Multicentre, randomized comparison of two-stent and provisional stenting techniques in patients with complex coronary bifurcation lesions: the DEFINITION II trial

AIM

The present study aimed to assess the benefits of two-stent techniques for patients with DEFINITION criteria-defined complex coronary bifurcation lesions.

METHODS AND RESULTS

In total, 653 patients with complex bifurcation lesions at 49 international centres were randomly assigned to undergo the systematic two-stent technique (two-stent group) or provisional stenting (provisional group). The primary endpoint was the composite of target lesion failure (TLF) at the 1-year follow-up, including cardiac death, target vessel myocardial infarction (TVMI), and clinically driven target lesion revascularization (TLR). The safety endpoint was definite or probable stent thrombosis. At the 1-year follow-up, TLF occurred in 37 (11.4%) and 20 (6.1%) patients in the provisional and two-stent groups, respectively [77.8%: double-kissing crush; hazard ratio (HR) 0.52, 95% confidence interval (CI) 0.30-0.90; P = 0.019], largely driven by increased TVMI (7.1%, HR 0.43, 95% CI 0.20-0.90; P = 0.025) and clinically driven TLR (5.5%, HR 0.43, 95% CI 0.19-1.00; P = 0.049) in the provisional group. At the 1 year after indexed procedures, the incidence of cardiac death was 2.5% in the provisional group, non-significant to 2.1% in the two-stent group (HR 0.86, 95% CI 0.31-2.37; P = 0.772).

CONCLUSION

For DEFINITION criteria-defined complex coronary bifurcation lesions, the systematic two-stent approach was associated with a significant improvement in clinical outcomes compared with the provisional stenting approach. Further study is urgently warranted to identify the mechanisms contributing to the increased rate of TVMI after provisional stenting.

STUDY REGISTRATION

http://www.clinicaltrials.com; Identifier: NCT02284750.

Coronary bifurcation lesions: Present status and future perspectives

Coronary bifurcation lesions (CBLs) are challenging and associated with a higher rate of adverse events than non-bifurcation lesions. In the era of drug-eluting stents, 2 primary interventional strategies for treating CBL include the complex strategy the main vessel (MV) and side-branch (SB) stenting, and the simple strategy MV stenting combined with provisional SB stenting. The meta-analysis of the simple vs. complex strategies demonstrated an increased incidence of myocardial infarction in the complex strategy. Likewise, the Tryton dedicated bifurcation stents, as compared with the simple strategy, increased the rate of myocardial infarction. In contrast, the Nordic-Baltic Bifurcation Study IV demonstrated that event rates were not significantly different comparing the simple vs. complex strategies in true bifurcation lesions involving a large SB. Fractional flow reserve (FFR) has emerged as a powerful catheter based tool for the functional assessment of a stenosis, but the role of FFR on the long-term outcomes of patients with CBL has not been studied. Given the recent evidence that Tryton stents (a dedicated bifurcation stent) increased event rates, and the lack of benefit from using 2-stent techniques (the Nordic Baltic Bifurcation Study IV) in true CBL, assessing the FFR of the SB seems now of outmost importance, but randomized data are lacking. An intravascular study showed that kissing balloon inflation (KBI) significantly reduced SB stenosis, restored stent lumen at the carina, and expanded stent in the proximal segment. However, a recent randomized study showed no significant benefit of routine KBI. This review highlights current concepts and future perspectives in patients with CBL.

Long-term treatment effect and adverse events of a modified jailed-balloon technique for side branch protection in patients with coronary bifurcation lesions

Background

Percutaneous coronary interventions (PCI) of bifurcation lesions is technically challenging and associated with lower success rates and higher frequency of adverse outcomes. In the present study, we aimed to evaluate the immediate and long-term treatment effect and adverse events of a new modified jailed-balloon technique on side branch (SB) during PCI on coronary bifurcation lesions.

Methods

This was a prospective study of 60 patients (49 males, 11 females, mean age 66 ± 10 years) with coronary bifurcation lesions treated at the Beijing Hospital between September 2014 and October 2015. They underwent main vessel (MV) stenting and modified jailed-balloon technique on the SB. All patients were followed with hospital visits at 9 months. Angiographic success, major adverse cardiac events (MACE), SB occlusion, and angina were evaluated.

Results

The majority of the patients had acute coronary syndrome (91.7%) and Medina 1.1.1. bifurcation lesions (71.7%). After MV stenting, thrombolysis in myocardial infarction (TIMI) 3 flow was established 100% of MV and 93.3% of SB. No SB occlusion occurred. The jailed SB balloon and wire could be successfully removed in all patients without damage or entrapment. The majority (91.7%) of patients achieved Canadian Cardiovascular Society I stage. There was no MACE during in-hospital stay and 9-month follow-up.

Conclusion

The modified JBT provided high rate of procedural success, excellent SB protection during MV stenting, and excellent immediate and long-term clinical outcomes.

High triglyceride-glucose index predicts cardiovascular events in patients with coronary bifurcation lesions: a large-scale cohort study

BACKGROUND

Coronary bifurcation lesion, as a complex coronary lesion, is associated with higher risk of long-term poor prognosis than non-bifurcation lesions. The triglyceride-glucose (TyG) index has been shown to predict cardiovascular (CV) events in patients with coronary artery disease (CAD). However, the prognostic value of the TyG index in patients with bifurcation lesions who are at high risk of CV events remains undetermined. Therefore, this study aimed to investigate the association between the TyG index and CV events in patients with bifurcation lesions.

METHODS

A total of 4530 consecutive patients with angiography-proven CAD and bifurcation lesions were included in this study from January 2017 to December 2018. The TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting plasma glucose (mg/dL)/2]. Patients were assigned into 3 groups according to TyG tertiles (T) (T1: <8.633; T2: 8.633-9.096 and T3: ≥9.096). The primary endpoint was CV events, including CV death, nonfatal myocardial infarction and nonfatal stroke at 3-year follow-up. Restricted cubic spline (RCS) analysis, Kaplan-Meier curves and Cox proportional hazard models were used to investigate the associations between the TyG index and study endpoints.

RESULTS

During a median follow-up of 3.1 years, 141 (3.1%) CV events occurred. RCS analysis demonstrated a linear relationship between the TyG index and events after adjusting for age and male sex (non-linear P = 0.262). After multivariable adjustments, elevated TyG index (both T2 and T3) was significantly associated with the risk of CV events (hazard ratio [HR], 1.68; 95% confidence interval [CI],1.06-2.65; HR, 2.10; 95%CI, 1.28-3.47, respectively). When study patients were further stratified according to glycemic status, higher TyG index was associated with significantly higher risk of CV events in diabetic patients after adjusting for confounding factors (T3 vs. T1; HR, 2.68; 95%CI, 1.17-6.11). In addition, subgroup analysis revealed consistent associations of the TyG index with 3-year CV events across various subgroups. Furthermore, adding the TyG index to the original model significantly improved the predictive performance.

CONCLUSIONS

High TyG index was associated with CV events in patients with bifurcation lesions, suggesting the TyG index could help in risk stratification and prognosis in this population.

Effect of stenosis eccentricity on the functionality of coronary bifurcation lesions-a numerical study

Interventional cardiologists still rely heavily on angiography for the evaluation of coronary lesion severity, despite its poor correlation with the presence of ischemia. In order to improve the accuracy of the current diagnostic procedures, an understanding of the relative influence of geometric characteristics on the induction of ischemia is required. This idea is especially important for coronary bifurcation lesions (CBLs), whose treatment is complex and is associated with high rates of peri- and post-procedural clinical events. Overall, it is unclear which geometric and morphological parameters of CBLs influence the onset of ischemia. More specifically, the effect of stenosis eccentricity is unknown. Computational fluid dynamic simulations, under a geometric multiscale framework, were executed for seven CBL configurations within the left main coronary artery bifurcation. Both concentric and eccentric stenosis profiles of mild to severe constriction were considered. By using a geometric multiscale framework, the fractional flow reserve, which is the gold-standard clinical diagnostic index, could be calculated and was compared between the eccentric and concentric profiles for each case. The results suggested that for configurations where the supplying vessel is stenosed, eccentricity could have a notable effect on and therefore be an important factor that influences configuration functionality.

Safety of hydrophilic guidewires used for side-branch protection during stenting and proximal optimization technique in coronary bifurcation lesions

BACKGROUND AND PROPOSE

In coronary bifurcation lesions (CBL), hydrophilic guidewires used for side-branch (SB) protection can be withdrawn from underneath the stent easier than other wires. However, the safety of which has not been investigated.

METHODS/MATERIALS

We performed scanning electron microscopic (SEM) examination of hydrophilic wires - the Whisper and Runthrough wires - used for SB protection during stenting and proximal optimization technique (POT) in 30 patients with CBL. The distal 15cm of the wire was examined every 1mm by SEM and 4500 segments were analyzed to investigate for wire fracture, polymer shearing (PS), and its correlations with post-stenting creatine kinase (CK)-MB release.

RESULTS

SEM examination showed no evidence for wire fracture. The total area of PS and the largest defect on the wire were significantly larger with the Whisper wire versus the Runthrough wire (0.15±0.04mm² vs. 0.026±0.01mm² and 0.04±0.05mm² vs. 0.01±0.01mm²; P<0.05, respectively). The total length of PS and the longest defect on the wire were significantly longer with the Whisper wire vs. the Runthrough wire (12.1±14.5mm vs. 2.7±3.0mm and 2.9±4.2mm vs. 1.0±1.2mm; P<0.05, respectively), but there were weak correlations between the extents of PS with CK-MB release.

CONCLUSIONS

Hydrophilic guidewires may be safely used for SB protection during stenting and POT in CBLs. The extent of PS was significantly greater with the Whisper wire than with the Runthrough wire, but its correlation with post-stenting CK-MB release was weak.

Jailing polymer jacketed guide-wires during bifurcation coronary interventions is associated with procedural myocardial infarction

AIM

To study the relationship of jailed polymer jacketed guide wires (PGW) with procedural myocardial infarction (PMI) after bifurcation coronary interventions.

METHODS

Consecutive bifurcation interventions performed from January 2010 to October 2014 were included in the study. Chart review was performed to obtain demographic, clinical and procedural data. PMI was defined as Creatine Kinase MB > 3 × upper reference limit of normal. Multivariate logistic regression was used to ascertain relationship of PGW use with PMI.

RESULTS

Two hundred and ninety-three patients (age 63.5 ± 12.3 years; 33.8% diabetic) were included in the study. Eighty point two percent (n = 235) were true bifurcation lesions use of PGW was associated with PMI on univariate analysis (OR = 4.1; P = 0.002). This association remained significant after adjusting for other possible risk factors (OR = 3.5; P = 0.02).

CONCLUSION

Our results suggest that PGW use for side branch protection may be associated with PMI. Randomized studies are needed to validate these findings.

Histopathologic and physiologic effect of bifurcation stenting: current status and future prospects

Introduction: Coronary bifurcation lesions are involved in up to 20% of all percutaneous coronary interventions (PCI). However, bifurcation lesion intervention is associated with a high complication rate, and optimal treatment of coronary bifurcation is an ongoing debate.Areas covered: Both different stenting techniques and a variety of devices have been suggested for bifurcation treatment, including the use of conventional coronary stents, bioresorbable vascular scaffolds (BVS), drug-eluting balloons (DEB), and stents dedicated to bifurcations. This review will summarize different therapeutic approaches with their advantages and shortcomings, with special emphasis on histopathologic and physiologic effects of each treatment strategy.Expert opinion: Histopathology and clinical data have shown that a more simple treatment strategy is beneficial in bifurcation lesions, achieving superior results. Bifurcation interventions through balloon angioplasty or placement of stents can importantly alter the bifurcation's geometry and accordingly modify local flow conditions. Computational fluid dynamics (CFD) studies have shown that the outcome of bifurcation interventions is governed by local hemodynamic shear conditions. Minimizing detrimental flow conditions as much as possible should be the ultimate strategy to achieve long-term success of bifurcation interventions.

Randomized non-inferiority TrIal comParing reverse T And Protrusion versus double-kissing and crush Stenting for the treatment of complex left main bifurcation lesions

BACKGROUND

The treatment of left main bifurcation stenoses remains challenging.

AIMS

We compare the "Reverse T and Protrusion" (reverse-TAP) technique to Double-Kissing and crush (DK-crush).

METHODS

The study was designed as non-inferiority trial, the primary endpoint was percentage stent expansion in the ostial side branch at optical coherence tomography.

RESULTS

52 consecutive patients (13 females, 17 diabetics, Syntax score 25 [22-29]) with complex coronary bifurcation lesions of the left main were randomized in a 1:1 ratio to Reverse-TAP or DK-crush stenting. The intervention was performed according to protocol in all patients in both randomization groups. Side branch stent expansion was 75 [67-90]% in the DK-crush group and 86 [75-95]% in the reverse-TAP group (one-sided 97.5% lower parametric confidence interval: - 0.28%; P < 0.01 for non-inferiority; P = 0.037 for superiority). Side branch balloon pressure during final kissing was higher in the DK-crush group (14 [12-16] vs. reverse-TAP: 13 [12-14]; P = 0.043). Procedural time was shorter with reverse-TAP (DK-crush: 32 [24-44] min vs reverse-TAP: 25 [22-33] min; P = 0.044). Other procedural parameters were not different between groups. There was no difference in any of the safety endpoints up to 1 month.

CONCLUSIONS

A reverse-TAP strategy for the interventional treatment of complex coronary lesions was non-inferior and superior to DK-crush for the primary endpoint side branch expansion while requiring less time. A larger study testing long-term clinical outcomes is warranted.

TRAIL REGISTRATION

NCT: NCT03714750.

[Bifurcation lesions : How should they be assessed and treated?]

Bifurcation lesions are a therapeutic challenge in the interventional treatment of coronary artery disease. Thus, consideration of anatomical aspects and selection of the most appropriate strategy for an individual bifurcation have an impact on the interventional outcome. Accordingly, assessment of the type of bifurcation stenosis, including the relevance of the side branches, vessel diameter and the angle between the two branches are critical for the optimal choice of interventional strategy. The fractional flow reserve (FFR) is a parameter that provides a measure of the severity of coronary stenosis and despite some limitations, FFR can be applied to bifurcation lesions. In addition, intravascular imaging tools, such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) can be used to determine anatomical configurations.

The impact of the use of bioresorbable vascular scaffolds and drug-coated balloons in coronary bifurcation lesions

BACKGROUND

Despite the improvement in techniques and tools, coronary lesions involving a bifurcation are still challenging and the outcome with drug-eluting stents is not always optimal. The role of bioresorbable vascular scaffolds (BVS) and drug-coated balloons (DCB) in this setting has not been adequately investigated yet.

RESULTS

From the databases of 6 italian centers with high proficiencies in newer technologies, we retrospectively collected all consecutive cases of coronary bifurcations managed or attempted with the implantation of at least one BVS in the main vessel and the use of one DCB in the side branch (SB). Primary study endpoint was the occurrence of major adverse cardiovascular events (MACE) at the longest available follow-up. Fourty patients fulfilled the enrollment criterion, 22.5% had diabetes and 50% an acute coronary syndrome. Average syntax score was 15.04 ± 7.18, all lesions were de novo, and 27 patients (67.5%) had a type 1,1,1 Medina lesion. Twenty-three lesions (57.5%) involved the proximal left anterior-descending artery/first diagonal branch. Only 32.5% of patients underwent an intravascular imaging-guided angioplasty. Average lesion length was 21.4 mm in the main vessel and 11.49 mm in the SB. MV was always predilated and BVS received a postdilation in 100% of the cases. In 42.5% of the cases, the DCB was used during final kissing balloon inflation, and in no cases, a stent/BVS was required in the SB. Procedural success was achieved in 100% of the cases. After an average follow-up of 15.5 (± 11.5) months, we observed no MACE with only one case of target vessel revasularization (2.5%).

CONCLUSIONS

Management of coronary bifurcation lesions with the use of newer technologies including BVS and DCB seems feasible and effective at mid-term and long-term clinical follow-up.

Randomized comparison between 2-link cell design biolimus A9-eluting stent and 3-link cell design everolimus-eluting stent in patients with de novo true coronary bifurcation lesions: the BEGIN trial

The appropriate stent platform for treating coronary bifurcation lesions (CBLs) remains controversial. Previous bench tests have demonstrated the superiority of a 2-link cell design to 3-link cell design for creating inter-strut dilation at the side branch ostium. This randomized multicenter prospective BEGIN trial compared the biodegradable polymer-based biolimus A9-eluting stent (2-link BES) with the durable polymer-based cobalt chromium everolimus-eluting stent (3-link EES) in 226 patients with de novo CBLs. Patients with true bifurcations, defined as > 50% stenosis in the main vessel and side branch (SB) and an SB diameter > 2.25 mm, were enrolled. Guide wire re-crossing to the distal cell (near the carina) in the jailed SB and final kissing inflation were recommended. The SB angiographic endpoint was < 50% stenosis diameter. Left-main CBLs (13.5% vs. 13.0%) and 2-stent technique (30.6% vs. 22.6%) rates were similar. The primary endpoints (minimum lumen diameter at the SB ostium measured at an independent core laboratory at the 8-month follow-up) were comparable (1.64 ± 0.50 mm vs. 1.63 ± 0.51 mm, p = 0.976). There was no significant difference in composite outcomes of cardiac death, myocardial infarction, or target vascular revascularization at 12 months (7.4% vs. 8.0%, p = 0.894). Two-link BES and 3-link EES showed similar 8-month angiographic and 1-year clinical outcomes for true CBLs.

Cardiovascular outcomes associated with crush versus provisional stenting techniques for bifurcation lesions: a systematic review and meta-analysis

Background

Percutaneous coronary intervention (PCI) for bifurcation lesions has often been challenging for Interventionists. Application of the correct intra-procedural technique is vital to generate beneficial outcomes after PCI. We aimed to systematically compare the post interventional cardiovascular outcomes which were reported using crush versus provisional stenting techniques for bifurcation lesions.

Methods

A computerized search was carried out through Medical Literature Analysis and Retrieval System Online, EMBASE, the Cochrane Central and through www.ClinicalTrials.gov for English publications comparing crush versus the provisional stenting techniques for coronary bifurcation lesions during PCI. Major adverse cardiac events, all-cause mortality, cardiac death, myocardial infarction, stent thrombosis, target vessel and target lesion revascularizations were the endpoints in this analysis. Odds ratios (OR) and 95% confidence intervals (CI) were generated during statistical analysis to represent the data.

Results

Six studies consisting of a total number of 2220 participants (1085 participants were assigned to the crush stenting technique and 1135 participants were assigned to the provisional stenting technique) enrolled between years 2004 and 2016 were included in this analysis.

During a follow-up time period from six to sixty months, major adverse cardiac events (OR: 0.73, 95% CI: 0.59–0.91; P = 0.005), target vessel revascularization (OR: 0.62, 95% CI: 0.43–0.89; P = 0.01) and target lesion revascularization (OR: 0.62, 95% CI: 0.45–0.85; P = 0.003) were significantly lower in patients who were assigned to the crush stenting technique. However, all-cause mortality (OR: 0.90, 95% CI: 0.48–1.68; P = 0.74), cardiac death (OR: 0.56, 95% CI: 0.29–1.08; P = 0.08), myocardial infarction (OR: 0.89, 95% CI: 0.62–1.27; P = 0.53) and stent thrombosis (OR: 0.72, 95% CI: 0.36–1.42; P = 0.34) were not significantly different.

Conclusion

In patients with coronary bifurcation lesions undergoing PCI, crush stenting technique was associated with significantly lower major adverse cardiac events and repeated revascularization without any change in mortality, myocardial infarction and stent thrombosis when compared to the provisional technique showing a benefit of crush over the provisional stenting technique during PCI.

Coronary Bifurcation Lesions

Percutaneous coronary intervention (PCI) with drug-eluting stent (DES) for the treatment of coronary bifurcation lesions (CBLs) is still technically demanding, mainly because of higher rates of both acute and chronic complication as compared with non-CBLs. Although provisional stenting (PS) is considered as the preferred strategy for most of the CBLs, a systematic two-stent technique (double kissing [DK] crush) should be considered in patients with complex left main (LM)-CBLs or non-LM-CBLs stratified by the DEFINITION criteria. Intracoronary imaging and/or physiologic evaluation should be used to optimize CBLs intervention. PCI with DES for the treatment of CBLs is technically demanding, mainly because of higher rates of both acute and chronic complication as compared with non-CBLs. PS is a default strategy for most of the CBLs. Double kissing (DK) crush is associated with better clinical outcomes compared with PS in patients with complex LM-CBLs or non-LM-CBLs stratified by the DEFINITION criteria. Intracoronary imaging and/or physiologic evaluation are useful tools to guide the treatment of CBLs. The use of drug-coated balloons in CBLs needs further data to support the clinical benefits.

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.

Imaging Guided Treatment of Bifurcation Lesions, Implications on Daily Practice

Treating coronary bifurcation lesions can always be challenging. Choice of bifurcation technique depends firstly on the complexity of the lesion but also on operators experience and skills. Occasionally, switching from one technique to another, during the course of the procedure, will be needed and this requires adequate knowledge of the procedural steps for each technique. Intravascular imaging enables the operator to choose between one or two stents strategy and offers guidance during the procedure. A patient was treated at our institution with three different bifurcation techniques while a switch to a two stent bifurcation technique was required, intravascular ultrasound guidance was available before and during the procedure. Choice of bifurcation strategy was based on imaging information acquired and after the completion of each bifurcation technique the bifurcation sites were recorded and analyzed.

Validation of the Cut-Plane Method for Accurate Measurement of Side-Branch Ostium Area in Coronary Bifurcation Lesions: A 3D-OCT Analysis

Objective

This study aimed to validate the effectiveness, accuracy, and feasibility of the cut-plane method for measuring the side branch (SB) ostium area in three-dimensional optical coherence tomography (3D-OCT) pullbacks performed in the main branch (MB).

Methods

A total of 109 sets of OCT pullbacks from the MB and SB of coronary artery bifurcation lesions were analyzed using Vivolight OCT software. Measurements of the SB ostium area from the MB and SB pullbacks were analyzed. Measurements of the SB ostium area from the actual SB pullback were used as a reference. 3D cut-plane analysis was used to estimate the correlations and mean errors with the reference measurements.

Results

Thirty-four sets of OCT images from the C7XR system and 75 sets from the CornarisTM system were analyzed using Vivolight software. There was a strong correlation between the reference measurements of the SB ostium area and the measurements obtained through 3D cut-plane analysis in the overall dataset (r = 0.925). This correlation was observed consistently with both the C7XR system (r = 0.955) and CornarisTM system (r = 0.900). Similar results were found in subset analyses of true and nontrue bifurcations (r = 0.936; r = 0.898, respectively) and in left main (LM) or non-LM bifurcation subsets (r = 0.932; r = 0.873, respectively).

Conclusions

There were strong correlations between measurements of the SB ostium area by 3D-OCT and the reference measurements, and thus may be a reliable and accurate alternative to direct OCT pullback examinations of the SB.

Coronary Bifurcation Stenting: Review of Current Techniques and Evidence

BACKGROUND

Coronary bifurcation stenting constitutes 20% of all PCI performed. Given the extensive prevalence of bifurcation lesions, various techniques have sought to optimally stent the bifurcation to improve revascularization while also decreasing rates of stent thrombosis and lesion recurrence. Advanced techniques, such as planned two-stent approaches, have been shown to have improved outcomes but also require fluoroscopy and procedure time, posing an economic argument as well as a patient-outcome one.

OBJECTIVE

Because of the many strategies posited in the literature, it becomes essential to objectively evaluate evidence from randomized controlled trials and meta-analyses to help determine the optimal stenting strategy.

METHODS

We reviewed the clinical evidence on the efficacy of coronary bifurcation stenting.

RESULTS

In this paper, we review the most recent randomized controlled trials and meta-analyses on the efficacy of various stenting techniques and advances in stenting technologies published to gauge the current state of understanding and chart where the field is heading.

CONCLUSION

Bifurcation stenting is a maturing problem in the field of interventional cardiology that is adapting to the needs of the patients and advances in technology.

Clinical Outcomes Following Simple or Complex Stenting for Coronary Bifurcation Lesions: A Meta-Analysis

Background

Stent placement remains a challenge for coronary bifurcation lesions. While both simple and complex stenting strategies are available, it is unclear which one results in better clinical outcomes. This meta-analysis aims to explore the long-term prognosis following treatment with the 2 stenting strategies.

Method

Randomized controlled trials found from searches of the PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were included in this meta-analysis. The complex stent placement strategy was identified as the control group, and the simple stent placement strategy was identified as the experimental group. Data were synthesized with a random effects model. The quality of the randomized controlled trials was assessed by Jadad scale scores. The clinical endpoints at 6 months, 1 year, and 5 years were analyzed.

Results

A total of 11 randomized controlled trials met the inclusion criteria. A total of 2494 patients were included in this meta-analysis. The odds ratio [OR] of the major adverse cardiac events (MACEs) at 6 months was 0.85 (95% confidence interval [CI] 0.53-1.35; P = .49, I ² = 0%). The OR of the MACEs at 1 year was 0.61 (95% CI 0.36-1.05; P = .08, I ² = 0%). The OR of the MACEs at 5 years was 0.69 (95% CI 0.51-0.92; P = .01, I ² = 0%). Compared with the complex strategy, the simple strategy was associated with a lower incidence of MACEs at 5 years.

Conclusion

Compared to the complex stenting strategy, the simple stenting strategy can better reduce the occurrence of long-term MACEs for coronary bifurcation lesions.

An observational study assessing the use of Sirolimus-eluting balloons for side-branch treatment in the provisional stenting of coronary bifurcations

Background

Drug eluting balloons (DEB) are a feasible method of rapid delivery of drug to a coronary vessel wall. Their efficacy has been established for the treatment of in-stent restenosis and small vessel disease but there is limited data for their use in bifurcation lesions.

Objective

The aim of this study was to assess the effectiveness of provisional upfront side-branch DEB use in bifurcation lesions compared to a simple balloon (POBA) or upfront 2 stent bifurcation strategy.

Methods

We conducted an observational study of 625 patients undergoing PCI to bifurcation lesions. All the patients had a DES deployed in the main vessel (MV). Decision on revascularization option for the side branch (SB) was made by the operator. The primary endpoint was target vessel failure. Secondary endpoints were target vessel myocardial infarction and all-cause mortality.

Results

311 patients had upfront DEB to the SB whilst the remaining were treated with either DES (188) or POBA (126). Baseline characteristics were similar aside from history of previous MI, which were higher in patients treated with DES or POBA, p = 0.009 whereas patients with previous CABG were likely to undergo DEB treatment (p = 0.004). TVF was more likely to occur in the POBA group (7.5 %) compared to the DEB (3.3 %) and DES (3.3 %) groups (p = 0.0019). There was no significant difference in TV-MI (p = 0.62) or death (p = 0.98) between the groups.

Conclusion

This study suggests that provisional bifurcation stenting with upfront Sirolimus DEB use in the SB is an effective treatment for non-LMS bifurcation PCI.

Coronary bifurcation lesion treatment with the BioMime™ Branch sirolimus-eluting coronary side-branch stent system: A single-center experience

BACKGROUND

Coronary bifurcation lesions (CBL) comprise 15 %-20 % of percutaneous coronary procedures and remain a challenge despite advances in stent and interventional techniques. The BioMime™ Branch sirolimus-eluting coronary side-branch stent (BBSES) is specifically designed for CBL treatment in conjunction with a standard drug-eluting stent (DES). We report the first single-center experience of treating complex CBL with the novel BBSES.

METHODS

This is a retrospective, single-center study involving consecutive prospectively identified patients who underwent treatment of true CBL with the BBSES. The protocol included BBSES+DES implantation in the CBL and simultaneous final kissing balloon inflation.

RESULTS

Fifty-eight CBL were treated in 58 consecutive patients (89.6 % men, mean age 69.0 ± 9.5 years) presenting primarily with stable angina (84.4 %) and true (Medina 1,1,1,) CBL. Procedural success was 100 % without major adverse cardiac events (MACE). At a median follow-up of 18 months, one sudden death was reported that was accounted as possible late stent thrombosis. One patient had spontaneous myocardial infarction due to subacute thrombosis of a DES implanted in the main vessel proximally to the BBSES before the index procedure. Another patient was hospitalized for atrial fibrillation.

CONCLUSIONS

This is the first clinical experience to date of true CBL treatment with the BBSES demonstrating high procedural success, no in-hospital MACE and sustained clinical results at a median follow-up of 18 months.

Late stent thrombosis as a complication of T and small protrusion bifurcation stenting: a case report

Background

A case of stent thrombosis as a complication of coronary bifurcation stenting is described. We review potential complications of bifurcation stenting and established guidelines.

Case summary

A 64-year-old man presented with a non-ST segment elevation myocardial infarction. High-sensitivity troponin I peaked at 99 000 ng/L (normal <5). He previously had coronary stenting for stable angina when residing in another country 2 years previously. Coronary angiography revealed no significant stenosis with TIMI 3 flow in all vessels. Cardiac magnetic resonance imaging demonstrated a left anterior descending artery (LAD) territory regional motion abnormality, late gadolinium enhancement consistent with recent infarction, and a left ventricular apical thrombus. Repeat angiography and intravascular ultrasound (IVUS) confirmed bifurcation stenting at the junction of the LAD and second diagonal (D2) with protrusion of several millimetres of the uncrushed proximal segment of the D2 stent in the LAD vessel lumen. There was under-expansion of the LAD stent in the mid-vessel and stent malapposition in the proximal LAD, extending into the distal left main stem coronary artery and involving the ostium of the left circumflex coronary artery. Percutaneous balloon angioplasty was performed along the length of the stent, including an internal crush of the D2 stent. Coronary angiography confirmed a uniform expansion of the stented segments and TIMI 3 flow. Final IVUS confirmed full stent expansion and apposition.

Discussion

This case highlights the importance of provisional stenting as a default strategy and familiarity with procedural steps in bifurcation stenting. Furthermore, it emphasizes the benefit of intravascular imaging for lesion characterization and stent optimization.