Clinical Outcomes and Treatment After Drug-Eluting Stent Failure

The contemporary use of intracoronary brachytherapy for instent restenosis: A review

In-stent restenosis (ISR) has been a major limitation in interventional cardiology and constitutes nearly 10 % of all percutaneous coronary interventions in the United States. Drug-eluting stent (DES) restenosis proves particularly difficult to manage and poses a high risk of recurrence and repeat intervention. Intra-coronary brachytherapy (IBT) has been traditionally viewed as a potential treatment modality for ISR. However, its use was hindered by procedural complexity, cost, and the advent of newer-generation DES. Recent data suggests promising results regarding IBT for the treatment of resistant DES-ISR. This review addresses the mechanism of action of IBT, procedural details, and associated risks and complications of its use. It will also highlight the available clinical evidence supporting the use of IBT and the future directions of its utilization in the treatment of ISR.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Coronary intravascular brachytherapy for in-stent restenosis: A review of the contemporary literature

Intracoronary stent restenosis (ISR) is a clinically relevant challenge in the modern era. Heterogeneity in patient- and lesion-specific factors can further compound this clinical challenge. Coronary intravascular brachytherapy (IVBT) was the standard therapeutic approach for ISR prior to the advent of drug-eluting stents (DES). Despite prospective data describing the superiority of DES over IVBT for treating de novo ISR, IVBT remains a treatment option for patients with complex disease. The purpose of this review is to evaluate the historical and contemporary literature surrounding IVBT in order to elucidate its role in modern cardiac care and to describe opportunities for future investigations to improve patient selection. Herein, we provide a review of the contemporary literature describing IVBT as a safe and effective treatment option for patients with recurrent, refractory ISR after multilayer DES and no good surgical or mechanical option. Combination therapy with emerging technologies such as DCBs may further increase efficacy.

Long-term outcomes after treatment of in-stent restenosis using the Absorb everolimus-eluting bioresorbable scaffold

Background

Early studies evaluating the performance of bioresorbable scaffold (BRS) Absorb in in-stent restenosis (ISR) lesions indicated promising short-term to mid-term outcomes.

Aims

To evaluate long-term outcomes (up to 5 years) of patients with ISR treated with the Absorb BRS.

Methods

We did an observational analysis of long-term outcomes of patients treated for ISR using the Absorb BRS (Abbott Vascular, Santa Clara, California, USA) between 2013 and 2016 at the Heart Centre Luzern. The main outcomes included a device-oriented composite endpoint (DOCE), defined as composite of cardiac death, target vessel (TV) myocardial infarction and TV revascularisation, target lesion revascularisation and scaffold thrombosis (ScT).

Results

Overall, 118 ISR lesions were treated using totally 131 BRS among 89 patients and 31 (35%) presented with an acute coronary syndrome. The median follow-up time was 66.3 (IQR 52.3–77) months. A DOCE had occurred in 17% at 1 year, 27% at 2 years and 40% at 5 years of all patients treated for ISR using Absorb. ScTs were observed in six (8.4%) of the cohort at 5 years.

Conclusions

Treatment of ISR using the everolimus-eluting BRS Absorb resulted in high rates of DOCE at 5 years. Interestingly, while event rates were low in the first year, there was a massive increase of DOCE between 1 and 5 years after scaffold implantation. With respect to its complexity, involving also a more unpredictable vascular healing process, current and future BRS should be used very restrictively for the treatment of ISR.

Waksman In-Stent Restenosis Classification: A mechanism-based approach to the treatment of restenosis

Despite contemporary advances in stent technology, in-stent restenosis (ISR) remains a common issue following percutaneous coronary intervention. A novel classification system based on underlying mechanism of action of restenosis was recently introduced. The Waksman In-Stent Restenosis Classification characterizes different patterns of ISR to best delineate the type of restenosis and help guide treatment. Intravascular imaging with either intravascular ultrasound or optical coherence tomography allows for real-time evaluation of ISR. We herein provide an illustrative review of the Waksman In-Stent Restenosis Classification.

Risk prediction of in-stent restenosis among patients with coronary drug-eluting stents: current clinical approaches and challenges

Introduction: In-stent restenosis (ISR) has been one of the biggest limitations to the success of percutaneous coronary intervention for the treatment of coronary artery disease (CAD). The introduction of drug-eluting stent (DES) was a revolution in the treatment of CAD because these devices drastically reduced ISR to very low levels (<5%). Subsequently, newer generation DES treatments have overcome the drawbacks of first-generation DES, i.e. delayed endothelialization, and late stent thrombosis. However, the issue of late ISR, including neoatherosclerosis after DES implantation especially in high-risk patients and complex lesions, still exists as a challenge to be overcome.Areas covered: We discuss the mechanisms of ISR development including neoatherosclerosis, past and current clinical status of ISR, and methods to predict and overcome this issue from pathological and clinical points of view.Expert opinion: The initial drawbacks of first-generation DES, such as delayed endothelial healing and subsequent risk of late stent thrombosis, have been improved upon by the current generation DES. To achieve better long-term clinical outcomes, further titration of drug-release and polymer degradation profile, strut thickness as well as material innovation are needed.

Outcomes with retrograde versus antegrade chronic total occlusion revascularization

OBJECTIVES

The aim of the study was to evaluate the outcomes of retrograde versus antegrade approach in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

The retrograde approach has increased the success rate of CTO PCI but has been associated with a higher risk for complications.

METHODS

We conducted a meta-analysis of studies published between 2000 and August 2019 comparing the in-hospital and long-term outcomes with retrograde versus antegrade CTO PCI.

RESULTS

Twelve observational studies (10,240 patients) met our inclusion criteria (retrograde approach 2,789 patients, antegrade approach 7,451 patients). Lesions treated with the retrograde approach had higher J-CTO score (2.8 vs. 1.9, p < .001). Retrograde CTO PCI was associated with a lower success rate (80.9% vs. 87.4%, p < .001). Both approaches had similar in-hospital mortality, urgent revascularization, and cerebrovascular events. Retrograde CTO PCI was associated with higher risk of in-hospital myocardial infarction (MI; odds ratio [OR] 2.37, 95% confidence intervals [CI] 1.7, 3.32, p < .001), urgent pericardiocentesis (OR 2.53, 95% CI 1.41-4.51, p = .002), and contrast-induced nephropathy (OR 2.12, 95% CI 1.47-3.08; p < .001). During a mean follow-up of 48 ± 31 months retrograde crossing had similar mortality (OR 1.79, 95% CI 0.84-3.81, p = .13), but a higher incidence of MI (OR 2.07, 95% CI 1.1-3.88, p = .02), target vessel revascularization (OR 1.92, 95% CI 1.49-2.46, p < .001), and target lesion revascularization (OR 2.08, 95% CI 1.33-3.28, p = .001).

CONCLUSIONS

Compared with antegrade CTO PCI, retrograde CTO PCI is performed in more complex lesions and is associated with a higher risk for acute and long-term adverse events.

Intravascular Brachytherapy for the Management of Repeated Multimetal-Layered Drug-Eluting Coronary Stent Restenosis

BACKGROUND

Because of the widespread acceptance of percutaneous coronary intervention with drug-eluting stents as an effective treatment strategy for in-stent restenosis, it is common to encounter multimetal layer stent restenosis in the recent years. This study aimed to evaluate the clinical outcomes of such patients treated with intravascular brachytherapy (IVBT) in comparison with other percutaneous options.

METHODS AND RESULTS

We enrolled patients who underwent percutaneous coronary intervention during the period between 2011 and 2015 for recurrent drug-eluting stents in-stent restenosis with at least 2 layers of stents at the lesion site. This analysis compared patients who underwent treatment with IVBT and those who did not (non-IVBT group). The primary end point measured was major adverse cardiac events defined as a composite of target lesion revascularization, myocardial infarction, and all-cause mortality at 12 months. Adjusted associations were measured using propensity score matching. A total of 328 percutaneous coronary intervention patients met the eligibility criteria, of which 197 patients received IVBT, and 131 patients underwent routine percutaneous intervention. The primary end point was significantly lower in patients undergoing IVBT (13.2% and 28.2%; P=0.01). A propensity score matching for risk factors of in-stent restenosis identified 182 patients. The advantages of IVBT with regard to 1-year major adverse cardiac events were confirmed in this matched cohort (13.2% and 30.8%; adjusted hazard ratio [95% CI]: 0.37 [0.18-0.73]; P<0.01).

CONCLUSIONS

In this analysis, IVBT led to significantly lower major adverse cardiac events in patients with multilayered drug-eluting stents restenosis when compared with other percutaneous options at 1-year follow-up.

Long-term outcome of brachytherapy treatment for coronary in-stent restenosis: Ten-year follow-up

OBJECTIVES

The objective of this study was to determine the long-term major adverse cardiac events (MACE) in patients treated with intracoronary brachytherapy (ICBT) for coronary in-stent restenosis (ISR).

BACKGROUND

ICBT was commonly used to treat coronary ISR prior to the availability of drug-eluting stents (DES). The long-term outcomes of ICBT for ISR remain unknown.

METHODS

Six hundred and eighty consecutive patients who underwent ICBT treated for ISR between September 1998 and April 2005 were included in the study. Clinical and angiographic data were collected and the long-term MACE were measured for all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR) at 10-year follow-up.

RESULTS

Patients were 63 ± 11 years old (66% male). The majority of patients were treated with a bare metal stent 670/680 (99%) prior to ICBT. Significant baseline clinical findings include high incidence of smokers 479/680 (70%), hyperlipidemia 638/680 (94%), and multivessel disease 526/680 (77%). The majority of target lesions were diffuse 407/680 (60%), and either in the left anterior descending 258/680 (38%) or right coronary artery 215/680 (32%). At 10-year follow-up, the rate of death was 25%, MI was 22.4%, and TVR was 48%.

CONCLUSION

MACE at 10-year follow-up following ICBT for ISR indicates steady rate of death and MI and declining rate of TVR after 5 years.

In-Stent Restenosis of Drug-Eluting Stents Compared With a Matched Group of Patients With De Novo Coronary Artery Stenosis

Drug-eluting stents (DES) significantly reduced the incidence of in-stent restenosis (ISR). However, ISR still exists in the contemporary DES era. Previously deemed to be a benign process, ISR leads to complex presentation and intervention. This study aimed to compare the presentation and outcome of DES-ISR versus de novo lesions. We performed a retrospective analysis of 11,666 patients receiving percutaneous coronary intervention from 2003 to 2017 and divided them into 2 groups by de novo stenosis and ISR. They were matched based on common cardiovascular risk factors at a 4:1 ratio, respectively. After matching, a total of 1,888 patients with 3,126 de novo lesions and 472 patients with 508 ISR lesions were analyzed. Patients with ISR presented more often with unstable angina (61% vs 45%, p <0.001) and less often with myocardial infarction (6% vs 14%, p <0.001). One-year composite major adverse cardiovascular event, defined as death, Q-wave myocardial infarction, and target vessel revascularization, was 10% in the de novo group and 17% in the ISR group (hazard ratio 1.98, 95% confidential interval 1.58 to 2.46, p <0.001). After adjusting for myocardial infarction presentation, hazard ratio of major adverse cardiovascular events was still higher for the ISR group at 1 year (2.03, 95% confidential interval 1.62 to 2.55, p <0.001). ISR of DES remains a therapeutic challenge and leads to complex presentation and worse outcomes compared with matched de novo patients. These data show that DES-ISR demands better appreciation and prevention with more precise stent technique and should motivate the continued development of fully bioresorbable scaffolds.

A novel approach to treat in-stent restenosis: 6- and 12-month results using the everolimus-eluting bioresorbable vascular scaffold

AIMS

The treatment of in-stent restenosis (ISR) remains challenging. Small case series have described successful utilisation of bioresorbable vascular scaffolds (BVS) (Absorb; Abbott Vascular, Santa Clara, CA, USA) to treat ISR. We report our experience with this novel approach.

METHODS AND RESULTS

Patients with ISR in native coronary arteries undergoing percutaneous coronary intervention (PCI) for ISR were treated using BVS. A total of 84 ISR lesions were treated in 65 patients. The mean age was 66±11 years, 28% had acute coronary syndrome (ACS) and 28% were diabetic. PCI was successful in all patients and all scaffolds were delivered and deployed successfully in the target lesion. All 65 patients had six-month follow-up and 49 patients had 12-month clinical follow-up. The target lesion revascularisation (TLR) rate was 3.1% at six months and 12.2% at 12 months. The mean duration from PCI to TLR was 301±148 days. No scaffold thrombosis occurred during the study period.

CONCLUSIONS

This proof of concept study demonstrates that ISR treatment utilising BVS is feasible and appears to have acceptable target lesion failure rates. Prospective randomised trials are necessary to assess whether BVS are more effective than drug-eluting stents or drug-eluting balloons to treat ISR.

Intracoronary Brachytherapy for Recurrent Drug-Eluting Stent Failure

OBJECTIVES

The study sought to report safety and long-term clinical efficacy of intravascular brachytherapy (VBT) for recurrent drug-eluting stent in-stent restenosis (DES-ISR).

BACKGROUND

Recurrent DES-ISR remains a therapeutic challenge, and VBT has been used selectively in recurrent DES failure.

METHODS

Patients undergoing VBT for recurrent DES-ISR were enrolled from a percutaneous coronary intervention registry. Clinical, procedural, VBT, and outcome data were collected for DES-ISR treated with radiation. Follow-up was obtained by phone call and clinic visits.

RESULTS

A total of 186 patients (283 lesions) were included. Mean age was 65 ± 11 years, and 115 (61.8%) were men. Mean time to failure from last failed DES implantation was 450.65 ± 50 days. Majority (95%) had >2 episodes of target lesion revascularization (TLR). Commonest presentation of DES-ISR was unstable angina (68, 30%). All lesions were treated with balloon angioplasty followed by VBT using Beta-Cath system (Best Vascular Inc., Springfield, Virginia) with a dose of 23 to 25 Gy at 2 mm from source center. Radiation was delivered to site of ISR, without procedural adverse events, in 99% cases. Incidence of TLR was 3.3% at 6 months, 12.1% at 1 year, 19.1% at 2 years, and 20.7% at 3 years. No subacute thrombosis event was noted. One patient had late thrombosis during a 3-year follow-up.

CONCLUSIONS

VBT for recurrent DES-ISR is safe, with low recurrence rates at 12 months post-procedure, and can be safely used as an effective short-term strategy. Overtime, there is a gradual attrition in patency requiring repeat intervention.

Laminin Receptor-Avid Nanotherapeutic EGCg-AuNPs as a Potential Alternative Therapeutic Approach to Prevent Restenosis

In our efforts to develop new approaches to treat and prevent human vascular diseases, we report herein our results on the proliferation and migration of human smooth muscles cells (SMCs) and endothelial cells (ECs) using epigallocatechin-3-gallate conjugated gold nanoparticles (EGCg-AuNPs) as possible alternatives to drug coated stents. Detailed in vitro stability studies of EGCg-AuNPs in various biological fluids, affinity and selectivity towards SMCs and ECs have been investigated. The EGCg-AuNPs showed selective inhibitory efficacy toward the migration of SMCs. However, the endothelial cells remained unaffected under similar experimental conditions. The cellular internalization studies have indicated that EGCg-AuNPs internalize into the SMCs and ECs within short periods of time through laminin receptor mediated endocytosis mode. Favorable toxicity profiles and selective affinity toward SMCs and ECs suggest that EGCg-AuNPs may provide attractive alternatives to drug coated stents and therefore offer new therapeutic approaches in treating cardiovascular diseases.

Management of drug eluting stent in-stent restenosis: A systematic review and meta-analysis

BACKGROUND

The optimal management for coronary drug eluting stent in-stent restenosis (DES ISR) is unclear. We performed a meta-analysis of observational and randomized studies to compare the outcomes of management of DES ISR using DES, drug eluting balloon (DEB), or balloon angioplasty (BA).

METHODS

Eligible studies (25 single arm and 13 comparative, including 4 randomized studies with a total of 7,474 patients with DES ISR) were identified using MEDLINE search and proceedings of international meetings. Outcomes studied include major adverse cardiac events (MACE), target lesion revascularization (TLR), target vessel revascularization (TVR), myocardial infarction (MI), stent thrombosis (ST), and mortality. Follow-up ranged from 0.5 to 3.5 years (mean 1.4 years).

RESULTS

The rate of TLR was significantly lower in the DES (odds ratio [OR] 0.50, 95% confidence interval [CI] 0.36-0.69) and DEB (OR 0.31, 95% CI 0.18-0.55) groups compared to BA. Similarly, TVR rate was significantly lower in the DES (OR 0.55, 95% CI 0.39-0.77) and DEB (OR 0.32, 95% CI 0.18-0.58) groups compared to BA. All other outcomes were similar between the DES/BA and DEB/BA comparisons. TLR was significantly lower in the DES group compared to BA for vessels < or > 2.75 mm.

CONCLUSION

Treatment of coronary DES ISR with DES or DEB is associated with a reduction in the risk of TLR and TVR compared to BA alone. The relative risk reduction for TLR with DES is similar to DEB. DEBs have a potential role in the treatment of DES ISR by avoiding placement of another layer of stent. © 2015 Wiley Periodicals, Inc.

In-stent restenosis of drug-eluting stents

Drug-eluting stents (DES) have emerged as an improved alternative to bare-metal stents by demonstrating reduced rates of restenosis and target lesion revascularization. This emergence has led to the unrestricted use of DES for various indications and lesions, and subsequently revealed DES in-stent restenosis as a novel interventional therapeutic dilemma. Recent insights regarding the patho-physiological processes and therapeutic alternatives have added to the accumulated knowledge regarding the appropriate approach to this phenomenon. This review aims to detail the mechanism and clinical presentation of, and therapeutic strategies for, the treatment of DES in in-stent restenosis.

Parvovirus B19 at the culprit coronary stenosis predicts outcome after stenting

BACKGROUND

Parvovirus (PV) B19 DNA is detected in endothelial cells and may cause endothelial dysfunction, which is involved in in-stent restenosis. We aimed at performing an exploratory analysis that evaluated if PVB19 DNA at the culprit coronary stenosis would be associated with an increased rate of major adverse cardiac events (MACE) after coronary stenting.

MATERIALS AND METHODS

Consecutive patients undergoing stent implantation for stable or unstable coronary artery disease were enroled. Serology for PVB19 infection and presence of DNA for PVB19 on balloons used for predilatation were assessed in all patients. MACE rate, as a composite of cardiac death, myocardial infarction (MI) or clinically driven target lesion revascularization (TLR) was obtained at 24 month follow-up. Adjusted hazard ratio (HR) with 95% confidence interval (CI) was calculated for variables associated with MACE.

RESULTS

One hundred and nine patients [age 66 ± 10, male sex 89 (82%)] were enroled. At 24-month follow-up, 18 patients experienced a MACE. Two patients (2%) experienced MI, while 16 patients (15%) experienced clinically driven TLR. At multiple Cox regression analysis, the presence of PVB19 DNA on the balloon and the use of bare-metal stents were independent predictors of MACE [HR 3·30, 95% CI (1·12-10·08), P = 0·03 and HR 4·19, 95% CI (1·60-10·94), P = 0·003].

CONCLUSIONS

PVB19 DNA detected on the balloon used for dilatation of coronary stenosis before stent implantation is associated with MACE rate at follow-up, mainly due to clinically driven TLR. The results of this exploratory analysis should be confirmed in a larger population.