Drug-Coated Balloons for the Prevention of Vascular Restenosis

Targeted NAD+ repletion via biomimetic nanoparticle enables simultaneous management of intimal hyperplasia and accelerated re-endothelialization: A proof-of-concept study toward next-generation of endothelium-protective, anti-restenotic therapy

Endovascular interventions often fail due to restenosis, primarily caused by smooth muscle cell (SMC) proliferation, leading to intimal hyperplasia (IH). Current strategies to prevent restenosis are far from perfect and impose significant collateral damage on the fragile endothelial cell (EC), causing profound thrombotic risks. Nicotinamide adenine dinucleotide (NAD+) is a co-enzyme and signaling substrate implicated in redox and metabolic homeostasis, with a pleiotropic role in protecting against cardiovascular diseases. However, a functional link between NAD+ repletion and the delicate duo of IH and EC regeneration has yet to be established. NAD+ repletion has been historically challenging due to its poor cellular uptake and low bioavailability. We have recently invented the first nanocarrier that enables direct intracellular delivery of NAD+ in vivo. Combining the merits of this prototypic NAD+-loaded calcium phosphate (CaP) nanoparticle (NP) and biomimetic surface functionalization, we created a biomimetic P-NAD+-NP with platelet membrane coating, which enabled an injectable modality that targets IH with excellent biocompatibility. Using human cell primary culture, we demonstrated the benefits of NP-assisted NAD+ repletion in selectively inhibiting the excessive proliferation of aortic SMC, while differentially protecting aortic EC from apoptosis. Moreover, in a rat balloon angioplasty model, a single-dose treatment with intravenously injected P-NAD+-NP immediately post angioplasty not only mitigated IH, but also accelerated the regeneration of EC (re-endothelialization) in vivo in comparison to control groups (i.e., saline, free NAD+ solution, empty CaP-NP). Collectively, our current study provides proof-of-concept evidence supporting the role of targeted NAD+ repletion nanotherapy in managing restenosis and improving reendothelialization.

Potential of dapagliflozin to prevent vascular remodeling in the rat carotid artery following balloon injury

BACKGROUND AND AIMS

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to reduce the risk of cardiovascular events independently of glycemic control. However, the possibility that SGLT2 inhibitors improve vascular restenosis is unknown. The aim of this study was to examine whether dapagliflozin could prevent neointima thickening following balloon injury and, if so, to determine the underlying mechanisms.

METHODS

Saline, dapagliflozin (1.5 mg/kg/day), or losartan (30 mg/kg/day) was administered orally for five weeks to male Wistar rats. Balloon injury of the left carotid artery was performed a week after starting the treatment and rats were sacrificed 4 weeks later. The extent of neointima was assessed by histomorphometric and immunofluorescence staining analyses. Vascular reactivity was assessed on injured and non-injured carotid artery rings, changes of target factors by immunofluorescence, RT-qPCR, and histochemistry.

RESULTS

Dapagliflozin and losartan treatments reduced neointima thickening by 32 % and 27 %, respectively. Blunted contractile responses to phenylephrine and relaxations to acetylcholine and down-regulation of eNOS were observed in the injured arteries. RT-qPCR investigations indicated an increased in gene expression of inflammatory (IL-1beta, VCAM-1), oxidative (p47phox, p22phox) and fibrotic (TGF-beta1) markers in the injured carotid. While these changes were not affected by dapagliflozin, increased levels of AT1R and NTPDase1 (CD39) and decreased levels of ENPP1 were observed in the restenotic carotid artery of the dapagliflozin group.

CONCLUSIONS

Dapagliflozin effectively reduced neointimal thickening. The present data suggest that dapagliflozin prevents restenosis through interfering with angiotensin and/or extracellular nucleotides signaling. SGLT2 represents potential new target for limiting vascular restenosis.

Comparative evaluation of local and downstream responses in two commercially available paclitaxel-coated balloons in healthy peripheral arteries of a swine model

OBJECTIVE

To investigate the local, downstream, and systemic effects of 2 different paclitaxel-coated balloons.

DESIGN

Preclinical study in healthy peripheral arteries of a swine model, with randomized allocation of the distribution of the devices: the test paclitaxel-coated balloon (PCB) (LuminorⓇ), a control PCB (IN.PACTⓇ), and a plain angioplasty balloon (OceanusⓇ), considering single (1×) and overlapping (3×) doses with simple blind histologic analysis.

METHODS

Twenty animals underwent balloon angioplasty at 1× or 3× doses in the external and internal branches of both femoral arteries and were followed-up for 28 days. Postprocedural and follow-up angiography were carried out. Comprehensive necropsy and histology were used to evaluate the local, downstream and systemic effects.

RESULTS

Angioplasty was successfully carried out in all animals. Significant protocol deviations appeared in 3 arteries (treated with Oceanus®) without clinical relevance. Those samples were excluded from the analysis. All the animals survived the follow-up period without major clinical issues. Local signs of drug toxicity were less marked with Luminor® than IN.PACT® at 1× dose, including endothelial loss (P = .0828), intima/media inflammation (P = .0004), transmural medial smooth muscle cell (SMC) loss (P = .0016), wall thickness loss (P = .0141), presence of fibrin in the vascular wall (P = .0054), and adventitial inflammation (P = .0080). A similar pattern was observed at the 3× dose for endothelial loss (P = .0011), intima/media inflammation (P < .0001), circumferential SMC loss (P = .0004), medial SMC replacement with proteoglycans (P = .0014), fibrin (P = .0034), and collagen content (P = .0205). Downstream vascular histologic changes were mild although more prevalent in the IN.PACT® 3× group (P = .006). No systemic effects of toxicity were detected in any of the samples analyzed.

CONCLUSION

Luminor® showed better healing pattern (lower inflammation, and endothelial and muscular loss) than IN.PACT® balloon. The effect was evident at single and triple doses. The prevalence of downstream lesions, albeit low, was higher with the triple dose of IN.PACT® compared with Luminor®.

Benefits and Challenges of Drug-Coated Balloons in Peripheral Artery Disease: From Molecular Mechanisms to Clinical Practice

Multiple clinical trials have reported favorable outcomes after drug-coated balloon therapy for peripheral artery disease in above-the-knee and below-the-knee lesions and in both de novo and in-stent restenosis. However, there are still insufficient data to identify and tackle the risk factors associated with a higher risk of restenosis, which is the primary concern for patients who are treated with an endovascular approach. A modern armamentarium, which includes improved lesion preparation techniques such as plaque modification balloons, mechanical atherectomy, intravascular lithotripsy, and imaging, is crucial for obtaining better long-term clinical outcomes. Moreover, a better understanding of the molecular properties of drug-coated balloons has led to improved devices that could tackle the shortcomings of previous generations. This comprehensive review focuses on drug-coated balloon technology as a tool to treat peripheral artery disease and the effects of the molecular mechanisms involved in preventing vascular restenosis.

Safety and efficacy of single antiplatelet therapy in a large cohort of patients treated with sirolimus-coated balloon: Post hoc analysis from the prospective EASTBOURNE registry

BACKGROUND

Drug coated balloons (DCB) are potentially less thrombogenic than drug eluting stents (DES).

AIMS

To explore the safety and the feasibility of single antiplatelet therapy in percutaneous coronary intervention with sirolimus-coated balloons.

METHODS

The All-comers Sirolimus-coated Balloon European Registry (EASTBOURNE) is a prospective investigator-driven registry assessing the performance of a novel sirolimus-coated balloon (SCB) in a real-world population. This prespecified post hoc analysis aimed at comparing the outcome in patients prescribed either single antiplatelet therapy (SAPT) or dual antiplatelet therapy (DAPT); choice of antiplatelet agent and duration of the regimen were at operator's discretion in both groups. Primary endpoint was target lesion revascularization (TLR) at 12 months. Secondary endpoints were bleeding grade 3-5 according to The Bleeding Academic Research Consortium (BARC) criteria and major adverse cardiovascular events (MACE) at 12 months follow-up.

RESULTS

Among 2123 patients enrolled in the study between September 2016 and November 2020, 113 patients (5.8 %) received SAPT while 1826 patients (94.1 %) received DAPT after SCB. The majority of the patients underwent DCB PCI for de novo lesions (n = 1091, 56.3 %) while 848 patients (47.7 %) had DCB revascularization for in-stent restenosis. No cases of TLR occurred in the SAPT group within one month after the index procedure, and no acute occlusive events were recorded during follow up in patients taking a single antiplatelet agent. Moreover, no differences in terms of TLR were observed between SAPT vs DAPT regimens nor in case of de novo treatment with an overall rate of TLR at 12 months of 7.7 % for SAPT and 5.6 % for DAPT (p = 0.6). The cumulative rate of MACE at 12 months was not different between SAPT and DAPT regimens (n = 12 [11.2 %] vs. n = 162 [8.9 %], p = 0.4), and results were consistent in the de novo and in-stent restenosis groups.

CONCLUSIONS

Our post hoc analysis of the EASTBOURNE registry suggests that the use of single antiplatelet agent after sirolimus-DCB PCI for both de novo or in-stent restenosis lesions is safe and effective and can help to contain the risk of bleeding in a selected population.

CONDENSED ABSTRACT

The manuscript aims to explore the feasibility of a single antiplatelet regimen following angioplasty using drug coated balloon with sirolimus. Among 2123 patients treated with sirolimus coated balloon (SCB), 113 patients (5.8 %) received a single antiplatelet therapy (SAPT) while 1826 patients (94.1 %) received dual antiplatelet therapy DAPT. No cases of target lesion revascularization occurred in the SAPT group within one month after the index procedure, and no acute occlusive events were recorded during follow up in patients taking a single antiplatelet agent. The cumulative rate of major adverse cardiovascular events at 12 months was not different between SAPT and DAPT regimens and results were consistent in the de novo and in-stent restenosis groups.

Drug-coated balloon angioplasty with provisional stenting versus primary stenting for the treatment of de novo coronary artery lesions: REC-CAGEFREE I trial rationale and design

BACKGROUND

Percutaneous coronary intervention (PCI) with primary stenting, which stands for stent implantation regardless of obtaining satisfactory results with balloon angioplasty, has superseded conventional plain old balloon angioplasty with provisional stenting. With drug-coated balloon (DCB), primary DCB angioplasty with provisional stenting has shown non-inferiority to primary stenting for de novo coronary small vessel disease. However, the long-term efficacy and safety of such a strategy to the primary stenting on clinical endpoints in de novo lesions without vessel diameter restrictions remain uncertain.

STUDY DESIGN

The REC-CAGEFREE I is an investigator-initiated, multicenter, randomized, open-label trial aimed to enroll 2270 patients with acute or chronic coronary syndrome from 43 interventional cardiology centers in China to evaluate the non-inferiority of primary paclitaxel-coated balloons angioplasty to primary stenting for the treatment of de novo, non-complex lesions without vessel diameter restrictions. Patients who fulfill all the inclusion and exclusion criteria and have achieved a successful lesion pre-dilatation will be randomly assigned to the two arms in a 1:1 ratio. Protocol-guided DCB angioplasty and bailout stenting after unsatisfactory angioplasty are mandatory in the primary DCB angioplasty group. The second-generation sirolimus-eluting stent will be used as a bailout stent in the primary DCB angioplasty group and the treatment device in the primary stenting group. The primary endpoint is the incidence of Device-oriented Composite Endpoint (DoCE) within 24 months after randomization, including cardiac death, target vessel myocardial infarction, and clinically and physiologically indicated target lesion revascularization.

DISCUSSION

The ongoing REC-CAGEFREE I trial is the first randomized trial with a clinical endpoint to assess the efficacy and safety of primary DCB angioplasty for the treatment of de novo, non-complex lesions without vessel diameter restrictions. If non-inferiority is shown, PCI with primary DCB angioplasty could be an alternative treatment option to primary stenting.

TRIAL REGISTRATION

Registered on clinicaltrial.gov (NCT04561739).

Hydrophilic Coating Microstructure Mediates Acute Drug Transfer in Drug-Coated Balloon Therapy

Drug-coated balloon (DCB) therapy is a promising endovascular treatment for obstructive arterial disease. The goal of DCB therapy is restoration of lumen patency in a stenotic vessel, whereby balloon deployment both mechanically compresses the offending lesion and locally delivers an antiproliferative drug, most commonly paclitaxel (PTX) or derivative compounds, to the arterial wall. Favorable long-term outcomes of DCB therapy thus require predictable and adequate PTX delivery, a process facilitated by coating excipients that promotes rapid drug transfer during the inflation period. While a variety of excipients have been considered in DCB design, there is a lack of understanding about the coating-specific biophysical determinants of essential device function, namely, acute drug transfer. We consider two hydrophilic excipients for PTX delivery, urea (UR) and poly(ethylene glycol) (PEG), and examine how compositional and preparational variables in the balloon surface spray-coating process impact resultant coating microstructure and in turn acute PTX transfer to the arterial wall. Specifically, we use scanning electron image analyses to quantify how coating microstructure is altered by excipient solid content and balloon-to-nozzle spray distance during the coating procedure and correlate obtained microstructural descriptors of coating aggregation to the efficiency of acute PTX transfer in a one-dimensional ex vivo model of DCB deployment. Experimental results suggest that despite the qualitatively different coating surface microstructures and apparent PTX transfer mechanisms exhibited with these excipients, the drug delivery efficiency is generally enhanced by coating aggregation on the balloon surface. We illustrate this microstructure-function relation with a finite element-based computational model of DCB deployment, which along with our experimental findings suggests a general design principle to increase drug delivery efficiency across a broad range of DCB designs.

A Comparison of 2 Paclitaxel-Coated Balloon Systems in Treatment of De Novo Coronary Artery Lesions

Background

In percutaneous coronary intervention (PCI) of de novo lesions, drug-coated balloons (DCB) have been shown to be a promising strategy to improve clinical outcomes of patients with small vessel disease. Evidence of this strategy in PCI of de novo coronary lesions in a real-world setting is limited. The objective of this study was to compare the 12-month outcomes of 2 paclitaxel-coated balloon systems for the treatment of all de novo coronary artery lesions.

Methods

All patients who were treated for de novo coronary artery stenosis with either SeQuent Please or In.Pact Falcon DCB at a single center from January 2014 to December 2018 were included. The primary end point was the composite of cardiac death, nonfatal myocardial infarction, and target vessel revascularization (3-point major adverse cardiovascular events) at 12 months.

Results

A total of 496 patients with 623 lesions, of which 144 were treated with SeQuent Please and 352 were treated with In.Pact Falcon were included in the study. Baseline patient, lesion and procedural characteristics at baseline were similar between groups. At 12-month follow-up, 3-point major adverse cardiovascular event outcomes were similar (4.2% vs 2.3% respectively; P = .272). Deaths due to cardiovascular events were few and similar between groups (2.7% vs 1.1% respectively; P = .20).

Conclusions

Both paclitaxel DCB systems have similar efficacy and safety outcomes, suggesting that both may be an appropriate treatment choice for patients with de novo lesions. However, a larger randomized controlled study is needed to confirm these findings.

Drug-Coated Balloon Angioplasty for Carotid Artery In-Stent Restenosis: Case Series

OBJECTIVES

Few case reports have demonstrated promising results of drug-coated balloons (DCBs) as an emerging management for carotid artery in-stent restenosis (CAISR). Herein, we report 6 cases of CAISR which were treated with a DCB with or without new stent deployment.

BACKGROUND

Carotid artery in-stent restenosis is a high-risk condition with an estimated incidence rate that varies widely from 6% to 40%. Several strategies are available now for the management of the CAISR including conventional balloon angioplasty, plaque modification balloon angioplasty, and new stent placement.

METHODS

A retrospective review of consecutive patients with a diagnosis of severe CAISR at Baylor Scott & White The Heart Hospital Plano from 2011 to 2021 was performed. This study was approved by the Baylor Scott & White Research Institute institutional review board.

RESULTS

Six patients underwent DCB angioplasty with or without stent placement under an embolic protection device. Resolution of CAISR was achieved in all cases with 0% to 10% residual stenosis in all cases. Following the procedure, 1 patient had a brief episode of syncope with balloon inflation with immediate recovery on deflation of the balloon. There were otherwise no significant neurological or cardiac events prior to discharge. All patients were asymptomatic at their follow-up visit with no neurological or cardiac events reported at 12, 24, and 36 months following the procedure.

CONCLUSION

While CAISR treatment remains a challenging condition, our study shows that the use of DCB with or without stent placement is a feasible and promising treatment option when compared with other conventional treatment options.

CLINICAL IMPACT

Carotid artery in-stent restenosis treatment remains a challenging condition. Our study shows that the use of drug coated balloon with or without stent placement is a feasible and promising treatment option when compared with current conventional treatment options.

Treatment of coronary lesions with a novel crystalline sirolimus-coated balloon

Background

There is mounting data supporting the use of drug-coated balloons (DCB) not only for treatment of in-stent restenosis (ISR), but also in native coronary artery disease. So far, paclitaxel-coated balloons represented the mainstay DCBs. The SeQuent® crystalline sirolimus-coated balloon (SCB) (B.Braun Medical Inc, Germany) represents a novel DCB, which allows a sustained release of the limus-drug. We evaluated its performance in an all-comer cohort, including complex coronary lesions.

Methods

Consecutive patients treated with the SeQuent® SCB were analyzed from the prospective SIROOP registry (NCT04988685). We assessed clinical outcomes, including major adverse cardiovascular events (MACE), target lesion revascularization (TLR), target vessel myocardial infarction (TV-MI) and cardiovascular death. Angiograms and outcomes were independently adjudicated.

Results

From March 2021 to March 2023, we enrolled 126 patients and lesions, of which 100 (79%) treated using a "DCB-only" strategy and 26 (21%) with a hybrid approach (DES + DCB). The mean age was 68 ± 10 years, 48 (38%) patients had an acute coronary syndrome. Regarding lesion characteristics, ISR was treated in 27 (21%), 11 (9%) underwent CTO-PCI and 59 (47%) of the vessels were moderate to severe calcified. Procedural success rate was 100%. At a median follow-up time of 12.7 (IQR 12; 14.2) months, MACE occurred in 5 patients (4.3%). No acute vessel closure was observed.

Conclusions

Our data indicates promising outcomes following treatment with this novel crystalline SCB in an all-comer cohort with complex coronary lesions. These results require further investigation with randomized trials.

Pathogenetic mechanisms of repeated adverse cardiovascular events development in patients with coronary heart disease: the role of chronic inflammation

Stent restenosis is the most unfavorable complication of interventional treatment for coronary heart disease. We already know from various literature sources that the causes for stent restenosis in patients are both mechanical damage (partial opening, stent breakage, extended stented area, calcification, incomplete stent coverage of atherosclerotic plaque, weak radial stiffness of the stent metal frame, lack of stent drug coating), and the neointimal hyperplasia formation which is closely related to the de novo atherosclerosis development, being a predictor of the recurrent cardiovascular event.

Prevention of in-stent restenosis with drug-eluting balloons in patients with postirradiated carotid stenosis accepting percutaneous angioplasty and stenting

OBJECTIVE

To investigate the technical safety and outcome of in-stent restenosis (ISR) prevention with drug-eluting balloon (DEB) in patients with postirradiated carotid stenosis (PIRCS) undergoing percutaneous angioplasty and stenting (PTAS).

METHODS

Between 2017 and 2021, we prospectively recruited patients with severe PIRCS for PTAS. They were randomly separated into two groups based on endovascular techniques performed with and without DEB. Preprocedural and early postprocedural (within 24 hours) MRI, short-term ultrasonography (6 months after PTAS), and long-term CT angiography (CTA)/MR angiography (MRA), 12 months after PTAS, were performed. Technical safety was evaluated based on periprocedural neurological complications and the number of recent embolic ischemic lesions (REIL) in the treated brain territory on diffusion-weighted imaging of early postprocedural MRI.

RESULTS

Sixty-six (30 with and 36 without DEB) subjects were enrolled, with one failure in techniques. For 65 patients in the DEB versus conventional groups, technical neurological symptoms within 1 month (1/29 (3.4%) vs 0/36; P=0.197) and REIL numbers within 24 hours (1.0±2.1 vs 1.3±1.5; P=0.592) after PTAS showed no differences. Peak systolic velocity (PSVs) on short-term ultrasonography was significantly higher in the conventional group (104.13±42.76 vs .81.95±31.35; P=0.023). The degree of in-stent stenosis (45.93±20.86 vs 26.58±8.75; P<0.001) was higher, and there were more subjects (n=8, 38.9% vs 1, 3.4%; P=0.029) with significant ISR (≥ 50%) in the conventional group than in the DEB group on long-term CTA/MRA.

CONCLUSIONS

We observed similar technical safety of carotid PTAS with and without DEBs. The number of cases of significant ISR were fewer and the degree of stenosis of ISR was less in primary DEB-PTAS of PIRCS than for conventional PTAS in the 12-month follow-up.

Drug-Coated Balloon Angioplasty for De Novo Lesions on the Left Anterior Descending Artery

BACKGROUND

Drug-coated balloons (DCB) are an emerging tool for modern percutaneous coronary intervention (PCI), but evidence on their use for de novo lesions on large vessels is limited.

METHODS

Consecutive patients undergoing DCB-based PCI on the left anterior descending artery in 2 Italian centers from 2018 to 2022 were retrospectively enrolled and compared with patients who received left anterior descending PCI with contemporary drug-eluting stents (DES). In-stent restenosis was excluded. The DCB group included both patients undergoing DCB-only PCI and those receiving hybrid PCI with DCB and DES combined. The primary end point was target lesion failure at 2 years, defined as the composite of target lesion revascularization, cardiac death, and target vessel myocardial infarction.

RESULTS

We included 147 consecutive patients undergoing DCB-based treatment on the left anterior descending artery and compared them to 701 patients who received conventional PCI with DES. In the DCB group, 43 patients (29.2%) were treated with DCB only and 104 (70.8%) with a hybrid approach; DCB length was greater than stent length in 55.1% of cases. Total treated length was higher in the DCB group (65 [40-82] versus 56 [46-66] mm; P=0.002), while longer DESs were implanted (38 [24-62] versus 56 [46-66] mm; P<0.001) and a higher rate of large vessels were treated (76.2% versus 83.5%; P=0.036) in the DES cohort. The cumulative 2-year target lesion failure incidence was not significantly different between the 2 groups (DCB, 4.1% versus DES, 9.8%; hazard ratio, 0.51 [95% CI, 0.20-1.27]; P=0.15). After a 1:1 propensity score matching resulting in 139 matched pairs, the DCB-based treatment was associated with a lower risk for target lesion failure at 2 years compared with DES-only PCI (hazard ratio, 0.2 [95% CI, 0.07-0.58]; P=0.003), mainly driven by less target lesion revascularization.

CONCLUSIONS

A DCB-based treatment approach for left anterior descending revascularization allows a significantly reduced stent burden, thereby potentially limiting target lesion failure risk at midterm follow-up.

Novel Payloads to Mitigate Maladaptive Inward Arterial Remodeling in Drug-Coated Balloon Therapy

Drug-coated balloon therapy is a minimally invasive endovascular approach to treat obstructive arterial disease, with increasing utilization in the peripheral circulation due to improved outcomes as compared to alternative interventional modalities. Broader clinical use of drug-coated balloons is limited by an incomplete understanding of device- and patient-specific determinants of treatment efficacy, including late outcomes that are mediated by postinterventional maladaptive inward arterial remodeling. To address this knowledge gap, we propose a predictive mathematical model of pressure-mediated femoral artery remodeling following drug-coated balloon deployment, with account of drug-based modulation of resident vascular cell phenotype and common patient comorbidities, namely, hypertension and endothelial cell dysfunction. Our results elucidate how postinterventional arterial remodeling outcomes are altered by the delivery of a traditional anti-proliferative drug, as well as by codelivery with an anti-contractile drug. Our findings suggest that codelivery of anti-proliferative and anti-contractile drugs could improve patient outcomes following drug-coated balloon therapy, motivating further consideration of novel payloads in next-generation devices.

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.

Coronary Drug-Coated Balloons for De Novo and In-Stent Restenosis Indications

Drug-coated balloons are approved outside the United States, not only for the treatment of peripheral arteries but also for coronary arteries. This review describes the technological basics, the scenarios of clinical application, and the current available data from clinical trials for the different coronary indications.

Clinical expert consensus document on drug-coated balloon for coronary artery disease from the Japanese Association of Cardiovascular Intervention and Therapeutics

Drug-coated balloon (DCB) technology was developed to deliver the antiproliferative drugs to the vessel wall without leaving any permanent prosthesis or durable polymers. The absence of foreign material can reduce the risk of very late stent failure, improve the ability to perform bypass-graft surgery, and reduce the need for long-term dual antiplatelet therapy, potentially reducing associated bleeding complications. The DCB technology, like the bioresorbable scaffolds, is expected to be a therapeutic approach that facilitates the "leave nothing behind" strategy. Although newer generation drug-eluting stents are the most common therapeutic strategy in modern percutaneous coronary interventions, the use of DCB is steadily increasing in Japan. Currently, the DCB is only indicated for treatment of in-stent restenosis or small vessel lesions (< 3.0 mm), but potential expansion for larger vessels (≥ 3.0 mm) may hasten its use in a wider range of lesions or patients with obstructive coronary artery disease. The task force of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) was convened to describe the expert consensus on DCBs. This document aims to summarize its concept, current clinical evidence, possible indications, technical considerations, and future perspectives.

Understudied factors in drug-coated balloon design and evaluation: A biophysical perspective

Drug-coated balloon (DCB) percutaneous interventional therapy allows for durable reopening of the narrowed lumen via physical tissue expansion and local anti-restenosis drug delivery, providing an alternative to traditional uncoated balloons or a permanent indwelling implant such as a conventional metallic drug-eluting stent. While DCB-based treatment of peripheral arterial disease (PAD) has been incorporated into clinical guidelines, DCB use has been recently curtailed due to reports that showed evidence of increased mortality risk in patients treated with paclitaxel (PTX)-coated balloons. Given the United States Food and Drug Administration's 2019 consequent warning regarding PTX-eluting DCBs and the subsequent marked reduction in clinical DCB use, there is now a critical need to better understand the compositional and mechanical factors underlying DCB efficacy and safety. Most work to date on DCB refinement has focused on designing both the enabling balloon catheter and alternate coatings composed of various drugs and excipients, followed by device evaluation in preclinical and clinical studies. We contend that improvement in DCB performance will require a better understanding of the biophysical factors operative during and following balloon deployment, and moreover that the elaboration and demonstrated control of these factors are needed to address current concerns with DCB use. This article provides a perspective on the biophysical interactions that govern DCB performance and offers new design strategies for the development of next-generation DCB devices.

The factors influencing the efficiency of drug-coated balloons

The drug-coated balloon (DCB) is an emerging percutaneous coronary intervention (PCI) device that delivers drugs to diseased vessels to decrease the rate of vascular stenosis. Recent clinical studies have demonstrated that DCBs tend to have both good safety and efficacy profiles, leading to extended application indications in the clinic, including in-stent restenosis (ISR) for metal stents such as drug-eluting stents (DESs), small vascular disease, bifurcation disease, large vascular disease, acute coronary syndrome (ACS), and high bleeding risk. However, some previous clinical data have suggested that DCBs performed less effectively than DESs. No studies or reviews have systematically discussed the improvement strategies for better DCB performance until now. Drug loss during the process of delivery to the target lesion and inefficient delivery of the coating drug to the diseased vascular wall are two key mechanisms that weaken the efficiency of DCBs. This review is the first to summarize the key influencing factors of DCB efficiency in terms of balloon structure and principles, and then it analyzes how these factors cause outcomes in practice based on current clinical trial studies of DCBs in the treatment of different types of lesions. We also provide some recommendations for improving DCBs to contribute to better DCB performance by improving the design of DCBs and combining other factors in clinical practice.

Synergistic effect of VEGF and SDF-1α in endothelial progenitor cells and vascular smooth muscle cells

Vascular endothelial growth factor (VEGF) is a potent agonist of angiogenesis that induces proliferation and differentiation of endothelial progenitor cells (EPCs) after vascular injury. Previous studies have suggested that stromal cell-derived factor 1-alpha (SDF-1α) and VEGF have a synergistic effect on vascular stenosis. The aim of the present study was to investigate whether VEGF and SDF-1α act synergistically in EPCs and vascular smooth muscle cells (VSMCs). In this study, EPCs were isolated from rat bone marrow and their morphology and function were studied. Subsequently, VEGF was delivered into EPCs using an adenoviral vector. Tube formation, migration, proliferation, and apoptosis of VEGF-overexpressing EPCs was analyzed. Then, EPCs were co-cultured with VSMCs in the presence or absence of SDF-1α, the migration, proliferation, apoptosis, and differentiation capacity of EPCs and VSMCs were analyzed respectively. The isolated EPCs showed typical morphological features, phagocytic capacity, and expressed surface proteins. While stable expression of VEGF remarkably enhanced tube formation, migration, and proliferation capacity of EPCs, apoptosis was decreased. Moreover, the proliferation, migration, and differentiation capacity of EPCs in the co-cultured model was enhanced in the presence of SDF-1α, and apoptosis was decreased. However, these effects were reversed in VSMCs. Therefore, our results showed that VEGF and SDF-1α synergistically increased the migration, differentiation, and proliferation capabilities of EPCs, but not VSMCs. This study suggests a promising strategy to prevent vascular stenosis.

Utilization of Drug-Coated Balloons for the Treatment of Coronary Lesions in the Elderly Population

Introduction: The use of drug-coated balloons (DCBs) has become more prevalent in the past few years for the treatment of in-stent restenosis (ISR) and de novo lesions. The absence of foreign polymer implantations potentially shortens the duration of dual anti-platelet therapy (DAPT), which can be beneficial for the elderly population. We aimed to investigate the safety and efficacy of the use of DCBs for the treatment of coronary lesions in elderly patients as compared to the younger population. Materials and methods: A database of 446 consecutive patients who underwent a procedure of DCB inflation in our institution was divided into two groups, below 70 years old and above 80 years old. We compared and analyzed the endpoints of total major adverse cardiovascular events (MACE), cardiovascular (CV) death, and all-cause mortality in both groups. Results: The difference in MACE between the two age groups was non-significant (p = 0.225); the difference in cardiovascular death was also non-significant (p = 0.086). All-cause mortality was significantly different (p < 0.0001) and can be attributed to the age of the patients. Conclusion: The utilization of DCBs for the treatment of coronary lesions may be as safe and effective for the elderly population as for the younger population and may allow a shorter period of DAPT therapy, which can lower the risk of bleeding.

New Ultrasound-Controlled Paclitaxel Releasing Balloon vs. Asymmetric Drug-Eluting Stent in Primary ST-Segment Elevation Myocardial Infarction - A Prospective Randomized Trial

BACKGROUND

Application of drug-coated balloons (DCBs) is popular for the treatment of percutaneous coronary intervention (PCI). A new DCB has been designed as ultrasound-controlled paclitaxel releasing. This study was conducted to determine whether a DCB-only strategy has a similar safety profile and equal angiographic and clinical outcomes to DES implantation in primary ST-elevation myocardial infarction (STEMI) patients, as well as determine the efficiency and safety of this new DCB.

METHODS AND RESULTS

Overall, 184 pretreated STEMI patients were randomized into DCB and DES groups with a 1:1 allocation. The main study end-point was late lumen loss (LLL) during the 9 months after PCI. Late lumen loss was reported to be 0.24±0.39 mm in the DCB group and 0.31±0.38 mm in the DES group (P=0.215). Diameter stenosis was 28.27±15.35% in the DCB group and 25.73±15.41% in the DES group (P=0.312). Major adverse cardiovascular events (MACEs) were reported in 3 patients (3.4%) in the DCB group and 4 patients (4.7%) in the DES group (P=0.718). TLR and TVR in the DCB group was 2.3%, 3.4% and 2.4%, 3.5% in the DES group (P=1.000), respectively. No cardiac death and stent thrombosis (ST) was found in the DCB group at 12 months clinical follow up.

CONCLUSIONS

The DCB-only strategy showed good angiographic and clinical outcomes in the 9- and 12-month follow-up periods, respectively. The VasoguardTM DCB is safe and feasible to treat STEMI patients.

Drug-Coated Balloon Versus Drug-Eluting Stent in Patients With Femoropopliteal Artery Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

In this systematic review and meta-analysis, we aimed to compare drug-coated balloon (DCB) to drug-eluting stent (DES) in patients with femoropopliteal lesions in terms of restenosis, target lesion revascularization (TLR), and mortality.

METHODS

A comprehensive literature search was performed through PubMed, Scopus, and Embase databases. The intervention group was patients receiving percutaneous balloon angioplasty using the DCB. The control group was patients receiving percutaneous intervention using the DES. The primary outcome was restenosis, and the secondary outcomes were TLR and mortality.

RESULTS

There were 4 studies comprising 812 patients (906 lesions) included in this systematic review and meta-analysis. The rate of restenosis was .19 [.13, .26] in DCB and .24 [.20, .28] in DES. There was a trend toward lower rate of restenosis (OR .73 [.52, 1.03], P = .074; I²: 46.3%) for DCB use compared to DES use. The rate of TLR was .11 [.08, .14] in DCB and .17 [.14, .21] in DES. TLR was lower (OR .61 [.41, .92], P = .017; I²: 1.2%) in the DCB group compared to the DES group. There were no significant differences in mortality (OR 1.38 [.78, 2.44], P = .268; I²: 0%) among the two groups. Meta-regression analysis showed that the rate of restenosis in DCB in this pooled analysis was affected by sex (reference: male, coefficient -.004, P = .009), smoking (coefficient: .003, P = .010), and total occlusion (coefficient: .008, P = .004).

CONCLUSION

DCB use in patients with femoropopliteal lesion was associated with similar rate of restenosis, lower TLR, and similar mortality rate compared to DES use.

pH-Responsive Nanoparticles for Delivery of Paclitaxel to the Injury Site for Inhibiting Vascular Restenosis

A high incidence of restenosis has been reported at the site of inflammation following angioplasty and stent implantation. The anti-proliferative drug paclitaxel (PTX) could help to reduce inflammation and restenosis; however, it has poor water solubility and serious adverse side effects at high doses. Given the presence of metabolic acidosis at the site of inflammation, we hypothesized that nanoparticles that are responsive to low pH could precisely release the loaded drug at the target site. We successfully constructed pH-responsive poly(D, L-lactic-co-glycolic acid) (PLGA) nanoparticles loaded with PTX and NaHCO3 as a pH-sensitive therapeutic agent (PTX-NaHCO3-PLGA NPs). The NPs exhibited remarkable pH sensitivity and a good safety profile both in vitro in rat vascular smooth muscle cells and in vivo in Sprague Dawley rats after tail vein injection. In the rat model, the PTX-NaHCO3-PLGA NPs treatment group showed suppressed intimal proliferation following balloon-induced carotid artery injury compared with that of the saline-treated control. Overall, these results demonstrate that our newly developed pH-responsive nanodrug delivery platform has the potential to effectively inhibit restenosis.

Drug-Coated Balloon Versus Plain Balloon Angioplasty for Hemodialysis Dysfunction: A Meta-Analysis of Randomized Controlled Trials

Background Both drug-coated balloon (DCB) angioplasty and conventional plain balloon angioplasty (PBA) can be implemented to treat hemodialysis dysfunction. The present study aims to compare the safety and efficacy of these 2 approaches by conducting a meta-analysis of available randomized controlled trials. Methods and Results PubMed, Cochrane Library, and Embase databases were queried from establishment to January 2021. A total of 18 randomized controlled trials including 877 and 875 patients in the DCB and PBA groups, respectively, were included in the present meta-analysis. Target lesion primary patency, circuit patency, target lesion revascularization, and mortality were pooled. Odds ratios (ORs) were reported with 95% CIs. Publication bias was analyzed with funnel plot and Egger test. Target lesion primary patency was higher among patients who underwent DCB (OR, 2.93 [95% CI, 2.13-4.03], P<0.001 at 6 months; OR, 2.47 [95% CI, 1.53-3.99], P<0.001 at 1 year). Also, the DCB group had a higher dialysis circuit patency at 6 months (OR, 2.42; 95% CI, 1.56-3.77 [P<0.001]) and 1 year (OR, 1.91; 95% CI, 1.22-3.00 [P=0.005]). Compared with the PBA group, the DCB group had lower odds of target lesion revascularization during follow-up (OR, 0.43 [95% CI, 0.23-0.82], P=0.001 at 6 months; OR, 0.74 [95% CI, 0.32-1.73], P=0.490 at 1 year). The OR of mortality was comparable between 2 groups at 6 months (OR, 1.18; 95% CI, 0.42-3.33 [P=0.760]) and 1 year (OR, 0.93; 95% CI, 0.58-1.48 [P=0.750]). Conclusions Based on evidence from 18 randomized controlled trials, DCB angioplasty is superior to PBA in maintaining target lesion primary patency and circuit patency among patients with dialysis circuit stenosis. DCB angioplasty also reduces target lesion revascularization with a similar risk of mortality compared with PBA.

Animal Models of Neointimal Hyperplasia and Restenosis: Species-Specific Differences and Implications for Translational Research

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Neointimal hyperplasia is the major factor contributing to restenosis after angioplasty procedures.

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Multiple animal models exist to study basic and translational aspects of restenosis formation.

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Animal models differ substantially, and species-specific differences have major impact on the pathophysiology of the model.

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Genetic, dietary, and mechanical interventions determine the translational potential of the animal model used and have to be considered when choosing the model.

The process of restenosis is based on the interplay of various mechanical and biological processes triggered by angioplasty-induced vascular trauma. Early arterial recoil, negative vascular remodeling, and neointimal formation therefore limit the long-term patency of interventional recanalization procedures. The most serious of these processes is neointimal hyperplasia, which can be traced back to 4 main mechanisms: endothelial damage and activation; monocyte accumulation in the subintimal space; fibroblast migration; and the transformation of vascular smooth muscle cells. A wide variety of animal models exists to investigate the underlying pathophysiology. Although mouse models, with their ease of genetic manipulation, enable cell- and molecular-focused fundamental research, and rats provide the opportunity to use stent and balloon models with high throughput, both rodents lack a lipid metabolism comparable to humans. Rabbits instead build a bridge to close the gap between basic and clinical research due to their human-like lipid metabolism, as well as their size being accessible for clinical angioplasty procedures. Every different combination of animal, dietary, and injury model has various advantages and disadvantages, and the decision for a proper model requires awareness of species-specific biological properties reaching from vessel morphology to distinct cellular and molecular features.

3D modelling of drug-coated balloons for the treatment of calcified superficial femoral arteries

Background/Objectives

Drug-coated balloon therapy for diseased superficial femoral arteries remains controversial. Despite its clinical relevance, only a few computational studies based on simplistic two-dimensional models have been proposed to investigate this endovascular therapy to date. This work addresses the aforementioned limitation by analyzing the drug transport and kinetics occurring during drug-coated balloon deployment in a three-dimensional geometry.

Methods

An idealized three-dimensional model of a superficial femoral artery presenting with a calcific plaque and treated with a drug-coated balloon was created to perform transient mass transport simulations. To account for the transport of drug (i.e. paclitaxel) released by the device, a diffusion-reaction equation was implemented by describing the drug bound to specific intracellular receptors through a non-linear, reversible reaction. The following features concerning procedural aspects, pathologies and modelling assumptions were investigated: (i) balloon application time (60–180 seconds); (ii) vessel wall composition (healthy vs. calcified wall); (iii) sequential balloon application; and (iv) drug wash-out by the blood stream vs. coating retention, modeled as exponential decay.

Results

The balloon inflation time impacted both the free and specifically-bound drug concentrations in the vessel wall. The vessel wall composition highly affected the drug concentrations. In particular, the specifically-bound drug concentration was four orders of magnitude lower in the calcific compared with healthy vessel wall portions, primarily as a result of reduced drug diffusion. The sequential application of two drug-coated balloons led to modest differences (~15%) in drug concentration immediately after inflation, which became negligible within 10 minutes. The retention of the balloon coating increased the drug concentration in the vessel wall fourfold.

Conclusions

The overall findings suggest that paclitaxel kinetics may be affected not only by the geometrical and compositional features of the vessel treated with the drug-coated balloon, but also by balloon design characteristics and procedural aspects that should be carefully considered.

Nanoparticles eluting stents for coronary intervention: Formulation, characterization and in vitro evaluation

Coronary artery disease (CAD) is currently a leading cause of death worldwide. In the history of percutaneous coronary intervention for the treatment of CAD, a drug-eluting stent (DES) is recognized as a revolutionary technology that has the unique ability to significantly reduce restenosis and provide both mechanical and biological solutions simultaneously to the target lesion. The aim of the research work was to design and fabricate DES coated with a nanoparticulate drug formulation. Sirolimus, an inhibitor of the smooth muscle cell (SMC) proliferation and migration, was encapsulated in polymeric nanoparticles. The nanoparticle formulation was characterized for various physicochemical parameters. Cell viability and cell uptake studies were performed using human coronary artery smooth muscle cells (HCASMCs). The developed nanoparticle formulation showed enhanced efficacy compared to plain drug solution and exhibited time-dependent uptake into the HCASMCs. The developed nanoparticle formulation was coated on the FlexinniumTM ultra-thin cobalt-chromium alloy coronary stent platform. The nanoparticle coated stents were characterized for morphology and residual solvent analysis. In-vitro drug release was also evaluated. Ex-vivo arterial permeation was carried out to evaluate the nanoparticle uptake from the surface of the stents. The characterization studies together corroborated that the developed nanoparticle coated stent can be a promising replacement of the current drug-eluting stents.

Novel Clinical Therapies and Technologies in Dialysis Vascular Access

The hemodialysis population continues to grow. Although procedures for dialysis have existed for >60 years, significant challenges with vascular access to support hemodialysis persist. Failure of arteriovenous fistulas (AVFs) to mature, loss of AVF and graft patency, thrombosis, and infection hinder long-term access, and add extra health care costs and patient morbidity. There have been numerous innovations over the last decade aimed at addressing the issues. In this study, we review the literature and summarize the recent evolution of drug delivery, graft development, minimally invasive AVF creation, and stem-cell therapy for hemodialysis access.

Predictors of Favorable Angiographic Outcomes After Drug-Coated Balloon Use for de novo Small Vessel Coronary Disease (DCB-ONLY)

We evaluated the angiographic parameter and clinical outcomes of drug-coated balloon (DCB) to assess the optimal angiographic criteria in de novo small vessel disease (SVD). Patients (n = 424, mean age: 64.4 ± 11.2 years, men: 69.8%) at 20 sites in Korea were prospectively enrolled. The primary end point was late luminal loss (LLL) at 9-month follow-up angiography. Secondary end points included restenosis rates, target lesion failure (TLF), and DCB-related thrombosis during the 12-month follow-up period. We included 403 patients for analysis excluding 21 patients who required bailout stenting. Baseline mean reference vessel .diameter was 2.52 ± 0.39 mm and mean minimal luminal diameter (MLD) was 0.71 ± 0.40 mm. The mean MLD was 1.54 ± 0.37 mm after DCB. Late luminal loss was -0.01 ± 0.43 mm and restenosis was noted in 26 patients (12.2%). Minimal luminal diameter >1.6 mm and %diameter stenosis (DS) <45% after DCB was associated maintenance of MLD without LLL at 9-months. Multivariate analysis demonstrated that %DS at baseline and post-MLD was associated with the restenosis. During 12-month follow-up, TLF was 2.6% including 1 cardiac death, 1 myocardial infarction, and 10 ischemia-driven target lesion revascularizations. Drug-coated balloon showed a low restenosis and lower LLL despite high in-segment DS. Post-MLD and % DS may be helpful to get optimal results in de novo SVD after DCB.

Treatment and Predictors of Recurrent Internal Carotid Artery In-Stent Restenosis

PURPOSE

We aimed to examine the effectiveness of different therapeutic options for and to identify the possible risk factors of recurrent internal carotid artery (ICA) in-stent restenosis (ISR).

METHODS

Forty-six ICA ISRs, which were reintervened at least once, were retrospectively analyzed regarding clinical and imaging characteristics, as well as invasive treatment type (percutaneous transluminal angioplasty [PTA] with a plain balloon, PTA with a drug-eluting balloon [DEB], re-stenting) used.

RESULTS

The median follow-up was 29.5 months (IQR, 8.5-52.8 months) in patients who underwent reintervention for ICA ISR. Stent occlusion occurred in 3 patients (6.5%). One ISR recurrence was noted in 10 patients (21.7%); reintervention was carried out in 7 cases (7/10 [70%]; PTA, N = 5; PTA with a DEB, N = 1; re-stenting, N = 1), while 3 patients (3/10; 30%) received best medical treatment. Two ISR recurrences were observed in 3 patients (6.5%); all of them underwent reintervention (PTA, N = 1; PTA with a DEB, N = 2). Three ISR recurrences were seen in 1 patient (2.2%), who was treated with PTA. No recurrence was observed in those patients, who had DEB treatment. Multiple logistic regression analysis revealed statin therapy to be a protective factor against recurrent ISR (OR, 0.17; 95% CI, 0.03-0.84; P = .029).

CONCLUSION

Our study suggests that PTA with a DEB is the most effective for the treatment of recurrent ISR, and confirms the importance of statin use in patients who have had a carotid reintervention.

PERK Inhibition Promotes Post-angioplasty Re-endothelialization via Modulating SMC Phenotype Changes

BACKGROUND

Drug-eluting stents impair post-angioplasty re-endothelialization thus compromising restenosis prevention while heightening thrombotic risks. We recently found that inhibition of protein kinase RNA-like endoplasmic reticulum kinase (PERK) effectively mitigated both restenosis and thrombosis in rodent models. This motivated us to determine how PERK inhibition impacts re-endothelialization.

METHODS

Re-endothelialization was evaluated in endothelial-denuded rat carotid arteries after balloon angioplasty and periadventitial administration of PERK inhibitor in a hydrogel. To study whether PERK in smooth muscle cells (SMCs) regulates re-endothelialization by paracrinally influencing endothelial cells (ECs), denuded arteries exposing SMCs were lentiviral-infected to silence PERK; in vitro, the extracellular vesicles isolated from the medium of PDGF-activated, PERK-upregulating human primary SMCs were transferred to human primary ECs.

RESULTS

Treatment with PERK inhibitor versus vehicle control accelerated re-endothelialization in denuded arteries. PERK-specific silencing in the denuded arterial wall (mainly SMCs) also enhanced re-endothelialization compared to scrambled shRNA control. In vitro, while medium transfer from PDGF-activated SMCs impaired EC viability and increased the mRNA levels of dysfunctional EC markers, either PERK inhibition or silencing in donor SMCs mitigated these EC changes. Furthermore, CXCL10, a paracrine cytokine detrimental to ECs, was increased by PDGF activation and decreased after PERK inhibition or silencing in SMCs.

CONCLUSIONS

Attenuating PERK activity pharmacologically or genetically provides an approach to accelerating post-angioplasty re-endothelialization in rats. The mechanism may involve paracrine factors regulated by PERK in SMCs that impact neighboring ECs. This study rationalizes future development of PERK-targeted endothelium-friendly vascular interventions.

Long-term outcome upon treatment of calcified lesions of the lower limb using scoring angioplasty balloon (AngioSculpt™)

AIMS

In peripheral artery disease (PAD), endovascular treatment success of heavily calcified lesions is often compromised by a number of vascular complications, such as recoils, dissections and need for target vessel re-interventions. The increasing use of scoring balloon techniques has raised the hope for better periprocedural outcomes; however, the knowledge regarding the actual benefits of the scoring balloon technique in comparison to standard therapy is still limited. Thus, the aim of the current study was to determine the safety and effectiveness of scoring balloon angioplasty in a real-life patients' collective with PAD.

METHODS AND RESULTS

A total of 425 patients with moderate to severely calcified femoropopliteal lesions received interventional treatment between 2011 and 2018 at the single center; 230 received a treatment with a scoring balloon (AngioSculpt™), and 195 received a plain procedure without AngioSculpt™. Key questions of this analysis were: (1) whether AngioSculpt™ can be used as a safe and effective stand-alone treatment in heavily calcified lesions in a 24-month follow-up, as well as (2) whether target lesion preparation with scoring balloon bears additional benefits to standard treatment (PTA ± stent implantation). In terms of freedom from target lesion revascularization there were no significant differences between AngioSculpt™ and standard procedure (82.3% vs. 78.1%, P > 0.05). Vessel preparation with balloon angioplasty had no additional effects on survival and amputation rates in comparison to standard treatment without AngioSculpt™ (P > 0.05). The deployment of a scoring balloon did not reduce the subsequent need for additional stent implantations (32.6%, and 32.3%, P > 0.05).

CONCLUSION

Lesion preparation with AngioSculpt™ scoring balloon represents a safe and effective tool in the treatment of complex femoropopliteal lesions. In this retrospective analysis, AngioSculpt™ scoring balloon angioplasty did not significantly improve vessel patency- both when used as an adjunctive in preparation for stenting and as stand-alone treatment. A prospective study is needed to further investigate the scoring balloon treatment options.

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 balloons for coronary artery disease: current concepts and controversies

Drug-coated balloons (DCBs) are a novel development for percutaneous coronary intervention. The first successful application was in-stent restenosis but in recent years, strong evidence has been released for its use in native small-vessels disease. Additional applications such as acute myocardial infarction, chronic total occlusion and bifurcation lesions are still under investigation. This article reviews the key studies evaluating the role of DCBs in several settings and reports on interesting cases where DCBs showed positive results for high-risk patients with neoplasm, as well as with high bleeding risk, planned surgery or renal injury. We also highlight a new biodegradable therapy for coronary bifurcation treatment, in which a bioresorbable vascular scaffold is implanted in the main branch, completed with a DCB angioplasty in the side branch when a treatment is deemed necessary.

Midterm Outcomes of Drug-Coated Balloon Angioplasty in Femoropopliteal Lesions in a Daily Practice Cohort

BACKGROUND

Most previous drug-coated balloon (DCB) angioplasty studies used strict inclusion and exclusion criteria and therefore might not be representative for daily practice. This study was performed to evaluate the midterm outcomes of DCB angioplasty in femoropopliteal artery disease and to identify risk factors for restenosis.

MATERIALS AND METHODS

All patients treated with DCB angioplasty between January 2015 and September 2016 were included. Provisional stents were placed if indicated. Data were retrospectively collected from digital patient records. No exclusion criteria were applied. The primary end point was primary patency. Secondary end points were primary assisted patency, secondary patency, clinically driven target lesion revascularization (CD-TLR) and major adverse events. All end points were calculated with the Kaplan-Meier analysis. The univariable and multivariable Cox regression analyses were performed to identify risk factors for restenosis.

RESULTS

A total of 109 patients (113 legs) were included (45% male; mean age, 72 ± 10). The rate of critical limb ischemia was 52% and total occlusions were treated in 38%. The mean follow-up was 24 ± 13 months. Primary patency rates were 87%, 79%, and 61% at 1, 2, and 3 years, respectively. Primary assisted patency rates were 95%; 89%, and 79%; secondary patency rates were 99%, 97%, and 91%; and CD-TLR rates were 6.9%, 14.3%, and 20.6% at 1, 2, and 3 years, respectively. Overall mortality and major target limb amputation rates were 18% and 5% at 3 years. Multivariable analysis demonstrated that only Trans-Atlantic Inter-Society Consensus (TASC) D lesions were associated with restenosis (P = 0.008).

CONCLUSIONS

DCB angioplasty is an effective and safe treatment option for femoropopliteal lesions in daily practice with excellent 1- and 2-year results. The 3-year results were slightly less favorable, which may be caused by the ongoing vascular disease or a late "catch-up" phenomenon. Only TASC D lesions were associated with loss of primary patency after adjustment for confounders.

Development of drug-coated balloon for the treatment of multiple peripheral artery segments

OBJECTIVE

Peripheral artery disease is the second most common cardiovascular disease. It can often occur in complex form when there is a presence of long, diffuse, and multiple lesions. Current treatments use either single long drug-coated balloons (DCBs) or multiple DCBs; however, treatment success is limited. The purpose of this study was to investigate the preclinical feasibility of our multiple-release Tailored Medical Devices DCB (MR-TMD-DCB) to treat multiple arterial segments using a single DCB.

METHODS

The MR-TMD-DCBs were developed using a two-layer coating approach. The DCBs were developed in a certified Current Good Manufacturing Practices facility using presterilized materials and reagent and then characterized for coating morphology, thermal and chemical changes, and in vitro particulate shedding. The drug loss, tissue uptake, and undelivered drug amounts were analyzed using an in vitro peripheral artery flow model and explanted pig arteries. Then, an in vivo survival study was performed using a healthy porcine model to measure the short-term drug uptake (seven swine; 14 treatments at day 1) and retention (seven swine; 14 treatments at day 7) in two different arterial segments after treatment with a single MR-TMD-DCB.

RESULTS

The coating on the MR-TMD-DCB was smooth and homogeneous with paclitaxel molecularly dispersed in its amorphous state. A negligible number of particulates were shed from the MR-TMD-DCB coating. A similar amount of drug was accurately delivered into two separate explanted arteries using a single MR-TMD-DCB during the in vitro flow model testing (707 ± 109 ng/mg in the first explanted artery and 783 ± 306 ng/mg in the second explanted artery). The MR-TMD-DCB treatment resulted in equivalent drug amounts in the two arterial segments at day 1 (63 ± 19 ng/mg in the first treatment site and 59 ±19 ng/mg in the second treatment site) and at day 7 (9 ± 6 ng/mg in the first treatment site and 10 ± 6 ng/mg in the second treatment site). In addition, the drug levels at each time point were in the clinically relevant range to prevent neointimal hyperplasia.

CONCLUSIONS

The MR-TMD-DCBs provided equivalent and clinically relevant drug retention levels into two different arterial segments. Thus, MR-TMD-DCBs can be used to accurately deliver drug into multiple arterial segments with the use of a single DCB. The clinical outcomes of these findings need further investigation. Future long-term pharmacokinetics and safety studies will be performed to evaluate the safety and efficacy of the MR-TMD-DCB.

Paclitaxel-Based Devices for the Treatment of PAD: Balancing Clinical Efficacy with Possible Risk

PURPOSE OF REVIEW

Paclitaxel-based endovascular devices have become the standard of care in symptomatic, medication-refractory peripheral artery disease (PAD) and in critical limb ischemia (CLI). This review examines the data on the efficacy and safety of these devices relative to standard balloon angioplasty (PTA) and bare metal stents (BMS).

RECENT FINDINGS

Randomized controlled trials (RCTs) have found that peripheral devices coated with paclitaxel result in superior patency rates and decreased target lesion revascularization (TLR) compared with non-drug-coated devices. Recently, a meta-analysis of randomized controlled trials unexpectedly reported an increase in mortality in patients treated with paclitaxel-coated devices (PCDs), resulting in the pausing of ongoing trials and a warning of safety from the FDA. Observational data that has been published since this time has not supported this safety concern. PAD is a common disease that severely impacts quality and length of life. PCDs are a promising therapy for patients with PAD, offering a more effective and durable intervention when compared with traditional PTA/BMS. A meta-analysis of RCTs identified a signal of harm with these devices which has now been replicated by the FDA. However, there is significant missing data from the trials analyzed by the meta-analysis and FDA, no plausible mechanism linking paclitaxel to death, and no correlation between paclitaxel dose and mortality. Analyses in observational data have found no safety signal. An FDA panel evaluating the validity of this late-mortality signal recently adjourned, emphasizing that the available data is incomplete. PCDs will remain on the market, and an active discussion is underway for developing an approach for improved post-market surveillance, device-labeling, and cause of death adjudication.

Intrinsic coating morphology modulates acute drug transfer in drug-coated balloon therapy

The hallmark of drug-coated balloon (DCB) therapy for the treatment of peripheral vascular disease is that it allows for reopening of the narrowed lumen and local drug delivery without the need for a permanent indwelling metal implant such as a stent. Current DCB designs rely on transferring drugs such as paclitaxel to the arterial vessel using a variety of biocompatible excipients coated on the balloons. Inherent procedural challenges, along with limited understanding of the interactions between the coating and the artery, interactions between the coating and the balloon as well as site-specific differences, have led to DCB designs with poor drug delivery efficiency. Our study is focused on two clinically significant DCB excipients, urea and shellac, and uses uniaxial mechanical testing, scanning electron microscopy (SEM), and biophysical modeling based on classic Hertz theory to elucidate how coating microstructure governs the transmission of forces at the coating-artery interface. SEM revealed shellac-based coatings to contain spherical-shaped microstructural elements whereas urea-based coatings contained conical-shaped microstructural elements. Our model based on Hertz theory showed that the interactions between these intrinsic coating elements with the arterial wall were fundamentally different, even when the same external force was applied by the balloon on the arterial wall. Using two orthogonal cell-based assays, our study also found differential viability when endothelial cells were exposed to titrated concentrations of urea and shellac, further highlighting the need to maximize coating transfer efficiency in the context of DCB therapies. Our results underscore the significance of the excipient in DCB design and suggest that coating microstructure modulates acute drug transfer during device deployment.

Drug-Eluting Balloons and Drug-Eluting Stents in the Treatment of Peripheral Vascular Disease

In the last 20 years, peripheral artery disease (PAD) has been increasingly recognized as a significant cause of morbidity and mortality in the United States. The endovascular treatment of PAD has seen a marked rise as minimally invasive techniques and devices have been refined. Two newer devices, drug-eluting stents and drug-eluting balloons, are on the forefront of the battle against limb loss from PAD. This review focuses on the data backing the use of drug-eluting technologies for use in the peripheral arterial system.

A New RF Heating Strategy for Thermal Treatment of Atherosclerosis

OBJECTIVES

Restenosis remains a challenge for the treatment of atherosclerosis due to the damage of the endothelial layer and induced proliferation of the smooth muscle cell.

METHODS

A new RF heating strategy was proposed to selectively ablate the atherosclerosis plaque, and to thermally inhibit the proliferation of smooth muscle cells, while keeping the endothelial cells intact. To achieve the goal, an internal cooling agent and distributed electrodes have been integrated in the new designed balloon catheter to focus the shape conformal energy onto the plaque shape. A three-dimensional (3-D) model with experimentally fitted parameters has been established to demonstrate the heating ability of the design and evaluate the microelectrodes configurations for different plaque geometries.

RESULTS

The 3-D shape of the lesions resulting from different electrodes settings is obtained. It is found that by individual control of the micro-electrodes, special shapes of the lesions can be formed, which can match the eccentric crescent plaques. Besides, through changing of the polarity of the electrodes, separate lesions can be reached. This suggests the possibility for treatment of disconnected plaques in situ.

CONCLUSION

By the control of RF heating and convection coefficient of the internal cooling agent, a targeted heating region away from the inner surface of the blood vessel can be realized.

SIGNIFICANCE

This study has illustrated the possibility of achieving a precision thermal treatment of atherosclerosis in favor of inhibiting further restenosis.

Balloons and Stents and Scaffolds: Preclinical Evaluation of Interventional Devices for Occlusive Arterial Disease

Atherosclerosis places a significant burden on humankind; it is the leading cause of mortality globally, and for those living with atherosclerosis, it can significantly impact quality of life. Fortunately, treatment advances have effectively reduced the morbidity and mortality related to atherosclerosis, with one such modality being percutaneous intervention (PCI) to open occluded arteries. Over the 40-year history of PCI, preclinical models have played a critical role in demonstrating proof of concept, characterizing the in vivo behavior (pharmacokinetics, degradation) and providing a reasonable assurance of biologic safety of interventional devices before entering into clinical trials. Further, preclinical models may provide insight into the potential efficacy of these devices with the appropriate study design and end points. While several species have been used in the evaluation of interventional devices, the porcine model has been the principal model used in the evaluation of safety of devices for both coronary and endovascular treatments. This article reviews the fundamentals of permanent stents, transient scaffolds, and drug-coated balloons and the models, objectives, and methods used in their preclinical evaluation.