologist in choosing the best, evidence-based technique, to treat commonly encountered coronary bifurcations.

RECENT FINDINGS

Current evidence supports the use of provisional stenting for most anatomically suitable bifurcation lesions. Newer techniques for side branch protection in provisional stenting have been developed. When a two-stent strategy is required, use of a double-kissing crush technique is favoured, particularly in left main bifurcations. For bifurcation PCI, as in all complex procedures, intravascular imaging plays a key adjunctive role in improving procedural success. PCI for coronary bifurcation lesions is an ever-growing field with significant advancements in techniques and technology.

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

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

Crush versus Culotte stenting techniques for coronary bifurcation lesions: A systematic review and meta-analysis of clinical trials with long-term follow-up

BACKGROUND

In patients with complex true coronary bifurcation lesions (CBLs), Crush or Culotte stenting has been the commonest approaches of percutaneous coronary intervention (PCI). However, the optimal one remains in debate.

METHODS

A systematic review and meta-analysis of cohort studies searched from PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese National Knowledge Infrastructure (CNKI), VIP information database, and WangFang Data Information Site, to compare the long-term safety and efficacy of PCI with Crush versus Culotte in patients with CBLs. The primary end point was target lesion revascularization (TLR) and secondary end points were a composite of major adverse cardiac events (MACE) including cardiac death (CD), myocardial infarction (MI), stent thrombosis (ST), and target vessel revascularization (TVR) by PCI or bypass surgery, and each individual component at long-term follow-up. Furthermore, omitting each study in turn was used to sensitivity analysis for high heterogeneity of studies.

RESULTS

A total of 7 studies were included to perform a meta-analysis, 3 randomized trials and 4 observational studies with 2211 patients, 1281 treated with Crush and 930 with Culotte. There was no significant difference in TLR and MACE between Crush and Culotte [RR 0.76, 95% CI (0.48-1.23), I = 57%; RR 0.78, 95% CI (0.47-1.29), I = 83%, respectively]. ST tended to be lower in patients treated with Crush [RR 0.61, 95% CI (0.37-1.01), I = 23%]. CD and MI were comparable between the 2 groups [RR 0.80, 95% CI (0.43-1.49), I = 0%; RR 0.74, 95% CI (0.49-1.13), I = 32%, respectively]. TVR was also associated with the similar risk [RR 0.76, 95% CI (0.49-1.16), I = 60%]. However, high heterogeneity was detected for TLR, MACE, and TVR, and the source of heterogeneity was DKCRUSH-III study by Chen, SL.

CONCLUSIONS

In the treatment of coronary bifurcation lesions, TLR and MACE were not significant difference between the Crush and Culotte groups, but TLR and MACE were also regarded as high heterogeneity mainly due to better outcomes achieved by DK Crush and there was a trend toward lower ST in the Crush group. Crush, particularly DK Crush, may be superior to conventional Culotte for treatment of CBLs.

PROSPERO REGISTRATION NUMBER

CRD42018111868.