Efficacy Of Drug-eluting Stents Research Articles

Safety and efficacy of drug-eluting stents versus heparin-bonded stents in treatment of femoropopliteal peripheral artery disease: study protocol for a multicentre, prospective randomised controlled trial in China (ELITE trial)

IntroductionEndovascular therapy has emerged as a prominent strategy for managing femoropopliteal peripheral artery disease, offering acceptable safety and efficacy compared with open surgical bypass. Both paclitaxel-eluting stents and heparin-bonded covered...

Safety and efficacy of drug-eluting stents for patients at high risk of bleedings: A network meta-analysis.

Among different coronary stents implanted in High Bleeding Risk (HBR) patients with an indication for short antiplatelet therapy, no comparisons in terms of efficacy have been provided. A Network Meta Analysis was performed including all randomized controlled trials comparing different coronary stents evaluated in HBR patients. Major Adverse Cardiovascular Events (MACEs) as defined by each included trial were the primary end point, whereas TLR (target lesion revascularization), TVR (target vessel revascularization), stent thrombosis and total and major (BARC3-5) bleedings were the secondary ones. A total of four studies (ONYX ONE, LEADERS FREE, SENIOR and HBR in BIO-RESORT) including 6637 patients were analyzed with different kind of stents and dual antiplatelet therapy (DAPT) length (1 or 6 months) on 12 months follow-up. About one-third of these patients were defined HBR due to indication for oral anticoagulation. All drug eluting stents (DESs) reduced risk of MACE compared to Bare Metal Stents (BMSs) when followed by a 1-month DAPT. At SUCRA analysis, Orsiro was the device with the highest probability of performing best. Rates of TLR and TVR were significantly lower when using Resolute Onyx, Synergy and BioFreedom stents in comparison to BMS when followed by 1-month DAPT, with Synergy ranking best. Synergy also showed a significantly lower number of stent thrombosis compared to BMS (RR 0.28, 95%CI 0.06-0.93), while Orsiro and Resolute Integrity showed the highest probability of performing best. In HBRs patients, all DESs were superior to BMSs in terms of efficacy and safety. Among DESs, Orsiro was the one with the highest ranking in terms of MACE, mainly driven by a reduced incidence of repeated revascularization and stent thrombosis.

Abstract TP202: Safety and Efficacy of Drug-Eluting Stents in Intracranial Atherosclerotic Disease: A Systematic Review and Meta-Analysis

Background: Advancements in arterial stenting technology have challenged prior notions favoring medical management over endovascular intervention for intracranial atherosclerotic disease (ICAD). Where previous conclusions were drawn from bare metal stent (BMS) technology, recent studies suggest drug-eluting stents (DES) are favorable over BMS due to their anti-proliferative effect. Methods: We conducted a systematic review and meta-analysis of the literature prior to August 2023 reviewing reports of ICAD treated with DES. Our target outcomes were incidence of any stroke, transient ischemic attack (TIA), or death within 30 days (post-procedural complications), ischemic stroke in the territory of the qualifying artery beyond 30 days (long-term complications), radiographically detected in-stent restenosis rate (ISR), and symptomatic ISR during follow-up. A subgroup analysis further stratified pre-procedural mean stenosis above and below 70% into severe and moderate cohorts, respectively. Results: PubMed and EMBASE query identified 518 candidate articles, from which 13 studies met inclusion criteria for a total of 475 patients and 508 ICAD lesions. Incidence of post-procedural complications was 8.1% (95% CI 3.1-15.1%) with subgroup analysis demonstrating significantly higher incidence in the severely stenotic group [10.4% (95% CI 5.7%-16.2%)] than the moderately stenotic group [3.0% (95% CI 0.7%- 6.8%)]. Long-term complications were 1.2% (95% CI 0.4%-2.4%). Radiographic ISR was 3.2% (95% CI 1.0%- 6.5%) and symptomatic ISR was 0.0% (95% CI 0.0%-0.5%). Conclusions: Our systematic review and meta-analysis suggest that DES can effectively reduce the risk of ISR and may be a viable treatment modality to reduce long-term complications in refractory ICAD patients.

A drug-free cardiovascular stent functionalized with tailored collagen supports in-situ healing of vascular tissues

Drug-eluting stent implantation suppresses the excessive proliferation of smooth muscle cells to reduce in-stent restenosis. However, the efficacy of drug-eluting stents remains limited due to delayed reendothelialization, impaired intimal remodeling, and potentially increased late restenosis. Here, we show that a drug-free coating formulation functionalized with tailored recombinant humanized type III collagen exerts one-produces-multi effects in response to injured tissue following stent implantation. We demonstrate that the one-produces-multi coating possesses anticoagulation, anti-inflammatory, and intimal hyperplasia suppression properties. We perform transcriptome analysis to indicate that the drug-free coating favors the endothelialization process and induces the conversion of smooth muscle cells to a contractile phenotype. We find that compared to drug-eluting stents, our drug-free stent reduces in-stent restenosis in rabbit and porcine models and improves vascular neointimal healing in a rabbit model. Collectively, the one-produces-multi drug-free system represents a promising strategy for the next-generation of stents.

Abstract 19047: Comparison of Drug-Eluting Stent With Bare-Metal Stent Implantation in Femoropopliteal Artery Disease: A Systematic Review and Meta-Analysis

Introduction: Trials comparing drug eluting stent (DES) versus bare metal stents (BMS) in patients undergoing endovascular therapy for femoropopliteal artery disease (FPAD) have shown variable results. Data indicating clear patency benefit of DES has not been definitively demonstrated. Methods: Medline, Embase, & Cochrane Central databases were searched to identify previous studies comparing efficacy of drug eluting stent versus bare metal stents in treatment of FPAD. The primary outcome of interest was risk of restenosis. Secondary outcomes included all-cause mortality, stent fracture, target vessel revascularization and primary patency. Odds ratios (OR) were pooled using a random-effect model while heterogeneity among studies was assessed using the Higgins I 2 value. Results: A total of 7 studies (5 RCTs and 2 retrospective cohorts) with 1786 patients were included in our analyses. The risk of target vessel revascularization was significantly reduced with the use of DES (OR: 0.69, 95% CI: 0.49-0.98, I 2 = 0) as compared with BMS. However, there was no significant difference observed in risk of restenosis (OR: 0.83, 95% CI 0.59-1.16), primary patency (OR: 1.09, 95% CI 0.91-1.29), stent fracture (OR: 0.84, 95% CI 0.27-2.67) and all-cause mortality (OR: 1.65, 95% CI 0.71-3.85). Conclusion: The risk of target vessel revascularization was significantly reduced with the use of DES implantation in patients with FPAD. However, DES does not seem to provide much benefit in terms of clinical outcomes. Further larger RCTs are needed to provide more evidence in the comparison between DES and BMS for FPAD.

Abstract 17686: Safety and Efficacy of Drug-Eluting Stents for Patients at High Risk of Bleedings: A Network Meta-Analysis

Introduction: Among different coronary stents implanted in High Bleeding Risk (HBR) patients with an indication for short antiplatelet therapy, no comparisons in terms of efficacy have been provided. Methods: A Network Meta Analysis was performed including all Randomized Controlled Trials comparing different coronary stents evaluated in HBR patients. Major Adverse Cardiovascular Events (MACEs) as defined by each included trial were the primary end point, whereas TLR (target lesion revascularization), TVR (target vessel revascularization), stent thrombosis and total and major (BARC3-5) bleedings were the secondary ones. Results: A total of 4 studies (ONYX ONE, LEADERS FREE, SENIOR and HBR in BIO-RESORT) including 6637 patients were analyzed with different kind of stents and DAPT length (1 or 6 months) on 12 months follow-up. About one third of these patients were defined HBR due to indication for oral anticoagulation. All Drug Eluting Stents (DESs) reduced risk of MACE compared to Bare Metal Stents (BMSs) when followed by a 1-month DAPT. At SUCRA analysis, Orsiro was the device with the highest probability of performing best. Rates of TLR and TVR were significantly lower when using Resolute Onyx, Synergy and BioFreedom stents in comparison to BMS when followed by 1-month DAPT, with Synergy ranking best. Synergy also showed a significantly lower number of stent thrombosis compared to BMS (RR 0.28, 95%CI 0.06-0.93), while Orsiro and Resolute Integrity showed the highest probability of performing best. Conclusion: In HBRs patients, all DESs were superior to BMSs in terms of efficacy and safety. Among DESs, Orsiro was the one with the highest ranking in terms of MACE, mainly driven by a reduced incidence of repeated revascularization and stent thrombosis

A bio-inspired nanoparticle coating for vascular healing and immunomodulatory by cGMP-PKG and NF-kappa B signaling pathways

Drug-eluting stents (DESs) implantation is an effective method to tackle in-stent restenosis (ISR), which has been considered as an efficient treatment for coronary atherosclerosis. Although fruitful results have been achieved in treating coronary artery diseases (CAD), concern has arisen regarding the long-term safety and efficacy of DESs, primarily due to adverse events such as delayed re-endothelialization, persistent inflammatory response, and late stent thrombosis (LST). Taking inspiration from the immunomodulatory functions of camouflage strategies, this study designed a bio-inspired nanoparticle-coated stent. Briefly, the platelet membrane-coated poly (lactic-co-glycolic acid)/Rapamycin nanoparticles (PNP) were sprayed onto stents, forming a homogenous nanoparticle coating. The bilayer of poly (lactic-co-glycolic acid) (PLGA) and platelet membrane works synergistically to promote the sustained-release effect of rapamycin. In vitro studies revealed that the PNP-coated surfaces promoted the competitive adhesion of endothelia cells while inhibiting smooth muscle cells. Subsequent in vivo studies demonstrated that these surfaces expedite re-endothelialization and elicit immunomodulatory effects by regulating the cGMP-PKG and NF-kappa B signaling pathways, influencing the biosynthesis cofactors and immune system signaling. The study successfully deviced a novel and biomimetic drug-eluting stent system, unraveling its detailed functions and molecular mechanism of action for enhanced vascular healing.

Safety and Efficacy of Contemporary Drug-Eluting Stents in Patients With ST-Segment Elevation Myocardial Infarction and a High Ischemic Risk.

BackgroundIn patients with ST-elevation myocardial infarction (STEMI) with a high risk of ischemic events, the safety and efficacy of drug-eluting stent (DES) are unclear.MethodsBased on the nationwide, multicenter, prospective registry, we selected 1,592 patients who underwent primary percutaneous coronary intervention (PCI) with everolimus-(EES) and zotarolimus-eluting stent (ZES) for STEMI with a high risk of an ischemic event. The occurrence of target lesion failure (TLF) for 3 years, defined as the composite of cardiac death, target vessel myocardial infarction (TV-MI), and ischemia-driven target lesion revascularization (ID-TLR), was evaluated.ResultsThe prevalence of high ischemic risk features was observed in 43.4% (2,744/6,325) of overall patients with STEMI. Among them, a total of 1,078 and 514 patients were treated with EES and ZES, respectively. At 3 years, the risk of TLF was not significantly different between the two groups (p = 0.93). In addition, the incidence of cardiac death, TV-MI, ID-TLR, and definite/probable stent thrombosis (ST) were also not different between the two groups. Moreover, elderly patients (age > 75 years) and PCI for the left main disease were identified as independent predictors of TLF.ConclusionImplantation of EES or ZES provided comparable clinical outcomes in STEMI patients and high ischemic risks.

De-escalation strategies of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention for acute coronary syndrome

Antiplatelet therapy is important for reducing systemic and local thrombotic events in patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Antiplatelet treatment regimens, along with dual antiplatelet therapy consisting of aspirin and a P2Y12 inhibitor for patients receiving PCI, have frequently changed over the years. With improvements in the understanding of the prognostic relevance of bleeding events in patients with PCI, as well as the safety and efficacy of drug-eluting stents, several randomized controlled trials (RCTs) have been conducted on antiplatelet treatment strategies associated with a more favorable balance between ischemic and bleeding risks. Several key RCTs for appropriate antiplatelet therapy in patients receiving PCI for ACS have been reported, and practical guidelines have been updated. This manuscript presents the results of major RCTs on de-escalation strategies of dual antiplatelet treatment in patients receiving PCI for ACS.

Do Drug-Eluting Stents Cause Late Stent Thrombosis?

Since the introduction of balloon angioplasty, restenosis has become the "Achillis tendon" of this mode of percutaneous coronary intervention (PCI). Stent implantation improves but does not eliminate restenosis. However, an iatrogenic disease, namely instent restenosis (ISR), emerges following placement of first- generation bare metal stents (BMS) and may be even more difficult to treat than the parent disease. Over the last few years, multiple randomised clinical trials have demonstrated the efficacy of drug-eluting stents (DES) to substantially reduce angiographic ISR and the clinical need for repeat revascularisation when compared with BMS.1-4 Moreover, these studies showed no short-term safety concerns, particularly the issue of stent thrombosis. The encouraging initial data led to subsequent widespread adoption of DES in interventional cardiology with utilisation of DES from 50% to >90% of all stent implantation. A recent meta- analysis5 of randomised controlled trials comparing sirolimus and derivatives or paclitaxel and derivatives eluting stents versus BMS with up to 12 months' follow up demonstrated a significant reduction of major adverse cardiac events (MACE; a composite of death, myocardial infarction [MI], and revascularisation) from 19.9% to 10.1% (odds ratio [OR] 0.46; 95% confidence intervals [CI] 0.41 to 0.52, p<0.001). The benefit is driven by reduction in revascularisation while rates of death and MI were not different between the two groups. Importantly, the occurrence of stent thrombosis was 0.7% with DES versus 0.8% with BMS (OR 0.71; 95% CI 0.41 to 1.25, p=0.24) at 1 year.

Safety and Efficacy of Drug Eluting Stents for Treatment of Transplant Renal Artery Stenosis

Transplant renal artery stenosis (TRAS) after renal transplantation is a common cause of graft dysfunction and failure. Endovascular intervention in the form of percutaneous transluminal angioplasty (PTA) and stenting has rapidly become the dominant treatment modality for the TRAS. There is a paucity of clinical data on the use of drug-eluting stent (DES) for TRAS. We investigated the outcomes of patients with clinically significant TRAS undergoing DES placement. A retrospective review of patients with clinically significant TRAS undergoing PTA with DES placement from June 2014 to April 2021 was conducted. Patients treated for TRAS exhibited uncontrolled hypertension and/or unexplained allograft dysfunction. Patient demographics, procedural details, and follow-up outcomes were collected. Primary endpoints were the in-stent primary patency and graft survival. Secondary endpoints were freedom from reintervention, primary-assisted patency, and access-related complications. Thirteen TRAS in 12 patients with graft function alteration were treated with DES. The median age was 57 years (interquartile range (IQR), 48-63 years), and 9 (70%) patients were male. The median follow-up was 9 months (IQR, 4-52 months). The most common comorbidity was hypertension (100%), coronary artery disease (83%), and diabetes. The median time from deceased donor transplant to intervention was 5.8 months (IQR, 3.5-6.7 months). TRAS was most commonly found at the juxta-ostial segment (77%). The procedure was performed with carbon dioxide angiography with minimal amount of iodinated contrast (median, 3 mL) under local anesthesia in 9 (69%), and general anesthesia in 4 (31%) patients. The median stent diameter was 4.5 mm (IQR, 4-5 mm), and the median stent length was 15 mm (IQR, 15-18 mm). No intraoperative complications occurred. The rates of stenosis-free primary patency of the DES and graft survival were 76% and 100%, respectively. All 3 reinterventions for restenosis resulted from the kinking of the transplant renal artery proximal to the DES, which were treated by extending the stent more proximally 1-2 mm into the external iliac artery. There were no access-related complications. The median time to reintervention was 0.9 months (range, 0.23-2 months). Freedom from reintervention and primary-assisted patency were 76% and 100%, respectively. Our study demonstrates that DES is a safe and effective treatment modality in patients with TRAS at short to mid-term follow-up. As all reinterventions after DES were performed due to kinking of the transplant renal artery proximal to the stent, bridging of the DES 1-2 mm into the external iliac artery is recommended.

Comparison of Drug-Eluting Stent With Bare-Metal Stent in Patients With Symptomatic High-grade Intracranial Atherosclerotic Stenosis

In-stent restenosis (ISR) is the primary reason for stroke recurrence after intracranial stenting in patients who were treated with a standard bare-metal stent (BMS). Whether a drug-eluting stent (DES) could reduce the risk of ISR in intracranial atherosclerotic stenosis (ICAS) remains unclear. To investigate whether a DES can reduce the risk of ISR and stroke recurrence in patients with symptomatic high-grade ICAS. A prospective, multicenter, open-label randomized clinical trial with blinded outcome assessment was conducted from April 27, 2015, to November 16, 2018, at 16 medical centers in China with a high volume of intracranial stenting. Patients with symptomatic high-grade ICAS were enrolled, randomized, and followed up for 1 year. Intention-to-treat data analysis was performed from April 1 to May 22, 2021. Patients were randomly assigned to receive DES (NOVA intracranial sirolimus-eluting stent system) or BMS (Apollo intracranial stent system) treatment in a 1:1 ratio. The primary efficacy end point was ISR within 1 year after the procedure, which was defined as stenosis that was greater than 50% of the luminal diameter within or immediately adjacent to (within 5 mm) the implanted stent. The primary safety end point was any stroke or death within 30 days after the procedure. A total of 263 participants (194 men [73.8%]; median [IQR] age, 58 [52-65] years) were included in the analysis, with 132 participants randomly assigned to the DES group and 131 to the BMS group. The 1-year ISR rate was lower in the DES group than in the BMS group (10 [9.5%] vs 32 [30.2%]; odds ratio, 0.24; 95% CI, 0.11-0.52; P < .001). The DES group also had a significantly lower ischemic stroke recurrence rate from day 31 to 1 year (1 [0.8%] vs 9 [6.9%]; hazard ratio, 0.10; 95% CI, 0.01-0.80; P = .03). No significant difference in the rate of any stroke or death within 30 days was observed between the DES and BMS groups (10 [7.6%] vs 7 [5.3%]; odds ratio, 1.45; 95% CI, 0.54-3.94; P = .46). This trial found that, compared with BMSs, DESs reduced the risks of ISR and ischemic stroke recurrence in patients with symptomatic high-grade ICAS. Further investigation into the safety and efficacy of DESs is warranted. ClinicalTrials.gov Identifier: NCT02578069.

Summary of Bifurcation Stenting Strategies and Outcomes in Women

AbstractSeveral studies have examined the efficacy of drug-eluting stents in acute and chronic coronary syndromes and demonstrated benefit in both men and women. However, the effect of gender on percutaneous coronary intervention (PCI) outcomes in more complex disease including bifurcation disease is less well-known. In particular, a two-stent or provisional strategy, for both left Main and non-Left Main bifurcation lesions, has been variable across the different studies. In addition, there is a notable geographic preference whereby a stepwise provisional strategy with culotte as a bailout technique is preferred in Europe while in Asia there is a predilection to DK Crush for a 2-stent strategy. Many of these trials, however, are underpowered to conduct subgroup analysis for outcomes in women. To date, the evidence suggests women have better outcomes with coronary artery bypass grafting in complex disease. The higher events in women undergoing PCI are largely driven by bleeding. Studies dedicated to evaluating outcomes after complex revascularization in women are desperately needed with long-term follow-up. This review examines the current landmark trials as they pertain to outcomes in women.

Efficacy of Drug-Eluting Stents in Diabetic Patients Admitted with ST-Elevation Myocardial Infarctions Treated with Primary Percutaneous Coronary Intervention.

Background: Diabetic patients show higher adverse ischemic event rates and mortality when undergoing percutaneous coronary intervention (PCI) in acute myocardial infarctions. Therefore, diabetic patients might benefit even more from modern-generation drug-eluting stents (DES). The aim of the present study was to compare adverse ischemic events and mortality rates between bare-metal stents (BMS) and DES in diabetic patients admitted with ST-elevation-myocardial infarction (STEMI) with non-diabetic patients as the control group. Methods: All STEMI patients undergoing emergency PCI and stent implantation documented between 2006 and 2019 in the Bremen STEMI registry entered the analysis. Efficacy was defined as a combination of in-stent thrombosis, myocardial re-infarction or additional target lesion revascularization at one year. Results: Of 8356 patients which entered analysis, 1554 (19%) were diabetics, while 6802 (81%) were not. 879 (57%) of the diabetics received a DES. In a multivariate model, DES implantation in diabetics compared to BMS was associated with lower rates of in-stent thrombosis (OR 0.16, 95% CI 0.05–0.6), myocardial re-infarctions (OR 0.35, 95%CI, 0.2–0.7, p < 0.01) and of the combined endpoint at 1 year ((ST + MI + TLR): OR 0.31, 95% CI 0.2–0.6, p < 0.01), with a trend towards lower 5-year mortality (OR 0.56, 95% CI 0.3–1.0, p = 0.058). When comparing diabetic to non-diabetic patients, an elevation in event rates for diabetics was only detectable in BMS (OR 1.78, 95% CI 0.5–0.7, p < 0.01); however, this did not persist when treated with a DES (OR 1.03 95% CI 0.7–1.6, p = 0.9). Conclusions: In STEMI patients with diabetes, the use of DES significantly reduced ischemic event rates and, unlike with BMS, adverse ischemic event rates became similar to non-diabetic patients.

Feasibility and Safety of Drug-Eluting Stent Implantation in Patients with End-Stage Liver Disease Prior to Liver Transplantation

In liver transplantation (LT) candidates with obstructive coronary artery disease, percutaneous coronary intervention (PCI) is indicated to facilitate transplant eligibility. Despite widespread drug-eluting stent (DES) use in contemporary practice, guidelines still recommend bare-metal stents (BMS) in LT candidates due to significant bleeding hazard. We sought to assess the safety and efficacy of DES with short dual-antiplatelet therapy (DAPT) duration in LT candidates.

In-Stent Restenosis and a Drug-Coated Balloon: Insights from a Clinical Therapeutic Strategy on Coronary Artery Diseases.

Coronary heart disease is a major cause of death and disability in developed countries. Stent implantation has become an efficacious treatment for a culprit lesion vessel of the coronary artery. However, 10%–20% restenosis is still an important complication that restricts the clinical safety and efficacy of drug-eluting stents. In-stent restenosis may lead to the recurrence of major cardiovascular adverse events, including angina pectoris, acute myocardial infarction, and even sudden cardiac death. These events are currently serious problems that occur after coronary stent implantation. Clinical physicians face a difficult choice for in-stent restenosis treatment. Recent studies indicate that a drug-coated balloon has promising clinical efficacy similar to the drug-eluting stents for treating coronary in-stent restenosis. Therefore, in this study, we highlight the progress of coronary intervention and the use of drug-coated balloons in the treatment of in-stent restenosis (ISR).

Safety and efficacy of drug eluting stents vs bare metal stents in patients with atrial fibrillation: A systematic review and meta-analysis

ObjectiveA systematic review and meta-analysis was performed to evaluate the safety and efficacy of drug-eluting stents (DES) vs bare-metal stents (BMS) in atrial fibrillation (AF) patients. MethodsWe systematically searched 5 engines until May 2019 for cohort studies and randomized controlled trials (RCTs). Primary outcomes were major bleeding and major adverse cardiac events (MACE) including cardiac death, myocardial infarction, target vessel revascularization (TVR) or stent thrombosis. Effects of inverse variance random meta-analyses were described with relative risks (RR) and their 95% confidence intervals (CI). We also stratified analyses by type (triple [TAT] vs dual [DAT]) and duration (short-vs long-term) of antithrombotic therapy. ResultsTen studies (3 RCTs; 7 cohorts) including 10,353 patients (DES: 59.6%) were identified. DES did not show higher risk of major bleeding than BMS (5.6% vs 6.9%, RR 1.07; 95%CI, 0.89–1.28, p = 0.47; I2 = 0%) or MACE (12% vs 13.6%; RR 0.96; 95%CI 0.81–1.13, p = 0.60; I2 = 44%). Although, DES almost decreased TVR risk (6.4% vs 8.4%, RR 0.78; 95%CI, 0.61–1.01, p = 0.06; I2 = 15%). Stratified analyses by type and duration of antithrombotic therapy showed no differences in major bleeding or MACE between both types of stents. In DES, long-term TAT showed higher major bleeding risk than long-term DAT (7.7% vs 4.7%, RR 1.48, 95%CI 1.08–2.03, p = 0.01; I2 = 12%). For both types of stents, MACE risk was similar between TAT and DAT. ConclusionsIn patients with AF undergoing PCI, DES had similar rate of major bleeding and MACE than BMS. DAT seems to be a safer antithrombotic therapy compared with TAT.

Vapor-Deposited Nanocoatings for Sustained Zero-Order Release of Antiproliferative Drugs.

Drug-eluting stents have been widely used in the treatment of coronary heart diseases, but the long-term efficacy has been dependent on the control of drug release kinetics. Though evenly distributed release with minimal burst release is much desired for the antiproliferative drugs used on stents, strategies for sustained zero-order release have not been specifically identified. We investigated vapor-based fabrication of polymer nanocoatings for the encapsulation of antiproliferative drugs. Drug release kinetics was regulated by adjusting the composition and thickness of the nanocoatings. Zero-order release of atorvastatin and sirolimus for 30 days was achieved using a poly(2-dimethylamino ethyl methacrylate-co-ethylene glycol diacrylate) (PDE) nanocoating with a monomer/cross-linker molar ratio of 0.78. The drug release rate was modulated using drug dose and coating thickness. The combination of coating surface and drug release suppressed the viability and proliferation of human coronary artery smooth muscle cells to below 57% at dose density as low as 10 μg/cm2. The PDE nanocoatings also reduced surface platelet adhesion without detrimental effect on red blood cells. The findings of this study demonstrate the potential of applying vapor-deposited polymer nanocoatings in modulating the release kinetics and thus improving the therapeutic efficacy of drug-eluting stents.

How does stent expansion alter drug transport properties of the arterial wall?

Stents have become the most successful device to treat advanced atherosclerotic lesions. However, one of the main issues with these interventions is the development of restenosis. The coating of stents with antiproliferative substances to reduce this effect is now standard, although such drugs can also delay re-endothelialization of the intima. The drug release strategy is therefore a key determinant of drug-eluting stent efficacy. Many mathematical models describing drug transport in arteries have been developed and, usually separately, models describing the mechanics of arterial tissue have been devised. However, the literature is lacking a comprehensive model that adequately takes into account both the mechanical deformation of the porous arterial wall and the resulting impact on drug transport properties. In this paper, we provide the most comprehensive study to date of the effect of stent mechanical expansion on the drug transport properties of a three-layer arterial wall. Our model incorporates the state-of-the art description of the mechanical properties of arterial tissue though an anisotropic, hyperelastic material model and includes a nonlinear saturable binding model to describe drug transport in the arterial wall. We establish relationships between mechanical force generated through device expansion and alteration in diffusion within the arterial wall and perform simulations to elucidate the impact of such alterations in spatio-temporal drug release and tissue uptake. Mechanical deformation of the arterial wall results in modified drug transport properties and tissue drug concentrations, highlighting the importance of coupling solid mechanics with drug transport.

Use of Paclitaxel Eluting Stents in Arteriovenous Fistulas: A Pilot Study.

PurposeWe report short-term patency outcomes of a proof of concept study conducted to determine the efficacy of drug-eluting stent (DES) for the treatment of arteriovenous fistula (AVF) stenosis in hemodialysis patients.Materials and MethodsThis is a single-center, retrospective observational study involving 10 patients with AVF dysfunction treated with DESs between January 2017 and December 2017. The primary outcome was AVF patency confirmed by sonographic and clinical assessment at 1 month and 6 to 9 months after treatment.ResultsA total of 12 DESs were deployed in 10 patients with dysfunctional AVF (radiocephalic: 7, brachiocephalic: 3). During the early follow up (mean: 28.6 days), primary access circuit and DES patency was 100%, with an average volume flow rate of 886.4 mL/min. Nine patients were available for short-term follow up (mean: 202.4 days; 1 unrelated death), with a mean volume flow rate of 1,048.9 mL/min. The primary DES patency was 7/9 (77.8%), and 3 patients required angioplasty at other parts of the circuit (primary access circuit patency: 4/9 [44.4%]). The assisted primary access circuit patency was 77.8%. In 2 patients, the ultrasound revealed that the DESs were thrombosed without any antecedent stenosis; they were salvaged with angioplasty. Both patients previously underwent 2 DESs implanted and recently stopped dual antiplatelet therapy. B-mode sonographic assessment at all timepoints showed minimal intimal ingrowth on the stent struts.ConclusionThis study demonstrates acceptable short-term patency for DESs in the treatment of AVF stenosis. Dual antiplatelet therapy is probably mandatory in the short term.