Emerging technologies: polymer-free phospholipid encapsulated sirolimus nanocarriers for the controlled release of drug from a stent-plus-balloon or a stand-alone balloon catheter

Paclitaxel-coated versus sirolimus-coated balloon angioplasty for coronary artery disease: A systematic review and meta-analysis

BACKGROUND

Although use of sirolimus-based analogs has shown superiority over paclitaxel in drug-eluting stents, the relative efficacy of these two agents released from drug-coated balloons (DCB) is unclear. The present meta-analysis is aimed to compare outcomes after percutaneous coronary intervention (PCI) with paclitaxel-coated balloons (PCB) versus sirolimus-coated balloons (SCB) for either in-stent restenosis or native de novo lesions.

METHODS

The study outcomes were 1) target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, or target lesion revascularization, and 2) follow-up angiographic parameters including late lumen loss (LLL), diameter stenosis, and minimal lumen diameter (MLD). Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated by using random-effects models.

RESULTS

A search of PubMed, EMBASE, and Cochrane Library from their inception to January 2024 identified five randomized clinical trials and three observational studies with a total of 1861 patients (889 in PCB and 972 in SCB groups). During 9-12 months of follow-up, there was no significant difference in TLF (OR 1.01, 95% CI 0.75-1.35) between the two groups. On follow-up angiography at 6-9 months, MLD (WMD 0.10, 95% CI 0.02-0.17) was larger in PCB but there was no statistically significant difference in LLL (WMD -0.11, 95% CI -0.23-0.02) and diameter stenosis (WMD -3.33, 95% CI -8.11-1.45).

CONCLUSIONS

Among patients undergoing DCB-only PCI, the risk of TLF was similar during 9-12 months of follow-up after PCB and SCB treatment. However, the MLD was larger favoring PCB over SCB on follow-up angiography.

Outcomes With Limus- vs Paclitaxel-Coated Balloons for Percutaneous Coronary Intervention: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Randomized controlled trials (RCTs) examining the outcomes with limus drug-coated balloons (DCBs) vs paclitaxel DCBs were small and underpowered for clinical endpoints.

OBJECTIVES

This study sought to compare the angiographic and clinical outcomes with limus DCBs vs paclitaxel DCBs for percutaneous coronary intervention (PCI).

METHODS

An electronic search of Medline, EMBASE, and Cochrane databases was performed through January 2024 for RCTs comparing limus DCBs vs paclitaxel DCBs for PCI. The primary endpoint was clinically driven target lesion revascularization (TLR). The secondary endpoints were late angiographic findings. Summary estimates were constructed using a random effects model.

RESULTS

Six RCTs with 821 patients were included; 446 patients received a limus DCB, and 375 patients received a paclitaxel DCB. There was no difference between limus DCBs and paclitaxel DCBs in the incidence of TLR at a mean of 13.4 months (10.3% vs 7.8%; risk ratio [RR]: 1.32; 95% CI: 0.84-2.08). Subgroup analysis suggested no significant interaction among studies for de novo coronary lesions vs in-stent restenosis (Pinteraction = 0.58). There were no differences in the risk of major adverse cardiovascular events, cardiac mortality, or target vessel myocardial infarction between groups. However, limus DCBs were associated with a higher risk of binary restenosis (RR: 1.89; 95% CI: 1.14-3.12), late lumen loss (mean difference = 0.16; 95% CI: 0.03-0.28), and a smaller minimum lumen diameter (mean difference = -0.12; 95% CI: -0.22 to -0.02) at late follow-up. In addition, late lumen enlargement occurred more frequently (50% vs 27.5%; RR: 0.59; 95% CI: 0.45-0.77) with paclitaxel DCBs.

CONCLUSIONS

Among patients undergoing DCB-only PCI, there were no differences in the risk of clinically driven TLR and other clinical outcomes between limus DCBs and paclitaxel DCBs. However, paclitaxel DCBs were associated with better late angiographic outcomes. These findings support the need for future trials to establish the role of new-generation limus DCBs for PCI.

Sirolimus-coated balloon in acute and chronic coronary syndromes: the PEACE study, a subanalysis of the EASTBOURNE registry

INTRODUCTION AND OBJECTIVES

The PEACE study (Performance of a sirolimus-eluting balloon strategy in acute and chronic coronary syndromes) investigated for the first time whether a sirolimus-coated balloon (SCB) (Magic Touch, Concept Medical, India) is associated with different outcomes depending on whether it is used in acute coronary syndromes (ACS) or chronic coronary syndromes (CCS).

METHODS

This was a post-hoc analysis from the all-comers EASTBOURNE Registry (NCT03085823). Out of 2083 patients enrolled, an SCB was used to treat 968 (46.5%) ACS and 1115 (53.5%) CCS patients. The primary endpoint was target lesion revascularization at 12 months, while secondary endpoints were angiographic success and major adverse cardiovascular events.

RESULTS

Baseline demographics, mean reference vessel diameter and mean lesion length were comparable between ACS and CCS. Predilatation was more commonly performed in ACS (P=.007). SCB was inflated at a standard pressure in both groups with a slight trend toward longer inflation time in ACS. Angiographic success was high in both groups (ACS 97.4% vs CCS 97.7%, P=.820) with limited bailout stenting. Similarly, at 12 months the cumulative incidence of target lesion revascularization (ACS 6.6% vs CCS 5.2%, P=.258) was comparable between ACS and CCS. Conversely, a higher rate of major adverse cardiovascular events in acute presenters was mainly driven by myocardial infarction recurrencies (ACS 10.4% vs CCS 8.3%, P=.009). In-stent restenosis showed a higher proportion of target lesion revascularization and major adverse cardiovascular events than de novo lesions, independently of the type of presentation at the index procedure.

CONCLUSIONS

This SCB shows good performance in terms of acute and 1-year outcomes independently of the clinical presentation.

Exploring the Potential of MIM-Manufactured Porous NiTi as a Vascular Drug Delivery Material

Porous nickel-titanium (NiTi) manufactured using metal injection molding (MIM) has emerged as an innovative generation of drug-loaded stent materials. However, an increase in NiTi porosity may compromise its mechanical properties and cytocompatibility. This study aims to explore the potential of porous NiTi as a vascular drug delivery material and evaluate the impact of porosity on its drug loading and release, mechanical properties, and cytocompatibility. MIM, combined with the powder space-holder method, was used to fabricate porous NiTi alloys with three porosity levels. The mechanical properties of porous NiTi were assessed, as well as the surface cell growth capability. Furthermore, by loading rapamycin nanoparticles onto the surface and within the pores of porous NiTi, we evaluated the in vitro drug release behavior, inhibitory effect on cell proliferation, and inhibition of neointimal hyperplasia in vivo. The results demonstrated that an increase in porosity led to a decrease in the mechanical properties of porous NiTi, including hardness, tensile strength, and elastic modulus, and a decrease in the surface cell growth capability, affecting both cell proliferation and morphology. Concurrently, the loading capacity and release duration of rapamycin were extended with increasing porosity, resulting in enhanced inhibitory effects on cell proliferation in vitro and inhibition of neointimal hyperplasia in vivo. In conclusion, porous NiTi holds promise as a desirable vascular drug delivery material, but a balanced consideration of the influence of porosity on both mechanical properties and cytocompatibility is necessary to achieve an optimal balance among drug-loading and release performance, mechanical properties, and cytocompatibility.

Nanotechnology in development of next generation of stent and related medical devices: Current and future aspects

Coronary stents have saved millions of lives in the last three decades by treating atherosclerosis especially, by preventing plaque protrusion and subsequent aneurysms. They attenuate the vascular SMC proliferation and promote reconstruction of the endothelial bed to ensure superior revascularization. With the evolution of modern stent types, nanotechnology has become an integral part of stent technology. Nanocoating and nanosurface fabrication on metallic and polymeric stents have improved their drug loading capacity as well as other mechanical, physico-chemical, and biological properties. Nanofeatures can mimic the natural nanofeatures of vascular tissue and control drug-delivery. This review will highlight the role of nanotechnology in addressing the challenges of coronary stents and the recent advancements in the field of related medical devices. Different generations of stents carrying nanoparticle-based formulations like liposomes, lipid-polymer hybrid NPs, polymeric micelles, and dendrimers are discussed highlighting their roles in local drug delivery and anti-restenotic properties. Drug nanoparticles like Paclitaxel embedded in metal stents are discussed as a feature of first-generation drug-eluting stents. Customized precision stents ensure safe delivery of nanoparticle-mediated genes or concerted transfer of gene, drug, and/or bioactive molecules like antibodies, gene mimics via nanofabricated stents. Nanotechnology can aid such therapies for drug delivery successfully due to its easy scale-up possibilities. However, limitations of this technology such as their potential cytotoxic effects associated with nanoparticle delivery that can trigger hypersensitivity reactions have also been discussed in this review. This article is categorized under: Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

A New Frontier for Drug-Coated Balloons: Treatment of "De Novo" Stenosis in Large Vessel Coronary Artery Disease

Background: Drug-coated balloons (DCB) are a well-established option for treating in-stent restenosis endorsed by European Guidelines on myocardial revascularization. However, in recent years, a strategy of "leaving nothing behind" with DCB in de novo coronary stenosis has emerged as an appealing approach. Methods: We performed a systematic review to evaluate the current literature on the use of drug-coated balloons in the treatment of de novo stenosis in large vessel disease. Results: Observational studies, as well as randomized studies, demonstrated the safety of DCB percutaneous coronary interventions (PCI) in large vessel disease. The rate of major adverse cardiac events is even lower compared to drug-eluting stents in stable coronary artery disease. Conclusions: DCB PCI is feasible in large vessel disease, and future large, randomized studies are ongoing to confirm these results.

A Prospective Randomized Trial Comparing Sirolimus-Coated Balloon With Paclitaxel-Coated Balloon in De Novo Small Vessels

BACKGROUND

There are no data comparing sirolimus-coated balloons (SCBs [MagicTouch, Concept Medical]) to paclitaxel-coated balloons (PCBs [SeQuent Please Neo, B. Braun]) for the treatment of de novo small vessel disease (SVD).

OBJECTIVES

This study sought to compare quantitative coronary angiographic outcomes at 6 months after treatment of de novo SVD with a PCB or SCB.

METHODS

This prospective, multicenter, noninferiority trial randomized 121 patients (129 SVD lesions) to treatment with an SCB or PCB, with balloon sizing determined using optical coherence tomography. The primary endpoint was noninferiority for the 6-month angiographic net lumen gain.

RESULTS

Angiographic follow-up was completed in 109 (90.1%) patients in the per-protocol analysis. The mean ± SD angiographic net gains were 0.25 ± 0.40 mm with SCBs vs 0.48 ± 0.37 mm with PCBs, resulting in SCBs failing to meet the 0.30 mm criterion for noninferiority (Pnoninferiority = 0.173), with an absolute difference of -0.23 mm (95% CI: -0.37 to -0.09) secondary to a smaller late loss (0.00 ± 0.32 mm vs 0.32 ± 0.47 mm; P < 0.001) and more frequent late lumen enlargement (53.7% vs 30.0%; OR: 2.60; 95% CI: 1.22-5.67; P = 0.014) with PCBs. Binary restenosis rates were 32.8% and 12.5% following treatment with SCBs and PCBs, respectively (OR: 3.41; 95% CI: 1.36-9.44; P = 0.012). The mean angiography-derived fractional flow ratio at follow-up was 0.86 ± 0.15 following treatment with SCBs and 0.91 ± 0.09 following PCBs (P = 0.026); a fractional flow ratio ≤0.80 occurred in 13 and 5 vessels after treatment with SCBs and PCBs, respectively.

CONCLUSIONS

The SCB MagicTouch failed to demonstrate noninferiority for angiographic net lumen gain at 6 months compared to the PCB SeQuent Please Neo.

The evolution and revolution of drug coated balloons in coronary angioplasty: An up-to-date review of literature data

European Society of Cardiology (ESC) guidelines gave class I A indication for use of DCB in in-stent restenosis. However, no indication exists for the usage of DCB in de novo lesions. Although the current generation DES offer excellent results, as we embark more complex lesions such as calcified lesion and chronic total occlusion, restenosis and stent thrombosis are higher and tend to increase within the years. There is increasing desire to leave nothing behind to abolish the risk of restenosis and stent thrombosis and hence the absorbable scaffolds were introduced, but with disappointing results. In addition, they take several years to be absorbed. Drug coated balloons offer an alternative to stents with no permanent implant of metal or polymer. They are already in use in in Europe and Asia and they have been approved for the first time in the United States for clinical trials specifically for restenotic lesions. There is emerging data in de novo lesions which have shown that DCB are noninferior and in some studies maybe even superior to current generation DES especially in small vessels. In this article, we provide a comprehensive review of the literature on this expanding technology focussing on the evidence in both re-stenotic and de novo lesions.

Pre-clinical investigation of liquid sirolimus for local drug delivery

Introduction

Sirolimus is currently being explored as an alternative drug to paclitaxel for the treatment of peripheral artery disease (PAD). To date, sirolimus has only been used as drug coatings for stents and balloons and no studies have yet demonstrated the delivery of sirolimus in liquid form. The purpose of this pilot study was to investigate the feasibility of the delivery of liquid sirolimus into arterial segments in a benchtop peripheral artery bioreactor.

Methods

The feasibility to deliver liquid therapy was first tested on four drug delivery devices using a fluorescently tagged liquid drug and an ex vivo porcine artery benchtop model. The four devices included the Bullfrog micro-infusion device, ClearWay RX catheter, Occlusion perfusion catheter (OPC), and the targeted adjustable pharmaceutical administration system (TAPAS). Penetration of the fluorescently tagged drug was measured via microscopic imaging and quantification of the depth of drug penetration into all device-treated tissue. Based on the penetration outcome, we then selected a single device to deliver liquid sirolimus into the ex vivo porcine artery model undergoing physiological flow and pressure conditions. The liquid sirolimus-treated arteries were collected from the ex vivo bioreactor at 1- and 24-hour post-delivery and arterial drug retention analyzed by liquid chromatography-tandem mass spectrometry.

Results

Fluorescent microscopy demonstrated that drug delivery with the OPC had greater drug penetration into the medial wall as compared to other devices (OPC: 234 ± 161 µm; TAPAS: 127 ± 68 µm; ClearWay: 118 ± 77 µm; Bullfrog: 2.12 ± 3.78 µm; p = 0.098). The results of the ex vivo flow-circuit bench top model showed that the OPC device successfully delivered the liquid sirolimus at 1-hour (5.17 ± 4.48 ng/mg) and 24-hour (0.78 ± 0.55 ng/mg).

Conclusions

These results demonstrate for the first time the ability to deliver liquid sirolimus directly to the medial layer of an artery via a liquid delivery catheter.

Paclitexel versus sirolimus-coated balloon in the treatment of coronary instent restenosis

BACKGROUND

Few studies compared paclitaxel-coated balloon (PCB) versus sirolimus-coated balloon (SCB) in the treatment of drug-eluting stent (DES) instent restenosis (ISR).

METHODS

Between November 5, 2009, and October 14, 2020, in our center 212 patients with first DES-ISR were treated with PCB (Restore®; Cardionovum GmbH, Bonn, Germany), whereas 230 patients were treated with SCB (Devoir®; MINVASYS SAS, Gennevilliers, France). Following a propensity matching, 186 patients were included into PCB group (PCB group), and in the SCB group (SCB group). The primary purpose of the study was the 1-year target lesion failure (TLF) rate, including cardiac death, target vessel-related myocardial infarction, and repeated target lesion or target vessel revascularization.

RESULTS

Procedural success occurred in all cases. Fully optimal predilation (that is, balloon-to-stent ratio >0.91, time of DCB inflation >60 sec, and residual percent diameter stenosis after lesion preparation <20%) was observed more often in the SCB group (126 [68%] patients versus 106 [57%] patients; P=0.042). One-year TLF occurred in 29 (15.5%) patients in the SCB group and in 32 (17%) patients in the PCB group (OR=1.12 [0.65-1.95]; P=0.78). By logistic Cox regression analysis fully optimal predilation (OR=0.06; 95% CI: 0.01-0.21; P<0.001) but not DCB type (OR=0.74; 95% CI: 0.41-1.31; P=0.29) was independent predictor of 1-year TLF.

CONCLUSIONS

The current study suggests that 1-year TLF is not statistically and clinically different in patients with DES ISR treated with a PCB and a SCB.

Treatment of Peripheral Artery Disease Using Injectable Biomaterials and Drug-Coated Balloons: Safety and Efficacy Perspective

The possibility of injectable biomaterials being used in the therapy of peripheral artery disease (PAD) is investigated in this article. We conducted a thorough review of the literature on the use and efficacy of biomaterials (BMs) and drug-coated balloons (DCBs). These BMs included hydrogels, collagen scaffolds, and nanoparticles. These BMs could be used alone or in combination with growth factors, stem cells, or gene therapy. The treatment of peripheral artery disease with DCBs is increasingly common in the field of interventional angiology. Studies have been carried out to examine the effectiveness of paclitaxel-coated balloons such as PaccocathTM in lowering the frequency with which further revascularization operations are required. PCB angioplasty and angioplasty without paclitaxel did not significantly vary in terms of mortality, according to the findings of a recent meta-analysis that included the results of four randomized controlled studies. On the other hand, age was found to be a factor that predicted mortality. There was a correlation between the routine utilization of scoring balloon angioplasty along with DCBs and improved clinical outcomes in de novo lesions. In both preclinical and clinical testing, the SelutionTM DCB has demonstrated efficacy and safety, but further research is required to determine whether or not it is effective and safe over the long term. In addition, we reviewed the difficulties involved in bringing injectable BMs-based medicines to clinical trials, including the approval processes required by regulatory bodies. Injectable BMs have a significant amount of therapeutic promise for PAD, which highlights the need for more research and clinical studies to be conducted in this field. In conclusion, this research focuses on the potential of injectable BMs and DCBs in the treatment of PAD as well as the hurdles that must be overcome in order to translate these treatments into clinical trials. In this particular field, there is a demand for further research as well as clinical trials.

Metal free percutaneous coronary interventions in all-comers: First experience with a novel sirolimus-coated balloon

BACKGROUND

Limus-eluting stents have become the mainstay for percutaneous coronary intervention (PCI). However, even with the latest generation drug-eluting stent, in-stent restenosis and very late stent thrombosis remain a concern. The Selution SLR™ drug-coated balloon (DCB) is a novel sirolimus-coated balloon that provides a controlled release of the antiproliferative drug. Herein we evaluated its performance in a real-world patient cohort with complex coronary artery lesions.

METHODS

Patients undergoing PCI using the Selution SLR™ DCB were analyzed from the prospective SIROOP registry. We evaluated procedural success and clinical outcomes, including major adverse cardiovascular event (MACE), cardiac death, target vessel myocardial infarction and target lesion revascularization.

RESULTS

From September 2020 to April 2021, we enrolled 78 patients (87 lesions) treated using a "DCB only" strategy. The mean age was 66.7 ± 10.4 years and 28 (36%) presented with an acute coronary syndrome. Almost all lesions were type B2/C 86 (99%) and 49 (63%) had moderate to severe calcifications. Procedural success was 100%. After a median follow-up of 11.2 months (interquartile range: 10.0-12.6), MACE occurred in 5 (6.8%) patients. No acute vessel closure was observed.

CONCLUSIONS

In complex coronary lesions, a "DCB only" strategy using the Selution SLR™ DCB is not just safe and feasible, but also seems to be associated with a low rate of MACE at 1-year follow-up. Our promising results warrant further evaluation in a dedicated comparative trial.

Utility of sirolimus coated balloons in the peripheral vasculature – a review of the current literature

Sirolimus-coated balloons (SCB) have demonstrated much promise as an alternative drug eluting device to the existing paclitaxel coated balloon platforms for the treatment of peripheral arterial disease (PAD). They have been well tested pre-clinically and have demonstrated anti-restenotic effects as well as clinical safety in its use for treatment of coronary artery disease. The existing approved SCBs have thus far demonstrated good short-term patency (12-months) and did not exhibit any major adverse events or device related shortcomings in its use for treatment of PAD. There are several studies ongoing which aim to further investigate the efficacy of existing SCBs and establish a direct comparison of its outcomes compared with plain balloon angioplasty. Also, SCB utility to salvage failing arteriovenous fistulas for haemodialysis patients has also been explored. We review the current progress made in the establishment of SCB in the treatment of PAD as well as highlight ongoing studies investigating the role of SCB in various settings.

The Ongoing Saga of the Evolution of Percutaneous Coronary Intervention: From Balloon Angioplasty to Recent Innovations to Future Prospects

The advances in percutaneous coronary intervention (PCI) have been, above all, dependent on the work of pioneers in surgery, radiology, and interventional cardiology. From Grüntzig's first balloon angioplasty, PCI has expanded through technology development, improved protocols, and dissemination of best-practice techniques. We can nowadays treat more complex lesions in higher-risk patients with favourable results. Guide wires, balloon types and profiles, debulking techniques such as atherectomy or lithotripsy, stents, and scaffolds all represent evolutions that have allowed us to tackle complex lesions such as an unprotected left main coronary artery, complex bifurcations, or chronic total occlusions. Best-practice PCI, including physiology assessment, imaging, and optimal lesion preparation are now the gold standard when performing PCI for sound indications, and new technologies such as intravascular lithotripsy for lesion preparation, or artificial intelligence, are innovations in the steps of 4 decades of pioneers to improve patient care in interventional cardiology. In the present review, major innovations in PCI since the first balloon angioplasty and also uncertainties and obstacles inherent to such medical advances are described.

Combined Analysis of Two Parallel Randomized Trials of Sirolimus-Coated and Paclitaxel-Coated Balloons in Coronary In-Stent Restenosis Lesions

BACKGROUND

Paclitaxel-coated balloons (PCBs) are a preferred treatment option for coronary in-stent restenosis. To date, data from randomized trials of alternative drug coatings are lacking. The aim of the randomized Malaysian and German-Swiss randomized trials was to investigate a novel sirolimus-coated balloon (SCB) compared with a PCB in in-stent restenosis.

METHODS

One hundred one patients with drug-eluting stent in-stent restenosis were enrolled in 2 identical randomized trials comparing the novel SCB (SeQuent SCB, 4 μg/mm²) with the clinically proven PCB (SeQuent Please, 3 μg/mm²). Primary end point was angiographic late lumen loss at 6 months. Secondary end points included procedural success, major adverse cardiac events, and individual clinical end points such as stent thrombosis, cardiac death, target lesion myocardial infarction, clinically driven target lesion revascularization, and binary restenosis.

RESULTS

Quantitative coronary angiography revealed no differences in baseline parameters. After 6 months, in-segment late lumen loss was 0.25±0.57 mm in the PCB group versus 0.26±0.60 mm in the SCB group. Mean difference between SCB and PCB was 0.01 (95% CI, -0.23 to 0.24). Noninferiority at a predefined margin of 0.35 was shown. Clinical events up to 12 months did not differ between the groups.

CONCLUSIONS

This first-in man comparison of a novel SCB with a crystalline coating showed similar angiographic and clinical outcomes in the treatment of coronary drug-eluting stent in-stent restenosis compared with PCB.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02996318, NCT03242096.

State-of-the-Art Endovascular Therapies for the Femoropopliteal Segment: Are We There Yet?

Peripheral arterial disease is an increasingly prevalent condition with significant associated morbidity, mortality, and health care expenditure. Endovascular interventions are appropriate for most patients with either ongoing symptoms of intermittent claudication despite lifestyle and medical optimization or chronic limb-threatening ischemia. The femoropopliteal segment is the most common arterial culprit responsible for claudication and the most commonly revascularized segment. Endovascular approaches to revascularization of the femoropopliteal segment are advancing with an evolving landscape of techniques for arterial access, device-based therapies, vessel preparation, and intraprocedural imaging. These advances have been marked by debate and controversy, notably related to the safety of paclitaxel-based devices and necessity of atherectomy. In this review, we provide a critical overview of the current evidence, practice patterns, emerging evidence, and technological advances for endovascular intervention of the femoropopliteal arterial segment.

Major adverse limb events in patients with femoro-popliteal and below-the-knee peripheral arterial disease treated with either sirolimus-coated balloon or standard uncoated balloon angioplasty: a structured protocol summary of the "SirPAD" randomized controlled trial

BACKGROUND

Peripheral arterial disease is a progressive atherosclerotic disease with symptoms ranging from an intermittent claudication to acute critical limb ischemia and amputations. Drug-coated balloons and stents were developed to prevent neo-intimal proliferation and restenosis after percutaneous transluminal angioplasty. Randomized controlled trials showed that drug-coated, notably paclitaxel-coated, devices reduce restenosis, late lumen loss, and the need for target lesion re-vascularization compared with uncoated ones. However, the size of these trials was too small to prove superiority for "hard" clinical outcomes. Moreover, available studies were characterized by too restrictive eligibility criteria. Finally, it remains unclear whether paclitaxel-coated balloons may impair long-term survival. Alternative drug-coated balloons, the so-called limus-based analogs, have been approved for clinical use in patients with peripheral arterial disease. By encapsulating sirolimus in phospholipid drug nanocarriers, they optimize adhesion properties of sirolimus and provide better bioavailability.

METHODS

In this investigator-initiated all-comer open-label phase III randomized controlled trial, we will evaluate whether sirolimus-coated balloon angioplasty is non-inferior and eventually superior, according to a predefined hierarchical analysis, to uncoated balloon angioplasty in adults with infra-inguinal peripheral arterial disease requiring endovascular angioplasty. Key exclusion criteria are pregnancy or breastfeeding, known intolerance or allergy to sirolimus, and participation in a clinical trial during the previous 3 months. The primary efficacy outcome is the composite of two clinically relevant non-subjective "hard" outcomes: unplanned major amputation of the target limb and endovascular or surgical target lesion re-vascularization for critical limb ischemia occurring within 1 year of randomization. The primary safety outcome includes death from all causes.

DISCUSSION

By focusing on clinically relevant outcomes, this study will provide useful information on the efficacy and safety of sirolimus-coated balloon catheters for infra-inguinal peripheral arterial disease in a representative ("all-comer") population of unselected patients. As regulatory agencies had raised safety concerns in patients exposed to paclitaxel-coated devices (versus uncoated ones), collect mortality data up to 5 years after randomization will be collected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04238546.

Treatment of Coronary De Novo Lesions by a Sirolimus- or Paclitaxel-Coated Balloon

OBJECTIVES

The aim of this randomized controlled trial was to investigate a novel sirolimus-coated balloon (SCB) compared with the best investigated paclitaxel-coated balloon (PCB).

BACKGROUND

There is increasing clinical evidence for the treatment of coronary de novo disease using drug-coated balloons. However, it is unclear whether paclitaxel remains the drug of choice or if sirolimus is an alternative, in analogy to drug-eluting stents.

METHODS

Seventy patients with coronary de novo lesions were enrolled in a randomized, multicenter trial to compare a novel SCB (SeQuent SCB, B. Braun Melsungen; 4 μg/mm²) with a PCB (SeQuent Please, B. Braun Melsungen; 3 μg/mm²). The primary endpoint was angiographic late lumen loss (LLL) at 6 months. Secondary endpoints included major adverse cardiovascular events and individual clinical endpoints such as cardiac death, target lesion myocardial infarction, clinically driven target lesion revascularization, and binary restenosis.

RESULTS

Quantitative coronary angiography revealed no differences in baseline parameters. After 6 months, in-segment LLL was 0.01 ± 0.33 mm in the PCB group versus 0.10 ± 0.32 mm in the SCB group. The mean difference between SCB and PCB was 0.08 (95% CI: -0.07 to 0.24). Noninferiority at a predefined margin of 0.35 was shown. However, negative LLL was more frequent in the PCB group (60% of lesions vs 32% in the SCB group; P = 0.019). Major adverse cardiovascular events up to 12 months also did not differ between the groups.

CONCLUSIONS

This first-in-human comparison of a novel SCB with a crystalline coating showed similar angiographic outcomes in the treatment of coronary de novo disease compared with a clinically proven PCB. However, late luminal enlargement was more frequently observed after PCB treatment. (Treatment of Coronary De-Novo Stenosis by a Sirolimus Coated Balloon or a Paclitaxel Coated Balloon Catheter Malaysia [SCBDNMAL]; NCT04017364).

Nanospheres encapsulated everolimus delivery into arterial wall-the tissue pharmacokinetics and vascular response experimental study

OBJECTIVE

This study aimed to evaluate the pharmacokinetic profile and tissue effects of everolimus delivered into arterial wall using biodegradable nanospheres.

BACKGROUND

Delivery of everolimus into the arterial wall is challenging due to its low-lipophilic profile.

METHODS

A pharmacokinetic study included 28 porcine coronary arterial segments initially injured with balloon angioplasty followed by the local delivery of everolimus encapsulated in nanospheres (EEN) via injection through a microporous delivery catheter. The animals were sacrificed at 1 hour, 1,7,28, and 90-day follow-up. In the tissue effects study 16 coronary bare metal stent (BMS) were implanted following EEN delivery, 15 BMS following nanospheres delivery without the drug (reference group) and 16 implanted BMS served as a control. Angiographic and histology follow-up was scheduled at 28 and 90-day.

RESULTS

The study showed high-everolimus concentrations in arterial tissue early after nanoparticles delivery followed by its gradual decrease to 1.15 ± 0.40 ng/mg at 90 days. Histology analysis showed favorable biocompatibility and healing profile with comparable area stenosis between groups at both time-points.

CONCLUSIONS

The present study demonstrates for the first time the safety, biocompatibility, and long-term retention of everolimus in arterial tissue after single local delivery of biodegradable nanospheres.

Drug-coated Balloons for Small Coronary Disease-A Literature Review

PURPOSE OF REVIEW

In the interventional treatment of coronary artery disease, new-generation drug-eluting stents (DES) currently are the standard treatment. In addition, drug-coated balloons (DCB) are a well-established option for the treatment of in-stent restenosis in both bare-metal stents (BMS) and DES, where DCBs deliver an antiproliferative drug without the necessity of re-implanting a stent. Since the field of use for DCB has increasingly been extended to other indications such as de novo lesions in small vessel disease (SVD), a review of literature may be useful.

RECENT FINDINGS

Recent randomized trial data show good efficacy and safety for DCB in de novo lesions, especially in small coronary arteries, and confirm long-term clinical efficacy and safety up to three years. DCB are an attractive and safe option in the treatment of de novo lesions in SVD.

Mid-term clinical outcomes from use of Sirolimus coated balloon in coronary intervention; data from real world population

BACKGROUND

Use of drug coated balloons (DCBs) in coronary intervention is escalating. There is a plethora of data on Paclitaxcel-DCB. However, when it comes of stents, Limus-drugs are preferred over Paclitaxel. There is very limited data on Sirolimus coated balloons (SCB). MagicTouch-SCB (Concept Medical, FL) elutes Sirolimus via nano-technology and have been used in our centers since March 2018. We report a mid-term follow-up with this relatively novel-technology.

METHODS AND RESULTS

We retrospectively analyzed all patients treated with MagicTouch-SCB between March-2018 and February-2019. Results are reported as cardiac-death, target-vessel myocardial-infarction (TVMI), target lesion revascularization (TLR) and Major Adverse Cardiac Events (MACE). During the study period, 288-patients (373-lesions) with a mean age of 65.8 were treated with MagicTouch-SCB. 84% (n = 241) were male, 155 (54%) were in the setting of acute coronary syndrome, 38% (n = 110) had diabetes and 62% (n = 233) were in de-novo lesions. Most lesions treated were in the LAD/diagonal-system (n = 170; 46%). Pre-dilatation was performed in 92% (n = 345) of cases. Bailout stenting was required in 9% lesions (n = 35). The mean diameter and length of SCBs were 2.64 ± 0.56 mm and 24 ± 8.9 mm respectively. During a median follow-up of 363 days (IQR: 278-435), cardiac death and TVMI occurred in 5-patients (1.7%) and 10-patients (3.4%) respectively, TLR per-lesion was 12%. The MACE rate was 10%. There were no documented cases of acute vessel closure.

CONCLUSIONS

The results from mid-term follow-up with this relatively new technology SCB is encouraging with a low rates of hard endpoints and acceptable MACE rates despite complex group of patients and lesion subsets.

Drug delivery to the pediatric upper airway

Pediatric upper airway disorders are frequently life-threatening and require precise assessment and intervention. Targeting these pathologies remains a challenge for clinicians due to the high complexity of pediatric upper airway anatomy and numerous potential etiologies; the most common treatments include systemic delivery of high dose steroids and antibiotics or complex and invasive surgeries. Furthermore, the majority of innovative airway management technologies are only designed and tested for adults, limiting their widespread implementation in the pediatric population. Here, we provide a comprehensive review of the most recent challenges of managing common pediatric upper airway disorders, describe the limitations of current clinical treatments, and elaborate on how to circumvent those limitations via local controlled drug delivery. Furthermore, we propose future advancements in the field of drug-eluting technologies to improve pediatric upper airway management outcomes.

Comparison Between Sirolimus- and Paclitaxel-Coated Balloon for Revascularization of Coronary Arteries: The SIRPAC (SIRolimus-PAClitaxel) Study

OBJECTIVE

Our study sought to compare the 12-month clinical outcome of patients treated with paclitaxel-coated balloons (PCB) vs. sirolimus-coated balloons (SCB) during coronary angioplasty.

BACKGROUND

Drug-coated balloons represent an established therapeutic tool for percutaneous coronary interventions (PCI). A comparison between PCB and SCB is still lacking.

METHODS

We performed an indirect comparison between two cohorts of patients previously included into two investigator-driven registries with clinical primary endpoints, 494 treated with the Elutax SV PCB (AR Baltic, Lithuania) from the DCB RISE registry, and 596 treated with the Magic Touch SCB (Concept Medical, India) from the EASTBOURNE registry. The primary endpoint was the rate of major adverse cardiovascular events (MACE) at 12-month clinical follow-up.

RESULTS

After propensity score matching, a total of 580 patients were well matched for baseline clinical and procedural characteristics and were analyzed. At 12 months there was no significant difference between the matched DCB RISE and EASTBOURNE cohorts in terms of the primary endpoint MACE (10.3% DCB RISE vs. 10.7% EASTBOURNE, p = 0.892). No significant difference was observed also regarding the rate of TLR (7.9% DCB RISE vs. 8.3% EASTBOURNE; p = 0.879, respectively). By multivariate analysis, insulin-dependent diabetes was the only predictor of MACE.

CONCLUSIONS

In the SIRPAC study, the first indirect comparison between paclitaxel-coated and sirolimus coated balloons, no significant difference in clinical endpoints were found at 12-month follow-up. Randomized studies are necessary to confirm these findings.

Paclitaxel- and Sirolimus-coated Balloons in Peripheral Artery Disease Treatment: Current Perspectives and Concerns

Drug-coated balloons (DCBs) have become an established therapy for the treatment of above-the-knee peripheral artery disease. The paclitaxel DCB has shown clinical benefit in terms of patency and freedom from re-intervention in multiple randomised trials. However, a recent meta-analysis has suggested an association between mortality and the use of paclitaxel-coated devices. Sirolimus is another potential choice of anti-proliferative agent for use in DCBs because of its wider therapeutic index and lower risk for dose-dependent toxicity. More recently, encapsulating sirolimus in micro-reservoirs or polymers has facilitated the development of effective sirolimus DCBs, some of which are available in Europe and Asia. In this review, the authors focus on paclitaxel and sirolimus DCB technologies from the standpoint of drug characteristics and clinical trials.

Single-Center Prospective Pilot Study of Sirolimus Drug-Coated Balloon Angioplasty in Maintaining the Patency of Thrombosed Arteriovenous Graft

PURPOSE

To investigate the use of a sirolimus drug-coated balloon (DCB) in the management of a thrombosed arteriovenous graft (AVG).

MATERIALS AND METHODS

A single-center prospective pilot study was conducted between October 2018 and October 2019. Twenty patients (age = 67.0 years ± 10; male = 35%; mean time on dialysis = 31 months) with thrombosed upper limb AVG were enrolled. After successful pharmacomechanical thrombectomy and adequate treatment of the graft vein junction, sirolimus DCB angioplasty was performed at the graft vein junction. The patients were followed-up for 6 months, and all adverse events occurring during the study period were recorded.

RESULTS

The primary circuit patency rates at 3 and 6 months were 76% and 65%, respectively, while the assisted-primary circuit patency rates at 3 and 6 months were 82% and 65%, respectively. The 3- and 6-month secondary circuit patency rates were 88% and 76%, respectively. Using Kaplan-Meier analyses, the estimated mean primary, assisted-primary, and secondary patencies were 285 days (95% confidence interval (CI) = 194-376 days), 319 days (95% CI = 221-416 days), and 409 days (95% CI = 333-485 days). No adverse event directly related to sirolimus DCB use was observed.

CONCLUSIONS

The results of this pilot study suggest that the application of sirolimus DCB at the graft vein junction after the successful thrombectomy of AVG may be a feasible option to improve patency outcomes.

A Prospective Multicenter Randomized Trial to Assess the Effectiveness of the MagicTouch Sirolimus-Coated Balloon in Small Vessels: Rationale and Design of the TRANSFORM I Trial

AIMS

The objective of the study is to assess the efficacy and safety of the novel Magic Touch sirolimus coated-balloon (SCB) when compared to the SeQuent Please Neo paclitaxel coated balloon (PCB) for the treatment of de-novo small vessel coronary artery diseases (SVD).

STUDY DESIGN

The TRANSFORM I study is a randomized, multicenter, non-inferiority trial with the intent to enroll a total of 114 patients with a de-novo SVD (≤2.5 mm). Vessel size will be pre-screened by on-line QCA. After successful pre-dilatation without major coronary dissections (type C-F) nor Thrombolysis In Myocardial Infarction trial [TIMI] grade flow ≤2, patients will be enrolled in a 1:1 randomization to receive treatment with either the novel SCB balloon or the comparative PCB balloon. The balloon sizing will be selected according to the lumen-based approach derived from optical coherence tomography (OCT). The primary endpoint is 6-month mean net lumen diameter gain (6-month minimum lumen diameter [MLD] minus baseline MLD) assessed by quantitative coronary analysis (QCA) with non-inferiority margin of 0.3 mm in per-protocol analysis. The clinical follow-up will be conducted up to 1 year. The enrollment started in September 2020 and will complete in April 2021.

CONCLUSIONS

The TRANSFORM I trial will assess the efficacy of novel SCB in terms of non-inferiority to conventional PCB with a novel OCT measurement approach in patients with a de-novo SVD. Clinical Trial Registration URL: https://clinicaltrials.gov. Unique identifier: NCT03913832.

Early (6 months) results of a pilot prospective study to investigate the efficacy and safety of sirolimus coated balloon angioplasty for dysfunctional arterio-venous fistulas: MAgicTouch Intervention Leap for Dialysis Access (MATILDA) Trial

Background

The aim of this pilot study was to evaluate the safety and efficacy of the MagicTouch™ sirolimus-coated balloon (SCB) catheter (Concept Medical Inc., Tampa, FL, US) on improving the patency of failing arterio-venous fistulas (AVF) with de novo and recurrent stenoses. MATILDA reports early outcomes at 3- and 6 months post intervention.

Methods

Single-centre, single-arm prospective pilot study of 33 (18 males; mean age 64.7±11.6 years) end-stage renal failure Asian patients with a dysfunctional AVF, who underwent SCB angioplasty between May 2019-January 2020. All procedures were performed under local anaesthetic without sedation and as day surgery. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 3 and 6 months.

Results

47 stenotic target lesions treated and 24/33 (72.7%) patients were for restenosis. Main indications for intervention was low/dropping access flow (21/33; 63.6%) and most common target lesion was in the juxta-anastomosis (19/47; 40.4%). There was 100% technical and procedural success. There were no peri-procedural complications related to the SCB. The target lesion primary patency rates at 3 and 6 months were 46/47 (97.9%) and 29/35 (82.9%) respectively. Circuit access patency rates at 3 and 6 months were 31/33 (93.9%) and 17/25 (68%) respectively. There was one (2.9%) death at 6 months and 4/33 (12.1%) overall to date, all from patients’ underlying co-morbidities.

Conclusions

SCB angioplasty for dysfunctional AVF circuits is a safe and efficacious modality in Asian haemodialysis patients at six months comparable if not better than the paclitaxel data reported to date in the literature.

Sirolimus-Eluting Balloon for the Treatment of Coronary Lesions in Complex ACS Patients: The SELFIE Registry

Background

Sirolimus-coated balloons (SCBs) represent a novel therapeutic option for both in-stent restenosis (ISR) and de novo coronary lesions treatment, especially in small vessels. Our registry sought to evaluate the procedural and clinical outcomes of such devices in a complex acute coronary syndrome (ACS) clinical setting.

Methods and Results

We treated 74 consecutive patients with percutaneous coronary intervention (PCI) with at least 1 SCB used for ISR and/or de novo coronary lesion in small vessels at our institution. Sixty-two patients presented with ACS, and their data were included in our analysis. The mean age was 67 ± 10 years, and patients presenting with ST-elevated myocardial infarction (STEMI) were 14 (23%). De novo lesions were 52%, whereas ISR was 48%. Procedural success occurred in 100% of the cases. At the 11 ± 7 months follow-up, major adverse cardiovascular events (MACEs) were 3 (4.8%). Cardiovascular death (CD) occurred in 1 (1.6%) patient and myocardial infarction (MI) in 2 patients (3.2%) as well as ischemia-driven target lesion revascularization (TLR). One probable subacute thrombosis occurred (1.6%) with no major bleedings. In a subgroup analysis, the incidence of MACE did not show significant differences between patients treated for de novo lesions and ISR (HR: 0.239; CI 95%: 0.003–16.761, p=0.509).

Conclusions

In the SELFIE prospective registry, SCB showed a good safety and efficacy profile for the treatment of coronary lesions, both ISR and/or de novo in small vessels, in a complex ACS population of patients at the 11 ± 7 months follow-up.

Drug-coated balloons: Technical and clinical progress

The advancement of drug-coated balloons (DCB) presents an alternative nonstent method in the percutaneous treatment of atherosclerotic lesions. While the current generation of drug-eluting stents (DES) are the device of choice, especially in coronary artery disease (CAD), DCB has potential applications in the treatment of de novo lesions, in-stent restenosis (ISR), bifurcations, and in peripheral artery disease (PAD). In terms of coronary clinical experience, DCB is used most in ISR scenarios and more data are collected to support the use of DCB in de novo lesions compared to best-in-class DES. The use of DCB in bifurcation side branch treatment has demonstrated safety, and with good angiographic and clinical outcomes, but more data from randomized trials will be required to assess its clinical value. For PAD, the clinical outcomes of DCB with and without debulking devices in diseased femoropopliteal arteries and treatment of below-the-knee (BTK) vessels with DCB are discussed. Current data demonstrated conflicting long-term safety outcomes in the use of paclitaxel devices in the femoral and/or popliteal arteries, while the role of DCB in BTK disease remains uncertain due to a lack of randomized controlled trial data. In summary, this review provides an overall view of current DCB technologies and progress, followed by an update on DCB clinical data in the treatment of CAD and PAD.

Treatment of Coronary Drug-Eluting Stent Restenosis by a Sirolimus- or Paclitaxel-Coated Balloon

OBJECTIVES

The aim of this randomized controlled trial was to investigate a novel sirolimus-coated balloon (SCB) compared with the best investigated paclitaxel-coated balloon (PCB).

BACKGROUND

Treatment of coronary in-stent restenosis (ISR) remains challenging. PCBs are an established treatment option outside the United States with a Class I, Level of Evidence: A recommendation in the European guidelines. However, their efficacy is better in bare-metal stent (BMS) ISR compared with drug-eluting stent (DES) ISR.

METHODS

Fifty patients with DES ISR were enrolled in a randomized, multicenter trial to compare a novel SCB (SeQuent SCB, 4 μg/mm²) with a clinically proven PCB (SeQuent Please Neo, 3 μg/mm²) in coronary DES ISR. The primary endpoint was angiographic late lumen loss at 6 months. Secondary endpoints included procedural success, major adverse cardiovascular events, and individual clinical endpoints such as stent thrombosis, cardiac death, target lesion myocardial infarction, clinically driven target lesion revascularization, and binary restenosis.

RESULTS

Quantitative coronary angiography revealed no differences in baseline parameters. After 6 months, in-segment late lumen loss was 0.21 ± 0.54 mm in the PCB group versus 0.17 ± 0.55 mm in the SCB group (p = NS; per-protocol analysis). Clinical events up to 12 months also did not differ between the groups.

CONCLUSIONS

This first-in-man comparison of a novel SCB with a crystalline coating shows similar angiographic outcomes in the treatment of coronary DES ISR compared with a clinically proven PCB. (Treatment of Coronary In-Stent Restenosis by a Sirolimus [Rapamycin] Coated Balloon or a Paclitaxel Coated Balloon [FIM LIMUS DCB]; NCT02996318).

Angiographic performance of a novel sirolimus-coated balloon in native coronary lesions: the FAtebenefratelli SIrolimus COated NATIVES prospective registry

AIMS

To evaluate the angiographic performance of a novel sirolimus-coated balloon (SCB) in de novo coronary lesions.

METHODS

Out of an all-comer prospective registry of patients treated with the SCB at our center from April 2016 to September 2017, we selected those treated for a de novo stenosis on a native vessel, with a scheduled angiographic control at at least 4 months after the index procedure. We performed a centralized, blinded core-lab adjudicated quantitative coronary angiography analysis. Primary endpoint was late lumen loss. Secondary endpoints were binary restenosis and target-lesion revascularization.

RESULTS

A total of 27 patients with native coronary arteries treated with SCB and with angiographic follow-up entered the study; seven patients were excluded because a stent was implanted at the lesion site during the index procedure. The degree of calcification (assessed with coronary angiography) was high in six patients (30%) and the average lesion length was 20.52 ± 6.88 mm. The reference vessel diameter was 2.32 ± 0.44 mm and the percentage diameter stenosis was 67 ± 12. Procedural success was obtained in all patients. After a median of 6.6 ± 2.5 months, late lumen loss was 0.09 ± 0.34 mm and the percentage diameter stenosis was 31 ± 18. We observed two cases (10%) of binary restenosis which underwent subsequent target-lesion revascularization: in one a drug-eluting stent was implanted, whereas the other patient was treated with paclitaxel-coated balloon. No myocardial infarction or death was observed during follow-up.

CONCLUSION

The use of a novel SCB in native coronary arteries was associated with good angiographic outcome at 6-month follow-up.

Drug-coated Balloons for Small Coronary Vessel Interventions: A Literature Review

Newer-generation drug-eluting stents (DES) are the standard of care for the treatment of symptomatic coronary artery disease. However, some lack of efficacy has been reported in small coronary arteries based on higher rates of target lesion restenosis, thrombosis and MI resulting in repeated interventions. Drug-coated balloons (DCBs) are an established treatment option for in-stent restenosis in both bare metal stents and DES and they can deliver an anti-proliferative drug into the vessel wall without implanting a stent. DCBs are a promising technique for selected de novo coronary lesions, especially in small vessel disease. In this article, the current evidence for the treatment of small vessel disease with DCBs will be reviewed.

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.

Nanoparticle eluting-angioplasty balloons to treat cardiovascular diseases

Nanoparticles (NPs) can be used to locally deliver anti-restenosis drugs when they are infused directly to the injured arteries after intervention procedures such as angioplasty. However, the efficacy of transferring NPs via infusion to the arterial wall is limited, at least partially, due to poor NP retention on the inner artery wall. To improve NP retention, angioplasty balloons coated with drug-loaded NPs were fabricated via either layer-by-layer (LbL) electrostatic coating or acrylic-based hydrogel (AAH) coating techniques. Three types of NPs, namely poly (lactide-co-glycolide) (PLGA), biodegradable photo-luminescent PLGA and urethane doped polyester were studied. The transfer efficacy of NPs from various coatings to the arterial wall were further evaluated to find the optimal coating conditions. The ex vivo NP transfer studies showed significantly more NPs being transferred to the rat arterial wall after the angioplasty procedure by the AAH coating (95% transfer efficiency) compared to that of the LbL technique (60%) and dip coating (20%) under flow conditions (10 dyn/cm²). Our results suggest that the AAH coating of drug-loaded NPs on the angioplasty balloon could potentially provide superior retention of drug-loaded NPs onto the arterial wall for a better local delivery of drug-loaded NPs to effectively treat arterial diseases.

Nanoparticles for Detection and Treatment of Peripheral Arterial Disease

Peripheral arterial disease (PAD) is defined as a slow, progressive disorder of the lower extremity arterial vessels characterized by chronic narrowing that often results in occlusion and is associated with loss of functional capacity. Although the PAD occurrence rate is increasing in the elderly population, outcomes with current treatment strategies are suboptimal. Hence, there is an urgent need to develop new technologies that overcome limitations of traditional modalities for PAD detection and therapy. In this Review, the application of nanotechnology as a tool that bridges the gap in PAD diagnosis and therapy is in focus. Several materials including synthetic, natural, biodegradable, and biocompatible materials are used to develop nanoparticles for PAD diagnostic and/or therapeutic applications. Moreover, various recent research approaches are being explored to diagnose PAD through multimodality imaging with different nanoplatforms. Further efforts include targeted delivery of various therapeutic agents using nanostructures as carriers to treat PAD. Last, but not least, despite being a fairly new field, researchers are exploring the use of nanotheranostics for PAD detection and therapy.

The SABRE Trial (Sirolimus Angioplasty Balloon for Coronary In-Stent Restenosis): Angiographic Results and 1-Year Clinical Outcomes

OBJECTIVES

The aim of this first-in-human study was to assess the safety and effectiveness of the Virtue sirolimus-eluting balloon in a cohort of patients with in-stent restenosis (ISR).

BACKGROUND

Angioplasty balloons coated with the cytotoxic drug paclitaxel have been widely used for ISR treatment. The Virtue angioplasty balloon (Caliber Therapeutics, New Hope, Pennsylvania) delivers sirolimus in a nanoencapsulated liquid formulation. This clinical trial is the first to examine a sirolimus-eluting balloon for ISR.

METHODS

In this prospective, single-arm feasibility study at 9 European centers, 50 ISR patients were treated with the Virtue balloon. Angiographic measurements at 6 months are reported, along with 12-month clinical follow-up.

RESULTS

Procedural success in the intention-to-treat population was 100%. The primary safety endpoint was target lesion failure (TLF) (cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization) assessed at 30 days (0%, n = 50). The primary performance endpoint was in-segment late lumen loss (LLL) at 6 months (0.31 ± 0.52 mm; n = 47). Secondary 6-month endpoints include binary restenosis (19.1%), diameter stenosis (30.3 ± 19.9%), and major adverse cardiac events (MACE) (10.2%, n = 49). In the 36-patient per-protocol population (excluding major protocol violations and previously stented ISR), LLL was 0.12 ± 0.33 mm at 6 months. Clinical outcomes at 1 year for the intention-to-treat group were 12.2% TLF and 14.3% MACE and for the per-protocol population were 2.8% TLF and 2.8% MACE.

CONCLUSIONS

This first-in-human study showed excellent procedural success for the Virtue sirolimus-eluting angioplasty balloon, 6-month LLL rates in line with current stent-free ISR treatment options, and clinical outcomes that warrant further evaluation in dedicated randomized studies.

In vivo delivery and long-term tissue retention of nano-encapsulated sirolimus using a novel porous balloon angioplasty system

AIMS

Among antirestenotic compounds, sirolimus displays a superior safety profile compared to paclitaxel, but its pharmacokinetic properties make it a challenging therapeutic candidate for single-time delivery. Herein we evaluate the feasibility of delivery, long-term retention and vascular effects of sirolimus nanoparticles delivered through a novel porous angioplasty balloon in normal porcine arteries and in a swine model of in-stent restenosis (ISR).

METHODS AND RESULTS

Sirolimus nanoparticle formulation was delivered via porous balloon angioplasty to 753 coronary artery segments for pharmacokinetic studies and 26 segments for biological effect of sirolimus delivery in different clinical scenarios (de novo [n=8], ISR [n=6] and following stent implantation [n=12]). Sirolimus coronary artery concentrations were above the target therapeutic level of 1 ng/mg after 26 days, and were >100-fold higher in coronary artery treatment sites than in distal myocardium and remote tissues at all time points. At 28 days, reduction in percent stenosis in formulation-treated sites compared to balloon angioplasty treatment was noted in all three clinical scenarios, with the largest effect seen in the de novo study.

CONCLUSIONS

Local coronary delivery of sirolimus nanoparticles in the porcine model using a novel porous balloon delivery system achieved therapeutic long-term intra-arterial drug levels without significant systemic residual exposure.