Clinical and angiographic outcome in the laser angioplasty for restenotic stents (LARS) multicenter registry

Contemporary technologies to modify calcified plaque in coronary artery disease

With aging society, one of the more challenging obstacles in percutaneous coronary interventions are calcified coronary lesions. Calcified lesions may impede stent delivery, limit balloon and stent expansion, cause uneven drug distribution, and hinder wire advancement. Even in the setting of acceptable procedural success, vessel calcification is independently associated with increased target lesion revascularization rates at follow-up and lower survival rates. In order to effectively manage such lesions, dedicated technologies have been developed. Atherectomy aims at excising tissue and debulking plaques, as well as compressing and reshaping the atheroma, generally referred to as lesion preparation that enables further balloon and/or stent expansion in contemporary clinical practice. In the current review, we will discuss the available methods for atherectomy, including rotational, orbital, and excimer laser coronary atherectomy, as well as intravascular lithotripsy. In addition, we will review the role of imaging in calcified lesions.

Contemporary use of excimer laser in percutaneous coronary intervention with indications, procedural characteristics, complications and outcomes in a university teaching hospital

Background

Excimer laser coronary atherectomy (ELCA) can be used as an adjunctive percutaneous coronary intervention treatment for challenging, heavily calcified lesions. Although previous studies have documented high rates of complication and restenosis, these predate the introduction of the smaller 0.9 mm laser catheter. As the coronary complexity has increased, there has been a renewed interest in the ELCA. This study investigates the indications, procedural characteristics, complications and outcomes of ELCA in a contemporary coronary interventional practice.

Methods

This single-centre study retrospectively analysed 50 patients treated with ELCA between January 2013 and January 2019.

Results

Patients had a mean age of 67.9±11.4 years with a male predominance (65.3%). 25 (50%) cases were performed in patients with stable angina. Failure to deliver the smallest available balloon/microcatheter was the most frequent indication in 32 (64%) cases for ELCA use. 30 (60%) of the procedures were performed via radial access. The 0.9 mm X-80 catheter was used in 41 (82%) of cases, delivering on average 9000±3929 pulses. ELCA-related complications included 2 coronary dissections and 1 perforation, all of which were covered with stents. No major complications could be directly attributed to the use of ELCA. There was one death and one case of stent thrombosis within 30 days of the procedure.

Conclusion

ELCA can be performed safely via the radial approach with a 0.9 mm catheter with a high success rate by suitably trained operators. The low procedure-related complications with contemporary techniques make this a very useful tool for complex coronary interventions, especially for difficult to dilate lesions and chronic total occlusion vessels.

Excimer Laser Atherectomy in Percutaneous Coronary Intervention: A Contemporary Review

Excimer laser coronary atherectomy (ELCA) during percutaneous coronary intervention (PCI) has been in use for more than twenty years. While early experiences were not favorable over balloon angioplasty alone, with improvement in operator technique, patient selection and technology, ELCA has established its own niche in contemporary PCI as a safe and effective atherectomy strategy. With growing experience in complex coronary interventions worldwide, ELCA has become one of the essential atherectomy tools offering unique advantages over other atherectomy devices. In the modern era, ELCA is commonly used for patients with in-stent restenosis, stent under expansion, balloon uncrossable lesions and chronic total occlusions. Technical success rates are reported to be >80% in most situations while procedural complication rates such as vessel dissection and perforation among others are reported to average 9% over the past 25 years with improvement over time. In this review, we provide a comprehensive systematic review of the ELCA system, its practical use, indications, and procedural techniques in the contemporary PCI era.

The impact of tissue characterization for in-stent restenosis with optical coherence tomography during excimer laser coronary angioplasty

We aimed to evaluate the impact of tissue characterization for in-stent restenosis (ISR) with optical computed tomography (OCT) during excimer laser coronary angioplasty (ELCA) in the drug-eluting stent (DES) era. The effect of ELCA for ISR according to differences in tissue characteristics is unclear. Fifty-three ISR lesions (7 bare metal stents and 46 drug-eluting stents) were treated with an ELCA catheter. After ELCA, balloon dilatation with either the scoring or non-compliant balloons was conducted. The procedure was completed by applying a drug-coated balloon. Tissue characterization and lumen measurement with OCT were performed thrice: (1) before percutaneous coronary intervention (PCI), (2) after ELCA, and (3) and after the procedure. Lesions were categorized into the homogenous, layered, and mixed groups. Follow-up angiograms were conducted 6-12 months after PCI. No significant differences in minimal lumen area (MLA) were observed before PCI. A significant difference was observed in MLA after ELCA among the three groups (homogeneous group: 1.75 ± 0.84 mm2, layered group: 1.72 ± 0.45 mm2, mixed group: 2.24 ± 0.70 mm2, P = 0.048). Final MLA was larger in the mixed group than in the homogeneous group (P = 0.028). No significant difference was observed in binary restenosis in the follow-up angiogram (homogeneous group 55.5%, layered group 33.3%, mixed group 33.3%; P = 0.311) and the target lesion revascularization rate (homogeneous 30.0%, layered 23.8%, mixed 25.0%; P = 0.923). Tissue characterization by OCT may predict the efficacy of ELCA and balloon angioplasty for ISR during the acute phase.

Current Role of Laser Angioplasty of Restenotic Coronary Stents

Treatment of in-stent restenosis (ISR) with conventional percutaneous transluminal coronary angioplasty (PTCA) causes significant recurrent neointimal tissue growth in 30-85%. Therefore, laser ablation of intrastent neointimal hyperplasia before balloon dilation can be an attractive alternative. However, the long-term outcomes of such treatment have not been studied thoroughly enough. This prospective case-control study evaluated angiographic and clinical outcomes of PTCA alone and a combination of excimer laser coronary angioplasty (ELCA) and adjunct PTCA in 125 patients with ISR. ELCA was performed before balloon dilation in 67 patients, PTCA alone was performed in 58 patients. Basic demographic and clinical data were comparable in both groups. Lesions included in ELCA group were longer (17.1 ±9.9 vs 13.6 ±9.1 mm; p=0.034), more complex (36.5% type C stenoses vs 14.3%; p=0.006), and more frequently had reduced distal blood flow (TIMI <3: 18.9% vs 4.8%; p=0.025) compared to lesions in the PTCA group. Immediate angiographic results of PTCA and ELCA + PTCA appeared to be comparable. PTCA alone was successful in 57 patients (98.3%), ELCA + PTCA, in 66 patients (98.5%). The rates of hospital complications were comparable (3.0% in ELCA group vs 8.6% in PTCA group). The 1-year follow-up showed that the rates of major adverse cardiac events (MACE) were comparable in the 2 groups (37.3% in ELCA group vs 46.6% in PTCA group). The rates of target vessel revascularization (TVR) within 1 year after the intervention were also similar in the 2 groups (32.8% vs 34.5%). The data mean that ELCA in patients with complex ISR is efficient and safe. Despite a higher complexity of lesions in the ELCA group, no increase in the rate of complications was registered.

Minimally invasive atherectomy with a virtual 3-Fr sheathless guiding catheter and a 0.9-mm excimer laser catheter for the treatment of coronary in-stent restenosis: a case report

A 50-year-old man underwent percutaneous coronary intervention for stent restenosis in his left anterior descending artery. After insertion of a 5-Fr sheathless guiding catheter through the right radial artery, optical coherence tomography (OCT) revealed a circumferential dense fibrotic plaque in the distal part of the stent. Therefore, we performed excimer laser coronary atherectomy using a 0.9-mm concentric catheter and dilatation with a drug-coated balloon catheter. Subsequent OCT revealed a circumferential reduction of the neointimal material. The patient's clinical course was uneventful, and he was discharged 2 days after the percutaneous coronary intervention without any access site complications.

Atherectomy devices: technology update

Atherectomy is a procedure which is performed to remove atherosclerotic plaque from diseased arteries. Atherosclerotic plaques are localized in either coronary or peripheral arterial vasculature and may have different characteristics depending on the texture of the plaque. Atherectomy has been used effectively in treatment of both coronary and peripheral arterial disease. Atherectomy devices are designed differently to either cut, shave, sand, or vaporize these plaques and have different indications. In this article, current atherectomy devices are reviewed.

Drug-eluting stents vs. intracoronary brachytherapy for in-stent restenosis: a meta-analysis

BACKGROUND

It has been reported that drug-eluting stents (DES) were superior to intracoronary brachytherapy (ICBT) in patients with in-stent restenosis (ISR). However, it is unknown whether there might be differences between DES and ICBT in terms of efficacy and safety in large sample size and long-term follow-up.

HYPOTHESIS

The aim of this study was to determine whether DES implantation remains favorable in large sample size and long-term follow-up when compared with ICBT among patients with ISR.

METHODS

We conducted a search in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials without language restrictions. A meta-analysis of 1942 cases from 12 controlled trials of DES vs ICBT for ISR was performed.

RESULTS

Drug-eluting stents were significantly more effective in reducing target-vessel revascularization (TVR) (odds ratio [OR]: 0.44, 95% confidence interval [CI]: 0.23-0.81, P = 0.009) and binary restenosis (OR: 0.34, 95% CI: 0.26-0.46, P<0.00001) compared with ICBT at midterm follow-up. There were no significant differences between DES and ICBT in cardiac death, myocardial infarction (MI), and late stent thrombosis at midterm follow-up. A statistical significance has been found between the 2 groups in TVR (OR: 0.61, 95% CI: 0.43-0.86, P = 0.005) at long-term follow-up. There were no significant differences in cardiac death and MI between the 2 groups at long-term follow-up.

CONCLUSIONS

These findings provide evidence that DES is superior to ICBT for the treatment of ISR in TVR and binary restenosis reduction, but not in cardiac death, MI, and late stent thrombosis reduction. © 2011 Wiley Periodicals, Inc. Yong-Guang Lu, MD, and Yan-Mei Chen, MD, contributed equally to this work. The authors have no funding, financial relationships, or conflicts of interest to disclose.

Drug-eluting stents versus bare-metal stents for treatment of bare-metal in-stent restenosis

OBJECTIVES

We compared the long-term outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) for treatment of bare-metal in-stent restenosis (ISR).

BACKGROUND

There are no randomized trials or observational studies directly comparing the safety and efficacy of DES versus BMS for treatment of bare-metal ISR.

METHODS

We examined data on all patients who underwent percutaneous coronary intervention (PCI) for ISR at Cleveland Clinic between 05/1999 and 06/2007. We compared the efficacy and safety of DES to BMS for treating bare-metal ISR. The primary end point was a composite of death, myocardial infarction (MI), or target lesion revascularization (TLR). The secondary endpoints were individual components of the primary endpoint.

RESULTS

Of the 931 patients identified over 8 years, 706 had bare-metal ISR and met our study criteria. Of the 706 patients with bare-metal ISR, 362 were treated with DES and 344 with BMS. There were 230 cumulative events for a median follow-up of 3.2 years. After adjusting for 27 variables, DES were associated with lower primary endpoint compared to BMS for treatment of bare-metal ISR (21% vs. 45%, adjusted hazard ratio [HR] 0.63; 95% confidence interval [CI], 0.42-0.95; P = 0.03). The individual secondary endpoint of death (8% vs. 24%, P = 0.005) favored DES, but MI (3% vs. 8%, P = 0.31), and TLR (13% vs. 20%, P = 0.23) failed to reach statistical significance.

CONCLUSIONS

In our multivariate analysis of patients with bare-metal ISR, DES use was associated with significantly lower death, MI, or TLR when compared to BMS.

The use of excimer laser for complex coronary artery lesions

Excimer laser coronary atherectomy (ELCA) has been used for coronary intervention for more than 20 years. Advances in delivery systems for laser energy using the xenon-chlorine pulsed laser catheter deliver higher energy density with lower heat production. The Spectranetics CVX-300 (Spectranetics, Colorado Springs, CO, USA) excimer laser catheter system has been used for the treatment of complex coronary lesions. We report our experience with the use of this advanced system for stenoses for which were unsuitable for standard percutaneous coronary intervention; for example, balloon-resistant lesions, chronic total occlusions, and for underexpanded stents in calcified lesions. ELCA may also be valuable for thrombus-containing lesion. We find ELCA to be indispensable in the catheterization laboratory for specific complex or calcified lesions. Its role should be explored in a large randomized trial of thrombus containing lesions and saphenous vein grafts.

Clinical outcome of patients undergoing low aggressive angioplasty combined with brachytherapy and short-term dual antiplatelet therapy for in-stent restenosis

OBJECTIVE

The impact of vessel injury on the outcome of patients undergoing percutaneous coronary intervention combined with brachytherapy for in-stent restenosis is under investigation. We report our clinical experience adopting a low aggressive balloon angioplasty technique, to limit vessel trauma, associated with brachytherapy and short-term dual antiplatelet therapy.

METHODS

Forty-nine consecutive patients, undergoing percutaneous coronary intervention with brachytherapy for symptomatic in-stent restenosis, were prospectively observed for a median time of 21 + or - 8 months. Clinical follow-up included anginal status, death, myocardial infarction and repeat revascularization; only patients with evidence of ischaemia repeated coronary angiography. Low aggressive angioplasty consisted in the use of a conventional balloon with a balloon to artery ratio < or = 1, avoiding high inflation pressures and the use of other devices. Dual antiplatelet therapy was continued for 3-6 months.

RESULTS

Early angiographic result was good and the need for additional stent implantation was low (3.9%). At follow-up, we did not observe death, acute myocardial infarction or stent thrombosis, but 10 patients repeated coronary angiography for recurrence of ischaemia: disease progression was present in two cases (4.1%). Restenosis emerged in the remaining eight patients (16.3%): two cases showed restenosis within the target lesion segment, one case within the injured segment, one case within the radiated segment, and four cases at the edges. The consequent new revascularization was surgical in three patients and percutaneous in seven patients.

CONCLUSIONS

Our data suggest that low aggressive angioplasty followed by brachytherapy and short-term dual antiplatelet therapy for in-stent restenosis is related to a good outcome, with a low restenosis rate and without stent thrombosis.

Critical limb ischemia: will atherectomy and laser-directed therapy be the answer?

The interventional treatment of peripheral atherosclerotic occlusive disease is increasingly becoming accepted as an appropriate initial form of therapy. Standard methods of treatment include balloon angioplasty and stent assisted angioplasty. Laser catheters and mechanical atherectomy catheters are newer tools, which can be utilized to assist in achieving and maintaining patency in these vessels. In this report, we review the efficacy, safety, and potential advantages of these ablative devices when used for the treatment of peripheral arterial occlusive disease.

Restenosis following implantation of bare metal coronary stents: pathophysiology and pathways involved in the vascular response to injury

This review summarizes the restenotic process that occurs after the implantation of bare metal coronary stents. The pathology of in-stent restenosis is distinct from that seen after balloon angioplasty and is characterized by neointimal proliferation and extracellular matrix deposition. The degree of neointimal proliferation is proportional to the amount of injury, the intensity of the inflammatory infiltrate and the association of stent struts with lipid-filled plaque. In-stent restenosis also appears to be associated with systemic markers of inflammation. Shear stress has an important influence on restenosis as does the presence and adhesiveness of vascular progenitor cells. Clinical predictors (e.g., artery size, stent length, diabetes, and gender) may affect the incidence of restenosis seen after stent placement. A number of catheter-based interventions have been used to treat in-stent restenosis. Although preliminary data suggest that the use of drug-eluting stents may be effective, only intracoronary radiation has shown consistent efficacy in randomized trials.

Routine sirolimus eluting stent implantation for unselected in-stent restenosis: insights from the rapamycin eluting stent evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry

OBJECTIVE

To assess the effectiveness of routine sirolimus eluting stent (SES) implantation for unselected patients with in-stent restenosis and to provide preliminary information about the angiographic outcome for lesion subgroups and for different in-stent restenosis patterns.

DESIGN

Prospective, single centre registry.

SETTING

Tertiary referral centre.

PATIENTS

44 consecutive patients (53 lesions) without previous brachytherapy who were treated with SES for in-stent restenosis were evaluated. Routine angiographic follow up was obtained at six months and the incidence of major adverse cardiovascular events was evaluated.

RESULTS

At baseline, 42% of the lesions were focal, 21% diffuse, 26% proliferative, and 11% total occlusions. Small vessel size (reference diameter < or = 2.5 mm) was present in 49%, long lesions (> 20 mm) in 30%, treatment of bypass grafts in 13%, and bifurcation stenting in 18%. At follow up, post-SES restenosis was observed in 14.6%. No restenosis was observed in focal lesions. For more complex lesions, restenosis rates ranged from 20-25%. At the one year follow up, the incidence of death was 0, myocardial infarction 4.7% (n = 2), and target lesion revascularisation 16.3% (n = 7). The target lesion was revascularised because of restenosis in 11.6% (n = 5).

CONCLUSIONS

Routine SES implantation is highly effective for focal in-stent restenosis and appears to be a promising strategy for more complex patterns of restenosis.

Clinical outcomes for sirolimus-eluting stent implantation and vascular brachytherapy for the treatment of in-stent restenosis

The purpose of this study was to compare the mid-term clinical outcome of sirolimus-eluting stent (SES) implantation and vascular brachytherapy (VBT) for in-stent restenosis (ISR). We assessed the 9-month occurrence of major adverse cardiac events (MACE) in 44 consecutive patients with ISR treated with SES implantation and 43 consecutive patients treated with VBT in the period immediately prior. Baseline clinical and angiographic characteristics of the two groups were similar. During follow-up, three patients (7%) died in the VBT group and none in the SES group. The incidence of myocardial infarction was 2.3% in both groups. Target lesion revascularization was performed in 11.6% of the VBT patients and 16.3% of the SES patients (P = NS). The 9-month MACE-free survival was similar in both groups (79.1% VBT vs. 81.5% SES; P = 0.8 by log rank). The result of this nonrandomized study suggests that sirolimus-eluting stent implantation is at least as effective as vascular brachytherapy in the treatment of in-stent restenosis.

Sonotherapy, antirestenotic therapeutic ultrasound in coronary arteries: the first clinical experience

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 +/- 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 +/- 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% +/- 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

Treatment of in-stent restenosis with excimer laser coronary angioplasty

Diffuse in-stent restenosis remains an important problem in percutaneous transluminal coronary angioplasty (PTCA). In this trial, we studied the early and mid-term outcomes of excimer laser coronary angioplasty (ELCA) on diffuse in-stent restenosis. ELCA was performed in 23 patients (19 males). The mean length of the lesions was 14.3 +/- 3 mm and the mean age was 58 +/- 7 years. The minimal lumen diameter (MLD) was measured by on-line quantitative coronary angiography. Before the procedure, MLD was 0.9 +/- 0.4. The Q/non-Q-wave myocardial infarction (MI), coronary artery bypass graft (CABG), PTCA, and mortality were recorded during the procedure and at 6 months follow up. The fluence of laser emission was 45 mj/m2 and the repetition rate was 25 pulses per second. Adjunctive balloon angioplasty was performed in all of the cases at a mean 7 +/- 2 atm pressure. The procedure was successfully performed in all of the cases. Type-B dissection developed, after ELCA in 1 patient (4%). Perforation, death, cerebrovascular accidents, emergency CABG, PTCA or Q/non-Q wave myocardial infarction were not observed. MLD was 0.9 +/- 0.4 mm before ELCA, 1.8 +/- 0.9 mm (P<0.05) after ELCA, and 3.1 +/- 0.7 mm after PTCA. At 6 months follow up, there were 2 (8.7%) Q-wave myocardial infarctions and 2 (8.7%) recurrent anginal pain cases. Control angiography was obtained in 20 cases (87%). Control angiography was not accepted by 3 patients. Their maximal exercise test was negative. Angiographic restenosis was observed in 6 cases (30%). The rate of target lesion revascularization (TLR) was 5 of 23 (22%) in the patients treated with ELCA. It is concluded, ELCA is a safe and efficient debulking technology for treating diffuse in-stent restenosis.

Can we prevent in-stent restenosis?

Nowadays stent placement has replaced balloon angioplasty as the most commonly performed percutaneous coronary interventional procedure, mainly because of its better acute and chronic outcome. As a result, in-stent restenosis (ISR) has become a widespread problem. The incidence of ISR varies from 10% to 50% and depends on the absence or presence of several risk factors, such as small vessel size, longer lesions, and diabetes. Intravascular ultrasound studies have demonstrated that ISR is mainly caused by neointimal proliferation; consequently, this pathologic process has become the target of many preventive and therapeutic approaches. This article provides an overview of such management strategies, highlighting the rather disappointing experiences with mechanical and systemic drug therapies; the relative merits and disadvantages of intracoronary radiation; and the exciting yet realistic promise, embodied by the recent advancements in drug-eluting stent technology, of potentially eradicating ISR in the near future.

Coronary in-stent restenosis: current status and future strategies

In-stent restenosis (ISR) is a novel pathobiologic process, histologically distinct from restenosis after balloon angioplasty and comprised largely of neointima formation. As percutaneous coronary intervention increasingly involves the use of stents, ISR is also becoming correspondingly more frequent. In this review, we examine the available studies of the histology and pathogenesis of ISR, with particular reference to porcine and other animal models. An overview of mechanical treatments is then provided, which includes PTCA, directional coronary atherectomy and high speed rotational atherectomy. Radiation-based therapies are discussed, including a summary of current problems associated with this modality of treatment. Finally, novel strategies for the prevention of ISR are addressed, including novel developments in stents and stent coatings, conventional drugs, nucleic acid-based drugs and gene transfer. Until recently, limited pharmacologic and mechanical treatment options have been available for both treatment and prevention of ISR. However, recent advances in gene modification and gene transfer therapies and, more particularly, in local stent-based drug delivery systems make it conceivable that the incidence of ISR will now be seriously challenged.