Efficacy of the proximal optimization technique on crossover stenting in coronary bifurcation lesions in the 3D-OCT bifurcation registry. Int J Cardiovasc Imaging. 2019;35:981-990. [PMID: 30887408 DOI: 10.1007/s10554-019-01581-1]

Routine intracoronary imaging-guided left main coronary intervention

Left main (LM) percutaneous coronary intervention (PCI) with routine intracoronary imaging guidance is recommended; however, its real-world effectiveness remains unclear. A total of 743 consecutive patients undergoing drug-eluting stent implantation for de novo unprotected LM lesions across 19 Japanese National Hospital Organization hospitals where routine imaging guidance was adopted were analyzed. The primary endpoint was 1-year major adverse cardiovascular and cerebrovascular events (MACCE), comprising all-cause death, cerebrovascular disorder, clinical-driven revascularization, and myocardial infarction. In this cohort, acute coronary syndrome was present in 31.2%, with 39.3% classified as Canadian Cardiovascular Society functional angina (CCS) class ≥ III. LM bifurcation lesions were observed in 78.0%, with two-stent implantation in 8.8%. MACCE occurred in 17.5%, with target lesion revascularization and cardiac death rates of 2.0% and 3.4%, respectively. Independent risk factors for MACCE included two-stent implantation (hazard ratio [HR], 2.49), mechanical cardiac support device use (HR, 2.17), CCS class ≥ III (HR, 2.07), 10% increase in left ventricular ejection fraction (HR, 0.72), and radial access (HR, 0.62). Routine imaging-guided LM-PCI is associated with favorable low rate of target lesion revascularization and cardiac death. However, severe left ventricular dysfunction and LM bifurcation treated with two-stent implantation increase risks, requiring more comprehensive management.

Impact of coronary bifurcation angle on stent malapposition in a randomized comparison between proximal optimization technique followed by side branch dilatation and kissing balloon inflation

Background

The impact of coronary bifurcation angle (BA) on incomplete stent apposition (ISA) after crossover stenting followed by side branch (SB) intervention has not been established.

Methods

A total of 100 crossover stentings randomly treated with proximal optimization technique followed by short balloon dilation in the SB (POT-SBD group, 48 patients) and final kissing balloon technique (KBT group, 52 patients) were analyzed in the PROPOT trial. Major ISA with maximum distance > 400 μm and its location was determined using optical coherence tomography before SB intervention and at the final procedure. The BA was defined as the angle between the distal main vessel and SB. Optimal POT was determined when the difference in stent volume index between the proximal and distal bifurcation was greater than the median value (0.86 mm3/mm) before SB intervention.

Result

Major ISA was more frequently observed in the POT-SBD than in the KBT group (35% versus 17%, p < 0.05). In the POT-SBD group, worsening ISA after SBD was prominent at the distal bifurcation. The BA was an independent predictor of major ISA (odds ratio 1.04, 95% confidence interval 1.00-1.07, p < 0.05) with a cut-off value of 59.5° (p < 0.05). However, the cases treated with optimal POT in the short BA (<60°) indicated the lowest incidence of major ISA. In the KBT group, BA had no significant impact.

Conclusion

A wide BA has a potential risk for the occurrence of major ISA after POT followed by SBD in coronary bifurcation stenting.

Success rate and influencing factors of a balloon-push technique: A new technique to remove side branch-jailed struts under three-dimensional optical coherence tomography guidance

BACKGROUND

Kissing balloon inflation with distal guide wire recross can cause severe stent deformation depending on the stent link location with respect to the carina. The balloon-push technique, by which an inflated balloon is forced into the SB from the proximal main vessel (MV), is a feasible way to remove jailed struts without causing severe stent deformation.

AIMS

We investigated the procedural success rate, patterns of jailed strut removal at side branch (SB) orifices, factors related to failure of jailed strut removal, and follow-up angiogram results of the balloon-push technique.

METHODS

Between September 2015 and December 2020, 51 bifurcation stenting cases in which the balloon-push technique was used were enrolled. Based on three-dimensional optical coherence tomography images, strut removal with 1 stent crown length was defined as successful. Strut removal patterns were classified into two types: parallel-slide type (stent struts shifted distally into the MV lumen without inversion) and under-carina type (stent struts shifted distally under the carina with strut inversion or strut slide).

RESULTS

Procedural success was attained in 39 cases (success rate: 76.5%). Parallel-slide type and under-carina type occurred in 43% and 33% of cases, respectively. Factors related to failure were trifurcation lesions and a smaller pushed balloon-SB artery ratio compared with those in success cases (0.95 ± 0.18 vs. 1.10 ± 0.22, p = 0.032). Follow-up angiography was performed in 37 cases, and 2 cases had binary in-stent restenosis.

CONCLUSIONS

Removal of jailed struts with the balloon-push technique was feasible, without severe stent deformation, in bifurcation stentings.

A novel technique of proximal optimization with kissing balloon inflation in bifurcation lesions

BACKGROUND

Percutaneous coronary interventions (PCI) of bifurcation lesions poses a technical challenge with a high complication rate. Kissing balloon inflation (KBI) and proximal optimization technique (POT) are used to correct bifurcation carina after stenting. However, both may still lead to uncomplete strut apposition to the side branch (SB) lateral wall. Proposed herein, is a new stent-optimization technique following bifurcation stenting consisting of a combination of POT and KBI called proximal optimization with kissing balloon inflation (POKI).

METHODS

Bench and in-vivo evaluations were performed. For the bench visualization bifurcated silicone mock vessel was used. The POKI technique was simulated using a 3.5 mm POT balloon. For the in-vivo evaluation patients with angiographic bifurcation lesions in a native coronary artery with diameter ≥ 2.5 mm and ≤ 4.5 mm, SB diameter ≥ 2.0 mm, and percentage diameter stenosis (%DS) more than 50% in the main vessel (MV) were included. Provisional stenting was the default strategy.

RESULTS

In total 41 vessels were evaluated. The target vessel was left main in 9 (22.0%) patients, left anterior descending artery - in 26 (63.4%), left circumflex artery - in 4 (9.8%) and right coronary artery - in 2 (4.9%). The predominant type of bifurcation was Medina 1-1-1 (61.8%). Baseline proximal MV DS% was 60.0 ± 23.7%, distal MV DS% - 58.8 ± 28.9% and SB DS% 53.0 ± 32.0%. The application of POKI was feasible in 41 (100%) of the vessels. Post-PCI residual DS at proximal MV was 11.5 ± 15.4%, distal MV - 6.6 ± 9.3%, and SB - 22.9 ± 28.5%. Both procedural and angiographic success was 100%.

CONCLUSIONS

POKI is a novel stent-optimization technique for bifurcation lesions. It showed excellent feasibility and success rate both in bench and in-vivo evaluation.

Vascular healing after kissing balloon inflation: Nine-month 3D optical coherence tomography analysis in corelab

Background

The jailing strut configuration with link-free and distal guidewire recrossing (LFD) at the side branch orifice (SBO) reduces incomplete stent apposition (ISA) after kissing balloon technique (KBT) in crossover stenting of coronary bifurcation lesions (CBLs). However, data regarding vascular healing after KBT are lacking. We investigated vascular healing 9 months after crossover stenting followed by KBT with optical coherence tomography (OCT) guidance in a prospective multicenter registry.

Methods

Fifty-nine patients with CBLs (LFD, 35 patients; non-LFD, 24 patients) were studied. The jailing configuration of the SB and the wire-recrossing position, incidence of ISA and uncovered struts, and neointima unevenness score (NUS) in the main vessel (MV) after 9 months were determined by off-line 3D-OCT in the core laboratory.

Results

The ISA rate was significantly higher at the SB ostium and distal MV after KBT in the non-LFD group, compared to the LFD group. After 9 months, incidence of ISA (18.3 ± 18.2 vs. 6.0 ± 8.7%, p < 0.01) and uncovered struts (8.7 ± 9.9 vs. 4.7 ± 7.3 %, p = 0.08) were higher at the SB ostium with higher SB restenosis in the non-LFD group. In distal MV, NUS was significantly higher (3.1 ± 1.1 vs. 2.5 ± 0.6, p < 0.05). In true-CBLs, an increase in uncovered struts and ISA rate was prominent in the proximal MV and opposite SB. No differences were observed in the 9-month clinical outcomes.

Conclusion

Visualization of the wire recrossing point and the SB-jailing strut pattern by OCT plays an important role to optimize the KBT in CBL stenting, resulting in favorable mid-term vascular healing.

Effect of proximal optimization technique on coronary bifurcation stent failure: Insights from the multicenter randomized PROPOT trial

OBJECTIVE

We investigated the effect of proximal optimization technique (POT) on coronary bifurcation stent failure (BSF) in cross-over stenting by comparing with the kissing balloon technique (KBT) in a multicenter randomized PROPOT trial.

BACKGROUND

POT is recommended due to increased certainty for optimal stent expansion and side branch (SB) wiring.

METHODS

We randomized 120 patients treated with crossover stenting into the POT group, which was followed by SB dilation (SBD), and the KBT group. Finally, 52 and 57 patients were analyzed by optical coherence tomography before SBD and at the final procedure, respectively. Composite BSF was defined as a maximal malapposition distance of >400 μm, or malapposed and SB-jailed strut rates of >5.95% and >21.4%, respectively.

RESULTS

Composite BSF before SBD in the POT and KBT groups was observed in 29% and 26% of patients, respectively. In the POT group, differences in stent volumetric index between the proximal and distal bifurcation (odds ratio [OR] 60.35, 95% confidential interval [CI] 0.13-0.93, p = 0.036) and between the proximal bifurcation and bifurcation core (OR: 3.68, 95% CI: 1.01-13.40, p = 0.048) were identified as independent risk factors. Composite BSF at final in 27% and 32%, and unplanned additional procedures in 38% and 25% were observed, respectively. Composite BSF before SBD was a risk factor for the former (OR: 6.33, 95% CI: 1.10-36.50, p = 0.039) and the latter (OR: 6.43, 95% CI: 1.25-33.10, p = 0.026) in the POT group.

CONCLUSION

POT did not result in a favorable trend in BSF. Insufficient expansion of the bifurcation core after POT was associated with BSF.

Clinical outcomes of the proximal optimisation technique (POT) in bifurcation stenting

BACKGROUND

Optimal deployment of coronary stents in a bifurcation lesion remains a matter of debate.

AIMS

We sought to capture the daily practice of bifurcation stenting by means of a worldwide registry and to investigate how post-implantation deployment techniques influence clinical outcomes.

METHODS

Data from the e-ULTIMASTER registry were used to perform an analysis of 4,395 patients undergoing percutaneous coronary intervention for bifurcation lesions. Inverse probability of treatment weights (IPTW) propensity score methodology was used to adjust for any baseline differences. The primary outcome of interest was target lesion failure (TLF) at one year (follow-up rate 96.2%).

RESULTS

The global one-year TLF rate was low (5.1%). The proximal optimisation technique (POT) was used in 33.9% of cases and was associated with a reduction in the adjusted TLF rate (4.0% [95% confidence interval: 3.0-5.1%] vs 6.0% [5.1-6.9%], p<0.01) due to a reduction of all components of this composite endpoint, except for cardiac death. Stent thrombosis was also positively impacted (0.4% [0.04-0.7%] vs 1.3% [0.8-1.7%], p<0.01). POT benefit was uniform across subgroups. Conversely, the use of the kissing balloon technique (36.5%) did not influence the adjusted TLF rate.

CONCLUSIONS

Despite a low one-year failure rate in this large bifurcation stenting cohort, POT was associated with a further reduction in the event rate and a uniform benefit across subgroups, suggesting systematic use of this deployment technique regardless of the bifurcation anatomy and stenting technique.

The importance of proximal optimization technique with intravascular imaging guided for stenting unprotected left main distal bifurcation lesions: The Milan and New-Tokyo registry

OBJECTIVES

This study evaluated the 5-years outcomes of intracoronary imaging-guided proximal optimization technique (POT) for percutaneous coronary intervention (PCI) in patients with unprotected left main distal bifurcation lesions (ULMD).

BACKGROUND

The long-term effects of POT with intracoronary imaging guide in PCI for ULMD have been unclear.

METHODS

Between January 2005 and December 2015, we identified 1832 consecutive patients who underwent DES implantation for ULM distal bifurcation lesions. Of them, 780 (56.1%) patients underwent POT with intravascular imaging guidance (optimal expansion group). Residual 611 (43.9%) patients did not undergo either POT or intravascular imaging or both (suboptimal expansion group). Analysis using propensity score adjustment was performed. The primary endpoint was target lesion failure (TLF) defined as a composite of cardiac death, target lesion revascularization (TLR), and myocardial infarction.

RESULTS

TLF rate at 5 years was significantly lower in optimal expansion group than that in suboptimal expansion group [adjusted HR 0.65, 95% CI (0.48-0.87), p = 0.004]. Cardiac mortality was significantly lower in optimal expansion group than that in suboptimal expansion group [adjusted HR 0.46, 95% CI (0.27-0.79), p = 0.004]. The multivariable analysis identified POT with intravascular imaging guide [adjusted HR 0.65, 95% CI (0.48-0.87), p = 0.004] as an independent predictor of TLF.

CONCLUSIONS

Intravascular imaging guided POT was strongly associated with the reduced risk of TLF at 5 years after PCI for ULMD, mainly driven by reducing cardiac mortality.

Proximal optimisation technique versus final kissing balloon inflation in coronary bifurcation lesions: the randomised, multicentre PROPOT trial

BACKGROUND

Clinical implications of the proximal optimisation technique (POT) for bifurcation lesions have not been investigated in a randomised controlled trial.

AIMS

This study aimed to investigate whether POT is superior in terms of stent apposition compared with the conventional kissing balloon technique (KBT) in real-life bifurcation lesions using optical coherence tomography (OCT).

METHODS

A total of 120 patients from 15 centres were randomised into two groups - POT followed by side branch dilation or KBT. Finally, 57 and 58 patients in the POT and KBT groups, respectively, were analysed. OCT was performed at baseline, immediately after wire recrossing to the side branch, and at the final procedure.

RESULTS

The primary endpoint was the rate of malapposed struts assessed by the final OCT. The rate of malapposed struts did not differ between the POT and KBT groups (in-stent proximal site: 10.4% vs 7.7%, p=0.33; bifurcation core: 1.4% vs 1.1%, p=0.67; core's distal edge: 6.2% vs 5.3%, p=0.59). More additional treatments were required among the POT group (40.4% vs 6.9%, p<0.01). At one-year follow-up, only one patient in each group underwent target lesion revascularisation (2.0% vs 1.9%).

CONCLUSIONS

POT followed by side branch dilation did not show any advantages over conventional KBT in terms of stent apposition; however, excellent midterm clinical outcomes were observed in both strategies.

Feasibility and efficacy of an ultra-short side branch-dedicated balloon in coronary bifurcation stenting

BACKGROUND

Side branch (SB) dilation with an ultra-short balloon after main vessel (MV) stenting may minimise stent failure in coronary bifurcation lesions.

AIMS

We sought to investigate the feasibility and efficacy of the Glider balloon (GB), a side branch (SB)-dedicated balloon 4 mm in length, in coronary bifurcation stenting.

METHODS

In bench testing, stent configuration was examined with micro-focus computed tomography after crossover stenting followed by GB dilation or kissing balloon inflation (KBI). In the clinical study we performed GB dilatation after MV stenting for 207 lesions in 194 patients. Failure of the GB dilation and additional procedures due to inducible stent failure were investigated as well as adverse cardiac events at 1-year follow-up.

RESULTS

In bench testing GB dilation maintained cross-sectional stent area without significant deformation and presented effective jailed strut removal in a high-angled bifurcation model. In the clinical study the cohort included left main, true bifurcation lesion, and two-stent treatment in 42.0%, 45.9%, and 14.0%, respectively. The proximal optimisation technique (POT) or POT-like inflation was performed in 82.1%. GB crossing failure, SB stenting due to dissection, and stent deformation requiring correction by KBI or MV dilation occurred in 8.7%, 1.4%, and 5.8%, respectively. Finally, simple GB dilation without KBI was completed in 91.8% for SB dilation. At one-year follow-up, target lesion revascularisation, cardiac death, myocardial infarction, and stent thrombosis were found in 7.2%, 2.1%, 2.1%, and 1.0%, respectively.

CONCLUSIONS

Simple GB dilation after adequate expansion of the proximal MV stent provided acceptable acute and long-term results as an alternative to KBI.

Percutaneous coronary intervention for bifurcation coronary lesions: the 15th consensus document from the European Bifurcation Club

The 15th European Bifurcation Club (EBC) meeting was held in Barcelona in October 2019. It facilitated a renewed consensus on coronary bifurcation lesions (CBL) and unprotected left main (LM) percutaneous interventions. Bifurcation stenting techniques continue to be refined, developed and tested. It remains evident that a provisional approach with optional side branch treatment utilising T, T and small protrusion (TAP) or culotte continues to provide flexible options for the majority of CBL patients. Debate persists regarding the optimal treatment of side branches, including assessment of clinical significance and thresholds for bail-out treatment. In more complex CBL, especially those involving the LM, adoption of dedicated two-stent techniques should be considered. Operators using such techniques have to be fully familiar with their procedural steps and should acknowledge associated limitations and challenges. When using two-stent techniques, failure to perform a final kissing inflation is regarded as a technical failure, since it may jeopardise clinical outcome. The development of novel technical tools and drug regimens deserves attention. In particular, intracoronary imaging, bifurcation simulation, drug-eluting balloon technology and tailored antiplatelet therapy have been identified as promising tools to enhance clinical outcomes. In conclusion, the evolution of a broad spectrum of bifurcation PCI components has resulted from studies extending from bench testing to randomised controlled trials. However, further advances are still needed to achieve the ambitious goal of optimising the clinical outcomes for every patient undergoing PCI on a CBL.

Difference in basic concept of coronary bifurcation intervention between Korea and Japan. Insight from questionnaire in experts of Korean and Japanese bifurcation clubs

The coronary bifurcation intervention varies among countries due to the differences in assessment of lesion severity and treatment devices. We sought to clarify the difference in basic strategy between South Korea and Japan. A total of 19 and 32 experts from Korean (KBC) and Japanese Bifurcation Clubs (JBC), respectively, answered a survey questionnaire concerning their usual procedure of coronary bifurcation intervention. JBC experts performed less two-stent deployment in the left main (LM) bifurcation compared to KBC experts (JBC vs. KBC: median, 1–10% vs. 21–30%, p < 0.0001) instead of higher performance of side branch dilation after cross-over stenting in both LM (60% vs. 21%, p = 0.001) and non-LM bifurcations (30% vs. 5%, p = 0.037). KBC experts more frequently performed proximal optimization technique (POT) in non-LM bifurcation (41–60% vs. 81–99%, p = 0.028) and re-POT in both LM (1–20% vs. 81–99%, p = 0.017) and non-LM bifurcations (1–20% vs. 81–99%, p = 0.0003). JBC experts more frequently performed imaging-guided percutaneous coronary intervention, whereas KBC experts more often used a pressure wire to assess side branch ischemia. JBC experts used a rotablator more aggressively under the guidance of optical coherence tomography. We clarified the difference in the basic strategy of coronary bifurcation intervention between South Korea and Japan for better understanding the trend in each country.

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).

Efficacy of coronary imaging on bifurcation intervention

During the coronary bifurcation intervention procedure, imaging including intravascular ultrasound and optical coherence tomography is essential to provide precise anatomy of the lesion and morphological information. This consensus document between the Korean Bifurcation Club and the Japanese Bifurcation Club summarizes practical guidelines and current evidences on lesion assessment, device selection, procedural guidance, and the optimization of bifurcation intervention by the imaging.

Use of the Bifurcation Optimization Stent System in cardiological settings

The bifurcation optimization stent system (BiOSS) LIM (Balton, Warsaw, Poland) stent is a dedicated coronary bifurcation stent. Its unique construction is developed in accordance with the anatomy of the coronary bifurcations, thus eliminating the carina displacement as a mechanism of side branch ostium compromise. Since its development in 2008, the BiOSS stent underwent several changes with the latest version created of sirolimus eluting cobalt-chromium stent. Results from registries and randomized clinical trials showed that implantation of the BiOSS stent is safe and effective with comparable results for major adverse cardiovascular events (MACE) and target lesion revascularisation rates between the BiOSS and regular drug-eluting stent groups. This stent provides alternative for coronary bifurcation treatment, especially when there is a large difference in diameter between the main vessel and the main branch.

Rescue treatment and follow-up intervention of a left main acute myocardial infarction with typical carina shift under 3D optical coherence tomography: A case report

BACKGROUND

Coronary intervention for bifurcation lesions is still challenging for interventional cardiologists. Left main (LM) bifurcation lesions have a higher risk due to the vast blood supply in this area and treatment choice is difficult. Ostial compromise of the side branch decreases patient prognosis, and its management is still an issue despite the different strategies and devices available.

CASE SUMMARY

A 42-year-old male patient was admitted to hospital due to chest pain and syncope. Coronary angiography showed acute LM occlusion. Following thrombus aspiration, a LM bifurcation lesion remained. Coronary angiography was repeated one week later, and at the same time, 3D optical coherence tomography (OCT) was carried out to better show the geometry of the bifurcation, which confirmed that the stenosis in the ostial left circumflex artery was caused by a long carina. After assessment of the plaque characteristics and the minimum lumen area, the cross-over strategy, kissing balloon inflation and proximal optimization technique were chosen to treat the bifurcation lesion. A “moving” carina was found twice during the intervention. Good stent apposition and expansion were confirmed by OCT after proximal optimization technique. The three-month follow-up showed good recovery and normal cardiac function.

CONCLUSION

3D-OCT can facilitate decision-making for coronary interventions in patients with critical bifurcation lesions.