Rectifying disorder of extracellular matrix to suppress urethral stricture by protein nanofilm-controlled drug delivery from urinary catheter

Urethral stricture secondary to urethral injury, afflicting both patients and urologists, is initiated by excessive deposition of extracellular matrix in the submucosal and periurethral tissues. Although various anti-fibrotic drugs have been applied to urethral stricture by irrigation or submucosal injection, their clinical feasibility and effectiveness are limited. Here, to target the pathological state of the extracellular matrix, we design a protein-based nanofilm-controlled drug delivery system and assemble it on the catheter. This approach, which integrates excellent anti-biofilm properties with stable and controlled drug delivery for tens of days in one step, ensures optimal efficacy and negligible side effects while preventing biofilm-related infections. In a rabbit model of urethral injury, the anti-fibrotic catheter maintains extracellular matrix homeostasis by reducing fibroblast-derived collagen production and enhancing metalloproteinase 1-induced collagen degradation, resulting in a greater improvement in lumen stenosis than other topical therapies for urethral stricture prevention. Such facilely fabricated biocompatible coating with antibacterial contamination and sustained-drug-release functionality could not only benefit populations at high risk of urethral stricture but also serve as an advanced paradigm for a range of biomedical applications.

Seven-year clinical outcomes in patients undergoing percutaneous coronary intervention with biodegradable polymer coated sirolimus-eluting stent: Results from a single-center real-world experience

Objective

The aim of the present study was to assess seven-year clinical outcomes of biodegradable polymer coated Supralimus sirolimus-eluting stent (S-SES) [Sahajanand Medical Technologies Pvt. Ltd., Surat, India] in real-world patients with coronary artery disease.

Methods

This observational, retrospective study was carried out in all 346 consecutive enrolled patients who underwent percutaneous coronary intervention (PCI) with the S-SES, between April 2008 and December 2009, at a single center. We analyzed major adverse cardiac events (MACE) [a composite of cardiac death, myocardial infarction (MI), target lesion revascularization (TLR) and target vessel revascularization (TVR)] as primary outcomes at seven-year follow-up.

Results

Out of 346 patients, seven-year follow-up was obtained in 327 (94.5%) patients and hence results were analyzed for 327 patients. At seven-year, MACE occurred in 41 (12.5%) patients, consisting of 23 (7.0%) cardiac deaths, 14 (4.3%) TLR, and 4 (1.2%) TVR. The incidence of late stent thrombosis was observed in 3 (0.9%) patients. At follow-up of seven-year, the cumulative event-free survival was found to be 84.7% by Kaplan-Meier method.

Conclusions

The present study demonstrated satisfactory and sustained seven-year clinical outcomes as evidenced by the low rates of MACE and ST for the biodegradable polymer coated S-SES.

An optical coherence tomography study of neointimal morphology and strut coverage at different time intervals from implantation of biodegradable polymer-coated sirolimus-eluting stents

OBJECTIVES

The aim of the study was to capture the evolution of neointima after implantation of a biodegradable polymer-coated, sirolimus-eluting, cobalt-chromium coronary stent system (BP-DES).

BACKGROUND

Optical coherence tomography (OCT) suggests that in-stent neointimal morphology influences clinical outcomes after DES implantation.

METHODS

Sixty patients treated with single BP-DES implantation were examined by quantitative coronary angiography (QCA) and OCT at 3, 6, and 12-month follow-up.

RESULTS

Median late lumen loss by QCA (mm) was 0.04 (IQR 0, 0.08), 0.17 (IQR 0, 0.32), and 0.14 (IQR 0.07, 0.31) at 3, 6, and 12-month follow-up respectively (P = 0.03). OCT cross-section multilevel analysis showed uncovered struts in 3.90%, 1.78%, and 0.02% of struts respectively (P = 0.03). The corresponding malapposition rates were 0.12%, 0.04%, and 0%. Lipid-rich neointima was observed only at 12-month follow-up in one restenotic lesion (0.77% cross-sections) that was accountable for the only target vessel revascularization. The homogeneous pattern was prevalent at all three time points, but its incidence displayed an upward trend (3 months: 59%; 6 months: 71%; 12 months: 88%) despite no difference in neointimal volume between 6 and 12 months. Conversely, a trend could be observed of decreasing incidence of heterogeneous pattern as the follow-up length increased.

CONCLUSIONS

In this study of a single-type BP-DES, the majority of stent struts were covered within 3 months from implantation. While the quantitative neointimal accumulation plateaued at 6 months with no further significant increase beyond 6 months, the neointima continued to evolve qualitatively and mature along with better strut coverage between 6 and 12 months after implantation.

The evolution of coronary stents

INTRODUCTION

Percutaneous coronary intervention (PCI) is 40 years old this year. From its humble beginnings of experimental work, PCI has transitioned over years with coronary artery stenting now a standard medical procedure performed throughout the world. Areas covered: The conversion from plain old balloon angioplasty (POBA) to the present era of drug eluting stents (DES) has been driven by many technological advances and large bodies of clinical trial evidence. The journey to present day practice has seen many setbacks, such as acute vessel closure with POBA; rates of instant restenosis with bare metal stents (BMS) and more recently, high rates of stent thrombosis with bioabsorbable platforms. This work discusses POBA, why there was a need for BMS, the use of inhibiting drugs to create 1^st generation DES, the change of components to 2^nd generation DES, the use of absorbable drug reservoirs and platforms, and possible future directions with Prohealing Endothelial Progenitor Cell Capture Stents. Expert commentary: This paper reviews the evolution from the original pioneering work to modern day practice, highlighting landmark trials that changed practice. Modern day contemporary practice is now very safe based on the latest drug eluting stents and supported by large datasets.

Comparative assessment of three drug eluting stents with different platforms but with the same biodegradable polymer and the drug based on quantitative coronary angiography and optical coherence tomography at 12-month follow-up

The aim of this study was to compare neointima proliferation in three drug-eluting stents (DES) produced by the same company (Balton, Poland) which are covered with a biodegradable polymer and elute sirolimus (concentration: 1.0 and 1.2 µg/mm²), but have different stent platforms and strut thickness: stainless steel Prolim^® (115 µm) and BiOSS LIM^® (120 µm) and cobalt-chromium Alex^® (70 µm). We analyzed data of patients with quantitative coronary angiography (QCA) and optical coherence tomography (OCT) at 12 months from BiOSS LIM Registry, Prolim Registry and Alex OCT clinical trial. There were 56 patients enrolled, in whom 29 Prolim^® stents were deployed, in 11-BiOSS LIM^® and in 16-Alex stents. The late lumen loss was the smallest in Prolim^® subgroup (0.26 ± 0.17 mm) and did not differ from Alex^® subgroup (0.28 ± 0.47 mm). This parameter was significantly bigger in BiOSS^® subgroup (0.38 ± 0.19 mm; p < 0.05). In OCT analysis there was no statistically significant difference between Prolim^® and Alex^® subgroups in terms of mean neointima burden (24.6 ± 8.6 vs. 19.27 ± 8.11%) and neointima volume (28.16 ± 15.10 vs. 24.51 ± 17.64 mm³). In BiOSS^® group mean neointima burden (30.9 ± 6.2%) and mean neointima volume (44.9 ± 4.9 mm³) were significantly larger. The morphological analysis revealed that in most cases in all groups the neointima was homogenous with plaque presence only around stent struts. In the QCA and OCT analysis regular DES (Prolim^® and Alex^®) obtained similar results, whereas more pronounced response from the vessel wall was found in the BiOSS^® subgroup.

Novel sirolimus-eluting stent Prolim® with a biodegradable polymer in the all-comers population: one year clinical results with quantitative coronary angiography and optical coherence tomography analysis

BACKGROUND

The aim of this study was to assess the safety and the efficacy of the novel sirolimus-eluting Prolim® stent with a biodegradable polymer in the all-comers population.

METHODS

We prospectively enrolled all patients with stable coronary artery disease or acute coronary syndrome treated with Prolim® stent between January and December 2013 in two interventional cardiology centers in Poland. Angiographic control was planned at 12 months, in which 15 % of patients (randomly chosen) underwent optical coherence tomography imaging. The primary end-point was the cumulative rate of cardiac death, myocardial infarction, and target lesion revascularization at 12 months.

RESULTS

There were 204 patients enrolled, in whom 238 Prolim® stents were deployed (1.17 stent per patient). The mean age was 68 ± 10 years and 32.8 % were females. The examined stent was implanted in 5.9 % in STEMI patients, in 21.6 % - in NSTE-ACS and in 72.5 % - in patients with stable coronary artery disease. The Prolim® stent was most frequently implanted in right coronary artery (38.2 %) followed by left anterior descending artery (34.0 %). The cumulative major adverse cardiovascular events rate at 12 months was 6.9 %, and the clinically-driven target lesion revascularization rate - 5.4 %. At 12 months in quantitative coronary angiography the late lumen loss was 0.21 ± 0.18 mm, and in optical coherence tomography the mean neointima burden was 24.6 ± 8.6 %.

CONCLUSIONS

Sirolimus-eluting Prolim® stent with a biodegradable polymer is a feasible device with a very good safety profile and long-term clinical effectiveness.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT02545985 .

Controlled Slow-Release Drug-Eluting Stents for the Prevention of Coronary Restenosis: Recent Progress and Future Prospects

Drug-eluting stents (DES) have become more widely used by cardiologists than bare metal stents (BMS) because of their better ability to control restenosis. However, recognized negative events, particularly including delayed or incomplete endothelialization and late stent thrombosis, have caused concerns over the long-term safety of DES. Although stent-based drug delivery can facilitate a drug's release directly to the restenosis site, a burst of drug release can seriously affect the pharmacological action and is a major factor accounting for adverse effects. Therefore, the drug release rate has become an important criterion in evaluating DES. The factors affecting the drug release rate include the drug carrier, drug, coating methods, drug storage, elution direction, coating thickness, pore size in the coating, release conditions (release medium, pH value, temperature), and hemodynamics after the stent implantation. A better understanding of how these factors influence drug release is particularly important for the reasonable use of efficient control strategies for drug release. This review summarizes the factors influencing the drug release from DES and presents strategies for enhancing the control of the drug's release, including the stent design, the application of absorbable stents, the development of new polymers, and the application of nanocarriers and improvements in the coating technology. Therefore, this paper provides a reference for the preparation of novel controlled slow-release DES.

A prospective, multi-centric, observational registry to evaluate performance of Excel™ DES in 'real world, all comers' patient population

OBJECTIVES

This study aims to assess the safety and efficacy of a biodegradable polymer-coated Rapamycin-Eluting Stent (Excel) used in conjunction with six-month dual antiplatelet therapy in daily practice.

BACKGROUND

The polymeric material of cardiac stents has been reported to adversely affect the safety profile of the drug-eluting stents and is also suspected to cause serious long-term complications. It has been proposed that the biodegradable polymer coatings may reduce such late-stage adverse effects.

METHODS

This is a prospective, multi-center registry of 654 patients from across 9 cardiology centers in India, who were enrolled and exclusively treated with Excel stents between February 2008 and May 2010. The recommended antiplatelet regimen included clopidogrel and aspirin for 6 months period, followed by lifelong aspirin therapy.

RESULTS

The study population included 46.94% diabetics, 24.31% smokers, 48.93% hypertensives and 14.98% hyperlipidemics. The cumulative rates of major adverse cardiac events were 0.153% at discharge and 1.38% at 12 months. The mean percentage of stenosis was 88.24 ± 9.17% No events occurred between 6 and 12 months.

CONCLUSIONS

This multi-center registry study on "real world, all comers" has, thus, showed that EXCEL™ stent which is PLA-coated biodegradable Rapamycin-Eluting Stent exhibited high efficacy and safety profile in treatment of patients undergoing PCI as evidenced by significantly lower rates of MACE and no case of stent thrombosis. There was no event even after DAPT was discontinued after 6 months.

RAPSTROM™ first-in-man study long-term results of a biodegradable polymer sustained-release sirolimus-eluting stent in de novo coronary stenoses

BACKGROUND

Durable polymers used for first-generation drug-eluting stents (DES) potentially contribute to persistent inflammation and late DES thrombosis. We report the first real-life human experience with the rapamycin-eluting biodegradable polymer-coated Rapstrom stent.

METHODS

All consecutive patients with single de novo native coronary stenosis (<30 mm and between 2.5 and 4.0 mm) were enrolled. Major adverse cardiac events (MACE) at 1 year (cardiac death, myocardial infarction [Q and non-Q], or ischemia-driven target lesion revascularization) were the primary end-point.

RESULTS

A total of 123 patients were enrolled. The stent was implanted without complications in all patients, and no MACE were recorded at 30 days. At 12-month follow-up 9 patients (7.3%) experienced a MACE and 4 (3.2%) required a target lesion revascularization, while 1 (1%) stent thrombosis was recorded. A planned angiographic follow-up (FU) was performed in 73 patients (59%) at 9.4 ± 2.6 months following the index procedure. In-stent late loss was 0.16 ± 0.09 mm, and in-segment late loss was 0.18 ± 0.8 mm.

CONCLUSION

The Rapstrom biodegradable polymer rapamycin-eluting stent appeared safe and efficacious in this first real-life human experience, due to a low late lumen loss. Larger randomized studies are required to confirm these preliminary results.

Meta-analysis of bioabsorbable versus durable polymer drug-eluting stents in 20,005 patients with coronary artery disease: an update

OBJECTIVES

To perform an updated meta-analysis comparing biodegradable polymer drug eluting stents (BP-DES) and durable polymer drug eluting stents (DP-DES).

BACKGROUND

BP-DES have been suggested to reduce late stent thrombosis (LST) rates as compared to first generation DP-DES. Recently, second generation DP-DES have replaced older DES, but comparison of these stents with BP-DES has not yielded consistent results.

METHODS

Medline/Web databases were searched for studies comparing BP-DES and DP-DES, and reporting rates of overall/cardiac mortality, myocardial infarction (MI), LST, target lesion revascularization (TLR) and target vessel revascularization (TVR) and late lumen loss (LLL), with a follow-up ≥6 months.

RESULTS

Twenty studies (20,005 patients) were included in the meta-analysis. Median follow-up time was 1 year. Compared with DP-DES, BP-DES showed lower LLL (in stent: weighted mean difference WMD -0.45 mm, 95% CI -0.66 to -0.24 mm, P = 0.00001; in segment: WMD -0.15 mm, 95% CI = -0.24 to -0.06 mm, P = 0.001) and lower rates of LST (OR 0.51, 95% CI = 0.30 to 0.86, P = 0.01), although they did not improve mortality, MI, TLR, and TVR rates. BP-DES coated with sirolimus or novolimus, in comparison with biolimus or paclitaxel, were associated with reduced LLL (P < 0.0001 for subgroups).

CONCLUSIONS

In comparison with DP-DES, BP-DES significantly reduce LLL and LST rates, without clear benefits on harder endpoints. The efficacy of BP-DES in preserving lumen patency seems larger for sirolimus and novolimus DES.

Role of biomaterials in prevention of in-stent restenosis

Coronary balloon angioplasty and coronary stenting are the procedures used in healing coronary artery disease. However, injury of arteries during angioplasty and stenting causes cell stimulations in tissue. Cell movement and thrombosis lead to re-narrowing of widened vessel called restenosis. Several new types of carriers and technology have been developed to suppress and/or prevent restenosis. Authors review the polymeric materials featured in drug/gene carrier systems, nanovehicles, and stent coating materials against restenosis.

Experience with biodegradable polymer coated sirolimus-eluting coronary stent system in "real-life" percutaneous coronary intervention: 24-month data from the manipal-s registry

INTRODUCTION

Despite the undeniable clinical efficacy of drug-eluting stents with durable polymers, concerns regarding their long-term safety have been raised, especially in more complex subsets. The Manipal-S Registry was designed to evaluate the safety and effectiveness of the biodegradable polymer coated Supralimus(®) Sirolimus-Eluting Coronary Stent for the treatment of coronary artery disease, across a wide range of patients who are treated in real-life clinical practice.

METHODS

All the consecutive 116 patients who underwent single-vessel or multiple vessel percutaneous coronary interventions with the use of Supralimus(®) sirolimus-eluting stents between September 2009 and December 2010, were included in this study. Patients were clinically followed-up at 1, 9, 12 and 24 months post-procedure. All clinical, procedural, and follow-up information were collected and analysed.

RESULTS

In total 116 patients, 126 lesions were implanted with 144 stents which had an average stent length of 25.8±8.0 mm. The incidences of any major adverse cardiac and cerebral events at 1, 9, 12 and 24 months were 0, 5 (4.3%), 8 (6.9%), and 10 (8.6%) respectively.

CONCLUSION

These 24-month results clearly provide evidence for safety and effectiveness of the Supralimus(®) Sirolimus-eluting coronary stent system with the biodegradable polymer in real-life patients, even in those with acute myocardial infarctions.

The Supralimus sirolimus-eluting stent

The use of biodegradable polymeric coatings has emerged as a potential bioengineering target to improve the vascular compatibility of coronary drug-eluting stents (DESs). This review summarizes the main features and scientific facts about the Supralimus sirolimus-eluting stent (Sahajanand Medical Technologies Ltd, Surat, India), which is a biodegradable polymer-based, sirolimus-eluting metallic stent that was recently introduced for routine use in Europe. The novel stent is built on a stainless steel platform, coated with a blend of biodegradable polymers (poly-l-lactide, poly-dl-lactide-co-glycolide and polyvinyl pyrrolidone; coating thickness is 4-5 µm). The active agent is the antiproliferative sirolimus in a dose load of 1.4 µg/mm(2), which is released within 48 days. The Supralimus stent was initially evaluated in the single-arm SERIES-I study, which showed binary angiographic restenosis rates of 0% (in-stent) and 1.7% (in-segment) and an in-stent late lumen loss of 0.09 ± 0.28 mm. The multicenter randomized PAINT trial compared two DESs with identical metallic platforms and biodegradable polymer carriers, but different agents (Infinnium [Sahajanand Medical Technologies Pvt Ltd] paclitaxel-eluting stent or Supralimus sirolimus-eluting stent) against bare stents. After 3 years, the pooled DES population had similar rates of cardiac death or myocardial infarction (9 vs 7.1%; p = 0.6), but a lower risk of repeat interventions (10 vs 29.9%; p < 0.01) than controls with bare stents. The incidence of definite or probable stent thrombosis in the pooled DES group was 2.3% (1st year: 1.8%; 2nd year: 0.4% and 3rd year: 0%). These results demonstrate that the novel Supralimus stents are effective in reducing reintervention, while potentially improving the safety profile by decreasing the risk of late-term thrombosis, even though further studies would be necessary to confirm these findings.

Development and Evaluation of Drug Eluting Stent Having Biphasic Release From a Single Layer of Biodegradable Polymer

In stent restenosis is the major disadvantage of percutaneous transluminal angioplasty. To overcome this limitation, drug eluting stents were introduced. We have developed novel sirolimus eluting stent using biocompatible and biodegradable polymer matrix. Developed stent have biphasic release profile for sirolimus from a single layer of polymer matrix, having blend of slow and fast degrading polymers. Coating integrity of coated stents were evaluated after crimping and postexpansion with the help of scanning electron microscopy while thickness of coated stent was measured using destructive test method. This shows that drug-polymers bilayer was uniformly coated with the average thickness of 5.2 μms. There was no deformation after crimping and expansion of the stent. We have also measured in vitro and in vivo release profiles of sirolimus from stents which shows biphasic release characteristics, i.e., initial burst period followed by sustained release. In vitro release profile is well correlated with in vivo release in blood and arterial tissues. Developed stents showed good efficacy and safety in porcine coronary artery model.

Biodegradable versus durable polymer drug eluting stents in coronary artery disease: insights from a meta-analysis of 5,834 patients

BACKGROUND

Biodegradable polymer drug eluting stents (BP-DES) have been developed to overcome the limitations of first generation durable polymer DES (DP-DES) but the clinical results of different BP-DES are not consistent. We performed a meta-analysis to compare the outcomes of BP-DES and DP-DES in the treatment of coronary artery disease (CAD).

METHODS AND RESULTS

Online databases including MEDLINE were searched for studies comparing BP-DES and DP-DES for obstructive CAD that reported rates for overall mortality, myocardial infarction (MI), late stent thrombosis (LST), target lesion revascularization (TLR) and late lumen loss (LLL) with a follow-up of ≥ 6 months. Ten studies (5834 patients) with a 1-year median follow-up were included in the meta-analysis. When comparing patients treated with DP-DES and BP-DES those treated with BP-DES had lower LLL (in-stent: weighted mean difference (WMD) -0.10 mm, 95% CI = -0.17 to -0.03 mm, p = 0.004; in-segment: WMD -0.06 mm, 95% CI = -0.10 to -0.01 mm, p = 0.01) with lower TLR rates (OR 0.67, 95% CI = 0.47 to 0.98, p = 0.04). However, BP-DES did not improve mortality (OR 0.97, 95% CI = 0.73 to 1.29, p = 0.83), MI (OR 1.13, 95% CI = 0.87 to 1.46, p = 0.36) or LST rates (OR 0.64, 95% CI = 0.36 to 1.16, p = 0.14). A pre-specified subgroup analysis of Biolimus BP-DES confirmed significant LLL reduction without differences in other clinical endpoints. Meta-regression analysis demonstrated a strong significant inverse correlation between LLL and reference coronary diameter (p < 0.001).

CONCLUSIONS

Our present meta-analysis showed that BP-DES when compared with DP-DES significantly reduced LLL and TVR but without clear benefits on mortality, MI and LST rates. (Clinicaltrials.gov identifier: NCT01466634).

Clinical performance of drug-eluting stents with biodegradable polymeric coating: a meta-analysis and systematic review

AIMS

Different biodegradable-polymer drug-eluting stents have not yet been systematically analysed. We sought to; 1) evaluate the risk of target lesion revascularisation (TLR) and definite stent thrombosis (DST) among different groups of biodegradable-polymer (BioPol) DES, and 2) to compare them with permanent polymer (PermPol) DES.

METHODS AND RESULTS

We searched PubMed and relevant sources from January 2005 until October 2010. Inclusion criteria were (a) Implantation of a drug-eluting stent with biodegradable polymer; (b) available follow-up data for at least one of the clinical end-points (TLR/DST) at short term (30 days) and/or mid-term (one year). A total of 22 studies, including randomised and observational studies, with 8264 patients met the selection criteria; nine studies (2042 patients) in whom biodegradable-polymer sirolimus eluting stents (BioPol-SES) were implanted, eight studies (1731 patients) in whom biodegradable-polymer paclitaxel eluting stents (BioPol-PES) were implanted, and seven studies (4491 patients) in whom biodegradable-polymer biolimus-A9 eluting stents (BioPol-BES) were implanted. At 30 days, there was a higher risk of DST (p=0.04) and subsequently TLR (p=0.006) in the BioPol-BES compared to BioPol-SES, with no significant difference in the other stent comparisons. At 1-year, there was higher risk of TLR in the BioPol-PES (p=0.01), and the BioPol-SES (p=0.04) compared to BioPol-BES. One-year stent thrombosis was not statistically different between the studied groups (overall p=0.2). In another analysis comprising seven randomised trials comparing BioPol-DES (3778 patients) and PermPol-DES (3291 patients), the risks of TLR and stent thrombosis at 1-year were not significantly different (p=0.5 for both).

CONCLUSIONS

Performance of different BioPol-DES seems to vary from each other. The short- and mid-term success rates may not be superimposable. Furthermore, they may not be necessarily better than PermPol-DES.

Current and future drug-eluting coronary stent technology

Despite the impressive benefits obtained following the introduction of the drug-eluting stent, safety concerns have been raised over their long-term safety with particular regard to stent thrombosis. Various mechanisms such as delayed endothelialization, local hypersensitivity and endothelial dysfunction owing to the durable polymer coating and/or the drug itself have been suggested as possible causes of this phenomenon. Therefore, to address these concerns, a newer-generation of drug-eluting stents has been developed and they are currently undergoing preclinical and clinical evaluation in order to increase both the safety and biocompatibility by optimizing the three major components of drug-eluting stents: the stent platform, the polymer and the drug. This article critically reviews the key clinical trials and the current status of these new coronary devices as well as preventing future perspectives for their continued development.

Drug-eluting stents for coronary artery disease: a review

Over the past decade the introduction of drug-eluting stents (DESs) has revolutionised the treatment of coronary artery disease. However, in recent years concern has arisen over the long-term safety and efficacy of DESs due to the occurrence of late adverse clinical events such as stent thrombosis. With this concern in mind, research and development is currently centred on increasing the long-term safety and efficacy of DESs. The aim of this paper is to provide a thorough review of currently approved and promising investigational DESs. With dozens of companies involved in the development of new and innovative anti-restenotic agents, polymeric coatings and stent platforms, it is intended that this review paper will provide a clear indication of how DESs are currently evolving and prove a valuable reference tool for future research in this area.

Novel drug-eluting stents in the treatment of de novo coronary lesions

Due to safety concerns in recent years, much effort has been devoted to improving the outcomes associated with drug-eluting stents (DESs). This review summarizes the current status of methodological and technical achievements reported in second-generation DES. Novel stents are described based on the component (the platform, the polymer, and the drug) that has undergone the most significant changes compared to earlier generation DES. An overview of the currently available evidence on the use of novel coronary devices in patients undergoing coronary revascularization is also reviewed.

Coronary stents: looking forward

Despite all the benefits of drug-eluting stents (DES), concerns have been raised over their long-term safety, with particular reference to stent thrombosis. In an effort to address these concerns, newer stents have been developed that include: DES with biodegradable polymers, DES that are polymer free, stents with novel coatings, and completely biodegradable stents. Many of these stents are currently undergoing pre-clinical and clinical trials; however, early results seem promising. This paper reviews the current status of this new technology, together with other new coronary devices such as bifurcation stents and drug-eluting balloons, as efforts continue to design the ideal coronary stent.

STELLIUM 1: First-in-man follow-up evaluation of bioabsorbable polymer-coated paclitaxel-eluting stent

BACKGROUND

Durable polymers used for first-generation drug-eluting stents (DES) potentially contribute to persistent inflammation and late DES thrombosis. The vascular response to the Stellium stent, which is coated with an absorbable polymer for slow release of low-dose paclitaxel, was evaluated in the present study.

METHODS AND RESULTS

The 37 patients with stable angina were implanted with 47 Stellium stents. Quantitative coronary angiography (QCA) was performed at baseline, and QCA and optical coherence tomography (OCT) were performed at 6 months post-implant. The primary endpoint was major adverse cardiac events (MACE). At 6 months, 1 case of MACE occurred because of total occlusion of a protected left main artery. In-stent and segment binary restenosis rates were both 0%. In-stent late loss was 0.19 ± 0.54 mm. Altogether, 5,564 struts were visualized by OCT and mean neointimal thickness was 150.03 ± 146.36 µm. The number of well-apposed struts with and without neointima overlay was 5,135 (92.29%) and 396 (7.12%), respectively. Peri-strut low intensity was observed in 518 struts (9.31%).

CONCLUSIONS

This first-in-man study of the Stellium stent shows the promising possibility of bioabsorbable polymeric surface coating paclitaxel-eluting stents out to 6 months. The low rate of peri-strut low intensity suggests low cellular toxicity of the Stellium stent compared with the first-generation DES.