Critical review and evidence implications of paclitaxel drug-eluting balloons and stents in peripheral artery disease

"Evolution of Drug-Coated Devices for the Treatment of Chronic Limb Threatening Ischemia"

For patients with Chronic Limb Threatening Ischemia (CLTI), endovascular approaches to revascularization are often employed as a component of multimodality care aimed at limb preservation. However, patients with CLTI are also prone to treatment failure, particularly following balloon angioplasty alone. Drug-coated devices utilizing Paclitaxel were developed to decrease restenosis but have been primarily studied in patients presenting with claudication. In recent years, data have emerged which describe the efficacy of drug-coated devices in the treatment of patients with CLTI. Concurrently, there has been major controversy surrounding the use of drug-coated devices in peripheral arterial disease. A historical narrative of the development and use of drug-coated devices for peripheral arterial disease is presented, along with discussion of major trials. Evidence argues that paclitaxel-based therapies for peripheral arterial disease (PAD) do not increase mortality risk compared to nondrug-coated devices. In CLTI patients, paclitaxel-based balloons and stents provide superior patency and freedom reintervention compared to nondrug-coated devices when treating femoropopliteal disease. However, the use of Paclitaxel-based therapies for below-the-knee (BTK) interventions has not been shown to provide clinically meaningful outcomes compared to nondrug-based therapies. Newer generation antiproliferative agents (Sirolimus, Everolimus) and delivery systems (bioabsorbable scaffolds) hold promise for BTK interventions with early data suggesting decreased rates of major amputation or major adverse limb events.

Drug-eluting devices for lower limb peripheral arterial disease

Peripheral arterial disease is the third leading cause of cardiovascular morbidity after coronary artery disease and stroke. Lower limb peripheral arterial disease commonly involves infrainguinal arteries, may impair walking ability (intermittent claudication) and may confer a significant risk of limb loss (chronic limb-threatening ischaemia), depending on the severity of ischaemia. Endovascular treatment has become the mainstay revascularisation option in both the femoropopliteal and the below-the-knee arterial segments. After crossing and preparing the lesion, treatment results in these arterial segments can be enhanced by using drug-coated devices (drug-eluting stents and drug-coated balloons) that mitigate the occurrence of restenosis. As for other medical devices, the use of drug-eluting devices is based on their demonstrated safety and efficacy profiles when applied in the distinct segments of the lower limb vasculature. In this state-of-the-art narrative review we provide an overview of the safety and efficacy of drug-coated devices when used in the femoropopliteal and below-the-knee arterial segments.

Different drugs in drug-eluting stents for peripheral artery disease: a systematic evaluation and Bayesian meta-analysis

Drug-eluting stents (DESs) have become the first-line treatment for symptomatic peripheral arterial disease (PAD). Currently, there are many types of DESs on the market. The same type of DESs has different concentrations, and various drugs in them show uneven efficacy. The selection of DESs remains controversial. This study was aimed at comparing the long-term real-world outcomes of different DESs in the treatment of peripheral arterial occlusive disease (PAOD). The databases including Cochrane Library, Embase, and PubMed were searched with a time frame until March 25, 2023. The primary patency (PP) and target lesion revascularization (TLR) at 6 months were used as the primary endpoints. A total of 32 studies (5467 patients) were eligible. At the six-month follow-up, DES-Evero 1 ug/mm2 ranked first in terms of PP, with a significant difference from BMSs (RR [95% CI] = 1.6). DES-Siro 0.9 ug/mm2, DES-Siro 1.4 ug/mm2, DES-Siro 1.95 ug/mm2, DES-PTX 0.167 ug/mm2, DES-PTX 1 ug/mm2 and covered stents (CSs) showed significantly better PPs than BMSs. In terms of TLR, DES-Siro 0.9 ug/mm2 (0.31) ranked first, and DES-Evero 1 ug/mm2 ranked last. Among the treatment modalities for PAD, different DESs showed overall encouraging results in improving PP and TLR compared with BMSs. DES-Evero 1 ug/mm2 showed the best PP, but it had the highest reintervention rate at 6 months. Sirolimus-eluting stents were not always more effective with higher concentrations of sirolimus. Among various DESs, sirolimus-eluting stents and everolimus-eluting stents were superior to paclitaxel-eluting stents.

Advanced Endovascular Techniques for Limb Salvage

As the number of patients affected by peripheral arterial disease continues to increase, new technical approaches and devices have been developed to provide effective and durable treatment options that will lead to improved outcomes. While the mainstay of endovascular intervention remains mostly balloon-based, several innovative techniques and technologies are in development that may provide new solutions. This review highlights recent endovascular advancements in the management of chronic limb-threatening ischemia and additional adjunctive devices that are needed to improve lesion patency, reduce the need for reintervention, and lead to better patient-centered functional outcomes.

Paclitaxel Protects against Isoproterenol-Induced Damage in Rat Myocardium: Its Heme-Oxygenase Mediated Role in Cardiovascular Research

(1) Background: In cardiovascular applications, paclitaxel inhibits smooth muscle cell proliferation and migration and significantly reduces the occurrence of restenosis and target lesion revascularization. However, the cellular effects of paclitaxel in the myocardium are not well understood; (2) Methods: Wistar rats were divided into four groups: control (CTRL), isoproterenol (ISO) treated (1 mg/kg) and two groups treated with paclitaxel (PAC), which was administrated (10 mg/kg/day) for 5 days by gavage/per os alone or in combination (ISO + PAC) 3 weeks after ISO treatment. Ventricular tissue was harvested 24 h later for measurements of heme oxygenase (HO-1), reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), NF-κB, TNF-α and myeloperoxidase (MPO); (3) Results: HO-1 protein concentration, HO-1 activity, SOD protein concentration and total glutathione significantly decreased in response to ISO treatment. When PAC was administered in conjunction with ISO, HO-1, SOD concentration and total glutathione were not different from control levels. MPO activity, NF-κB concentration and TNF-α protein concentration were significantly increased in the ISO-only group, while the levels of these molecules were restored when PAC was co-administered; (4) Conclusions: Oral administration of PAC can maintain the expression of important antioxidants, anti-inflammatory molecules, HO-1, SOD and GSH, and suppress the production of TNF-α, MPO and NF-κB, which are involved in myocardial damage. The principal component of this cellular defense seems to be the expression of HO-1.

A systematic review and meta-analysis of sirolimus-eluting stents for treatment of below-the-knee arterial disease

OBJECTIVE

We performed a systematic review and meta-analysis to analyze the efficacy and safety of sirolimus-eluting stents (SESs) in the treatment of below-the-knee (BTK) arterial disease.

METHODS

An electronic literature search was conducted from inception to July 24, 2021. Retrospective, prospective, and randomized studies that had used SESs to treat BTK arterial disease and had reported the primary patency, technical success, target lesion revascularization, and/or mortality were included. Meta-analyses of the proportions were conducted to derive pooled summary statistics of the outcomes. Where Kaplan-Meier curves were provided for primary patency, a meta-analysis of the individual patient data was conducted via a graphic reconstruction tool to estimate primary patency at various follow-up points. For studies comparing SESs and bare metal stents (BMSs), a two-stage meta-analysis was performed to compare the 6-month primary patency of SESs vs BMSs.

RESULTS

Ten studies across 13 publications, including 995 patients, were retrieved for analysis. In the meta-analysis of proportions, across six studies (n = 339 patients), the pooled 6-month primary patency was 87.3% (95% confidence interval [CI], 81.6%-92.1%). Across seven studies (n = 283 patients), the pooled 6-month mortality was 5.4% (95% CI, 1.4%-11.2%). An individual patient data analysis of three studies (n = 282 patients) yielded a primary patency rate of 95.2% (95% CI, 92.7%-97.8%), 82.8% (95% CI, 78.3%-87.6%), 79.8% (95% CI, 75.0%-85.0%), and 79.8% (95% CI, 75.0%-85.0%) at 6, 12, 18, and 24 months, respectively. The 12-month target lesion revascularization rate across four studies (n = 324 patients) was 9.6% (95% CI, 6.4%-13.4%). In the two-stage meta-analysis of 6-month primary patency across three studies (n = 168 patients), the use of SESs was significantly favored over BMSs (risk ratio, 1.28; 95% CI, 1.12-1.46; P < .001).

CONCLUSIONS

The overall evidence suggests that the use of SESs appears to be safe and offers favorable outcomes for BTK arterial disease compared with BMSs.

Endovascular treatment of high-risk peripheral vascular occlusive lesions: a review of current evidence and emerging applications of intravascular lithotripsy, atherectomy, and paclitaxel-coated devices

Endovascular treatment of peripheral arterial disease has evolved and expanded rapidly over the last 20 years. New technologies have increased the diversity of devices available and have made it possible to approach even the most challenging and high-risk lesions using endovascular techniques. In this review, we examine the clinical evidence available for several categories of endovascular devices available to treat peripheral arterial disease, including intravascular lithotripsy, atherectomy, and drug-coated devices. The best application for some technologies, such as intravascular lithotripsy and atherectomies, have yet to be identified. In contrast, drug-coated devices have an established role in patients at high risk for long-term failure, but have been the subject of much controversy, given recent concerns about possible adverse effects of paclitaxel. Future investigation should further assess these technologies in patients with complex disease using updated staging systems and outcomes with direct clinical relevance, such as functional improvement, wound healing, and freedom from recurrent symptoms.

2-Year Outcomes of the Eluvia Drug-Eluting Stent for the Treatment of Complex Femoropopliteal Lesions

OBJECTIVES

The aim of this study was to evaluate the 2-year performance of a polymer-based drug-eluting stent (DES) for the treatment of complex femoropopliteal lesions.

BACKGROUND

Despite the promising early outcomes of the Eluvia DES, the long-term safety and efficacy of the device in a real-world scenario remain unclear.

METHODS

Between March 2016 and December 2018, 130 patients (137 lesions) with symptomatic femoropopliteal disease were included in this study. The primary outcome measure of this analysis was primary patency. Secondary patency, freedom from target lesion revascularization, freedom from surgical conversion, and overall mortality and morbidity were additionally analyzed.

RESULTS

The majority of patients presented with lifestyle-limiting claudication (n = 90 [69%]). The mean lesion length was 194 ± 108 mm, 74% of the lesions (n = 101) were chronic total occlusions, and 72% (n = 99) were calcified. Moderate to severe calcification (Peripheral Arterial Calcium Scoring Scale score 3 or 4) was observed in 48% of the treated vessels (n = 67). At 24 months, the Kaplan-Meier estimate of primary patency was 71%, whereas both the secondary patency rate and freedom from target lesion revascularization were 80%. Overall survival amounted to 85%. Freedom from major amputation was 98%, while freedom from surgical conversion was 89%. Degeneration of the vessel wall was observed in 27 lesions (20%).

CONCLUSIONS

In this study, use of the Eluvia polymer-based DES for the treatment of complex femoropopliteal disease showed promising 2-year results. Nonetheless, a relatively high rate of vessel wall degeneration was observed after DES deployment.

Paclitaxel Exposure and Dosage of Drug-coated Devices for the Treatment of Femoropopliteal Peripheral Artery Disease

The role of paclitaxel in the treatment of femoropopliteal peripheral arterial disease is currently ambiguous. A summary-level meta-analysis of randomised trials published in 2018 demonstrated that paclitaxel-coated devices were associated with an increased all-cause mortality in those who underwent treatment at 2 years and 5 years. Further evaluation has been undertaken to establish whether there is a specific dose response, mechanism or reproducible signal. At this time, there has been no confirmation of dose response, as was initially asserted by the summary-level meta-analysis. No mechanism of harm has been identified. Although an association with increased mortality has been confirmed by patient-level meta-analysis, the strength of the signal has been inconsistent. The information suggests there is only an association between paclitaxel-coated devices and increased all-cause mortality, not causation. The authors encourage additional studies designed to follow long-term results after treatment with paclitaxel-coated devices, using real patient data, before a conclusion can be made.

Pain Management in People with Diabetes-Related Chronic Limb-Threatening Ischemia

Management of neuropathic pain in people with diabetes has been widely investigated. However, little attention was paid to address ischemic-related pain in patients with diabetes mellitus who suffered from chronic limb-threatening ischemia (CLTI), the end stage of lower extremity arterial disease (LEAD). Pain management has a tremendous influence on patients' quality of life and prognosis. Poor management of this type of pain owing to the lack of full understanding undermines patients' physical and mental quality of life, which often results in a grim prognosis, such as depression, myocardial infarction, lower limb amputation, and even mortality. In the present article, we review the current strategy in the pain management of diabetes-related CLTI. The endovascular therapy, pharmacological therapies, and other optional methods could be selected following comprehensive assessments to mitigate ischemic-related pain, in line with our current clinical practice. It is very important for clinicians and patients to strengthen the understanding and build intervention strategy in ischemic pain management and possible adverse consequence.

The current status of drug-coated devices in lower extremity peripheral artery disease interventions

Lower limb peripheral artery disease is a leading cause of cardiovascular disease morbidity and mortality. Endovascular revascularization is often indicated to improve walking function and to prevent limb loss but restenosis in the treated vessel segment remains a concern that limits the overall effectiveness of the treatment. The most promising technique to prevent restenosis is the use of drug-coated devices, and the most common drug used to coat lower limb balloon angioplasty balloons and stents is paclitaxel. A systematic review and meta-analysis in 2018 reported a possible increase in late mortality attributable to paclitaxel-coated devices. Since then, their use has been brought into question. Here, we present an update of data focusing on the efficacy and safety of paclitaxel-coated devices in lower limb treatment applications. While paclitaxel-coated devices appear to reduce restenosis rates it is still unclear how these surrogate marker improvements translate to direct patient benefits and uncertainty remains as to whether paclitaxel-coated devices confer an increased risk of long-term mortality. Available randomized clinical data is hampered by trial heterogeneity, insufficient power, potential attrition bias and the lack of a plausible mechanistic explanation. An important step forward is that the ongoing trials that were temporarily halted due to the Katsanos et al. report have now both commenced recruitment and may ultimately resolve this clinical dilemma by virtue of their larger sample sizes. Other possible ways forward are the ongoing investigation of alternative anti-proliferative coating agents and use of new sophisticated vascular imaging techniques to more clearly identify patients at risk of restenosis already in the preoperative setting.

Comparison of morphometric, structural, mechanical, and physiologic characteristics of human superficial femoral and popliteal arteries

Peripheral arterial disease differentially affects the superficial femoral (SFA) and the popliteal (PA) arteries, but their morphometric, structural, mechanical, and physiologic differences are poorly understood. SFAs and PAs from 125 human subjects (age 13-92, average 52±17 years) were compared in terms of radii, wall thickness, and opening angles. Structure and vascular disease were quantified using histology, mechanical properties were determined with planar biaxial extension, and constitutive modeling was used to calculate the physiologic stress-stretch state, elastic energy, and the circumferential physiologic stiffness. SFAs had larger radii than PAs, and both segments widened with age. Young SFAs were 5% thicker, but in old subjects the PAs were thicker. Circumferential (SFA: 96→193°, PA: 105→139°) and longitudinal (SFA: 139→306°, PA: 133→320°) opening angles increased with age in both segments. PAs were more diseased than SFAs and had 11% thicker intima. With age, intimal thickness increased 8.5-fold, but medial thickness remained unchanged (620μm) in both arteries. SFAs had 30% more elastin than the PAs, and its density decreased ~50% with age. SFAs were more compliant than PAs circumferentially, but there was no difference longitudinally. Physiologic circumferential stress and stiffness were 21% and 11% higher in the SFA than in the PA across all ages. The stored elastic energy decreased with age (SFA: 1.4→0.4kPa, PA: 2.5→0.3kPa). While the SFA and PA demonstrate appreciable differences, most of them are due to vascular disease. When pathology is the same, so are the mechanical properties, but not the physiologic characteristics that remain distinct due to geometrical differences.

Long-term safety of paclitaxel drug-coated balloon-only angioplasty for de novo coronary artery disease: the SPARTAN DCB study

OBJECTIVES

We aimed to investigate long-term survival of paclitaxel DCB for percutaneous coronary intervention (PCI).

BACKGROUND

Safety concerns have been raised over the use of paclitaxel devices for peripheral artery disease recently, following a meta-analysis suggesting increased late mortality. With regard to drug-coated balloon (DCB) angioplasty for coronary artery intervention however, there is limited data to date regarding possible late mortality relating to paclitaxel.

METHODS

We compared all-cause mortality of patients treated with paclitaxel DCB to those with non-paclitaxel second-generation drug-eluting stents (DES) for stable, de novo coronary artery disease from 1st January 2011 till 31st December 2018. To have homogenous groups allowing data on safety to be interpreted accurately, we excluded patients with previous PCI and patients treated with a combination of both DCB and DES in subsequent PCIs. Data were analysed with Kaplan-Meier curves and Cox regression statistical models.

RESULTS

We present 1517 patients; 429 treated with paclitaxel DCB and 1088 treated with DES. On univariate analysis, age, hypercholesterolaemia, hypertension, peripheral vascular disease, prior myocardial infarction, heart failure, smoking, atrial fibrillation, decreasing estimated glomerular filtration rate (eGFR) [and renal failure (eGFR < 45)] were associated with worse survival. DCB intervention showed a non-significant trend towards better prognosis compared to DES (p = 0.08). On multivariable analysis age, decreasing eGFR and smoking associated with worse prognosis.

CONCLUSION

We found no evidence of late mortality associated with DCB angioplasty compared with non-paclitaxel second-generation DES in up to 5 years follow-up. DCB is a safe option for the treatment of de novo coronary artery disease.

Aneurysmal Degeneration After Paclitaxel-Eluting Balloon Angioplasty

Aneurysmal degeneration after peripheral angioplasty is a potentially serious complication. In this case, the patient underwent repeated angioplasty of a prior vein bypass graft utilizing a paclitaxel-coated balloon. He subsequently developed a progressive aneurysmal degeneration, threatening his bypass, which ultimately required an urgent exclusion with a covered stent. This case represents a rare complication of peripheral bypass graft related to percutaneous intervention as well as paclitaxel-coated devices and warns other practitioners of the increased scrutiny and caution one should exercise in the use of such interventions.

Pre-Clinical Investigation of Liquid Paclitaxel for Local Drug Delivery: A Pilot Study

The purpose of this pilot study was to investigate the feasibility of a perfusion catheter to deliver liquid paclitaxel into arterial segments. A clinically relevant rabbit ilio-femoral injury model was utilized to determine the impact of liquid paclitaxel delivered locally into the vessel wall using a perfusion catheter at 1 h to 14 days. Treatment by two clinically available forms of liquid paclitaxel, a solvent-based (sb) versus an albumin-bound (nab), along with a control (uncoated balloons), were investigated. Pharmacokinetic results demonstrated an increase in the retention of the sb-paclitaxel versus the nab-paclitaxel at 1 h; however, no other differences were observed at days one, three, and seven. Histological findings at 14 days showed significantly less neointimal area in the sb-paclitaxel treated arteries as compared with the nab-paclitaxel and the uncoated balloon-treated arteries. Additionally, percent area stenosis was significantly less in the sb-paclitaxel group. These results support the concept of local liquid delivery of paclitaxel into the arterial segments.

Diffuse Cutaneous Manifestations after Drug-Coated Balloon Angioplasty

We present here a case of an uncommon cutaneous manifestation after paclitaxel-coated balloon angioplasty. In this case, the patient underwent drug-coated balloon angioplasty for stenosis of a prior vein bypass graft. The patient subsequently developed extensive cutaneous lesions not confined to a single arterial distribution. This case represents a rare complication related to paclitaxel-eluting balloons and provides a cautionary tale as well as clinical acumen for providers in using such devices in their practice.

Zilver PTX peripheral paclitaxel-eluting stent: a technology evaluation

INTRODUCTION

The Zilver PTX stent was the first self-expanding drug-coated stent approved by the United States Food and Drug Administration (US FDA) for use in the superficial femoral artery (SFA) above the knee. The main objective of this article is to review the design, safety, and efficacy of the Zilver PTX stent which was engineered to outperform bare metal stents (BMS) in this challenging environment.

AREAS COVERED

An evaluation of the Zilver PTX peripheral paclitaxel-coated stent design and a review of the current preclinical and clinical evidence regarding the use of this stent.

EXPERT OPINION

Stent implantation for the treatment of peripheral arterial disease (PAD) in the SFA was initially seen as a salvage option; however, stenting is now routinely offered as initial therapy for patients suffering from claudication and critical limb ischemia. The Zilver PTX stent has established efficacy and safety profiles for paclitaxel in the SFA; however, the development of biocompatible polymers capable of extending the elution time of anti-proliferative agents may lead to more effective stent platforms.

New Innovations and Devices in the Management of Chronic Limb-Threatening Ischemia

As the number of patients afflicted by chronic limb-threatening ischemia (CLTI) continues to grow, new solutions are necessary to provide effective, durable treatment options that will lead to improved outcomes. The diagnosis of CLTI remains mostly clinical, and endovascular revascularization remains mostly balloon-based. Multiple innovative techniques and technologies are in development or in early usage that may provide new solutions. This review categorizes areas of advancement, highlights recent developments in the management of CLTI and looks forward to novel devices that are currently under investigation.

Nutritional status and outcomes of superficial femoral artery stenting due to intermittent claudication

BACKGROUND

The pathogenesis of in-stent restenosis is still not clear. The aim of this study was to determine the nutritional status of patients with lower limb ischemia and the risk of target lesion revascularization (TLR) after superficial femoral artery (SFA) stenting.

METHODS

Numerous parameters of nutritional status assessment were compared between 70 patients undergoing SFA endovascular intervention with a self-expandable plane stent due to life-limiting intermittent claudication and 40 patients undergoing carotid artery stenting (CAS). All subjects were followed up for at least 1 year in relation to outcomes such as clinically driven TLR occurrence.

RESULTS

Patients undergoing SFA stenting had a lower prevalence of overweight and obesity than those who underwent CAS (51.43% vs. 72.50%; P=0.031). An increase in Ankle-Brachial Index of >0.15 after SFA stenting (early end-point) was positively associated with greater handgrip strength (HGS), fat-free mass, skeletal muscle mass and waist-to-hip ratio. Freedom from TLR (late end-point) was significantly related to a higher waist-to-height ratio (WHtR), HGS and Geriatric Nutritional Risk Index (GNRI) Score. The 1-year risk of TLR for patients with a WHtR of ≥61.39 amounted to odds ratio; 95% confidence interval: 0.21; 0.05-0.25; P=0.021.

CONCLUSIONS

Parameters of nutritional status assessment were associated with early and late outcomes of SFA stenting in patients with intermittent claudication. Abdominal fat distribution and higher HGS and GNRI scores lowered the 1-year risk of TLR. Further study is needed to determine the pathomechanism of the obesity paradox, sarcopenia and undernutrition in relation to outcomes of endovascular interventions.