Immediate and long-term results of "T" stenting for bifurcation coronary lesions

Randomised comparison of provisional side branch stenting versus a two-stent strategy for treatment of true coronary bifurcation lesions involving a large side branch: the Nordic-Baltic Bifurcation Study IV

Background

It is still uncertain whether coronary bifurcations with lesions involving a large side branch (SB) should be treated by stenting the main vessel and provisional stenting of the SB (simple) or by routine two-stent techniques (complex). We aimed to compare clinical outcome after treatment of lesions in large bifurcations by simple or complex stent implantation.

Methods

The study was a randomised, superiority trial. Enrolment required a SB≥2.75 mm, ≥50% diameter stenosis in both vessels, and allowed SB lesion length up to 15 mm. The primary endpoint was a composite of cardiac death, non-procedural myocardial infarction and target lesion revascularisation at 6 months. Two-year clinical follow-up was included in this primary reporting due to lower than expected event rates.

Results

A total of 450 patients were assigned to simple stenting (n=221) or complex stenting (n=229) in 14 Nordic and Baltic centres. Two-year follow-up was available in 218 (98.6%) and 228 (99.5%) patients, respectively. The primary endpoint of major adverse cardiac events (MACE) at 6 months was 5.5% vs 2.2% (risk differences 3.2%, 95% CI −0.2 to 6.8, p=0.07) and at 2 years 12.9% vs 8.4% (HR 0.63, 95% CI 0.35 to 1.13, p=0.12) after simple versus complex treatment. In the subgroup treated by newer generation drug-eluting stents, MACE was 12.0% vs 5.6% (HR 0.45, 95% CI 0.17 to 1.17, p=0.10) after simple versus complex treatment.

Conclusion

In the treatment of bifurcation lesions involving a large SB with ostial stenosis, routine two-stent techniques did not improve outcome significantly compared with treatment by the simpler main vessel stenting technique after 2 years.

Trial registration number

NCT01496638.

A randomised comparison of Conventional versus Intentional straTegy in patients with high Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion: rationale and design of the CIT-RESOLVE trial

INTRODUCTION

The intentional strategy (aggressive side branch (SB) protection strategy: elective two-stent strategy or jailed balloon technique) is thought to be associated with lower SB occlusion rate than conventional strategy (provisional two-stent strategy or jailed wire technique). However, most previous studies showed comparable outcomes between the two strategies, probably due to no risk classification of SB occlusion when enrolling patients. There is still no randomised trial compared the intentional and conventional strategy when treating bifurcation lesions with high risk of SB occlusion. We aim to investigate if intentional strategy is associated with significant reduction of SB occlusion rate compared with conventional strategy in high-risk patients.

METHODS AND ANALYSIS

The Conventional versus Intentional straTegy in patients with high Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion (CIT-RESOLVE) is a prospective, randomised, single-blind, multicentre clinical trial comparing the rate of SB occlusion between the intentional strategy group and the conventional strategy group (positive control group) in a consecutive cohort of patients with high risk of side branch occlusion defined by V-RESOLVE score, which is a validated angiographic scoring system to evaluate the risk of SB occlusion in bifurcation intervention and used as one of the inclusion criteria to select patients with high SB occlusion risk (V-RESOLVE score ≥12). A total of 21 hospitals from 10 provinces in China participated in the present study. 566 patients meeting all inclusion/exclusion criteria are randomised to either intentional strategy group or conventional strategy group. The primary endpoint is SB occlusion (defined as any decrease in thrombolysis in myocardial infarction flow grade or absence of flow in SB after main vessel stenting). All patients are followed up for 12-month postdischarge.

ETHICS AND DISSEMINATION

The protocol has been approved by all local ethics committee. The ethics committee have approved the study protocol, evaluated the risk to benefit ratio, allowed operators with a minimum annual volume of 200 cases to participate in the percutaneous coronary intervention procedure and permitted them to perform both conventional and intentional strategies. Written informed consent would be acquired from all participants. The findings of the trial will be shared by the participant hospitals and disseminated through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02644434; Pre-results.

Serial Morphological Changes of Side-Branch Ostium after Paclitaxel-Coated Balloon Treatment of De Novo Coronary Lesions of Main Vessels

PURPOSE

The effects on the side-branch (SB) ostium, following paclitaxel-coated balloon (PCB) treatment of de novo coronary lesions of main vessels have not been previously investigated. This study was aimed at evaluating the serial morphological changes of the SB ostium after PCB treatment of de novo coronary lesions of main vessels using optical coherence tomography (OCT).

MATERIALS AND METHODS

This prospective, single-center observational study enrolled patients with de novo lesions, which were traversed by at least one SB (≥1.5 mm) and were treated with PCB. The SB ostium was evaluated with serial angiographic and OCT assessments pre- and post-procedure, and at 9-months follow-up.

RESULTS

Sixteen main vessel lesions were successfully treated with PCB, and 26 SBs were included for analysis. Mean SB ostial lumen area increased at 9-months follow-up (0.92±0.68 mm² pre-procedure, 1.03±0.77 mm² post-procedure and 1.42±1.18 mm² at 9-months). The SB ostial lumen area gain was 0.02±0.24 mm² between pre- and post-procedure, 0.37±0.64 mm² between post-procedure and 9-months, and 0.60±0.93 mm² between pre-procedure and 9-months. The ostial lumen area increased by 3.9% [interquartile range (IQR) of -33.3 to 10.4%] between pre- and post-procedure, 52.1% (IQR of -0.7 to 77.3%) between post-procedure and 9-months and 76.1% (IQR of 18.2 to 86.6%) between pre-procedure and 9-months.

CONCLUSION

PCB treatment of de novo coronary lesions of main vessels resulted in an increase in the SB ostial lumen area at 9-months.

Three-year clinical outcome of patients with bifurcation treatment with second-generation Resolute and Xience V stents in the randomized TWENTE trial

BACKGROUND

Only limited data from large randomized clinical trials have been published on the long-term performance of second-generation drug-eluting stents in bifurcation lesions.

METHODS

We investigated in patients in the randomized TWENTE trial the long-term safety and efficacy of treating bifurcation lesions with 2 widely applied second-generation drug-eluting stents, the zotarolimus-eluting Resolute stent (Medtronic Inc, Santa Rosa, CA) and the everolimus-eluting Xience V stent (Abbott Vascular, Santa Clara, CA). Three-year follow-up was available in 99.3%. Patients were categorized into treatment for ≥1 bifurcation lesion versus treatment for nonbifurcation lesions only.

RESULTS

Among the 1,391 patients of the TWENTE trial, 362 (26%) were treated for bifurcation lesions. At 3-year follow-up, target-vessel failure did not differ between patients treated for bifurcation versus nonbifurcation lesions (13.1% vs 12.6%; P = .84), whereas the periprocedural myocardial infarction rate was higher in patients with bifurcation lesions (6.9% vs 3.1%; P < .01). Of the 362 patients with bifurcation lesion treatment, 179 (49.4%) were treated with Resolute and 183 (50.6%) with Xience V. There was no significant difference in target-vessel failure between the Resolute and Xience V groups with bifurcation treatment (13.6% vs 12.6%; P = .78), and their incidence of definite-or-probable stent thrombosis was low and similar (1.1% vs 0.5%, respectively; P = .62).

CONCLUSION

Despite a significant difference in periprocedural myocardial infarction, 3-year clinical outcome after implantation of second-generation stents was favorable and similar for patients with and without bifurcation lesions. In addition, we observed no difference in long-term clinical outcome after bifurcation lesion treatment with Resolute and Xience V stents.

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.

First-in-human experience with the Medtronic Bifurcation Stent System

AIMS

The BRANCH study was a prospective, multicentre, non-randomised, single arm trial to investigate the feasibility, safety, efficacy, and performance of the bare metal Medtronic Bifurcation Stent System for the treatment of de novo bifurcation lesions.

METHODS AND RESULTS

Sixty patients were enrolled in the study. After a learning curve of one case at seven centres, 53 patients from six centres were prospectively treated. The primary endpoint was target vessel failure (TVF) at 30 days. Secondary endpoints included acute device, lesion, and procedure success and TVF at 12 months. Medina complex bifurcation lesions (1,1,1; 1,1,0; 1,0,1; 0,1,1) were treated in 71.7%. The stent was successfully implanted in 86.8% of cases. Acute device, lesion, and procedure success rates were 83.0%, 92.5%, and 88.7%, respectively. TVF occurred in 2/52 patients (3.8%) at 30 days. No other major adverse cardiac adverse events (MACE) occurred through 30 days follow-up. At 12 months, TVF occurred in 6/47 (12.8%) patients, and MACE occurred in 5/47 (10.6%) patients.

CONCLUSIONS

Results from the BRANCH study demonstrate that the Medtronic Bifurcation Stent System is safe and can be successfully and effectively deployed in a variety of bifurcation lesions with good clinical outcomes.

Stenting of complex lesions: an overview

Contemporary management of coronary artery disease relies increasingly on percutaneous techniques combined with medical therapy. Although percutaneous coronary intervention (PCI) can be performed successfully in most lesions, several difficult lesion subsets continue to present unique technical challenges. These complex lesions may be classified according to anatomic criteria, including extensive calcification, thrombus, and chronic occlusions, or by location, such as bifurcations, saphenous vein grafts and unprotected left main. PCI of these lesions often requires novel devices, such as drug-eluting stents, hydrophilic guidewires, distal protection balloons or filters, thrombectomy catheters, rotational atherectomy, and cutting balloons. An integrated approach that combines these devices with specialized techniques and adjunctive pharmacologic agents has greatly improved PCI success rates for these complex lesions.

Anatomic and Functional Evaluation of Bifurcation Lesions Undergoing Percutaneous Coronary Intervention

Background— We sought to investigate the mechanism of geometric changes after main branch (MB) stent implantation and to identify the predictors of functionally significant “jailed” side branch (SB) lesions.

Methods and Results— Seventy-seven patients with bifurcation lesions were prospectively enrolled from 8 centers. MB intravascular ultrasound was performed before and after MB stent implantation, and fractional flow reserve was measured in the jailed SB. The vessel volume index of both the proximal and distal MB was increased after stent implantation. The plaque volume index decreased in the proximal MB (9.1�3.0 to 8.4�2.4 mm 3 /mm, P =0.001), implicating plaque shift, but not in the distal MB (5.4�1.8 to 5.3�1.7 mm 3 /mm, P =0.227), implicating carina shifting to account for the change in vessel size (N=56). The mean SB fractional flow reserve was 0.71�0.20 (N=68) and 43% of the lesions were functionally significant. Binary logistic-regression analysis revealed that preintervention % diameter stenosis of the SB (odds ratio=1.05; 95% CI, 1.01 to 1.09) and the MB minimum lumen diameter located distal to the SB ostium (odds ratio=3.86; 95% CI, 1.03 to 14.43) were independent predictors of functionally significant SB jailing. In patients with ≥75% stenosis and Thrombolysis In Myocardial Infarction grade 3 flow in the SB, no difference in poststent angiographic and intravascular ultrasound parameters was found between SB lesions with and without functional significance.

Conclusions— Both plaque shift from the MB and carina shift contribute to the creation/aggravation of an SB ostial lesion after MB stent implantation. Anatomic evaluation does not reliably predict the functional significance of a jailed SB stenosis.

Clinical Trial Registration: http://www.clinicaltrials.gov. Unique Identifier: NCT00553670.

Randomized trial of simple versus complex drug-eluting stenting for bifurcation lesions: the British Bifurcation Coronary Study: old, new, and evolving strategies

BACKGROUND

The optimal strategy for treating coronary bifurcation lesions remains a subject of debate. With bare-metal stents, single-stent approaches appear to be superior to systematic 2-stent strategies. Drug-eluting stents, however, have low rates of restenosis and might offer improved outcomes with complex stenting techniques.

METHODS AND RESULTS

Patients with significant coronary bifurcation lesions were randomized to either a simple or complex stenting strategy with drug-eluting stents. In the simple strategy, the main vessel was stented, followed by optional kissing balloon dilatation/T-stent. In the complex strategy, both vessels were systematically stented (culotte or crush techniques) with mandatory kissing balloon dilatation. Five hundred patients 64+/-10 years old were randomized; 77% were male. Eighty-two percent of lesions were true bifurcations (>50% narrowing in both vessels). In the simple group (n=250), 66 patients (26%) had kissing balloons in addition to main-vessel stenting, and 7 (3%) had T stenting. In the complex group (n=250), 89% of culotte (n=75) and 72% of crush (n=169) cases were completed successfully with final kissing balloon inflations. The primary end point (a composite at 9 months of death, myocardial infarction, and target-vessel failure) occurred in 8.0% of the simple group versus 15.2% of the complex group (hazard ratio 2.02, 95% confidence interval 1.17 to 3.47, P=0.009). Myocardial infarction occurred in 3.6% versus 11.2%, respectively (P=0.001), and in-hospital major adverse cardiovascular events occurred in 2.0% versus 8.0% (P=0.002), respectively. Procedure duration and x-ray dose favored the simple approach.

CONCLUSIONS

When coronary bifurcation lesions are treated, a systematic 2-stent technique results in higher rates of in-hospital and 9-month major adverse cardiovascular events. This difference is largely driven by periprocedural myocardial infarction. Procedure duration is longer, and x-ray dose is higher. The provisional technique should remain the preferred strategy in the majority of cases. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov. Unique identifier: NCT 00351260.

Clinical and angiographic outcome of stenting of unprotected left main coronary artery bifurcation narrowing

PURPOSE

Improvements in techniques and equipments may result in the wider applicability of percutaneous coronary intervention (PCI) for unprotected left main coronary artery (ULMCA) stenosis. This report is a prospective study focused on the feasibility, effectiveness and long-term results of stenting for treatment of ULMCA bifurcation lesions.

METHODS

From November 2002 to October 2003, 57 consecutive patients were stented with bare metal stents and the technique of kissing balloon followed by T-provisional stenting was applied for ostial left anterior descending, left circumflex or distal left main coronary lesion.

RESULTS

Mean age was 69.5+/-10.7 years. Acute coronary syndrome occurred in 68.4% of patients with a majority of two or three vessel disease (45.10% and 35.30% respectively). GpIIbIIIa inhibitors were used in only 5.8% of cases. Angiographic success was obtained in 100% of patients. Hospital stay was 7.03+/-2.26 days without major adverse cardiac events. At eight months follow-up, cardiac death was 1.7%, non-fatal myocardial infarction 5.1% and target vessel revascularisation 22.8% including CABG 15.7% and repeated PCI 10.5% with an angiographic restenosis rate of 29.8%.

CONCLUSION

In the setting of coronary stenting of the ULMCA stenosis, the use of bare metal stents can no longer be considered contemporary technique and another strategy such as coated stent may be needed.

[Clinical and angiographic outcomes after implantation of drug-eluting stents in bifurcation lesions with the crush stent technique]

The most common approach in the treatment of bifurcation lesions is stenting only the main branch (MB) with provisional T-stenting of the side branch (SB). However, some bifurcation lesions may have extensive disease within a large SB requiring stenting of this vessel. The "crush" technique, which has been proposed as an alternative approach to other strategies to treat complex bifurcations, is a relatively simple technique that ensures complete coverage of the SB ostium. Previous series have reported its safety and feasibility, but limited data are available about the long-term outcomes. We report our experience on 21 consecutive patients (pts) treated with the "crush" technique with drug-eluting stents (DES) between November 2005 and March 2007. Clinical follow-up was 18+/-7 months for 19 pts (90%), and angiographic follow-up was completed in 66% of pts (N=14), at a mean time of 8.5+/-4 months. Mean pt age was 70+/-11 years; 33% (N=7) had diabetes mellitus, and mean preoperative logistic EUROSCORE predicted 11% mortality rate. The left anterior descending artery/diagonal and the distal left main were the most frequent bifurcation locations (52 and 43% of cases respectively), with a type 1,1,1 of the Medina classification of bifurcation lesions in 62% of pts, and an angulation MB-SB below 50 degrees in 66% of cases. Final kissing balloon dilation was performed in 90% of pts (N=20). Stent diameter and length were similar between MB and SB. The procedure was successfull in 100% of cases in the MB and 95% of cases in the SB. Procedure-related CK elevation above 2 ULN was seen in two pts (9.5%), without ECG modification. One pt had subacute stent thrombosis 5 days after his procedure. At the end of follow-up, target vessel revascularization (TVR) was required in four pts (19%), and target lesion revascularisation (TLR) in three pts (14%) whom had focal restenosis in the SB ostium (one pt) and in the MB and SB ostia (one pt). Sudden death occurred in one pt 14 months after his procedure. In conclusion, when an effective strategy for stenting both branches is planned, the "crush" technique with final kissing balloon can be safely used by experienced operators to treat complex bifurcation lesions with DES. The safety profile and TLR rate in our small series of "crush" stenting were similar to that of other studies reported thus far.

Randomized Study of the Crush Technique Versus Provisional Side-Branch Stenting in True Coronary Bifurcations

Background— Sirolimus-eluting stents have been reported to be effective in the treatment of coronary bifurcations. Still, it has not been fully clarified which strategy would provide the best results with true bifurcation lesions.

Methods and Results— The CACTUS trial (Coronary bifurcations: Application of the Crushing Technique Using Sirolimus-eluting stents) is a prospective, randomized, multicenter study comparing 2 different techniques of stenting, with mandatory final kissing-balloon inflation, in true bifurcations: (1) elective “crush” stenting and (2) stenting of only the main branch, with provisional side-branch T-stenting. From August 2004 to June 2007, 350 patients were enrolled in 12 European centers. The primary angiographic end point was the in-segment restenosis rate, and the primary clinical end point was the occurrence of major adverse cardiac events (cardiac death, myocardial infarction, or target-vessel revascularization) at 6 months. At 6 months, angiographic restenosis rates were not different between the crush group (4.6% and 13.2% in the main branch and side branch, respectively) and the provisional stenting group (6.7% and 14.7% in the main branch and side branch, respectively; P =NS). Additional stenting on the side branch in the provisional stenting group was required in 31% of lesions. Rates of major adverse cardiac events were also similar in the 2 groups (15.8% in the crush group versus 15% in the provisional stenting group, P =NS).

Conclusions— In most bifurcations with a significant stenosis in both branches, a provisional strategy of stenting the main branch only is effective, with the need to implant a second stent on the side branch occurring in approximately one third of cases. The implantation of 2 stents does not appear to be associated with a higher incidence of adverse events at 6 months.

Comparative study of simple versus complex stenting of coronary artery bifurcation lesions in daily practice in Chinese patients

BACKGROUND

Recently, several randomized and controlled trials have demonstrated great advantages of a drug-eluting stent (DES) with respect to significant reduction in restenosis and recurrence of symptoms, and improvement in clinical outcomes after percutaneous coronary intervention (PCI). Little is known about the comparative effects of the 1-DES plus the kissing balloon technique with the 2-DES for bifurcation angioplasty in a Chinese population.

METHODS

From April 2004 to June 2006, 566 consecutive Chinese patients underwent DES implantation for true bifurcation lesions, including 346 1-DES with the kissing balloon technique (300 male, 57.7 +/- 11.5 y old) and 220 2-DES (183 male, 58.1 +/- 10.7 y old) were analyzed. Clinical and angiographic follow-up was performed after 7 mo.

RESULTS

The major adverse cardiac event (MACE) rates were higher in the 2-DES group than in the 1-DES group (5.5% versus 2.0%; p = 0.032), which was mainly contributed to by acute myocardial infarction (AMI) (4.5% versus 1.4%; p = 0.032), rather than death and target lesion revascularization (TLR) (0% versus 0.5%; p = 0.389, 1.4% versus 2.7%; p = 0.352). Stent thrombosis rates were higher in the 2-DES group than in the 1-DES group (0.6% versus 2.7%; p = 0.042), except for 1 late-stent thrombosis in the 2-DES group, and all of them were subacute stent thrombosis (2 in the 1-DES group and 5 in the 2-DES group). The 7 mo angiographic follow-up rate was 36.4%. In the main branch there was no difference in restenosis rate in the 1-DES group compared with the 2-DES group (9.8% versus 11.9%; p = 0.652), but in the side branch the restenosis rate was higher in the 1-DES group (33.6% versus 15.5%; p = 0.004). However, there was no difference in in-segment late loss between the 2 groups, either in the main or side branch.

CONCLUSION

Compared with the 2-DES strategy, if a final kissing balloon could be achieved, the 1-DES strategy may be more efficient and safe.

Left main coronary artery stenosis: state-of-the-art

Patients with stenosis of the left main coronary artery present difficult challenges. The risks associated with this lesion have been known since the early days of angiography when patients were found to have increased mortality during follow-up. This information led to the general guidelines that surgical revascularization should be considered the treatment of choice in patients with significant left main coronary artery stenosis. Current advances in invasive cardiology have brought important information to the field. Intravascular ultrasound is now used routinely to evaluate angiographically indeterminate lesions with criteria now set forward as to what constitutes an indication for revascularization. Stents have even further dramatically changed the landscape. There are substantial issues, however, that need to addressed. These include the following: (1) the effect of specific lesion location on outcome - it is known that patients with distal bifurcation left main disease have worse outcome; (2) the potential for subacute thrombosis of the left main coronary artery; (3) the impact of left ventricular function and patient comorbidities irrespective of the degree and location of left main coronary artery stenosis; and (4) the risk-benefit ratio of stenting versus coronary artery bypass graft surgery. These issues are currently being addressed in two seminally important trials including the SYNTAX trial, which randomizes patients with left main and/or three-vessel disease to either coronary artery bypass graft surgery or a TAXUS drug-eluting stent. This trial is in the final stages of patient recruitment and will have important implications for the field. The other trial is the COMBAT trial, which is focused exclusively on left main coronary artery stenosis and randomizes patients with left main coronary artery disease either to a Sirolimus-eluting stent (Cypher, Johnson and Johnson Cordis, USA) or to coronary artery bypass graft surgery. The field of left main coronary artery disease continues to expand in terms of the evidence available for optimal patient evaluation and selection of treatment modalities.

Drug-eluting stents for the treatment of bifurcation lesions: a randomized comparison between paclitaxel and sirolimus stents

BACKGROUND

Drug-eluting stents have been shown to reduce restenosis in many types of lesions. The purpose of this article is to assess the efficacy of sirolimus- and paclitaxel-eluting stents in patients with bifurcation lesions.

METHODS

Between June 2003 and October 2004, 205 patients were enrolled in a prospective randomized trial; 103 patients were assigned to sirolimus stents and 102 patients to paclitaxel stents. All patients were treated by provisional T-stenting.

RESULTS

There were no differences between groups in terms of age, risk factors, clinical condition, location of the bifurcation lesion, or other technical factors. Angiographic data and immediate results were also similar in both groups. Three patients developed inhospital non-Q-wave acute myocardial infarction (2 from the sirolimus group and 1 from the paclitaxel group). Follow-up angiography was obtained in 109 patients (53%). In the sirolimus group, 5 patients developed restenosis (9%): 1 at the main vessel, 2 at the side branch, and 2 in both branches. In contrast, 16 patients from the paclitaxel group had restenosis (29%): 6 at the main vessel, 5 at the side branch, and 5 in both branches. Target lesion revascularization at 24 +/- 5 months post stenting occurred in 4 patients from the sirolimus group (4%) and in 13 from the paclitaxel group (13%) (P < .05). Late loss at the main vessel in the sirolimus group patients was 0.31 +/- 0.59 versus 0.60 +/- 0.77 mm in patients from the paclitaxel group (P < .05).

CONCLUSIONS

Patients with bifurcation lesions treated by sirolimus showed significantly lower rates of late loss, restenosis and target lesion revascularization than patients treated with paclitaxel-eluting stents.

Feasibility and safety of intra-coronary Beta irradiation with 144Ce/Pr for prevention of restenosis after percutaneous transluminal coronary angioplasty of in-stent restenotic lesions

BACKGROUND

Endovascular brachytherapy is a proven and efficacious treatment of coronary in-stent restenosis with established long-term benefit. Owing to its complexity and logistic inconveniences, brachytherapy did not find wide acceptance, especially in the current drug-eluting stents era. We conducted a single center, non-randomized pilot trial with 144Ce/Pr, utilizing a new high-energy Beta emitting source, for prevention of restenosis after percutaneous treatment of in-stent restenotic lesions.

METHODS AND RESULTS

Thirty consecutive patients presenting in-stent restenosis were enrolled in the study. After conventional balloon angioplasty, 144Ce/Pr was applied to the dilated coronary segment at a dose of 21Gy. Technical feasibility, safety and efficacy of 144Ce/Pr at 9 months clinical and angiographic follow-up were tested. Thirty-seven arterial segments were irradiated with 100% technical success and no in-hospital major adverse cardiac events (MACE). Five MACE were observed (13.5% of the treated segments) during 9 months follow-up, including four target lesion revascularizations and one episode of acute coronary syndrome secondary to sudden late thrombotic occlusion of the irradiated segment.

CONCLUSIONS

The study confirmed the safety and the feasibility of the intra-coronary Beta irradiation utilizing the 144Ce/Pr source. It also shows some practical advantages compared to traditional Gamma or other Beta sources. Considering the high-risk restenosis profile of the selected patients (i.e. diffuse in-stent restenosis, bifurcation lesions, small vessels) these results are encouraging in terms of restenosis prevention. Late acute thrombosis remains a problem requiring further improvement.

Novel stent system for bifurcation lesions: Examination by intravascular ultrasound

Bifurcation disease represents a mechanical and biological challenge for definitive interventional treatment. This case report discusses an experience with a novel stent system designed for the treatment of bifurcation lesions.

Acute and long-term outcomes of the novel side access (SLK-View™) stent for bifurcation coronary lesions: A multicenter nonrandomized feasibility study

OBJECTIVE

To evaluate technical feasibility and procedural safety of SLK-View stent for treating bifurcation lesions.

BACKGROUND

Percutaneous treatment of coronary bifurcation lesions represents a technical challenge. Several stenting techniques and dedicated devices have proven unsuccessful, with high rates of side branch occlusion at index procedure and follow-up.

METHODS

Eighty one patients with 84 de novo coronary artery lesions involving a major side branch underwent SLK-View (Advanced Stent Technologies, Inc., Pleasanton, CA) stent implantation with subsequent kissing balloon post dilatation. SLK-View stent is a new scaffolding device incorporating a side aperture that allows access to the side-branch of a bifurcation after deployment of the stent in main vessel. All patients underwent angiographic follow-up at 6 months. Procedural, in-hospital, and 6-month follow-up outcomes were examined.

RESULTS

The lesions were located in left main (n = 11), left anterior descending (n = 50), left circumflex (n = 8), right coronary artery (n = 7), and 1 ramus intermedius. The most frequent lesions (44.1%) were true bifurcations. Successful stent delivery to bifurcation was accomplished in 82/84 of the cases (97.6%). Technical success was obtained in 99 and 94% of main vessel and side branches, respectively. Stenting in side-branch was performed in 21 lesions (25%). Side-branches were accessed effectively in 100% of bifurcations postprocedurally. Binary restenosis rate at 6-month follow-up was 28.3% and 37.7% for main vessel and side-branch, respectively. TLR rate at 6-month follow-up was 21% and CABG rate of 6%.

CONCLUSION

In this consecutive multicenter series of patients with coronary bifurcation lesions, this novel side-branch access stent proved feasible, with a high procedural success rate, while maintaining side-branch access.

Sirolimus-eluting stent for in-stent restenosis of left main coronary artery in takayasu arteritis

A 53-year-old woman with Takayasu arteritis was admitted to hospital because of worsening exertional angina. Coronary angiography revealed 90% ostial stenosis in the left main coronary artery (LMCA), which also involved the bifurcation of the relatively short LMCA. Because the patient refused coronary bypass surgery, she underwent percutaneous coronary intervention (PCI) and the stenosis was successfully dilated. However, the exertional angina recurred a few months later and again after the second PCI. Finally, a sirolimus-eluting stent was deployed in the in-stent restenotic lesion. The patient has been free from angina pectoris for 6 months after the last PCI and follow-up coronary angiography indicated no restenosis in the LMCA.

The FRONTIER Stent Registry

OBJECTIVES

The goal of this study was to evaluate the safety and performance of the Multi-Link Frontier coronary bifurcation stent system (Guidant Corp., Santa Clara, California), a novel dedicated device designed for permanent side branch (SB) access, stent delivery by simultaneous kissing balloon inflation, and optimal main branch (MB) and SB ostium scaffolding.

BACKGROUND

The treatment of coronary bifurcation lesions remains challenging, and various approaches using stents have been proposed.

METHODS

The primary end point was the 180-day incidence of major adverse cardiac events (MACE) per intent-to-treat analysis. Secondary end points included device success, 30-day MACE, angiographic restenosis, and target lesion revascularization (TLR) rates at 180 days.

RESULTS

After a learning phase of two cases per center, 105 patients were prospectively included in 11 centers. The left anterior descending coronary artery/diagonal bifurcation was the target in 80% of cases. The Frontier stent was successfully implanted in 96 patients (91%), and procedural success was obtained in 93%. Two patients suffered in-hospital myocardial infarction (MI) secondary to SB occlusion, and one patient underwent elective coronary artery bypass grafting. At 30 days and 6 months, the MACE rates were 2.9% and 17.1% (no death, no subacute stent thrombosis, Q-wave MI 1.0% and 1.9%, non-Q-wave MI 1.0% and 1.9%, TLR 1.0% and 13.3%). The MB in-stent restenosis was 25.3%, in-segment 29.9%. The SB restenosis was 29.1%. The overall restenosis rate for any branch was 44.8%.

CONCLUSIONS

The results of this Frontier registry demonstrate the safety and performance of this dedicated stent system for the treatment of bifurcation lesions. The device can be successfully implanted in more than 90% of all cases, with a high procedural success rate and low 30-day and 6-month MACE rates.

Nine-Month Outcome of Patients Treated by Percutaneous Coronary Interventions for Bifurcation Lesions in the Recent Era

OBJECTIVES

The aim of this research was to determine the influence of bifurcation lesions on the outcome of patients undergoing percutaneous coronary intervention (PCI) in the recent era.

BACKGROUND

The treatment of bifurcation lesions by PCI has been associated with an increased complication rate. Whether recent improvements of interventional practice have translated into improved outcomes in this patient subgroup is unknown.

METHODS

The 11,482 patients enrolled in the Prevention of Restenosis with Tranilast and its Outcomes (PRESTO) were stratified according to the presence (n = 1,412) or absence (n = 10,068) of at least one bifurcation lesion treated by PCI. Baseline characteristics and outcome of patients undergoing PCI for bifurcation lesions were compared to those of patients treated for nonbifurcation lesions.

RESULTS

Patients treated for bifurcation lesions were less likely to have prior myocardial infarction (MI), prior coronary artery bypass graft surgery, and had a higher proportion of current stable angina (p < 0.01 for all comparisons). Bifurcation lesions involved more frequently the left anterior descending coronary artery and were more complex (angulated, eccentric, ostial, and tortuous) than nonbifurcation lesions. Percutaneous coronary intervention of bifurcation lesions was characterized by less frequent stent implantation (71% vs. 80%); PCI of bifurcation lesions was associated with an increased rate of combined end point death/MI/target vessel revascularization (TVR) at nine months (18% vs. 15%, p = 0.002) because of increased rates of TVR (17% vs. 14%, p < 0.001), whereas death (1%) and MI (1%) were not different between groups.

CONCLUSIONS

Percutaneous coronary intervention of bifurcation lesions is associated with higher TVR at follow-up. However, the risk of death, MI, death/MI was similar in patients treated for bifurcation or nonbifurcation lesions.

New Approaches to Ostial and Bifurcation Lesions

Percutaneous coronary intervention of bifurcation lesions is associated with lower procedural success rates, and an increased subsequent rate of major adverse cardiac events and restenosis. Currently, an array of stenting possibilities suggests a rational approach to treat various bifurcation lesions with appropriate techniques. This is however seldom the case. The main problems of treating bifurcation lesions remain plaque shift leading to (threatened) side branch occlusion, and either too much or insufficient side branch ostial stent coverage predisposing to impaired side branch access or restenosis, respectively. This paper reviews the available technologies and their relative merits.

Rapamycin-eluting stents for the treatment of bifurcated coronary lesions: a randomized comparison of a simple versus complex strategy

BACKGROUND

Rapamycin-eluting stents (RES) have been shown to reduce restenosis in many types of lesions. However, the ideal strategy for the treatment of coronary bifurcated lesions has not been established to date. This randomized study compares 2 strategies for the RES treatment of bifurcation lesions: a simple approach (stenting the main vessel and balloon dilatation for the side branch [SB]) versus a complex approach (stents for both vessels).

METHODS

To compare both strategies, a randomized study was conducted in 91 patients with true coronary bifurcation lesions. All patients received an RES at the main vessel, covering the SB. Patients from group A (n = 47) were assigned to balloon dilation of the involved SB (simple strategy); patients in group B (n = 44) were randomized to receive a second stent at the SB origin (complex strategy). There were no differences between groups regarding baseline clinical and angiographic data.

RESULTS

Major adverse cardiac events occurred in 3 patients from group A (2 non-Q-wave myocardial infarctions and 1 target lesion revascularization). Six-month angiographic reevaluation was obtained in 80 patients (88%). Restenosis of the main vessel was observed in 1 (2%) patient from group A and in 4 (10%) from group B. Restenosis of the SB appeared in 2 (5%) patients from group A and in 6 (15%) from group B.

CONCLUSIONS

Both strategies are effective in reducing the restenosis rate, with no differences in terms of clinical outcome. Elective SB stenting seems to provide no advantages over the simpler stent jail followed by SB balloon dilation.

Dynamic flow alterations dictate leukocyte adhesion and response to endovascular interventions

Although arterial bifurcations are frequent sites for obstructive atherosclerotic lesions, the optimal approach to these lesions remains unresolved. Benchtop models of arterial bifurcations were analyzed for flow disturbances known to correlate with vascular disease. These models possess an adaptable geometry capable of simulating the course of arterial disease and the effects of arterial interventions. Chronic in vivo studies evaluated the effect of flow disturbances on the pattern of neointimal hyperplasia. Acute in vivo studies helped propose a mechanism that bridges the early mechanical stimulus and the late tissue effect. Side-branch (SB) dilation adversely affected flow patterns in the main branch (MB) and, as a result, the long-term MB patency of stents implanted in pig arteries. Critical to this effect is chronic MB remodeling that seems to compensate for an occluded SB. Acute leukocyte recruitment was directly influenced by the changes in flow patterns, suggesting a link between flow disturbance on the one hand and leukocyte recruitment and intimal hyperplasia on the other. It is often impossible to simultaneously maximize the total cross-sectional area of both branches and to minimize flow disturbance in the MB. The apparent trade-off between these two clinically desirable goals may explain many of the common failure modes of bifurcation stenting.

Randomized Study to Evaluate Sirolimus-Eluting Stents Implanted at Coronary Bifurcation Lesions

Background— A sirolimus-eluting stent (Cypher, Cordis Corp) has been reported to markedly decrease restenosis in selected lesions; higher-risk lesions, including coronary bifurcations, have not been studied.

Methods and Results— This prospective study evaluated the safety and efficacy of sirolimus-eluting stents for treatment of coronary bifurcation lesions. Patients were randomly assigned to either stenting of both branches (group A) or stenting of the main branch with provisional stenting of the side branch (SB) (group B). Eighty-five patients (86 lesions) were enrolled. There was 1 case of unsuccessful delivery of any device at the bifurcation site. Given the high crossover, more lesions were treated with 2 stents (n=63) than with stent/balloon (n=22). Clinical follow-up at 6 months was completed in all patients and angiographic follow-up in 53 patients in group A (85.5%) and 21 in group B (95.4%). One patient died suddenly 4.5 months after the procedure. There were 3 cases of stent thrombosis (3.5%). The total restenosis rate at 6 months was 25.7%, and it was not significantly different between the double-stenting (28.0%) and the provisional SB-stenting (18.7%) groups. Fourteen of the restenosis cases occurred at the ostium of the SB and were focal. Target lesion revascularization was performed in 7 cases; target vessel failure occurred in 15 cases (17.6%).

Conclusions— These results are an improvement compared with historical controls using bare metal stents. Restenosis at the SB remains a problem. At this time, no statement can be made regarding the most appropriate technique to use when treating bifurcations with the Cypher stent.

Restenosis due to underexpansion of sirolimus-eluting stent in a bifurcation lesion

Even in the drug-eluting stent era, percutaneous coronary intervention in bifurcation lesions is complex and technically demanding, and considerable expertise is required. This case report describes in-stent restenosis due to stent underexpansion after kissing stents using sirolimus-eluting stents.

Coronary restenosis after sirolimus-eluting stent implantation: morphological description and mechanistic analysis from a consecutive series of cases

BACKGROUND

We describe the clinical and morphological patterns of restenosis after sirolimus-eluting stent (SES) implantation.

METHODS AND RESULTS

From 121 patients with coronary angiography obtained >30 days after SES implantation, restenosis (diameter stenosis >50%) was identified in 19 patients and 20 lesions (located at the proximal 5-mm segment in 30% or within the stent in 70%). Residual dissection after the procedure or balloon trauma outside the stent was identified in 83% of the proximal edge lesions. Lesions within the stent were focal, and stent discontinuity was identified in some lesions evaluated by intravascular ultrasound.

CONCLUSIONS

Sirolimus-eluting stent edge restenosis is frequently associated with local trauma outside the stent. In-stent restenosis occurs as a localized lesion, commonly associated with a discontinuity in stent coverage. Local conditions instead of intrinsic drug-resistance to sirolimus are likely to play a major role in post-SES restenosis.

Technical feasibility, safety, and clinical outcome of stenting of unprotected left main coronary artery bifurcation narrowing

This study was performed to evaluate the acute and long-term results of stenting for unprotected left main coronary artery (LMCA) bifurcation lesions. Sixty-three consecutive patients with an unprotected LMCA bifurcation lesion and normal left ventricular function were included. Stenting was performed with (n = 32) or without debulking atherectomy (n = 31) at the operator's discretion. Slotted-tube stents, coil stents, or bifurcation stents were used. The procedural success rate was 100%. In-hospital events including stent thrombosis, Q-wave myocardial infarction, and emergency bypass surgery did not occur in any patients. The angiographic follow-up rate was 86% (43 of the 50 eligible patients), and the restenosis rate was 28% (parent vessel only 14%, side branch only 9%, and both 5%). Restenosis at the parent vessel occurred less frequently in the debulking group than in the nondebulking group (5% vs 33%, respectively, p = 0.02). In multivariate analysis, the debulking procedure was an independent predictive factor of restenosis for the parent vessel (odds ratio 0.10, 95% confidence intervals 0.01 to 0.91, p = 0.04). Clinical follow-up was obtained in all patients at 19.9 +/- 13.7 months. There were 2 deaths (noncardiac origin), but no myocardial infarction during follow-up. Target lesion revascularization was required in 6 patients. The event-free survival rate (death, nonfatal myocardial infarction, and repeat revascularization) was 86% at the end of the follow-up period. In conclusion, stenting for an unprotected LMCA bifurcation lesion may be performed with a high procedural success rate and a favorable clinical outcome in selected patients with normal left ventricular function, suggesting that stenting would be an effective alternative to surgery in these patients.

Immediate and long-term clinical and angiographic results from Wiktor stent treatment for true bifurcation narrowings

From January 1996 to December 1998, 90 consecutive patients with true bifurcation lesions underwent percutaneous coronary angioplasty with Wiktor stent implantation in our centers. In 1 group (group I, n = 45), a simple approach (main vessel stenting and balloon angioplasty of the side branch) was pursued. In the other group (group II, n = 45), both the main vessel and the side branch were stented ("T" technique). There was no significant difference in clinical and angiographic characteristics between the 2 groups. Angiographic and procedural successes were 100% and 95.6%, respectively, in both groups. Angiographic results for the side branch were better in group II than in group I. In-hospital and long-term (12 month) major cardiac events were similar in the 2 groups. Target lesion revascularization was 15.5% in group I and 35.5% in group II (p = 0.12). In the main vessel, restenosis rate was 12.5% in group I and 25% in group II (p = 0.15). In the side branch, restenosis rate was 37.5% in group II and 12.5% in group I (p = <0.05; odds ratio 2.42; 95% confidence interval 1.05 to 6.26). Event-free probability at 12 months was 61% in group II and 80% in group I (p = 0.10). When dealing with true bifurcation lesions, a simple strategy is associated with a lower risk of restenosis in the side branch. In contrast, a complex approach does not appear to give any benefit in terms of early or long-term outcome or restenosis rate.

Stenting of bifurcation lesions: a rational approach

The occurrence of stenosis in or next to coronary bifurcations is relatively frequent and generally underestimated. In our experience, such lesions account for 15%-18% of all percutaneous coronary intervention > (PCI). The main reasons for this are (1) the coronary arteries are like the branches of a tree with many ramifications and (2) because of axial plaque redistribution, especially after stent implantation, PCI of lesions located next to a coronary bifurcation almost inevitably cause plaque shifting in the side branches. PCI treatment of coronary bifurcation lesions remains challenging. Balloon dilatation treatment used to be associated with less than satisfactory immediate results, a high complication rate, and an unacceptable restenosis rate. The kissing balloon technique resulted in improved, though suboptimal, outcomes. Several approaches were then suggested, like rotative or directional atherectomy, but these techniques did not translate into significantly enhanced results. With the advent of second generation stents, in 1996, the authors decided to set up an observational study on coronary bifurcation stenting combined with a bench test of the various stents available. Over the last 5 years, techniques, strategies, and stent design have improved. As a result, the authors have been able to define a rational approach to coronary bifurcation stenting. This bench study analyzed the behavior of stents and allowed stents to be discarded that are not compatible with the treatment of coronary bifurcations. Most importantly, this study revealed that stent deformation due to the opening of a strut is a constant phenomenon that must be corrected by kissing balloon inflation. Moreover, it was observed that the opening of a stent strut into a side branch could permit the stenting, at least partly, of the side branch ostium. This resulted in the provocative concept of "stenting both branches with a single stent." Therefore, a simple approach is currently implemented in the majority of cases: stenting of the main branch with provisional stenting of the side branch. The technique consists of inserting a guidewire in each coronary branch. A stent is then positioned in the main branch with a wire being "jailed" in the side branch. The wires are then exchanged, starting with the main branch wire that is passed through the stent struts into the side branch. After opening the stent struts in the side branch, kissing balloon inflation is performed. A second stent is deployed in the side branch in the presence of suboptimal results only. Over the last 2 years, this technique has been associated with a 98% angiographic success rate in both branches. Two stents are used in 30%-35% of cases and final kissing balloon inflation is performed in > 95% of cases. The in-hospital major adverse cardiac events (MACE) rate is around 5% and 7-month target vessel revascularization (TVR) is 13%. Several stents specifically designed for coronary bifurcation lesions are currently being investigated. The objective is to simplify the approach for all users. In the near future, the use of drug-eluting stents should reduce the risk of restenosis.

An introduction to provisional stenting

Provisional or conditional stenting should be defined as the use of stents limited to those conditions and cases in which the operator, despite an aggressive balloon angioplasty technique with large balloons and high pressure, has been unable to obtain a result that ensures optimal chances of early and late patency. The paramount issue is how to discriminate the patients with optimal results after balloon angioplasty for whom additional stent implantation is unlikely to improve or may even worsen long-term outcome. The better results of elective stent implantation in the OPUS study suggest that visual assessment of the PTCA result is not sufficient to detect lesions with suboptimal lumen gain after PTCA. The addition of physiologic parameters (Doppler flow velocity measurements, fractional flow reserve) has improved the results of the provisional stent group, with the best outcome observed when complex lesions and multivessel treatment were included in these studies (FROST, DESTINI). Intravascular ultrasound, although more expensive and time-consuming, has the additional advantage to guide the dilatation strategy.