Local paclitaxel delivery for the prevention of restenosis: biological effects and efficacy in vivo

Coronary stent failure: role of a blended approach with drug-coated balloons for complex lesions

The management of coronary artery disease by means of percutaneous approach have been focused initially to overcome the recoil and acute occlusion after vessel ballooning; therefore, to develop and improve metallic stent platforms, and later drug-eluting technologies. Contemporarily, the necessity emerged to optimize interventional procedures using functional physiologic tests and intravascular imaging guidance, but still stent failures, especially in the complex lesion setting, continue to be not negligible. This comprehensive review is focused on the technology of drug-coated balloons as a tool to treat coronary artery disease without the need for metal implantation but still eluting antirestenotic drugs such as paclitaxel or sirolimus. We delve into these technologies, the drugs, the technical aspects of the deployment and the most updated evidence also proposing a dedicated interventional algorithm. There is solid data to support the use of drug-coated balloons in patients with in-stent restenosis and de-novo small coronary artery disease but also new evidence with promising results from recent studies indicate the feasibility of this approach in complex coronary interventions, bifurcation lesions and larger coronary vessels. In this state-of-the-art review, we also propose a blended approach based on the combination of drug-eluting stents and drug-coated balloons, keeping in mind the necessity to reduce the total stent length in order to reduce the long-term risk of complications.

Safety and Effectiveness of Passeo-18 Lux Drug-Coated Balloon Catheter in Infrainguinal Endovascular Revascularization in the Korean Population: A Multicenter Post-Market Surveillance Study

OBJECTIVE

To evaluate the safety and clinical outcomes of the Passeo-18 Lux drug-coated balloon (DCB) in endovascular revascularization procedures under real-world conditions in a Korean population with atherosclerotic disease of the infrainguinal arteries, including below-the-knee (BTK) arteries.

MATERIALS AND METHODS

Eight institutions in the Republic of Korea participated in this prospective, multicenter, single-arm, post-market surveillance study. Two hundred patients with Rutherford class 2-5 peripheral arterial disease and infrainguinal lesions suitable for endovascular treatment were competitively enrolled. Data were collected at baseline, the time of intervention, discharge, and 1-, 6-, 12-, and 24-month follow-up visits. The primary safety endpoint was freedom from major adverse events (MAE) within 6 months (except when limiting the time frame for procedure- or device-related mortality to within 30 days), and the primary effectiveness endpoint was freedom from clinically driven target lesion revascularization (CD-TLR) within 12 months after the procedure.

RESULTS

A total of 197 patients with 332 target lesions were analyzed. Two-thirds of the patients had diabetes mellitus, and 41.6% had chronic limb-threatening ischemia. The median target lesion length was 100 mm (interquartile range: 56-133 mm). Of the target lesions, 35.2% were occlusions, and 14.8% were located in the BTK arteries. Rate of freedom from MAE was 97.9% at 6 months, and the rate of freedom from CD-TLR was 95.0% and 92.2% at 12 and 24 months, respectively. Subgroup analysis of 43 patients and 49 target lesions involving the BTK arteries showed rate of freedom from MAE of 92.8% at 6 months and rates of freedom from CD-TLR of 88.8% and 84.4% at 12 and 24 months, respectively.

CONCLUSION

The results of the present study, including the BTK subgroup analysis, showed outcomes comparable to those of other DCB studies, confirming the safety and effectiveness of Passeo-18 Lux DCB in the Korean population.

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.

Comparison of angiographic change in side-branch ostium after drug-coated balloon vs. drug-eluting stent vs. medication for the treatment of de novo coronary bifurcation lesions

OBJECTIVES

Data on side-branch (SB) ostial effect after drug-coated balloon (DCB) treatment in the context of de novo coronary bifurcation lesions are limited. We aimed to investigate the angiographic outcomes of SB ostium after DCB treatment compared with drug-eluting stents (DESs) implantation in the main vessel (MV) or optimal medical therapy (OMT) for the treatment of de novo coronary bifurcation lesions.

METHODS

Serial angiographic changes in the SB ostium were compared between DCB, DES, and medication alone for MV treatment. Δ value was calculated by subtracting the follow-up value from the pre-procedure value.

RESULTS

A total of 132 bifurcation lesions were included for analysis (44 lesions in DCB group; 38 lesions in DES group; 50 lesions in OMT group). The minimal lumen diameter (MLD) of SB ostium showed an increase at follow-up in the DCB group, whereas a decrease was observed in both the DES and OMT groups (ΔMLD: -0.16 ± 0.45 mm for DCB group vs. 0.50 ± 0.52 mm for DES group vs. 0.08 ± 0.38 mm for OMT group, p < 0.001). The diameter stenosis (DS) of SB ostium showed a marked decrease at follow-up in the DCB group, in contrast to an increase observed in both the DES and OMT groups (ΔDS: 8.01 ± 18.96% for DCB group vs. -18.68 ± 18.60% for DES group vs. -2.05 ± 14.58% for OMT group, p < 0.001).

CONCLUSIONS

In de novo coronary bifurcation lesions, DCB treatment on the MV demonstrated favorable angiographic outcomes in the SB ostium at 6-9 month follow-up compared to DES implantation or OMT.

Predictors of late lumen enlargement after drug-coated balloon angioplasty for de novo coronary lesions

BACKGROUND

Late lumen enlargement (LLE) - a positive remodelling phenomenon - after drug-coated balloon (DCB) angioplasty for stable coronary disease contributes to a lower restenosis rate. However, lesion characteristics promoting LLE remain unclear.

AIMS

This study aimed to investigate predictive lesion characteristics for LLE using serial optical frequency domain imaging (OFDI) following DCB angioplasty for de novo coronary artery lesions.

METHODS

This retrospective, single-centre observational study included patients with angina pectoris who underwent paclitaxel-coated balloon angioplasty without stenting under OFDI guidance as well as follow-up OFDI. OFDI endpoints were lumen volume, plaque phenotype, and procedure-associated dissection. LLE was defined as a ≥10% increase in the lumen volume of the treated lesion at follow-up.

RESULTS

Between August 2016 and December 2019, among patients with successful DCB angioplasty, 108 lesions (83 patients) had available follow-up imaging after a median of 6.1 months. LLE was detected in 44 (40.7%) lesions. Fibrous/fibrocalcific and layered plaques had significantly larger lumen volumes at follow-up than immediately after the index procedure, whereas lipid plaques exhibited no significant difference. Medial dissection with an arc >90° revealed an increased lumen volume. Multivariate analysis showed that layered plaques (odds ratio [OR] 8.73, 95% confidence interval [CI]: 1.92-39.7; p=0.005) and medial dissection with an arc >90° (OR 4.65, 95% CI: 1.63-13.3; p=0.004) were independent LLE predictors.

CONCLUSIONS

Layered plaques and extensive medial dissection after DCB angioplasty were associated with higher LLE occurrence in de novo coronary lesions. These findings may be clinically applicable to DCB therapeutic strategies based on plaque features.

Drug-Coated Balloons in the Management of Coronary Artery Disease

Drug-coated balloons (DCBs) are specialized coronary devices comprised of a semicompliant balloon catheter with an engineered coating that allows the delivery of antiproliferative agents locally to the vessel wall during percutaneous coronary intervention. Although DCBs were initially developed more than a decade ago, their potential in coronary interventions has recently sparked renewed interest, especially in the United States. Originally designed to overcome the limitations of conventional balloon angioplasty and stenting, they aim to match or even improve upon the outcomes of drug-eluting stents without leaving a permanent implant. Presently, in-stent restenosis is the condition with the most robust evidence supporting the use of DCBs. DCBs provide improved long-term vessel patency compared with conventional balloon angioplasty and may be comparable to drug-eluting stents without the need for an additional stent layer, supporting their use as a first-line therapy for in-stent restenosis. Beyond the treatment of in-stent restenosis, DCBs provide an additional tool for de novo lesions for a strategy that avoids a permanent metal scaffold, which may be especially useful for the management of technically challenging anatomies such as small vessels and bifurcations. DCBs might also be advantageous for patients with high bleeding risk due to the decreased necessity for extended antiplatelet therapy, and in patients with diabetes and patients with diffuse disease to minimize long-stented segments. Further studies are crucial to confirm these broader applications for DCBs and to further validate safety and efficacy.

Applications of Nanotechnology in the Field of Cardiology

Cardiovascular diseases (CVDs) are a leading cause of death globally, demanding innovative therapeutic strategies. Nanoformulations, including nanoparticles, address challenges in drug delivery, stem cell therapy, imaging, and gene delivery. Nanoparticles enhance drug solubility, bioavailability, and targeted delivery, with gas microbubbles, liposomal preparations, and paramagnetic nanoparticles showing potential in treating atherosclerosis and reducing systemic side effects. In stem cell therapy, nanoparticles improve cell culture, utilizing three-dimensional nanofiber scaffolds and enhancing cardiomyocyte growth. Gold nanoparticles and poly(lactic-co-glycolic acid) (PLGA)-derived microparticles promote stem cell survival. Stem cell imaging utilizes direct labeling with nanoparticles for magnetic resonance imaging (MRI), while optical tracking employs dye-conjugated nanoparticles. In gene delivery, polymeric nanoparticles like polyethylenimine (PEI) and dendrimers, graphene-based carriers, and chitosan nanoparticles offer alternatives to virus-mediated gene transfer. The potential of magnetic nanoparticles in gene therapy is explored, particularly in hepatocellular carcinoma. Overall, nanoparticles have transformative potential in cardiovascular disease management, with ongoing research poised to enhance clinical outcomes.

Endovascular Drug Delivery

Drug-eluting stents (DES) and balloons revolutionize atherosclerosis treatment by targeting hyperplastic tissue responses through effective local drug delivery strategies. This review examines approved and emerging endovascular devices, discussing drug release mechanisms and their impacts on arterial drug distribution. It emphasizes the crucial role of drug delivery in modern cardiovascular care and highlights how device technologies influence vascular behavior based on lesion morphology. The future holds promise for lesion-specific treatments, particularly in the superficial femoral artery, with recent CE-marked devices showing encouraging results. Exciting strategies and new patents focus on local drug delivery to prevent restenosis, shaping the future of interventional outcomes. In summary, as we navigate the ever-evolving landscape of cardiovascular intervention, it becomes increasingly evident that the future lies in tailoring treatments to the specific characteristics of each lesion. By leveraging cutting-edge technologies and harnessing the potential of localized drug delivery, we stand poised to usher in a new era of precision medicine in vascular intervention.

Drug-coated balloons versus drug-eluting stents in patients with acute myocardial infarction undergoing percutaneous coronary intervention: an updated meta-analysis with trial sequential analysis

BACKGROUND

Drug-coated balloons (DCBs) are an established strategy for coronary artery disease. However, the new generation drug-eluting stent (DES) is recommended for patients with Acute myocardial infarction (AMI) for coronary artery revascularization. Our aim is to provide a comprehensive appraisal of the efficacy of DCBs in patients with AMI undergoing PCI.

METHODS

We searched the WOS, PubMed, Scopus, and Cochrane CENTRAL till March 2023, for studies that compared DCBs versus DES in patients with AMI undergoing PCI. We used a random-effects model to compare major adverse cardiac events (MACE), cardiac death, all-cause death, myocardial infarction, target lesion revascularization (TLR), stent thrombosis, Late lumen Loss (LLL), and minimum lumen diameter (MLD) between the two groups.

RESULTS

Thirteen studies comprising 2644 patients were included. The pooled OR showed non-inferiority of DCB over DES in terms of MACE (OR = 0.89, 95% CI [0.57 to 1.40], p = 0.63). When we defined MACE as a composite of cardiac death, MI, and TLR; the pooled OR favored DCB over DES (OR = 0.50, 95% CI [0.28 to 0.9], p = 0.02). Moreover, DCB was not inferior to DES in terms of all-cause mortality (OR = 0.88, 95% CI: 0.43 to 1.8, p = 0.73), cardiac mortality, (OR = 0.59, 95% CI: 0.22 to 1.56, p = 0.29), MI (OR = 0.88, 95% CI: 0.34 to 2.29, p = 0.79), stent thrombosis (OR = 1.21, 95% CI: 0.35 to 4.23, p = 0.76), TLR (OR = 0.9, 95% CI: 0.43 to 1.93, p = 0.8), LLL (MD = -0.6, 95% CI: -0.3 to 0.19, p = 0.64), or MLD (MD = -0.4, 95% CI: -0.33 to 0.25, p = 0.76).

CONCLUSION

Our meta-analysis indicated that DCB intervention was not inferior to DES in the PCI setting in patients with AMI, and can be recommended as a feasible strategy in AMI.

PROSPERO REGISTRATION

CRD42023412757.

[Angioplasty with Sirolimus-coated Balloon: the New Standard in the Treatment of PAD?]

Endovascular revascularisation with paclitaxel-coated balloons for the treatment of peripheral artery disease has been shown to be an effective therapeutic option in the femoropopliteal segment. The antiproliferative effect of paclitaxel prevents restenosis. In contrast, in the infra-popliteal segment, the evidence is currently conflicting. However, there is evidence of an increased risk of amputation and mortality from the second year after angioplasty with paclitaxel-coated balloons. This may be due to a dose-dependent cytotoxic effect of paclitaxel. Sirolimus-coated balloons might therefore be an alternative because sirolimus is cytostatic rather than cytotoxic and thus has a wide therapeutic window.Three single-arm pilot studies (50, 25, and 50 patients, respectively) show that angioplasty with sirolimus-coated balloons leads to comparable results to those reported from paclitaxel-coated balloons (late lumen loss at 6 months: 0.29 mm; primary patency at 12 months: femoropopliteal 79%-82%, infra-popliteal 59%; freedom from target lesion revascularization at 12 months: femoropopliteal 83%-94%, infra-popliteal 86%). Randomised controlled trials comparing standard balloon angioplasty and paclitaxel-coated balloons for the treatment of intermittent claudication or chronic limb-threatening ischaemia are active and are expected to provide efficacy and safety results from mid 2024.This review presents the results of pilot studies on angioplasty with sirolimus-coated balloons for the treatment of peripheral artery disease and reviews currently ongoing randomised controlled trials.

Drug-coated balloon strategy following orbital atherectomy for calcified coronary artery compared with drug-eluting stent: One-year outcomes and optical coherence tomography assessment

BACKGROUND

Percutaneous coronary intervention (PCI) for calcified coronary artery remains challenging in the drug-eluting stent (DES) era. While recent studies reported the efficacy of orbital atherectomy (OA) combined with DES for calcified lesion, the effectiveness of drug-coated balloon (DCB) following OA has not been fully elucidated.

METHODS

Between June 2018 and June 2021, 135 patients who received PCI for calcified de novo coronary lesions with OA were enrolled and divided into two groups; OA followed by DCB (n = 43) if the target lesion achieved acceptable preparation, or second- or third-generation DESs (n = 92) if the target lesion showed suboptimal preparation between June 2018 and June 2021. All patients underwent PCI with optical coherence tomography (OCT) imaging. The primary endpoint was 1-year major adverse cardiac event (MACE), that was a composite of cardiac death, nonfatal myocardial infarction, or target lesion revascularization.

RESULTS

Mean age was 73 years and 82% was male. In OCT analysis, maximum calcium plaque was thicker (median: 1050 µm [interquartile range (IQR): 945-1175 µm] vs. 960 µm [808-1100 µm], p = 0.017), calcification arc tended to larger (median: 265° [IQR: 209-360°] vs. 222° [162-305°], p = 0.058) in patients with DCB than in DES, and the postprocedure minimum lumen area was smaller in DCB compared with minimum stent area in DES (median: 3.83 mm² [IQR: 3.30-4.52 mm² ] vs. 4.86 mm² [4.05-5.82 mm² ], p < 0.001). However, 1 year MACE free rate was not significantly different between 2 groups (90.3% in DCB vs. 96.6% in DES, log-rank p = 0.136). In the subgroup analysis of 14 patients who underwent follow-up OCT imaging, late lumen area loss was lower in patients with DCB than DES, despite lower lesion expansion rate in DCB than DES.

CONCLUSIONS

In calcified coronary artery disease, DCB alone strategy (if acceptable lesion preparation was performed with OA) was feasible compared with DES following OA with respect to 1-year clinical outcomes. Our finding indicated using DCB with OA might be reduce late lumen area loss for severe calcified lesion.

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.

Response to pre-dilatation with POBA can predict target lesion revascularization after DCB angioplasty for de novo small coronary artery lesions

Objective

To assess the determinants of target lesion revascularization (TLR) after drug-coated balloon (DCB) angioplasty for de novo small coronary artery lesions.

Methods

This retrospective study enrolled consecutive lesions from patients that were in a stable condition and had undergone successful DCB treatment for de novo small coronary artery lesions. The study endpoint was TLR and major adverse cardiac events at 12 months.

Results

A total of 68 patients with 83 lesions were enrolled in the study. Of these, 11 (13.3%) lesions required TLR. Mean ± SD pre-dilatation balloon diameters were similar in the non-TLR (2.33 ± 0.72 mm) and TLR (2.18 ± 0.36 mm) groups. A comparison of the two groups showed that post/pre-lumen area ratio during pre-dilatation (%) by plain old balloon angioplasty (POBA) was significantly and negatively associated with TLR and the optimal cut-off point was 170%. Cox proportional hazard and multivariate regression analyses showed that post/pre-lumen area ratio was the only independent predictor of TLR (hazard ratio 0.9318; 95% confidence interval 0.9001, 0.9645).

Conclusion

Greater pre-dilatation using POBA, assessed as the post/pre-lumen area ratio, may be independently associated with a lower 12-month TLR rate in patients undergoing DCB angioplasty for de novo small coronary lesions.

Angiographic characteristics of vasculopathy in patients with idiopathic inflammatory myopathies and systemic sclerosis

To describe the peripheral angiographic features of vasculopathy in idiopathic inflammatory myopathies (IIM) and systemic sclerosis (SSc) in comparison to polyarteritis nodosa (PAN). Angiograms of 47 extremities (24 upper and 23 lower) of 11 patients with IIM (n = 5) and SSc (n = 6), and 12 patients with PAN who presented with critical limb ischemia were retrospectively analyzed with regards to the presence of stenosis, occlusion, aneurysms and delayed distal flow, and degree of neovascularization. Diffuse narrowing was more frequent (66.1 vs. 38.0%, p = 0.001), whereas multifocal stenosis (6.5% vs. 26.8%, p = 0.002), abrupt occlusion (11.3% vs. 29.6%, p = 0.010) and aneurysm formation (1.6% vs. 11.3%, p = 0.037) were less frequent in IIM/SSc than PAN. In distal arteries, tapered occlusion (95.5% vs. 76.0%, p = ns) and delayed flow (77.3% vs. 48.0%, p = 0.039) were more common in IIM/SSc than PAN. After 1 year, auto- or surgical amputation tended to be more frequent in IIM/SSc than PAN (36.4% vs. 16.7%, p = ns). In conclusion, diffuse narrowing, tapered occlusion and delayed distal flow on conventional angiograms tend to be more frequent in IIM/SSc than PAN. Further studies are needed to verify these findings in a larger prospective cohort.

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.

Drug-coated balloon versus drug-eluting stent in acute myocardial infarction: A protocol for systematic review and meta-analysis

BACKGROUND

Previous studies comparing the published literature on drug-eluting stents (DES) and drug-coated balloon (DCB) have drawn divergent conclusions, as these studies are limited by small sample sizes. To overcome these limitations, we thus conducted a high-quality systematic review and meta-analysis to assess the efficacy and safety of DCB versus DES for patients with acute myocardial infarction (AMI). It was hypothesized that DCB use at the AMI is associated with decreased risk of cardiovascular disease and death.

METHODS

The electronic databases Embase, Medline, PubMed, and Cinahl were searched from the earliest available date until August 2021. Study included in our study had to meet all of the following inclusion criteria: all randomized controlled trials to assess the efficacy and safety of DES versus DCB in the treatment of AMI were considered eligible for analysis; participants received DCB or DES; reporting the available data on cardiac death, all-cause death, myocardial infarction, target lesion revascularization, target vessel revascularization, major adverse cardiac events, and stent thrombosis. Review Manager Software (v 5.3; Cochrane Collaboration) was used for the meta-analysis. Two of us independently assessed the risk of bias in the included studies using parameters defined in the Cochrane Handbook for Systematic Reviews of Interventions criteria.

RESULTS

It was hypothesized that DCB use at the AMI is associated with decreased risk of cardiovascular disease and death.

REGISTRATION NUMBER

10.17605/OSF.IO/AVTYW.

The impact of percutaneous peripheral interventions on endothelial function

Background: Treatment of symptomatic peripheral artery disease (PAD) through endovascular interventions is the primary revascularization strategy. Interventions restore perfusion but may cause severe injury to the vascular endothelium, which regulates vascular tone. Endothelial dysfunction is involved in the progression of cardiovascular disease, with higher incidences of vascular events. We aimed to determine the impact of percutaneous interventions on change in endothelial function. Patients and methods: Endothelial function was determined using flow-mediated dilation (FMD) before, the day after lower limb intervention with paclitaxel-coated balloons or stent guided interventions and after a six-month follow-up in the target limb, control limb and the systemic circulation in 42 PAD patients aged 70.2±9 years and 66% men. Additionally, macro- and microvascular function were assessed. Results: In PAD patients aged 70.2±9 years and 66% men, we observed an immediate enhancement of macro-, microvascular and endothelial function after endovascular treatment (FMD of superficial femoral artery (SFA) 3.7±0.2% to 4.1±0.1%, n=42, p=0.02), a sustained long-term improvement after 6-months (FMD SFA 3.7±0.2% to 4.2±0.1%, n=42, p=0.01), and moreover an improved systemic endothelial function (FMD brachial artery 4.3±0.1% to 4.7±0.2, n=42, p=0.01) following peripheral interventions. Subgroup analysis however revealed that following paclitaxel-based percutaneous intervention, the paclitaxel dosage applied was inversely related to the chronic improvement in local endothelial function (r=-0.6, n=22, p=0.005) without evidence for systemic effects (r=-0.25, p=0.27). Conclusions: We demonstrate an improved local and systemic endothelial function after treatment of atherosclerotic peripheral disease with a distinguished response after endovascular intervention with higher dosage of applied paclitaxel restraining the benefits. Further studies have to determine the optimal interventional strategy with respect to different treatment modalities to maintain vessel functions.

Optical coherence tomography analysis of late lumen enlargement after paclitaxel-coated balloon angioplasty for de-novo coronary artery disease

BACKGROUND

Paclitaxel-coated balloon angioplasty for de-novo coronary artery lesions causes late lumen enlargement (LLE), however, the mechanisms and predictors of LLE have not been elucidated.

METHODS AND RESULTS

We retrospectively analyzed 91 consecutive patients with 95 de-novo coronary lesions, who underwent paclitaxel-coated balloon angioplasty without stenting from August 2018 to July 2019 as well as follow-up coronary angiography and optical coherence tomography (OCT). The mean follow-up duration was 8.2 ± 2.9 months. The target lesion revascularization rate was 7.3%. OCT demonstrated LLE in 50.5% of lesions. The lesions with LLE had a higher incidence of vessel enlargement (76.6 vs. 29.2%, p < .01), regression of plaque or dissection flap (55.3 vs. 10.4%, p < 0.01; 40.4 vs. 14.6%, p < .01, respectively), and reattachment and healing of dissection flaps (74.5 vs. 27.1%, p < .01) compared with those without LLE. Preprocedure thick-cap fibroatheroma plaques and postprocedure deep dissection reaching the tunica media were positive predictors of LLE (hazard ratio, HR 3.74 [1.93-7.25], p < .001; HR 2.04 [1.02-4.05], p < .05, respectively).

CONCLUSIONS

OCT analysis after paclitaxel-coated balloon treatment of de-novo coronary artery lesions revealed that the mechanism of LLE was associated with vessel enlargement, healing of dissection flaps, and regression of plaque or dissection flap. Preprocedure thick-cap fibroatheroma plaques and postprocedure deep dissection reaching the tunica media on OCT were predictors of LLE.

Drug-coated balloons in the treatment of acute myocardial infarction (Review)

Drug-eluting stents are the standard revascularization strategy for the treatment of symptomatic coronary artery disease. However, in-stent restenosis (ISR), stent thrombosis and reinfarction of target lesions following stent implantation present challenges. Drug-coated balloons (DCBs), which deliver antiproliferative drugs into the vessel wall without stent implantation, are a novel treatment option for percutaneous coronary intervention and have been proven to act as a promising strategy in the treatment of ISR and coronary small vessel disease. However, their role in acute myocardial infarction (AMI) remains unclear. The present review discusses current evidence for the treatment of AMI with DCBs.

Long term outcome after treatment of de novo coronary artery lesions using three different drug coated balloons

OBJECTIVE

To evaluate the long-term efficacy of three currently available drug coated balloons (DCB) for the treatment of de-novo coronary lesions.

METHODS

This was a retrospective analysis of prospectively collected data from the Swedish Coronary Angiography and Angioplasty Registry. Between 2009 and 2017, three currently available DCB brands used in the treatment of de novo lesions were included. Outcomes were clinically driven restenosis and target lesion thrombosis (TLT) (per device) and major adverse cardiac events (MACE) including death, myocardial infarction or target vessel revascularization (per patient) at 4 years. Multivariable Cox regression models were used to adjust for differences.

RESULTS

We included 6715 lesions treated with DCBs, 4483 SeQuent® Please (S-DCB), 1071 IN.PACT Falcon (I-DCB) and 1161 Pantera® Lux (P-DCB), in 5670 patients. The mean DCB diameter was 2.4 mm. Bailout stenting occurred in 6.7% of lesions. Angiographic success was 98.5%. The overall cumulative rate of restenosis was 5.5% (299 events). The risk for reported restenosis did not significantly differ between I-DCB vs S-DCB, adjusted hazard ratio (aHR) 0.96; 95% confidence interval (CI) 0.69-1.34, P-DCB vs S-DCB aHR 0.88; 95% CI 0.63-1.23 and I-DCB vs P-DCB aHR 1.10; 95% CI 0.72-1.68. The cumulative risk for TLT was 0.8% in all three DCBs. The risk for MACE or individual components of MACE did not differ between the three patient-groups.

CONCLUSION

In de novo coronary lesions, we found comparable long-term efficacy with three currently available DCB brands. DCB angioplasty was feasible with low risk for long-term restenosis and TLT.

Semi-continuous production of the anticancer drug taxol by Aspergillus fumigatus and Alternaria tenuissima immobilized in calcium alginate beads

Taxol is the most profitable drug ever developed in cancer chemotherapy; however, the market demand for the drug greatly exceeds the supply that can be sustained from its natural sources. In this study, Aspergillus fumigatus TXD105-GM6 and Alternaria tenuissima TER995-GM3 were immobilized in calcium alginate beads and used for the production of taxol in shake flask cultures. In an effort to increase the taxol magnitude, immobilization conditions were optimized by response surface methodology program (RSM). The optimum levels of alginate concentration, calcium chloride concentration, and mycelium fresh weight were 5%, 4%, and 15% (w/v), respectively. Under these conditions, taxol production by the respective fungal strains was intensified to 901.94 μg L^-1 and 529.01 μg L^-1. Moreover, the immobilized mycelia of both strains were successfully used in the repeated production of taxol for six different fermentation cycles. The total taxol concentration obtained in all cycles reached 4540.14 μg L^-1 by TXD105-GM6 and 2450.27 μg L^-1 by TER995-GM3 strain, which represents 7.85- and 6.31-fold increase, as compared to their initial titers. This is the first report on the production of taxol in semi-continuous fermentation. To our knowledge, the taxol productivity achieved in this study is the highest reported by academic laboratories for microbial cultures which indicates the future possibility to reduce the cost of taxol production.

The Current State of MicroRNAs as Restenosis Biomarkers

In-stent restenosis corresponds to the diameter reduction of coronary vessels following percutaneous coronary intervention (PCI), an invasive procedure in which a stent is deployed into the coronary arteries, producing profuse neointimal hyperplasia. The reasons for this process to occur still lack a clear answer, which is partly why it remains as a clinically significant problem. As a consequence, there is a vigorous need to identify useful non-invasive biomarkers to differentiate and follow-up subjects at risk of developing restenosis, and due to their extraordinary stability in several bodily fluids, microRNA research has received extensive attention to accomplish this task. This review depicts the current understanding, diagnostic potential and clinical challenges of microRNA molecules as possible blood-based restenosis biomarkers.

Drug-eluting balloons versus drug-eluting stents for small vessel coronary artery disease: a meta-analysis

OBJECTIVE

We aimed to conduct a network meta-analysis of treatments for small vessels coronary artery disease between drug-eluting balloon (DEB) and drug-eluting stent (DES).

METHOD

A meta-analysis comparing DEB and DES outcomes was performed using the Medline, Embase, and Cochrane databases. The primary outcome was target lesion revascularization (TLR) or target vessel revascularization (TVR), and myocardial infarction (MI), death and major adverse cardiovascular events (MACE) were secondary outcomes. A total of six studies on 1813 patients were included.

RESULTS

There was no significant difference in rates of TLR or TVR in the patients treated with the DEB strategy compares with the DES strategy [odds ratio (OR) = 0.96, 95% confidence interval (CI) 0.57-1.61, P = 0.89] within a follow-up period of 9-24 months. There was a significant reduction in rates of MI and death in the patients treated with a DCB strategy compared with those treated with a DES strategy (3.7%, 17 of 460 vs 6.1%, 36 of 595; 2.4%, 11 of 460 vs 6.1%, 36 of 595, respectively), and this difference was statistically significant (OR = 0.53, 95% CI 0.29-0.96, P = 0.04; OR = 0.44, 95% CI 0.22-0.88, P = 0.02, respectively). There was no difference between DEB and DES strategies in rates of MACE (OR = 0.94, 95% CI 0.66-1.33, P = 0.73).

CONCLUSION

In summary, this study demonstrates that treatment of small vessel (diameter ≤ 3 mm) coronary artery disease (CAD) with DEB may lead to improving outcomes compared with the use of DES within a follow-up period of 9-24 months. Further large clinical trials are needed to verify this conclusion.

Anti-HIV, antitumor and immunomodulatory activities of paclitaxel from fermentation broth using molecular imprinting technique

In this study, a single component paclitaxel was obtained from fermentation broth by molecular imprinting technique, and its antiviral, antitumor and immunomodulatory activities were studied. The results showed that paclitaxel had a good inhibitory activity on human breast cancer MCF-7 cells and showed a concentration- dependent relationship with an IC50 of about 15 μg/mL in the sulforhodamine B assay. At the same time, paclitaxel exerted a weak inhibitory activity on cervical cancer Hela cells. In addition, paclitaxel not only inhibited the invasion of HIV-1 pseudovirus into cells, but also exhibited inhibitory activity to a certain extent after viral invasion of the cells. At a paclitaxel concentration of 20 μg/mL, the inhibition of HIV-1 pseudovirus reached about 66%. The inhibition of HIV-1 protease activity was concentration-dependent. At a concentration of 20 μg/mL, the inhibitory effect of paclitaxel on HIV-1 protease was similar to that of the positive control pepstatin A, being 15.8%. The HIV-1 integrase inhibiting activity of paclitaxel was relatively weak. Paclitaxel significantly up-regulated the expression of interleukin-6.

Stentless treatment strategy for left circumflex artery ostial stenosis: Directional coronary atherectomy followed by drug-eluting balloon

A 60-year-old man with history of exertional angina pectoris was referred for treatment of an ostial left circumflex (LCX) coronary artery stenosis. The branch angle between left anterior descending artery (LAD) and LCX was shallow, therefore stent implantation seemed at risk of "carina shift" of plaque to the LAD ostium as well as higher in-stent restenosis. Therefore, directional coronary atherectomy (DCA, Atherocut™, L-size, NIPRO, Osaka, Japan) was performed at the ostium of the LCX lesion. After evaluating plaque accumulation using intravascular ultrasound (IVUS), DCA was circumferentially performed 16 times, from 2 atm to 3 atm, using an 8 fr guide system. Although angiogram and IVUS showed excellent results, adjunctive balloon dilatation with 3.5 mm paclitaxel-coated balloon was performed to prevent restenosis. At 8 months, the patient reported being angina-free, and subsequent follow-up angiogram showed no restenosis of LCX. Paclitaxel-coated balloon following DCA for LCX ostial stenosis seems to be safe and effective for both acute and chronic results, suggesting a potential stentless therapeutic option. <Learning objective: Directional coronary atherectomy in combination with drug-eluting balloon may be a potential stentless therapeutic option, especially for the ostial stenosis of left circumflex artery.>.

Strain improvement and immobilization technique for enhanced production of the anticancer drug paclitaxel by Aspergillus fumigatus and Alternaria tenuissima

UV and gamma irradiation mutagenesis was applied on Aspergillus fumigatus and Alternaria tenuissima in order to improve their producing ability of paclitaxel. Among the screened mutants, two stable strains (designated TXD105-GM6 and TER995-GM3) showed the maximum paclitaxel production. Paclitaxel titers of the two respective mutants were dramatically intensified to 1.22- and 1.24-fold, as compared by their respective parents. Immobilization using five different entrapment carriers of calcium alginate, agar-agar, Na-CMC, gelatin, and Arabic gum was successfully applied for production enhancement of paclitaxel by the two mutants. The immobilized cultures were superior to free-cell cultures and paclitaxel production by the immobilized mycelia was much higher than that of the immobilized spores using all the tried carriers. Moreover, calcium alginate gel beads were found the most conductive and proper entrapment carrier for maximum production of paclitaxel. The feasibility of the paclitaxel production by the immobilized mycelia as affected by incubation period, medium volume, and number of beads per flask was adopted. Under the favorable immobilization conditions, the paclitaxel titers were significantly intensified to 1.31- and 1.88-fold by the respective mutants, as compared by their free cultures. The obtained paclitaxel titers by the immobilized mycelia of the respective mutants (694.67 and 388.65 μg L^-1) were found promising in terms of fungal production of paclitaxel. Hence, these findings indicate the future possibility to reduce the cost of producing paclitaxel and suggest application of the immobilization technique for the biotechnological production of paclitaxel at an industrial scale.

Paclitaxel-Coated Balloon Angioplasty Versus Drug-Eluting Stent in Acute Myocardial Infarction: The REVELATION Randomized Trial

OBJECTIVES

This study sought to assess the efficacy and safety of a drug-coated balloon (DCB) strategy versus drug-eluting stent (DES) in primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

In primary percutaneous coronary intervention for STEMI, stenting has proved to be beneficial with regard to repeat revascularization, but not recurrent myocardial infarction or death, compared with balloon angioplasty alone. A strategy of DCB angioplasty without stenting might abolish the potential disadvantages of stent implantation while reducing the probability of restenosis observed in plain old balloon angioplasty.

METHODS

In the prospective, randomized, single-center REVELATION trial, we compared DCB with DES in patients presenting with STEMI. Patients with a new, nonseverely calcified culprit lesion in a native coronary artery and a residual stenosis of <50% after pre-dilatation were randomized to treatment with a DCB or DES. The primary endpoint was fractional flow reserve at 9 months, allowing for a functional measurement of the infarct-related lesion.

RESULTS

A total of 120 patients were included. At 9 months after enrolment, the mean fractional flow reserve value was 0.92 ± 0.05 in the DCB group (n = 35) and 0.91 ± 0.06 in the DES group (n = 38) (p = 0.27). One abrupt vessel closure requiring treatment occurred after treatment with DCB. Up to 9-months follow-up, 2 patients required nonurgent target lesion revascularization (1 in each group).

CONCLUSIONS

In the setting of STEMI, the DCB strategy was noninferior to DES in terms of fractional flow reserve assessed at 9 months. Furthermore, it seemed to be a safe and feasible strategy. (Revascularization With Paclitaxel-Coated Balloon Angioplasty Versus Drug-Eluting Stenting in Acute Myocardial Infarction [REVELATION]; NCT02219802).

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.

Meta-analysis of the effects of drug-coated balloons among patients with small-vessel coronary artery disease

OBJECTIVE

This study evaluated the clinical value of drug-coated balloons for patients with small-vessel coronary artery disease (SVD).

METHODS

A computerized literature search was performed using the databases to conduct a meta-analysis and evaluate the clinical value of drug-coated balloons among patients with SVD.

RESULTS

This review enrolling 1545 patients receiving drug-coated balloons and 1010 patients receiving stents (including drug-eluting stents and bare-metal stents). The meta-analysis results showed that the incidence of major adverse cardiovascular events among patients with SVD did not significantly differ between the drug-coated balloon group and the stent group within 1 postoperative year (odds ratio = 0.81, P = .5). A subgroup analysis showed that the incidence of myocardial infarction among the drug-coated balloon group was significantly lower than that among the stent group (odds ratio = 0.58, P = .04). Nevertheless, the late lumen loss of the drug-coated balloon group was significantly lower than that of the stent group (mean difference = 0.31, P = .01).

CONCLUSIONS

Drug-coated balloons can be used to effectively reduce the incidence of myocardial infarction in patients with SVD within 1 year and decrease the extent of late lumen loss without increasing the incidence of major adverse cardiovascular events.

Safety and Long-Term Efficacy of Drug-Coated Balloon Angioplasty following Rotational Atherectomy for Severely Calcified Coronary Lesions Compared with New Generation Drug-Eluting Stents

Objectives

This study sought to assess the safety and long-term efficacy of drug-coated balloons (DCB) following aggressive intracoronary image-guided rotational atherectomy (iRA) for severe coronary artery calcification (CAC), and to compare this strategy with new generation drug-eluting stents (nDES) following iRA.

Background

Ischemic events following the treatment of CAC is still relatively high. Thus, more innovative strategies are required.

Methods

We evaluated 123 consecutive patients (166 lesions) with de novo CAC undergoing an iRA (burr size; 0.7 of the mean reference diameter by intracoronary imaging) followed by DCB (DCB-iRA; 54 patients, 68 lesions) or nDES (nDES-iRA; 69 patients, 98 lesions). Follow-up angiography was obtained at > 6 months.

Results

The target vessels (right coronary and circumflex), bifurcation (67.6% versus 47.9%), reference diameter (2.28mm versus 2.49mm), and lesion length (11.89mm versus 18.78mm) were significantly different between the two groups. The median follow-up was 732 days. TLR and TVR in DCB-iRA and nDES-iRA at 3 years were similar: 15.6% versus 16.3% (P=0.99) and 15.6% versus 23.3% (P=0.38). In 41 well-matched lesion pairs after propensity score analysis, the cumulative incidence of TLR and TVR in DCB-iRA and nDES-iRA at 3 years was 12.9% versus 16.3% (P=0.70) and 12.9% versus 26.1% (P=0.17), respectively. On QCA analysis, although the acute gain was smaller in DCB-iRA (0.85 mm versus 1.53 mm, P<0.001), the minimum lumen diameter at follow-up was similar (1.69 mm versus 1.87 mm, P=0.29). The late lumen loss was lower (0.09 mm versus 0.52 mm, P=0.009) in DCB-iRA.

Conclusions

DCB-iRA is feasible for CAC.

Long-term efficacy of drug coated balloons compared with new generation drug-eluting stents for the treatment of de novo coronary artery lesions

BACKGROUND

Studies comparing drug coated balloons (DCB) with new generation drug-eluting stents (nDES) for the treatment of de novo coronary artery lesions are lacking.

METHODS

From 2009 to 2016, DCB or nDES used for treatment of de novo coronary lesions at our institution were included, in total 1,197 DEB and 6,458 nDES. We evaluated target lesions restenosis (TLR) and definite target lesion thrombosis (TLT). Propensity score modeling were utilized to study adjusted associations between treatment and outcomes.

RESULTS

Median follow-up was 901days. DCB patients were older, with higher cardiovascular risk profile. Bailout stenting after DCB was performed in 8% of lesions. The cumulative rate of TLR and TLT was 7.0 vs. 4.9% and 0.2 vs. 0.8% for DCB vs. nDES, respectively. Before adjustment, DCB was associated with a higher risk of TLR [hazard ratio (HR) 1.44; 95% confidence interval (CI) 1.07-1.94] and a non-significantly lower risk of TLT (HR 0.30; 95% CI 0.07-1.24), compared to nDES. In the propensity matched population consisted of 1,197 DCB and 1,197 nDES, treatment with DCB was associated with similar risk for TLR (adjusted HR 1.05; 95% CI 0.72-1.53) but significantly lower risk for TLT (adjusted HR 0.18; 95% CI 0.04-0.82) compared to nDES.

CONCLUSIONS

Treatment with DCB was associated with a similar risk of TLR and a lower risk of definite TLT compared with nDES. In selected cases, DCB appears as a good alternative to nDES for the treatment of de novo coronary lesions.

Midterm results with drug-coated balloons for SFA lesions in patients with CLI: comparison with conventional bypass surgery

BACKGROUND

Endovascular treatment of symptomatic peripheral artery disease has gained widespread acceptance. The efficacy and safety of drug-coated balloon (DCB) angioplasty in the setting of critical limb ischemia in comparison to conventional surgery has not been demonstrated. We have compared our results with DCB angioplasty to conventional bypass surgery in patients with critical limb ischemia (CLI).

METHODS

A total of 187 patients with CLI treated over a 6-year period between 2006 and 2012 by a single operative team constituted the study population. Between 2006 and 2009, all patients underwent conventional surgery. Between 2009 and 2012, the investigators adopted endovascular approach with the use of IN.PACT Admiral (Medtronic Inc., Santa Rosa, CA, USA). Data collection was achieved prospectively.

RESULTS

A total 210 procedures (100 surgery, 110 endovascular) were performed over a 6-year period. A 72% of all bypasses were performed using saphenous vein grafts with above-the-knee bypass as the technique of choice in 80% of the cases. 6-mm DCB was used in 41% of the patients. Procedural success rates (98% vs. 99%, NS) as well as clinical success rates (99% vs. 99%, P=NS) and operative mortality (3.7% vs. 2%, NS) was similar in both groups. Primary patency for DCB vs. bypass groups 91.8% vs. 88.9%, respectively (P=0.31) at 12 months and 82.7% vs. 82.8% at 24 months, respectively (P=0.28). Freedom from clinically-driven target lesion revascularization at 12 months was similar in both groups (87.6% vs. 85%, P=0.33). Primary patency for DCB vs. bypass groups at 24 months was 82.7% vs. 82.8%, respectively (P=0.28).

CONCLUSIONS

DCB angioplasty yields comparable results to surgery in the setting of critical ischemia. The efficacy and the safety of DCBs in more complex lesions is to be investigated with randomized trials.

Linear Micro-patterned Drug Eluting Balloon (LMDEB) for Enhanced Endovascular Drug Delivery

In-stent restenosis (ISR) often occurs after applying drug eluting stents to the blood vessels suffering from atherosclerosis or thrombosis. For treatment of ISR, drug eluting balloons (DEB) have been developed to deliver anti-proliferative drugs to the lesions with ISR. However, there are still limitations of DEB such as low drug delivery efficiency and drug loss to blood flow. Although most researches have focused on alteration of drug formulation for more efficient drug delivery, there are few studies that have attempted to understand and utilize the contact modality of DEB drug delivery. Here, we developed a linear micro-patterned DEB (LMDEB) that applied higher contact pressure to enhance drug stamping to vascular tissue. Ex vivo and in vivo studies confirmed that higher contact pressure from micro-patterns increased the amount of drug delivered to the deeper regions of vessel. Finite element method simulation also showed significant increase of contact pressure between endothelium and micro-patterns. Quantitative analysis by high performance liquid chromatography indicated that LMDEBs delivered 2.3 times higher amount of drug to vascular tissue in vivo than conventional DEBs. Finally, efficacy studies using both atherosclerotic and ISR models demonstrated superior patency of diseased vessels treated with LMDEB compared to those treated with DEB.

Positive Vessel Remodelling

Since its introduction, the success of percutaneous transluminal coronary angioplasty (PTCA) has been jeopardised by recoil, neointima proliferation, and luminal renarrowing; however, the benefit of positive remodelling has not gained widespread attention. While vessels will remodel positively up to a certain stage in the development of atherosclerosis, the therapeutic application of this process remains low. The prevention of vessel shrinkage during the healing process, which represents the predominant mechanism of restenosis after PTCA, is a prerequisite of long-term success in PTCA. The antiproliferative drugs that are currently used mainly on stents are known to be capable of this. Primary clinical studies have reported that positive remodelling leads to beneficial effects in coronary and peripheral angioplasty if no foreign body is inserted, and a paradigm change in percutaneous coronary intervention towards far fewer implants is within reach.

Drug-eluting balloon: design, technology and clinical aspects

A drug-eluting balloon is a non-stent technology in which the effective homogenous delivery of anti-proliferative drugs is processed by the vessel wall through an inflated balloon. This is done to restore luminal vascularity in order to treat atherosclerosis, in-stent restenosis and reduce the risk of late thrombosis without implanting a permanent foreign object. The balloon technology relies on the concept of targeted drug delivery, which helps in the rapid healing of the vessel wall and prevents the proliferation of smooth muscle cells. Several drug eluting devices in the form of coated balloons are currently in clinical use, namely DIOR^®, PACCOCATH^®, SeQuent^®Please and IN.PACT™. The device varies in terms of the material used for making the balloon, the coating techniques, the choice of coated drug and the release pattern of the drug at the site. This review gives an insight into the evolution, rationale and comparison of the marketed drug-eluting balloons. Here, different coating techniques have been analysed for the application and critical analysis of available DEB technologies, and a technical comparison has been done.

Paclitaxel-Coated Balloon for Femoropopliteal Artery Disease

PURPOSE OF THE REVIEW

Percutaneous transluminal angioplasty is an established form of therapy for femoropopliteal artery disease. Currently, percutaneous transluminal angioplasty (PTA) is carried out using standard balloon with or without deployment of a stent but is associated with a high rate of restenosis and stent-related complications. Treatment options for restenosis, especially in-stent restenosis, are limited. Drug-coated balloons promise to reduce the rates of restenosis by effective delivery of antiproliferative agent (paclitaxel) directly to vessel wall without the need for a permanent implant. In this review, we look at the technology and rationale behind drug-coated balloons and examine the evidence available so far.

RECENT FINDINGS

Recently, several studies tested the effectiveness of paclitaxel-coated balloon angioplasty compared to that of standard PTA in both de novo lesions and in-stent restenosis of femoropopliteal artery. Paclitaxel-coated balloon use resulted in reduced rates of restenosis and favourable clinical outcomes in both these lesion groups. However, in complex lesions, there is still lack of data to support the use of these balloons. Paclitaxel-coated balloon is a safe and effective therapeutic option in patients with both de novo lesions and in-stent restenosis involving femoropopliteal artery. In light of the new evidence, it is time to consider incorporation of this effective therapeutic option into clinical practice. However, further research is needed for the use of paclitaxel-coated balloons in complex femoropopliteal lesions like calcified lesions especially as adjuncts to cutting balloons and debulking strategies.

ISAR-PEBIS (Paclitaxel-Eluting Balloon Versus Conventional Balloon Angioplasty for In-Stent Restenosis of Superficial Femoral Artery): A Randomized Trial

Background

Paclitaxel‐eluting balloon (PEB) angioplasty has superior efficacy compared with conventional balloon angioplasty (BA) for de novo lesions of superficial femoral artery (SFA). Studies investigating the angiographic and clinical performance of PEB angioplasty versus BA for in‐stent restenosis of SFA are limited. We performed a randomized trial to investigate angiographic and clinical performance of PEB versus BA for in‐stent restenosis of SFA.

Methods and Results

Patients with symptomatic in‐stent restenosis of SFA were randomly assigned to either PEB or BA at 2 centers in Munich, Germany. The primary end point was the percentage diameter stenosis at 6‐ to 8‐month follow‐up angiography. Secondary end points were the rate of binary restenosis at follow‐up angiography and target lesion revascularization, target vessel thrombosis, ipsilateral amputation, bypass surgery of the affected limb, and all‐cause mortality at 24‐month follow‐up. Seventy patients were assigned to PEB (n=36) or BA (n=34). Mean lesion length was 139±67 mm, and roughly one third of lesions were completely occluded at the time of the index procedure. At control angiography, the percentage diameter stenosis (44±33% versus 65±33%, P=0.01) and binary restenosis were significantly reduced with PEB versus BA (30% versus 59%, P=0.03). At 24‐month follow‐up, PEB was associated with a significant reduction of target lesion revascularization in comparison to BA (19% versus 50%, P=0.007). There was no difference with respect to other outcomes of interest.

Conclusions

In patients with in‐stent restenosis of SFA, a percutaneous therapy with PEB compared with BA has superior angiographic performance at 6 to 8 months and improved clinical efficacy up to 24‐month follow‐up.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01083394.

Production of paclitaxel with anticancer activity by two local fungal endophytes, Aspergillus fumigatus and Alternaria tenuissima

Among 60 fungal endophytes isolated from twigs, bark, and mature leaves of different plant species, two fungal isolates named TXD105 and TER995 were capable of producing paclitaxel in amounts of up to 84.41 and 37.92 μg L^-1, respectively. Based on macroscopic and microscopic characteristics, ITS1-5.8S-ITS2 rDNA sequence, and phylogenetic characteristic analysis, the two respective isolates were identified as Aspergillus fumigatus and Alternaria tenuissima. In the effort to increase paclitaxel magnitude by the two fungal strains, several fermentation conditions including selection of the proper fermentation medium, agitation rate, incubation temperature, fermentation period, medium pH, medium volume, and inoculum nature (size and age of inoculum) were tried. Fermentation process carried out in M1D medium (pH 6.0) and maintained at 120 rpm for 10 days and at 25 °C using 4% (v/v) inoculum of 5-day-old culture stimulated the highest paclitaxel production to attain 307.03 μg L^-1 by the A. fumigatus strain. In the case of the A. tenuissima strain, fermentation conditions conducted in flask basal medium (pH 6.0) and maintained at 120 rpm for 14 days and at 25 °C using 8% (v/v) inoculum of 7-day-old culture were found the most favorable to attain the highest paclitaxel production of 124.32 μg L^-1. Using the MTT-based assay, fungal paclitaxel significantly inhibited the proliferation of five different cancer cell lines with 50% inhibitory concentration values varied from 3.04 to 14.8 μg mL^-1. Hence, these findings offer new and alternate sources with excellent biotechnological potential for paclitaxel production by fungal fermentation.