Drug-Coated Balloons Versus Second-Generation Drug-Eluting Stents for the Management of Recurrent Multimetal-Layered In-Stent Restenosis

Comparison of Different PCI Strategies for Coronary DES In-stent Restenosis: A Bayesian Network Meta-analysis

Background

Though superior to bare-metal stents (BMS), drug-eluting stents (DES) based PCI still have significant in-stent restenosis (ISR). Balloon angioplasty (BA), drug-coated balloons (DCBs), and DES are common modalities to treat ISR. The existing guidelines recommend treating ISR with either DCB or DES for BMS-ISR and DES-ISR, despite differences in the underlying mechanisms. Because DES are currently the most used stents worldwide, we performed a network meta-analysis (NMA) to compare DES-ISR treatment strategies.

Methods

We searched Cochrane Central Register of Controlled Trials, PubMed, Embase, and Scopus for relevant studies published until March 30, 2024 and performed a Bayesian NMA to synthesize direct and indirect evidence. The primary outcome was a target lesion revascularization (TLR) at follow-up.

Results

Of 1202 studies, 30 were deemed eligible, with 15 being randomized studies. This included 8016 patients with DES-ISR who were assigned to 12 different PCI strategies. In the NMA for DES-ISR, paclitaxel-eluting stent (76.42) was the most effective strategy for TLR; paclitaxel-coated balloon (PCB) and scoring balloon angioplasty (75.88) for major adverse cardiovascular events (MACE); sirolimus-coated balloon (SCB) for target lesion failure (64.16), myocardial infarction (93.57), and stent thrombosis (98.53); and PCB for all-cause death (76.39) and cardiac death (83.74) based on SUCRA value. BA-based strategies were less effective alternatives for DES-ISR treatment with DCB or DES.

Conclusions

DES and DCB PCI such as PCB and SCB should be considered for treatment of coronary DES-ISR to achieve the most clinical efficacy and safety benefits for MACE. Further studies are required for more robust evidence on different treatment strategies.

Intravascular imaging and functional assessment for coronary in-stent restenosis: Current status and future directions

Despite significant advancements in drug-eluting stent technology, in-stent restenosis (ISR) still occurs in approximately 10 % of patients undergoing percutaneous coronary intervention, remaining a significant global health concern. The mechanisms underlying ISR are complex and multifactorial, yet recent innovations in intravascular imaging and functional assessment have substantially advanced our understanding, enabling more targeted and personalized therapies. This review synthesizes the latest insights into ISR, emphasizing the pivotal roles of advanced imaging modalities, such as optical coherence tomography (OCT) and intravascular ultrasound, and functional assessments like quantitative flow ratio and optical flow ratio in guiding ISR management. Additionally, we explore the clinical implications of in-stent neoatherosclerosis and calcified nodules as key pathological mechanisms influencing restenosis progression and patient outcomes. The review also highlights the significance of OCT-based ISR classifications in refining treatment approaches. By integrating these diagnostic and therapeutic advances, this work provides clinicians and researchers with an updated foundation and actionable insights for optimizing ISR management through tailored, imaging-guided strategies.

Recurrent drug eluting stent, in-stent restenosis (DES-ISR): Epidemiology, pathophysiology & treatment

Coronary artery in-stent restenosis (ISR) is driven by neointimal hyperplasia and neo-atherosclerosis in previously placed stents. Drug eluting stents (DES) have been adopted as first line therapy for the initial episode of ISR. However, recurrent ISR has limited durable salvage options. In this article we review the pathophysiology, incidence, and management options of recurrent DES- ISR.

Recent Advances in the Treatment of Coronary In-Stent Restenosis

In-stent restenosis (ISR) remains the predominant cause of stent failure and the most common indication for repeat revascularization. Despite technological advances in stent design, ISR continues to pose significant challenges, contributing to increased morbidity and mortality among patients undergoing percutaneous coronary interventions. In the last decade, intravascular imaging has emerged as an important method for identifying the mechanisms behind ISR and guiding its treatment. Treatment options for ISR have expanded to include balloon angioplasty, cutting or scoring balloons, intravascular lithotripsy, atheroablative devices, drug-eluting stents, drug-coated balloons, surgical revascularization, and intravascular brachytherapy. The aim of the current review is to describe the classification and mechanisms of ISR, provide a comprehensive and updated overview of the evidence supporting different treatment strategies, suggest a management algorithm, and present insights into future developments in the field.

Drug-coated balloons versus drug-eluting stents in patients with in-stent restenosis: An updated meta-analysis with trial sequential analysis

BACKGROUND

Drug-coated balloons (DCB) have promising results in the management of in-stent restenosis (ISR), still their role remains a major challenge, and not well established in contemporary clinical practice.

AIMS

To provide a comprehensive appraisal of the efficacy and safety of DCBs in patients with in-stent restenosis (ISR).

METHODS

We searched PubMed, Scopus, web of Science, Ovid, and Cochrane Central from inception until 30 March, 2023. We included randomized controlled trials (RCTs) that compared DCB versus DES in ISR patients. Our primary endpoints were major adverse cardiac events (MACE) and late lumen loss (LLL). Secondary clinical endpoints were all-cause death, cardiac death, MI, TLR, TVR, and stent thrombosis, and angiographic outcomes were MLD, and in-stent binary restenosis.

RESULTS

Ten RCTs comprising 1977 patients were included in this meta-analysis. The incidence of MACE was 15.57% in the DCB group compared to 14.13% in the DES group, with no significant difference in the risk of MACE following DCB (odds ratio [OR] 1.04, 95% confidence interval [CI]: 0.87 to 1.44). Compared with the DES intervention, the risk of LLL was comparable to the DCB intervention (mean difference [MD] -0.08, 95% CI: -0.18 to 0.02), while the incidence of TLR was increased in the DCB intervention (OR: 1.54, 95% CI: 1.2 to 1.99).

CONCLUSION

DCB was comparable to DES implantation is ISR patients regarding clinical outcomes, however it showed an increase in TLR events. Moreover, a RCT with large sample size and longer follow-up duration is warrened to validate these results.

Recurrent Revascularization at 10 Years After Percutaneous Treatment of Drug-Eluting Stent Restenosis

BACKGROUND

Treatment of patients with recurrence of in-stent restenosis (ISR) remains particularly challenging, with data and guideline recommendations for repeat percutaneous coronary intervention being scant.

OBJECTIVES

The aim of this study was to investigate the long-term incidence of recurrent revascularization events after percutaneous treatment of drug-eluting stent (DES) ISR.

METHODS

In this post hoc analysis, 402 patients (500 lesions) assigned to plain balloon (PB), drug-coated balloon (DCB), or DES treatment in the randomized ISAR-DESIRE 3 (Efficacy Study of Paclitaxel-Eluting Balloon, -Stent vs. Plain Angioplasty for Drug-Eluting Stent Restenosis) trial were followed up over a median of 10.3 years. The primary endpoint was total repeat target lesion revascularization (R-TLR) including all, first and recurrent, events.

RESULTS

At the end of follow-up, first R-TLR was required in 204 lesions, 82 in the PB group, 70 in the DCB group, and 52 in the DES group. The total number of R-TLRs was 373: 162 in the PB group, 124 in the DCB group, and 87 in the DES group. During the first year of follow-up, the risk for total R-TLR was reduced by DCB (HR: 0.36; 95% CI: 0.24-0.54) and DES (HR: 0.23; 95% CI: 0.14-0.38) treatment compared with PB treatment. After 1 year, the risk for total R-TLR was nonsignificantly reduced by DCB treatment (HR: 0.77; 95% CI: 0.51-1.16) and significantly reduced by DES treatment (HR: 0.61; 95% CI: 0.39-0.95) compared with PB treatment. Risk in the DCB and DES groups was similar during (HR: 1.54; 95% CI: 0.89-2.69) and after (HR: 1.26; 95% CI: 0.82-1.92) 1 year.

CONCLUSIONS

The total number of R-TLRs over 10 years after treatment of patients with DES ISR was high. DCBs and particularly DES were able to reduce the need for both first and recurrent revascularization compared with PB treatment.

Comparison of Recurrent With First-Time In-Stent Restenosis

Recurrent in-stent restenosis (Re-ISR) remains a therapeutic challenge. We aimed to investigate the clinical characteristics, treatment, and long-term outcomes in patients with Re-ISR compared with those with first-time ISR (First-ISR). This retrospective study consecutively enrolled patients who underwent percutaneous coronary intervention (PCI) for ISR in Fuwai Hospital between January 2017 and December 2018. Re-ISR was defined as a second event of ISR after a previous successful treatment of the ISR lesion. The primary outcome was defined as a composite of all-cause death, spontaneous myocardial infarction, and repeat revascularization. A total of 2,006 patients (2,154 lesions) with ISR underwent successful PCI were enrolled and categorized into 2 groups: the Re-ISR group (246 patients/259 lesions) and the First-ISR group (1,760 patients/1,895 lesions). During a mean follow-up of 36 months, the primary outcomes occurred in 80 patients (32.5%) in the Re-ISR group and 349 patients (19.3%) in the First-ISR group (p <0.001 by log-rank test), major driven by spontaneous myocardial infarction (4.9% vs 2.7%, p = 0.049) and repeat revascularization (30.1% vs 16.5%, p <0.001). The multivariable Cox regression analysis revealed that Re-ISR was independently associated with a higher rate of major adverse cardiovascular events (adjusted hazard ratio 1.88, 95% confidence interval 1.39 to 2.53, p <0.001) and repeated revascularization (adjusted hazard ratio 2.09, 95% confidence interval 1.53 to 2.84, p <0.001). The relation remained consistent after the propensity score analysis. In conclusion, in the present cohort of patients who underwent PCI for ISR, Re-ISR was significantly associated with a higher risk of long-term outcomes than First-ISR.

Mechanisms and treatment outcomes of ostial right coronary artery in-stent restenosis

BACKGROUND

Despite a high rate of in-stent restenosis (ISR) after stenting the right coronary artery (RCA) ostium, the mechanism of ostial RCA ISR is not well understood.

AIMS

We aimed to clarify the cause of ostial RCA ISR using intravascular ultrasound (IVUS).

METHODS

Overall, 139 ostial RCA ISR lesions were identified with IVUS, pre-revascularisation. Primary ISR mechanisms were classified as follows: 1) neointimal hyperplasia (NIH); 2) neoatherosclerosis; 3) ostium not covered by the stent; 4) stent fracture or deformation; 5) stent underexpansion (old minimum stent area <4.0 mm2 or stent expansion <50%); or 6) a protruding calcified nodule.

RESULTS

The median duration from prior stenting was 1.2 (first quartile 0.6, third quartile 3.1) years. The primary mechanisms of ISR were NIH in 25% (n=35) of lesions, neoatherosclerosis in 22% (n=30), uncovered ostium in 6% (n=9) (biological cause 53%, n=74), stent fracture or deformation in 25% (n=35), underexpansion in 11% (n=15), and protruding calcified nodules in 11% (n=15) (mechanical cause 47%, n=65). Including secondary mechanisms, 51% (n=71) of ostial RCA ISRs had stent fractures that were associated with greater hinge motion of the ostial-aorta angle during the cardiac cycle. The Kaplan-Meier rate of target lesion failure at 1 year was 11.5%. When the mechanically caused ISRs were treated without new stents, they suffered a higher subsequent event rate (41.4%) compared with non-mechanical causes or mechanical causes treated without restenting (7.8%, unadjusted hazard ratio 6.44, 95% confidence interval: 2.33-17.78; p<0.0001).

CONCLUSIONS

Half of the ostial RCA ISRs were due to mechanical causes. Subsequent event rates were high, especially in mechanically caused ISRs treated without the implantation of a new stent.

Derivation and validation of the ISAR score to predict the risk of repeat percutaneous coronary intervention for recurrent drug-eluting stent restenosis

BACKGROUND

The treatment of drug-eluting stent (DES) in-stent restenosis (ISR) is challenging as it has a high risk of recurrence.

AIMS

The aim of this analysis was to develop and validate a model to predict the risk of repeat percutaneous coronary intervention (PCI) for recurrent DES-ISR.

METHODS

A retrospective, observational analysis was performed including consecutive patients treated with PCI for DES-ISR at two centres in Germany. Included patients were randomly divided into training and validation cohorts. Two regression analyses identified factors associated with repeat PCI for recurrent DES-ISR up to 1 year. The discriminative ability of the resultant model was then compared to a benchmark ISR classification model using bootstrap resampling. A classification and regression tree analysis and a numerical scoring system (the ISAR score) were used to predict the risk of repeat PCI for recurrent DES-ISR based on the identified predictors.

RESULTS

We included 1,986 patients in the current analysis, divided randomly into training (1,471 patients, 1,778 lesions) and validation (515 patients, 614 lesions) cohorts. Four factor variables (a non-focal ISR pattern, a time interval to ISR of <6 months, ISR of the left circumflex artery and ISR in a calcified vessel) were associated with repeat PCI for recurrent DES-ISR at 1-year follow-up. On bootstrap resampling analysis, the C-statistic for the model including these four variables was 0.60 (95% confidence interval [CI]: 0.57-0.63), whereas the C-statistic for the benchmark ISR classification model was 0.54 (95% CI: 0.52-0.57), a difference that was statistically significant (delta C-statistic 0.062; 95% CI: 0.035-0.094; p<0.001). The cumulative incidence of repeat PCI for recurrent DES-ISR was over three times higher in DES-ISR lesions with an ISAR score of ≥3 in comparison to lesions with an ISAR score of 0.

CONCLUSIONS

This study developed and validated a risk prediction model for repeat PCI for recurrent DES-ISR at 1-year follow-up. This model served to generate the ISAR score, a standardised tool that can be used to predict the 1-year risk of repeat PCI for recurrent DES-ISR.

In-Stent Restenosis

In-stent restenosis (ISR) remains a potential complication after percutaneous coronary intervention, even in the era of drug-eluting stents, and its treatment remains suboptimal. Neoatherosclerosis is an important component of the pathology of ISR and is accelerated in drug-eluting stents compared with bare-metal stents. Coronary angiography is the gold standard for evaluating the morphology of ISR, although computed tomography angiography is emerging as an alternative noninvasive modality to evaluate the presence of ISR. Drug-coated balloons and stent reimplantation are the current mainstays of treatment for ISR, and the choice of treatment should be based on clinical background and lesion morphology.

Coronary In-Stent Restenosis: JACC State-of-the-Art Review

The introduction and subsequent iterations of drug-eluting stent technologies have substantially improved the efficacy and safety of percutaneous coronary interventions. However, the incidence of in-stent restenosis (ISR) and the resultant need for repeated revascularization still occur at a rate of 1%-2% per year. Given that millions of drug-eluting stents are implanted each year around the globe, ISR can be considered as a pathologic entity of public health significance. The mechanisms of ISR are multifactorial. Since the first description of the angiographic patterns of ISR, the advent of intracoronary imaging has further elucidated the mechanisms and patterns of ISR. The armamentarium and treatment strategies of ISR have also evolved over time. Currently, an individualized approach using intracoronary imaging to characterize the underlying substrate of ISR is recommended. In this paper, we comprehensively reviewed the incidence, mechanisms, and imaging characterization of ISR and propose a contemporary treatment algorithm.

Outcomes and prognostic factors of patients treated for in-stent restenosis: a retrospective single-center experience

BACKGROUND

The incidence of in-stent restenosis (ISR) remains relatively common despite the use of drug-eluting stents. Outcomes and prognostic factors following ISR revascularization are still being investigated. We aimed to describe the outcomes following different ISR treatment strategies in order to identify prognostic factors associated with worse outcomes.

RESULTS

In a retrospective cohort study, we included patients who were admitted to our department and treated for ISR, from January 2017 to December 2018. All patients were followed up for a median period of 24 months. Major cardiac adverse event (MACE) was a composite outcome of the following events: myocardial infarction, target vessel revascularization, target lesion revascularization or cardiovascular death. MACEs were collected during follow-up. Our population consisted of 116 patients. Mean age was 60 years old with a sex ratio of 2.8. During follow-up, 44 patients (37.9%) had at least one MACE. Independent factors identified by multivariate logistic regression were ISR of the proximal left anterior descending artery [Odds ratio (OR) = 1.29; 95% confidence interval (95% CI) 1.16-1.81; p = 0.05], diffuse ISR [OR = 2.16; 95% CI 1.1-3.47; p = 0.022], double or triple vessel disease [OR = 2.97; 95% CI 1.2-6.8; p = 0.008], two or more stents per lesion [OR = 1.82; 95% CI 1.14-2.21, p = 0.031] and absence of post-dilatation in the initial angioplasty [OR = 1.32; 95% CI 1-1.35; p = 0.04].

CONCLUSIONS

Our study suggested that ISR is related to poor outcomes. Identifying prognostic factors would play a key role in the refinement of interventional techniques.

Comparison of Drug-Coated Balloon Angioplasty vs. Drug-Eluting Stent Implantation for Drug-Eluting Stent Restenosis in the Routine Clinical Practice: A Meta-Analysis of Randomized Controlled Trials

Introduction: In-stent restenosis (ISR) remains a challenging issue despite the great advance of drug-eluting stents (DES). In addition, the consensus was lacking regarding the optimal strategy for DES-ISR. Therefore, we aimed to evaluate angiographic and clinical outcomes of the two most effective treatments DES vs. drug-eluting balloon (DCB) for patients with DES-ISR. Methods: This meta-analysis used the data from the randomized controlled trials (RCTs), which were identified by a systematic search in the databases of PubMed, Embase, and Cochrane Library. Target lesion revascularization (TLR) was regarded as the primary endpoint. In addition, the late angiographic outcomes and other clinical outcomes, namely, cardiac death, myocardial infarction (MI), target vessel revascularization, stent thrombosis, and major adverse cardiac events, were also included for analysis. Results: Five RCTs with about 1,193 patients were included in this meta-analysis for the analysis. For the primary endpoint, the overall pooled outcomes suggested repeat DES implantation was associated with a significant reduction in the term of TLR compared with DCB angioplasty (risk ratio = 1.53, 95% CI 1.15-2.04, p = 0.003). But no significant difference in angiographic outcomes and other clinical endpoints were observed between DES and DCB. In the subgroup analysis, DCB was inferior to new-generation DES (NG-DES)/everolimus-eluting stent (EES) in the term of TLR. In addition, this non-significant trend was also noted in the subgroup of the paclitaxel-eluting stent (PES) vs. DCB. For the angiographic endpoints, EES, not PES, was associated with larger minimum lumen diameter [mean difference (MD) = -0.25, 95% CI -0.38 to -0.11, p = 0.0003], lower percent diameter stenosis (MD = 7.29%, 95% CI 2.86-11.71%, p = 0.001), and less binary restenosis (OR = 2.20, 95% CI 1.18-4.11, p = 0.01). But NG-DES/EES was comparable to DCB in cardiac death, MI, and stent thrombosis. Conclusions: For the patients with DES-ISR, treatment with DES, especially NG-DES/EES could reduce the risk of TLR significantly compared to DCB at long-term follow-up.

Is Coronary Brachytherapy Staging a Comeback for the Treatment of In-Stent Restenosis?

PURPOSE OF REVIEW

The catheter-based coronary intervention has become a well-established therapeutic modality for obstructive coronary artery disease. However, in-stent restenosis remains a significant limitation of coronary intervention despite the use of newer devices. Intravascular brachytherapy was introduced to treat recurrent in-stent restenosis but only modestly adopted. This review will discuss the mechanism of intracoronary brachytherapy, available clinical evidence of brachytherapy in recurrent in-stent restenosis treatment, and the future of coronary brachytherapy in coronary intervention.

RECENT FINDINGS

Drug-eluting stents have an inherent limitation as they leave a permanent metal layer inside an artery when deployed. Recently, drug-coated balloon technology has emerged to treat coronary artery disease as a combination of balloon angioplasty and local drug delivery without leaving a metal layer behind. Recent European guidelines recommended using drug-coated balloons when treating in-stent restenosis treatment, while the US guidelines have not yet addressed the use of drug-coated balloons in such cases. Coronary brachytherapy is a valuable addition to treat these challenging diseases despite several logistic issues. If there are newer technologies with easier setup, such as drug-coated balloons, coronary brachytherapy resurgence is improbable in the contemporary era, although it may not become obsolete.

Coronary Intravascular Brachytherapy for Recurrent Coronary Drug-Eluting Stent In-Stent Restenosis: A Systematic Review and Meta-Analysis

OBJECTIVE

To examine the outcomes with intravascular brachytherapy (IVBT) in recurrent in-stent restenosis (ISR).

BACKGROUND

Recurrent ISR can be challenging to treat and IVBT can be used for recurrent ISR but has received limited study.

METHODS

We performed a systematic review and meta-analysis of five observational studies, including 917 patients (1014 lesions) with recurrent ISR, defined as having at least two prior ISR episodes with previous treatment with a stent, who underwent treatment with IVBT. Outcomes of interest included target vessel revascularization (TVR), myocardial infarction (MI), and all-cause mortality.

RESULTS

During a mean follow-up of 24 ± 7 months, the incidence of TVR was 29.2% (95% CI 18.0-40.4%). The incidence of MI and all-cause mortality were 4.3% (95% CI 1.7%-6.9%) and 7.3% (95% CI 3.2-11.5%), respectively. At one- and two-years after PCI the incidence of TVR was 17.5% (95% CI 13.6%-21.4%) and 26.7% (95% CI 16.6%-36.9%), respectively and the incidence of MI was 3.1% (95% CI 2-4.2%) and 3.9% (95% CI 1-6.8%), respectively.

CONCLUSION

Intravascular brachytherapy can be used to treat recurrent ISR, although TVR is needed in approximately one of four patients at two years.

Clinical implication of neointimal burden in in-stent restenosis treated with drug-coated balloon

BACKGROUND

Although drug-coated balloon (DCB) angioplasty is a well-established drug-eluting stent (DES) in-stent restenosis (ISR) strategy, there are minimal data regarding the association of neointimal burden on optical coherence tomography (OCT) before and after DCB and adverse clinical events. This study aimed to investigate the clinical impact of neointimal burden measured with OCT in patients with DES ISR after DCB angioplasty.

METHODS

From 2010 through 2013, a total of 122 patients with 122 ISR lesions were treated with DCB, which was preceded and followed by OCT examination. Major adverse cardiac events (MACE, a composite occurrence of cardiovascular cardiac death, nonfatal myocardial infarction [MI], or target lesion revascularization [TLR]) were evaluated.

RESULTS

MACE occurred in 27 patients (4 nonfatal MIs and 23 TLRs) during the follow-up (median: 55.3 months, interquartile range 43.1-66.0). The mean lumen area was significantly smaller (3.21 ± 2.42 mm² vs. 4.80 ± 2.53 mm² , p = .005) and the mean percentage of neointimal volume derived by OCT was greater (49.3 ± 9.2% vs. 38.3 ± 17.5%, p = .006) in patients with MACE before DCB angioplasty. The pre-procedural mean percentage of neointimal volume (cut-off 50%, area under the receiver operating characteristic [ROC] curve = 0.644, 95% confidence interval [CI] = 0.531-0.758, p = .022) and post-procedural mean percentage of neointimal volume (cut-off 25%, area under ROC curve = 0.659, 95% CI = 0.546-0.773, p = .012) were identified as significant parameters to predict MACE.

CONCLUSION

The OCT-derived mean percentages of neointimal volume before and after DCB angioplasty can be important parameters for predicting future MACE in patients with DES ISR.

Northwell intracoronary brachytherapy for the treatment of recurrent drug eluting stent in-stent restenosis (NITDI study group)

OBJECTIVE

The purpose of this study is to report on safety, short-term and long-term clinical efficacy following intracoronary brachytherapy (ICBT) for restenosis (ISR) in patients with drug eluting stents (DES).

BACKGROUND

ICBT is an effective treatment for ISR of bare metal stents (BMS) but its utilization has waned due to the advent of DES. ISR following DES occurs at a frequency of 8% or greater.

METHOD

A retrospective analysis was performed on patients treated on an institutional review board (IRB) approved protocol using ICBT for DES ISR between January 2011 and October 2016. All patients were followed for 24 months for procedural complications, mortality, clinical ISR/target lesion revascularization (TLR) and stroke.

RESULTS

A total of 290 patients were identified with a mean age of 66.6 years. All of them had high rates of typical coronary artery disease risk factors. Our primary outcome, composite of in-hospital mortality, myocardial infarction (MI), safety outcomes and procedural failure was noted in 1(0.3%) patient who had a MI. No other secondary outcome was noted in-hospital. At 1-year follow up, 12.4% patients had ISR, 1.7% patients died, and 1 (0.3%) had ischemic stroke. At 2-year, 14.7% had ISR, and total 6 (2.1%) patients had MI.

CONCLUSION

ICBT demonstrates excellent technical success rates for treatment, safety, and reasonable efficacy over 2-years to be free from recurrent clinical ISR. This study represents the largest ICBT data for DES ISR to date among very complex lesion subsets, however, more prospective data will be needed to determine the optimal patient for treatment.

Long-term clinical safety and efficacy of drug-coated balloon in the treatment of in-stent restenosis: A meta-analysis and systematic review

OBJECTIVES

The aim of this study was to evaluate the long-term clinical safety and efficacy of drug-coated balloon (DCB) in the treatment of in-stent restenosis (ISR).

BACKGROUND

There is a long-term safety issue in peripheral arterial disease patients treated with paclitaxel-coated balloon, this has also raised concerns on DCB in coronary intervention.

METHODS

Nine randomized controlled trials (RCTs) and nine observational studies (OSs) were included with a total of 3,782 patients (1,827 in the DCB group, 1,955 in the drug-eluting stent [DES] group) being analyzed. The primary outcome measure-major adverse cardiovascular events (MACEs), target lesion revascularization (TLR), target vessel revascularization (TVR), myocardial infarction (MI), cardiac death (CD), stent thrombosis (ST), all-cause death (AD), and coronary angiography outcomes included late lumen loss (LLL), minimum luminal diameter (MLD), diameter stenosis (DS) were analyzed.

RESULTS

DCB treatment significantly reduced the LLL (MD: -0.13; [CI -0.23 to -0.03], p = .01). No difference was found for MLD (MD: -0.1; [CI -0.24 to 0.04], p = .17) and DS% (RR = 0.98 [CI 0.80-1.20], p = .86). There was no significant difference in TLR, TVR, MI, CD, ST, AD, and the overall incidence of MACEs between the two groups up to 3 years follow-up. Subgroup analysis for different type of ISR and DES showed no significant difference in the incidence of endpoints, and there is no difference when considering RCTs or OSs only.

CONCLUSIONS

The safety and efficacy of the DCB and DES in the treatment of ISR is comparable at up to 3 years follow-up.

Comparison of drug-eluting balloon with repeat drug-eluting stent for recurrent drug-eluting stent in-stent restenosis

OBJECTIVE

Approximately, 10-20% of patients with drug eluting stent (DES) in-stent restenosis (ISR) will develop recurrent ISR; yet, the optimal management of recurrent DES-ISR is unknown. We sought to compare the outcomes of recurrent DES-ISR treated with drug eluting balloons (DEB) to those with repeated implantation of new-generation DES.

METHODS

A total of 172 patients with recurrent DES-ISR were enrolled and stratified into two cohorts: the repeated DES implantation (Re-DES) group and the DEB group. The primary endpoint was the 1-year incidence of major adverse cardiovascular events (MACE).

RESULTS

Ninety-three patients treated with DEB and 79 patients with Re-DES implantation were analyzed. Both groups had comparable baseline characteristics. Lesser residual stenosis was achieved in the Re-DES group (11.3 ± 3.2% vs. 22.4 ± 4.3%; P = 0.00) than in the DEB group. However, the incidence of MACE and target lesion revascularization (TLR) were less in the DEB group (17.2% vs. 32.9%; P = 0.02 and 15.1% vs. 27.8%; P = 0.04, respectively). For the ≥3 metal-layered DES-ISR subgroup, DEB drastically reduced the incidences of MACE and TLR compared with Re-DES (20.0% vs. 57.9%; P = 0.02 and 16.0% vs. 47.4%; P = 0.04, respectively). Survival analysis demonstrated that MACE-free survival was significantly higher in the DEB group compared with the Re-DES group, whether the metal layers were ≥3 or 2. Multivariate analysis revealed that the risk factors of MACE were diabetes mellitus, ≥3 metal-layered DES ISR, and repeat DES deployment.

CONCLUSIONS

For recurrent DES-ISR, DEB may improve clinical outcomes compared with Re-DES implantation, especially for ≥3 metal-layered DES-ISR.

Drug-coated balloon treatment in coronary artery disease: Recommendations from an Asia-Pacific Consensus Group

Coronary artery disease (CAD) is currently the leading cause of death globally, and the prevalence of this disease is growing more rapidly in the Asia-Pacific region than in Western countries. Although the use of metal coronary stents has rapidly increased thanks to the advancement of safety and efficacy of newer generation drug eluting stent (DES), patients are still negatively affected by some the inherent limitations of this type of treatment, such as stent thrombosis or restenosis, including neoatherosclerosis, and the obligatory use of dual antiplatelet therapy (DAPT) with unknown optimal duration. Drug-coated balloon (DCB) treatment is based on a leave-nothing-behind concept and therefore it is not limited by stent thrombosis and long-term DAPT; it directly delivers an anti-proliferative drug which is coated on a balloon after improving coronary blood flow. At present, DCB treatment is recommended as the first-line treatment option in metal stent-related restenosis linked to DES and bare metal stent. For de novo coronary lesions, the application of DCB treatment is extended further, for conditions such as small vessel disease, bifurcation lesions, and chronic total occlusion lesions, and others. Recently, several reports have suggested that fractional flow reserve guided DCB application was safe for larger coronary artery lesions and showed good long-term outcomes. Therefore, the aim of these recommendations of the consensus group was to provide adequate guidelines for patients with CAD based on objective evidence, and to extend the application of DCB to a wider variety of coronary diseases and guide their most effective and correct use in actual clinical practice.

Comparison of clinical outcomes of two different types of paclitaxel-coated balloons for treatment of patients with coronary in-stent restenosis

Drug-coated balloon (DCB) angioplasty has been shown to be a promising option for the treatment of coronary in-stent restenosis (ISR). We compared the clinical outcomes of patients with ISR who were treated with two commonly used paclitaxel-containing DCBs, the Pantera Lux (PL) and SeQuent Please (SP). A total of 491 patients with 507 ISR lesions [PL-DCB in 127 (26%) patients and SP-DCB in 364 (74%) patients] underwent DCB angioplasty for ISR lesions. The major adverse cardiac events (MACEs), including cardiac death, target lesion-related myocardial infarction, and target lesion revascularization, were assessed. There were no significant differences in each occurrence of MACE and cardiac death: 16 MACEs (61 per 1000 person-years) in the PL-DCB group and 55 (60 per 1000 person-years) MACEs in the SP-DCB group, log-rank p = 0.895, and three cardiac deaths (11 per 1000 person-years) in the PL-DCB group and ten cardiac deaths (11 per 1000 person-years) in the SP-DCB group, log-rank p = 0.849. Diabetes mellitus under insulin treatment [hazard ratio (HR) 2.71; 95% confidence interval (CI) 1.31-5.60; p = 0.007], chronic kidney disease (HR 1.99; 95% CI 1.01-3.92; p = 0.045), early-onset ISR (HR 1.99; 95% CI 1.18-3.36; p = 0.010), and recurrent ISR (HR 1.89; 95% CI 1.08-3.32; p = 0.026) were associated with the occurrence of MACE after DCB angioplasty. There was no significant difference of MACE between PL-DCB and SP-DCB treatment in patients with ISR. Patients with insulin-treated diabetes, chronic kidney disease, early-onset ISR, and recurrent ISR were at a higher risk of MACE after DCB angioplasty.

Cardiovascular stents: overview, evolution, and next generation

Compared to bare-metal stents (BMSs), drug-eluting stents (DESs) have been regarded as a revolutionary change in coronary artery diseases (CADs). Releasing pharmaceutical agents from the stent surface was a promising progress in the realm of cardiovascular stents. Despite supreme advantages over BMSs, in-stent restenosis (ISR) and long-term safety of DESs are still deemed ongoing concerns over clinically application of DESs. The failure of DESs for long-term clinical use is associated with following factors including permanent polymeric coating materials, metallic stent platforms, non-optimal drug releasing condition, and factors that have recently been supposed as contributory factors such as degradation products of polymers, metal ions due to erosion and degradation of metals and their alloys utilizing in some stents as metal frameworks. Discovering the direct relation between stent materials and associating adverse effects is a complicated process, and yet it has not been resolved. For clinical success it is of significant importance to optimize DES design and explore novel strategies to overcome all problems including inflammatory response, delay endothelialization, and sub-acute stent thrombosis (ST) simultaneously. In this work, scientific reports are reviewed particularly focusing on recent advancements in DES design which covers both potential improvements of existing and recently novel prototype stent fabrications. Covering a wide range of information from the BMSs to recent advancement, this study mostly sheds light on DES's concepts, namely stent composition, drug release mechanism, and coating techniques. This review further reports different forms of DES including fully biodegradable DESs, shape-memory ones, and polymer-free DESs.

Drug-Eluting Balloons versus Second-Generation Drug-Eluting Stents for Treating In-Stent Restenosis in Coronary Heart Disease after PCI: A Meta-Analysis

BACKGROUND

In-stent restenosis (ISR) remains a common problem following percutaneous coronary intervention (PCI). However, the best treatment strategy remains uncertain. There is some controversy over the efficacy of drug-eluting balloons (DEBs) and second-generation drug-eluting stents (DESs) for treating ISR.

METHODS

A meta-analysis was used to compare the efficacy of the DEB and second-generation DES in the treatment of ISR. The primary endpoint is the incidence of target lesion revascularization (TLR). The secondary endpoint is the occurrence of target vessel revascularization (TVR), myocardial infarction (MI), all-cause death (ACM), cardiac death (CD), major adverse cardiac events (MACEs), minimum luminal diameter (MLD), late luminal loss (LLL), binary restenosis (BR), and percent diameter stenosis (DS%).

RESULTS

A total of 12 studies (4 randomized controlled trials and 8 observational studies) including 2020 patients with a follow-up of 6-25 months were included in the present study. There was a significant difference in the MLD between the two groups during follow-up (P=0.007, RR = 0.23, and 95% CI: 0.06-0.4 mm). There was no significant difference in LLL, BR, or DS% and the overall incidence of MACEs between the two groups. Subgroup analysis showed no significant difference in the incidence of primary and secondary endpoints when considering RCTs or observational studies only.

CONCLUSIONS

The efficacy of the DEB and second-generation DES in the treatment of ISR is comparable. However, our results need further verification through multicenter randomized controlled trials.

Drug-Eluting Balloon versus New-Generation Drug-Eluting Stent for the Treatment of In-Stent Restenosis: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Currently, drug-eluting balloon (DEB) appears to be an attractive alternative option for the treatment of in-stent restenosis (ISR). Nevertheless, the clinical outcomes of DEB have seldom been compared to those of new-generation drug-eluting stent (DES). Thus, this meta-analysis aimed to evaluate the safety and efficacy of DEB compared to those of new-generation DES in the treatment of ISR.

METHODS

A comprehensive search of electronic databases including PubMed, EMBASE, and Cochrane Library up to November 2, 2017 was performed to identify pertinent articles comparing DEB to new-generation DES for the treatment of ISR. In addition, conference proceedings for the scientific sessions of the American College of Cardiology, American Heart Association, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics, and EuroPCR were also searched. The primary endpoint was target lesion revascularization (TLR) at the longest follow-up. Dichotomous variables were presented as risk ratios (RR s) with 95% confidence intervals (CI s), while the overall RR s were estimated using the Mantel-Haenszel random-effects model.

RESULTS

Five randomized controlled trials (RCTs) and eight observational studies involving 2743 patients were included in the present meta-analysis. Overall, DEB was comparable to new-generation DES in terms of TLR (RR = 1.24, 95% CI: 0.89-1.72, P = 0.21), cardiac death (RR = 1.55, 95% CI: 0.89-2.71, P = 0.12), major adverse cardiovascular event (RR = 1.21, 95% CI: 0.98-1.48, P = 0.07), myocardial infarction (RR = 1.12, 95% CI: 0.72-1.76, P = 0.62), and stent thrombosis (RR = 0.95, 95% CI: 0.38-2.42, P = 0.92). However, DEB was associated with higher risk of all-cause mortality than new-generation DES (RR = 1.65, 95% CI: 1.09-2.50, P = 0.02). This was especially true in the real-world observational studies (RR = 1.79, 95% CI: 1.12-2.88, P = 0.02). In RCTs, however, no significant difference was found between the two treatment strategies in the risk of all-cause mortality.

CONCLUSIONS

The current meta-analysis showed that DEB and new-generation DES had comparable safety and efficacy for the treatment of ISR in RCTs. However, treatment with DEB was associated with higher risk of all-cause mortality in the real-world nonrandomized studies.

Surface Modification of Cardiovascular Stent Material 316L SS with Estradiol-Loaded Poly (trimethylene carbonate) Film for Better Biocompatibility

A delay in the endothelialization process represents a bottleneck in the application of a drug-eluting stent (DES) during cardiovascular interventional therapy, which may lead to a high risk of late restenosis. In this study, we used a novel active drug, estradiol, which may contribute to surface endothelialization of a DES, and prepared an estradiol-loaded poly (trimethylene carbonate) film (PTMC-E5) on the surface of the DES material, 316L stainless steel (316L SS), in order to evaluate its function in improving surface endothelialization. All the in vitro and in vivo experiments indicated that the PTMC-E5 film significantly improved surface hemocompatibility and anti-hyperplasia, anti-inflammation and pro-endothelialization properties. This novel drug-delivery system may provide a breakthrough for the surface endothelialization of cardiovascular DES.

Controlling Molecular Weight of Hyaluronic Acid Conjugated on Amine-rich Surface: Toward Better Multifunctional Biomaterials for Cardiovascular Implants

The molecular weights (MWs) of hyaluronic acid (HA) in extracellular matrix secreted from both vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) play crucial roles in the cardiovascular physiology, as HA with appropriate MW influences important pathways of cardiovascular homeostasis, inhibits VSMC synthetic phenotype change and proliferation, inhibits platelet activation and aggregation, promotes endothelial monolayer repair and functionalization, and prevents inflammation and atherosclerosis. In this study, HA samples with gradients of MW (4 × 10³, 1 × 10⁵, and 5 × 10⁵ Da) were prepared by covalent conjugation to a copolymerized film of polydopamine and hexamethylendiamine (PDA/HD) as multifunctional coatings (PDA/HD-HA) with potential to improve the biocompatibility of cardiovascular biomaterials. The coatings immobilized with high-MW-HA (PDA/HD-HA-2: 1 × 10⁵ Da; PDA/HD-HA-3: 5 × 10⁵ Da) exhibited a remarkable suppression of platelet activation/aggregation and thrombosis under 15 dyn/cm² blood flow and simultaneously suppressed the adhesion and proliferation of VSMC and the adhesion, activation, and inflammatory cytokine release of macrophages. In particular, PDA/HD-HA-2 significantly enhanced VEC adhesion, proliferation, migration, and functional factors release, as well as the captured number of endothelial progenitor cells under dynamic condition. The in vivo results indicated that the multifunctional surface (PDA/HD-HA-2) created a favorable microenvironment of endothelial monolayer formation and functionalization for promoting reendothelialization and reducing restenosis of cardiovascular biomaterials.

Usefulness of Intracoronary Brachytherapy for Patients With Resistant Drug-Eluting Stent Restenosis

In-stent restenosis (ISR) remains a concern even in the drug-eluting stent (DES) era and carries a high risk of recurrence. Brachytherapy is being used as an alternative treatment for resistant ISR, yet the safety and efficacy of this approach has not been well studied. We analyzed the outcomes of 101 patients who underwent coronary brachytherapy for resistant DES ISR. Baseline demographic, clinical, procedural, and outcome data were collected by phone and from electronic records. Comorbidities and overt cardiovascular disease were highly prevalent. Median previous stent layers were 2 with a maximum of 5 layers. Procedural angiographic success rate was 97% and median time to discharge was 1 day after brachytherapy. The primary outcome of target vessel revascularization was 24% at 1 year, 32% at 2 years, and 42% at 3 years. The rate of nonfatal myocardial infarction was 0% at 1 year, 3.5% at 2 years, and 6% at 3 years. The rate of all-cause mortality was 8.5% at 1 year, 12% at 2 years, and 16% at 3 years. We observed only 1 case of late stent thrombosis. After multivariable adjustment, female gender (hazard ratio 2.37, 95% confidence interval 1.02 to 5.52, p = 0.04) and diffuse ISR pattern (hazard ratio 2.95, 95% confidence interval 1.21 to 7.17, p = 0.01) were independently associated with the primary outcome. In conclusion, brachytherapy is feasible for the treatment of resistant DES ISR and is associated with high immediate procedural success and reasonable efficacy in a complex patient population. This approach might be used as an alternative for these patients.

Drug-eluting balloons versus drug-eluting stents for the management of in-stent restenosis: A meta-analysis of randomized and observational studies

OBJECTIVES

The aim of this study was to evaluate the efficacy of drug-eluting balloons (DEB) with drug-eluting stents (DES) in patients with in-stent restenosis (ISR).

BACKGROUND

DES implantation and DEB were available strategies in percutaneous coronary intervention (PCI) for ISR, but the optimal management for ISR lesions remains controversial.

METHODS

Electronic databases were searched for randomized controlled trials and observational cohort studies which reported the clinical outcomes of using DEB comparing with DES implantation in patients with ISR. Clinical endpoints such as major adverse cardiovascular events (MACE), death, and myocardial infarction were assessed.

RESULTS

Five randomized controlled trials and five observational cohort studies with 962 patients in the DEB group and 908 patients in the DES group met inclusion criteria. There was no significant difference between DEB and DES in major clinical outcomes, such as MACE (OR 1.01; 95% CI: 0.64-1.58; p=0.97; I²=0%), all-cause death (OR 1.04; 95% CI: 0.54-1.98; p=0.91; I²=0%), cardiovascular death (OR 1.44; 95% CI: 0.57-3.65; p=0.44; I²=0%), stent thrombosis (OR 0.61; 95% CI: 0.16-2.33; p=0.47; I²=0%), and myocardial infarction (OR 1.02; 95% CI: 0.53-1.94; p=0.96; I²=0%). DEB was associated with a significant increase in target lesion revascularization (OR 1.54; 95% CI: 1.10-2.15; p=0.01; I²=57%).

CONCLUSION

Treatment of ISR using DEB led to comparable clinical outcomes with DES implantation.

Application of drug-coated balloon in coronary artery intervention: challenges and opportunities

In recent decades, the outcomes of coronary heart disease (CHD) have markedly improved, which can be partly attributed to the use of novel drugs (especially statins and antiplatelet drugs) and partly to the evolution of percutaneous coronary intervention (PCI). From percutaneous transluminal coronary angioplasty to bare-metal stent and then to drug-eluting stent, every step of PCI is attractive to interventional cardiologist, great progress has been made for patients with CHD. In the past few years, some successor devices for treating CHD have emerged. Undoubtedly, drug-coated balloon (DCB), which was recommended by 2014 ESC Guidelines on myocardial revascularization, is a “shining star” among them. DCB involves a semi-compliant angioplasty balloon coated with an anti-proliferative agent that can exert antirestenotic efficacy by permeating into the vessel wall during balloon contact. This review discusses the conception and merits, preclinical data, emerging clinical indications, and results from clinical trials of this novel interventional technology. Although DCB has shown authentic efficacy in the treatment of in-stent restenosis, its use in de novo coronary lesions is still in dispute. Hence, concerns and the future direction of DCB are also covered in this paper.

Recurrent in-stent restenosis, certainty of its origin, uncertainty about treatment

Treatment of recurrent in-stent restenosis is a real brainteaser for the interventional cardiologist who cannot resort to the guidelines to have indications about the type of treatment to be preferred. The use of intracoronary imaging may provide insights into the underlying mechanisms of this complication and use of drug-coated balloons may be a valid alternative and especially a thoughtful treatment when the repeated and perseverant use of drug-eluting stents clearly fails. In this setting, we present a review of the literature about this interesting topic, going deep into the heart of the problem, its origin and possible treatment options.

Impact of Angiographic Result After Predilatation on Outcome After Drug-Coated Balloon Treatment of In-Stent Coronary Restenosis

This study investigates clinical outcomes after drug-coated balloon (DCB) treatment for in-stent restenosis (ISR) based on the angiographic result achieved after predilatation and before DCB treatment. Among ISR lesions treated with DCBs, 166 lesions with angiography immediately after predilatation were analyzed. The lesions were divided into 2 groups according to angiographic results after predilatation: (1) "adequate" defined as the presence of Thrombolysis In Myocardial Infarction 3 flow, residual stenosis ≤30%, and no major dissections (n = 98 lesions) or (2) "inadequate" (n = 68 lesions). The reference vessel diameters were larger (2.88 ± 0.39 vs 2.64 ± 0.52 mm, p = 0.001) and lesion lengths shorter in the adequate group (15.4 ± 11.2 vs 19.7 ± 13.9 mm, p = 0.04). During a median follow-up of 808 days, the cumulative target lesion revascularization (TLR) rate was lower in the adequate group (20.3% vs 35.5% at 2 years; p = 0.04). Multivariate analysis indicated that an angiographically inadequate result before DCB treatment was an independent predictor of TLR, even after adjusting for reference vessel diameter and lesion length (hazard ratio 1.99, 95% confidence interval 1.02 to 3.87, p = 0.04). In conclusion, angiographic results after lesion preparation appear to be a good predictor of TLR after DCB treatment for ISR.