Effect of everolimus-eluting stents in different vessel sizes (from the pooled FUTURE I and II trials)

Sirolimus-Coated Balloon With a Microsphere-Based Technology for the Treatment of De Novo or Restenotic Coronary Lesions

BACKGROUND

Non stent-based local drug delivery with drug-coated balloon (DCB) is an alternative to drug-eluting stent with favorable clinical applicability in the treatment of selected coronary lesions. Our purpose was to report the initial performance, safety and efficacy evaluations of a novel sirolimus-coated balloon in the treatment of coronary lesions.

METHODS

This was a phase I (first-in-man), prospective, multicenter, single-arm trial evaluating the novel SELUTION SLR™ DCB (M.A. Med Alliance SA, Nyon, Switzerland), which incorporates a polymeric microsphere-based technology for controlled and continuous release of sirolimus, in the treatment of de novo or restenotic lesions.

RESULTS

A total of 56 patients/lesions were enrolled between November/2018 and March/2019. Diabetes was found in 46.6 %, and de novo lesions represented 79.6 % of cases. Device and procedural/clinical success were 100 % and 96.4 %, respectively. There was only one major adverse cardiac event (target lesion revascularization) reported at late follow-up. By quantitative coronary angiography analysis, mean % diameter stenosis was 30.5 ± 16.7 %, late lumen loss was 0.26 ± 0.45 mm and angiographic binary restenosis occurred in 4 of 45 cases at 6-month angiographic follow-up.

CONCLUSION

The novel SELUTION sirolimus-coated balloon demonstrated safety and efficacy in the treatment of diseased coronary vessels, including absence of mortality and relatively low late lumen loss at late follow-up.

Cardiovascular protection associated with cilostazol, colchicine and target of rapamycin inhibitors

ABSTRACT

An alteration in extracellular matrix production by vascular smooth muscle cells is a crucial event in the pathogenesis of vascular diseases such as aging-related, atherosclerosis and allograft vasculopathy. The human target of rapamycin (TOR) is involved in the synthesis of extracellular matrix by vascular smooth muscle cells. TOR inhibitors reduce arterial stiffness, blood pressure, and left ventricle hypertrophy and decrease cardiovascular risk in kidney graft recipients and patients with coronary artery disease and heart allograft vasculopathy. Other drugs that modulate extracellular matrix production such as cilostazol and colchicine have also demonstrated a beneficial cardiovascular effect. Clinical studies have consistently shown that cilostazol confers cardiovascular protection in peripheral vascular disease, coronary artery disease, and cerebrovascular disease. In patients with type 2 diabetes, cilostazol prevents the progression of subclinical coronary atherosclerosis. Colchicine reduces arterial stiffness in patients with Familial Mediterranean Fever and patients with coronary artery disease. Pathophysiological mechanisms underlying the cardioprotective effect of these drugs may be related to interactions between the cytoskeleton, TOR signaling and cyclic AMP synthesis that remain to be fully elucidated. Adult vascular smooth muscle cells exhibit a contractile phenotype and produce little extracellular matrix. Conditions that upregulate extracellular matrix synthesis induce a phenotypic switch toward a synthetic phenotype. TOR inhibition with rapamycin reduces extracellular matrix production by promoting the change to the contractile phenotype. Cilostazol increases the cytosolic level of cyclic AMP, which in turn leads to a reduction in extracellular matrix synthesis. Colchicine is a microtubule-destabilizing agent that may enhance the synthesis of cyclic AMP.

Second generation drug-eluting stents: a focus on safety and efficacy of current devices

Introduction: Percutaneous coronary intervention (PCI) represents the most frequent procedure performed in medicine. Second generation drug eluting stents (DES) have been developed to reduce the rates of late and very late complications of first generation DES.Areas covered: To improve long-term efficacy and safety of patients undergoing PCI, second generation DES have been developed with novel stent platforms, biocompatible durable and biodegradable polymers and newer antiproliferative agents. In this review we provide an overview of second generation DES and their clinical trials, discussing safety and effectiveness of these devices, and outlining clinical indication for use.Expert commentary: Numerous clinical trials have demonstrated the safety and efficacy of second generation DES over the last decade. These devices represent the gold standard treatment in stable and acute coronary syndromes.

Prospective randomized comparison of clinical and angiographic outcomes between everolimus-eluting vs. zotarolimus-eluting stents for treatment of coronary restenosis in drug-eluting stents: intravascular ultrasound volumetric analysis (RESTENT-ISR trial)

AIMS

At present no proven standard treatment for drug-eluting stent (DES) restenosis is available, and the efficacy and safety of everolimus-eluting stent (EES) and zotarolimus-eluting stent (ZES) for DES restenosis are limited. The purpose of this prospective, randomized 9-month intracoronary ultrasound (IVUS) and 3-year clinical follow-up study was to compare the effects of EESs and ZESs on neointima volume and major adverse cardiovascular events (MACEs) such as death, myocardial infarction (MI), target lesion revascularization (TLR) and stent thrombosis in DES restenosis patients.

METHODS AND RESULTS

Patients were eligible for this study if they were between 40 and 75 years old with in-stent restenosis >50% by quantitative coronary angiographic analysis in DES or within 5 mm of the stent edges with signs of ischaemia. Eligible patients (n = 304, 146 women and 158 men) were randomly assigned to receive either EES (158 patients) or ZES (146 patients). The primary endpoint of the study was to compare neointima volume between the EES and ZES groups at the 9-month follow-up IVUS. MACEs, including death, non-fatal MI, stent thrombosis and the need for repeated TLR within 3 years, were noted. The 9-month angiographic and IVUS follow-up showed no significant differences in late lumen loss (0.40 ± 0.56 vs. 0.45 ± 0.61 mm, P = 0.57, respectively) and neointima volume (0.51 ± 0.48 vs. 0.56 ± 0.54 mm³/1 mm, P = 0.47, respectively) in the EES and the ZES groups. Composite MACEs such as death, MI, stent thrombosis and TLR during 3-year follow-up were comparable between the two groups [15.8% (n = 25) in the EES group and 22.6% (n = 33) in the ZES group, P = 0.276], independent of de novo DES type, sex, age, body mass index, presence of diabetes, hypertension and dyslipidaemia.

CONCLUSIONS

Patients with first- and second-generation DES restenosis, both EES and ZES implantation were effective and safe in reducing neointima volume and late loss with a comparable rate of MACEs independent of cardiovascular risk factors.

Vessel Size and Long-Term Outcomes After Limus-Based Drug-Eluting Stent Implantation Focusing on Medium- and Small-Diameter Vessels

Introduction:

This study aimed to evaluate the efficacy and safety of limus-based drug-eluting stent (DES) implanted in medium or small coronary vessels during a very long-term follow-up period.

Methods:

A total of 2383 patients treated with 2916 limus-based DES between April 2003 and March 2015 were evaluated. The enrolled patients were stratified into 3 groups according to the reference vessel diameter: group A: ≤2.5 mm; group B: 2.51 to 3.00 mm; group C: 3.01 to 3.50 mm.

Results:

Group A had a significantly higher loss index and binary restenosis rate than the other 2 groups at 9 months of angiographic follow-up. Group A also had a significantly higher rate of target lesion revascularization and a lower rate of major adverse cardiovascular event–free survival than the other 2 groups after a follow-up period of 68 ± 59 months. The long-term cardiovascular event–free survival curves based on a Cox regression model showed large vessel size, and second-generation DES had better outcomes.

Conclusion:

An inverse relationship between vessel size (≤3.5 mm) and clinical outcomes was noted in patients who received limus-based DES implantation.

Long-term clinical outcomes of everolimus-eluting stent versus paclitaxel-eluting stent in patients undergoing percutaneous coronary interventions: a meta-analysis

BACKGROUND

Everolimus -eluting stent (EES) is common used in patients undergoing percutaneous coronary interventions (PCI). Our purpose is to evaluate long-term clinical outcomes of everolimus -eluting stent (EES) versus paclitaxel-eluting stent (PES) in patients undergoing percutaneous coronaryinterventions (PCI) in randomized controlled trials (RCTs).

METHODS

We searched Medline, EMBASE, Cochrane Library, CNKI, VIP and relevant websites ( https://scholar-google-com.ezproxy.lib.usf.edu/ ) for articles to compare outcomes between everolimus-eluting stent and paclitaxel-eluting stent without language or date restriction. RCTs that compared the use of everolimus -eluting stent and paclitaxel-eluting stent in PCI were included. Variables relating to patient, study characteristics, and clinical endpoints were extracted. Meta-analysis was performed using RevMan 5.2 software.

RESULTS

We identified 6 published studies (from three randomized trials) more on everolimus-eluting stent (n = 3352) than paclitaxel-eluting (n = 1639), with follow-up duration ranging from 3, 4 and 5 years. Three-year outcomes of everolimus-eluting stent compared to paclitaxel-eluting were as following: the everolimus-eluting stent significantly reduced all-cause death (relative risk [RR]:0.63; 95% confidence interval [CI]: 0.46. to 0.82), MACE (RR: 0.56; 95% CI: 0.41 to 0.77), MI (RR: 0.64; 95% CI: 0.48 to 0.86), TLR (RR: 0.72; 95% CI: 0.59 to 0.88), ID-TLR (RR: 0.74; 95% CI: 0.59 to 0.92) and ST (RR: 0.54; 95% CI: 0.32 to 0.90). There was no difference in TVR between the everolimus-eluting and paclitaxel-eluting (RR: 0.76; 95% CI: 0.58 to 1.10); Four-year outcomes of everolimus-eluting compared to paclitaxel-eluting: the everolimus-eluting significantly reduced MACE (RR: 0.44; 95% CI: 0.18 to 0.98) and ID-TLR (RR: 0.47; 95 % CI: 0.23 to 0.97). There was no difference in MI (RR: 0.48; 95% CI: 0.16 to 1.46), TLR (RR: 0.46; 95% CI: 0.20 to 1.04) and ST ((RR: 0.34; 95% CI: 0.05 to 2.39). Five-year outcomes of everolimus-eluting stent compared to paclitaxel-eluting: There was no difference in ID-TLR (RR: 0.67; 95% CI: 0.45 to 1.02) and ST (RR: 0.71; 95% CI: 0.28 to 1.80).

CONCLUSIONS

In the present meta-analysis, everolimus-eluting appeared to be safe and clinically effective in patients undergoing PCI in comparison to PES in 3-year clinical outcomes; there was similar no difference in reduction of ST between EES and PES in long-term(≥ 4 years) clinical follow-ups. Everolimus-eluting is more safety than paclitaxel-eluting in long-term clinical follow-ups, whether these effects can be applied to different patient subgroups warrants further investigation.

Everolimus-eluting stent platforms in percutaneous coronary intervention: comparative effectiveness and outcomes

Despite the remarkable benefits obtained following the introduction of the first-generation drug-eluting stent (DES), concerns were raised over its long-term safety, particularly with regard to very late (beyond 1 year) stent thrombosis. Newer-generation DESs have been developed to overcome this limitation using novel stent platforms, new drugs, more biocompatible durable polymers, and bioabsorbable polymers or backbones. To date, new-generation DESs have virtually replaced the use of first-generation DESs worldwide. In this review article, we discuss in detail the design, pharmacology, and mechanism of action of the newer-generation permanent and bioresorbable everolimus-eluting platforms. Furthermore, we present and evaluate the current evidence on the performance and safety of these devices compared to those of other available stent platforms.

Effects of everolimus on macrophage-derived foam cell behavior

PURPOSE

The purpose of this study was to investigate the effects of everolimus on foam cell (FC) viability, mRNA levels, and inflammatory cytokine production to better understand its potential inhibitory effects on atheroma progression.

METHODS AND MATERIALS

Human THP1 macrophage-derived FC were formed using acetylated LDL (acLDL, 100 μg/mL) for 72 hours, followed by everolimus treatment (10(-5)-10(-11) M) for 24 hours. FC viability was quantified using fluorescent calcein AM/DAPI staining. FC lysates and media supernatants were analyzed for apoptosis and necrosis using a Cell Death ELISA(PLUS) assay. FC lysates and media supernatants were also analyzed for inflammatory cytokine (IL1β, IL8, MCP1, TNFα) mRNA levels and protein expression using quantitative reverse transcription real-time polymerase chain reaction (QPCR) and a Procarta® immunoassay, respectively. mRNA levels of autophagy (MAP1LC3), apoptosis (survivin, clusterin), and matrix degradation (MMP1, MMP9) markers were evaluated by Quantigene® Plex assay and verified with QPCR. Additionally, hypercholesterolemic rabbits received everolimus-eluting stents (EES) for 28 or 60 days. RAM-11 immunohistochemical staining was performed to compare %RAM-11 positive area between stented sections and unstented proximal sections. Statistical significance was calculated using one-way ANOVA (p≤0.05).

RESULTS

Calcein AM/DAPI staining showed that FC exposed to everolimus (10(-5) M) had significantly decreased viability compared to control. FC apoptosis was significantly increased at a high dose of everolimus (10(-5)M), with no necrotic effects at any dose tested. Everolimus did not affect endothelial (HUVEC) and smooth muscle (HCASMC) cell apoptosis or necrosis. Everolimus (10(-5)M) significantly increased MAP1LC3, caused an increased trend in clusterin (p=0.10), and significantly decreased survivin and MMP1 mRNA levels in FC. MCP1 cytokine mRNA levels and secreted protein expression was significantly decreased by everolimus (10(-5) M) in FC. Percentage of RAM-11 positive area exhibited a reduction trend within sections stented with EES compared to unstented proximal sections at 60 days (p=0.09).

CONCLUSION

Everolimus, a potent anti-proliferative agent used in drug-eluting stents and bioresorbable vascular scaffolds, may inhibit atheroma progression and/or promote atheroma stabilization through diminished viability of FC, decreased matrix degradation, and reduced pro-inflammatory cytokine secretion.

EXECUTIVE SUMMARY

We explored the effects of everolimus on the behavior of human THP1 macrophage-derived foam cells in culture, including cell viability, mRNA levels, and pro-inflammatory cytokine production. We conclude that everolimus, a potent anti-proliferative agent used in drug-eluting stents/bioresorbable vascular scaffolds, may potentially inhibit atheroma progression and/or promote atheroma stabilization through diminished viability of foam cells, decreased matrix degradation, and reduced pro-inflammatory cytokine secretion.

Everolimus-coated tympanostomy tube on rat tympanic membrane

OBJECTIVES

Everolimus is an immunosuppressant and an antiproliferative macrolide agent which is used for coronary stent coating for local inhibition of in-stent restenosis. The aim of this study was to evaluate the effect of everolimus-coated tympanostomy tubes in rat tympanic membrane.

STUDY DESIGN

Prospective controlled animal study.

MATERIALS AND METHODS

Twenty-one Sprague-Dawley rats were included in the study. They were bilaterally myringotomized. An everolimus-coated fluoroplastic tympanostomy tube was inserted into one ear of each of the rats (everolimus-coated TT Group; n=21) and a standard fluoroplastic tympanostomy tube was applied to the contralateral ear of the same rats (Standard TT Group; n=21). Tympanic membranes and tubes were routinely examined otomicroscopically every other day for two months. Then the membranes were harvested and evaluated histologically.

RESULTS

In everolimus-coated tubes, the tube obstruction was found to be significantly lower than in standard tubes (p<0.05). The tube extrusion rate was less for everolimus-coated tubes than for standard tubes, but no statistically significant difference was observed between the two tubes. There was no statistically significant difference in the incidence of otorrhea between two tubes. Histopathological examination under light microscope revealed that everolimus-coated tubes resulted in less fibrosis and less inflammation in tympanic membranes than standard tubes (p<0.01).

CONCLUSION

The study shows the potential role of everolimus-coating of tympanostomy tubes in reducing tube obstruction. In addition, inflammatory reaction and fibrosis were observed to be significantly less with these tubes.

Comparison of vascular response to the everolimus-eluting stent versus the paclitaxel-eluting stent: intravascular ultrasound results from the SPIRIT III trial

AIMS

The purpose of this study was to investigate the vascular response of the everolimus-eluting stent (EES) compared with the paclitaxel-eluting stent (PES) using serial intravascular ultrasound (IVUS).

METHODS AND RESULTS

Data were obtained from the SPIRIT III trial, a multicentre, 2:1 randomised, controlled study comparing EES and PES in de novo native coronary artery lesions. IVUS images were eligible for volumetric analysis at eight-month follow-up in 158 lesions (EES: 113, PES: 45). At eight months, EES had a smaller neointimal volume index (VI: mm3/mm) (EES: 0.4±0.4 vs. PES: 0.8±0.8 mm3/mm, p=0.002) and also a smaller % neointimal obstruction (EES: 7.1±6.7% vs. PES: 11.1±10.5%, p=0.005) compared with PES. While there was no significant change in vessel VI with EES, there was a significant increase in vessel VI in PES during eight-month follow-up (EES: 0.1±1.2 vs. PES: 1.2±0.8 mm3/mm, p=0.001). There were no statistical differences in the frequency of edge dissection or incomplete stent apposition between the two groups.

CONCLUSIONS

Detailed IVUS analysis confirmed significantly less neointimal hyperplasia with EES compared with PES. While there was no increase in vessel volume with EES during the eight-month follow-up period, vessel enlargement was seen at the stented segment in PES.

Antirestenotic mechanisms of everolimus on human coronary artery smooth muscle cells: inhibition of human coronary artery smooth muscle cell proliferation, but not migration

Everolimus, a pharmaceutical component of drug-eluting stents, inhibits coronary vessel restenosis, but the antirestenotic mechanisms of action remain unclear. Here, we describe the effects of everolimus on key contributors to vessel restenosis, smooth muscle cell proliferation, and migration. In a dose-dependent fashion, everolimus reduced human coronary artery smooth muscle cell (HCASMC) proliferation without toxicity in a bimodal fashion, with accentuated potency occurring at 10 μM. Everolimus arrested the majority of HCASMCs in G1-phase, whereas it reduced the fraction of cells in S-phase at doses that inhibited DNA synthesis (bromodeoxyuridine incorporation). Consistent with this, Western blotting demonstrated that everolimus reduced activation and expression of G1-phase cell cycle progression factors, including p70S6K and cyclin D, respectively, decreased levels of proliferating cell nuclear antigen, and attenuated growth factor/serum-induced phosphorylation of the cell cycle phase transition intermediate, retinoblastoma protein. Everolimus did not, however, affect HCASMC migration. These observations suggest that everolimus acts as an antiproliferative, but not antimigratory, compound to account for at least some of the clinical efficacy exhibited by this drug as an antirestenotic agent. Moreover, everolimus-induced inhibition of the mammalian target of rapamycin complex 1 and regulation of cyclin-mediated cell cycle progression actions likely account for the antiproliferative effects of this compound on HCASMCs.

Everolimus-eluting stents: update on current clinical studies

Everolimus-eluting stents (EES) have become the most commonly implanted coronary stents worldwide. This review describes and analyzes the clinical data supporting the use of EES, focusing primarily on published, randomized, controlled trials. Everolimus-eluting stents have been shown to have less restenosis, stent thrombosis, and periprocedural myocardial infarction compared with earlier generation paclitaxel-eluting stents (PES). Lower rates of adverse events for EES compared with PES were generally seen in all subgroups, with the notable exception of patients with diabetes mellitus. There have been fewer, randomized, clinical trials comparing EES with either sirolimus-eluting stents or zotarolimus-eluting stents, although very good results with EES have been observed in the trials that have been performed. Recent clinical trial data suggest that this excellent safety and efficacy profile is maintained in a next-generation EES designed to have improved mechanical properties and radiopacity.

Drug-eluting stents perform better than bare metal stents in small coronary vessels: a meta-analysis of randomised and observational clinical studies with mid-term follow up

BACKGROUND

We tested drug-eluting stent (DES) and bare metal stent (BMS) performance in small coronary vessels by means of meta-analysis of all available clinical studies.

METHODS

The analysis included randomised controlled trials (RCT), subgroups of RCT and observational studies with a follow-up of at least six months comparing the use of DES and BMS during percutaneous interventions involving small coronary arteries (diameter<3mm). The primary endpoint was target vessel failure (TVF); the others were pooled and isolated major adverse cardiovascular events (MACE), stent thrombosis (ST), binary restenosis and late lumen loss at the longest available follow-up. The effect of treatment was evaluated in terms of odds ratios (OR) and 95% confidence intervals (95% CI) for binary variables, and mean difference (MD)± standard deviation (SD) for continuous variables. Fixed- or random-effect models were used depending on the statistical heterogeneity of studies. The analyses of major endpoints were stratified by study type, length of follow-up, and type of DES.

RESULTS

We pooled 12 studies involving 3182 patients. Trial heterogeneity was a minor issue. TVF (OR: 0.35; CI: 0.24-0.51), MACE (OR: 0.36; CI: 0.29-0.45), binary restenosis (OR: 0.15; CI: 0.12-0.20) and late lumen loss (MD: -0.46; SD: -0.55 to -0.38) all significantly improved with DES treatment; ST (OR: 0.63; CI: 0.34-1.17) was not statistically different between studies.

CONCLUSIONS

DES are superior to BMS in terms of their efficacy in managing small coronary arteries (diameter<3mm), and at least equivalent in terms of safety. The use of DES should be considered the treatment of choice in this setting.

The real world experience of the everolimus-eluting coronary stent system: audit of everolimus-eluting coronary stents

AIMS

To investigate the safety and efficacy of everolimus-eluting stents (EES) in a real world population, including those with high-risk characteristics and complex lesions.

METHODS

In this report, we analyze 2-year outcomes in 500 consecutive unselected patients treated with EES between April 2007 and March 2008. All patients were followed for 2 years for adverse events.

RESULTS

There were 995 EES deployed in 792 lesions. The indication for the coronary procedure was acute coronary syndrome in 94.2% of patients. Bifurcations were involved in 21% of lesions, 3.5% degenerated vein grafts, 2.7% left main stem stenoses, 33% multivessel disease, 4.5% in-stent restenosis, and 79.1% AHA/ACC classification B2/C lesions. The major adverse cardiac event rate (composite of cardiovascular death, acute myocardial infarction, target lesion revascularization) was 10.6%. Target lesion revascularization was required in 4.0% patients, 1.4% for in-stent thrombosis. These event rates are comparable with studies involving lower risk patients and less complex coronary lesions.

CONCLUSION

The use of EES, even in this real world, high-risk population, continues to demonstrate safety and efficacy rates comparable with current studies in more selected patient groups and, therefore, may justify current practice to utilize EES in "off label" situations.

How safe and how good are drug-eluting stents?

Percutaneous transluminal coronary angioplasty revolutionized therapy for coronary artery disease. This early promise of a viable alternative to surgical treatment of coronary artery disease was thwarted by the high rates of angiographic restenosis. The advent of stenting reduced the rates of restenosis, although it was hindered by the new problem of in-stent restenosis. It was demonstrated that in-stent restenosis was the result of a new pathology in the form of neointimal hyperplasia, which was a maladaptive healing response to bare-metal stent implantation. Recently, the introduction of drug-eluting stents (DES) technology has offered a new solution to the problem of restenosis. Current evidence suggests that although DES have reduced restenosis rates, important concerns have been raised regarding increased stent thrombosis, myocardial infarction and death. The purpose of this article is to examine the efficacy and safety data of DES as highlighted in recent publications and to further discuss the biomolecular mechanisms of accelerated endothelization and stent thrombosis. In addition, we will examine some of the newer stent technologies available.

Off-label use of drug-eluting versus bare metal stents: a lesion-specific systematic review of long-term outcomes

OBJECTIVE

The purpose of this systematic review was to evaluate differences in lesion-specific outcomes with the "off-label" use of drug-eluting stents (DES) versus bare metal stents (BMS).

METHODS

MEDLINE, PubMed, the Cochrane databases, and other Web were searched for studies evaluating off-label use of DES and BMS with the same characteristics. Of 1,258 abstracts or manuscripts reviewed, 112 studies were included (total N = 23,438). Studies were excluded if patients received both types of stent or no stent; lesion type was unknown; lesion-specific outcomes for ≥6 months were unavailable; or <25 patients were enrolled.

RESULTS

Overall mortality at 6-12 months was approximately 3% for BMS and DES for off-label use. Increase in mortality was greater from 6-12 months to 2 years with BMS than with DES (3.3%-9.1%; 2.8%-4.1%); however, rates were similar at 3 years (BMS: 18.8%; DES:15.3%). Myocardial Infarction rates were similar for both types at 6-12 months (BMS: 6.5%; DES: 6.0%). Overall rates of stent thrombosis were 1.8% and 1.7% for BMS and DES, respectively. Similar or slightly lower rates of stent thrombosis were seen for most lesion types, except higher rates for small vessels for BMS (5.2%) and true bifurcation for DES (3.3%). Rates of target lesion revascularization (TLR) were 7.5% for BMS and 19.6% for DES at 6-12 months. At 2-years TLR remained lower than DES. When the combined group was compared to registry data alone, similar values were seen.

CONCLUSIONS

Rates of mortality, myocardial infarction (MI), and stent thrombosis were similar in patients receiving BMS or DES, while TLR rates were lower in DES patients.

3-year clinical follow-up of the XIENCE V everolimus-eluting coronary stent system in the treatment of patients with de novo coronary artery lesions: the SPIRIT II trial (Clinical Evaluation of the Xience V Everolimus Eluting Coronary Stent System in the Treatment of Patients with de novo Native Coronary Artery Lesions)

OBJECTIVES

This paper reports the 3-year clinical outcomes of the XIENCE V (Abbott Vascular, Santa Clara, California) everolimus-eluting stent (EES) compared with the TAXUS (Boston Scientific, Natick, Massachusetts) paclitaxel-eluting stent (PES) in the randomized SPIRIT II (Clinical Evaluation of the Xience V Everolimus Eluting Coronary Stent System in the Treatment of Patients with de novo Native Coronary Artery Lesions) study.

BACKGROUND

The Xience V EES is a new-generation drug-eluting stent (DES) that might offer advantages over the first-generation DES in terms of improved clinical outcomes and a better safety profile.

METHODS

The SPIRIT II trial was a multicenter, prospective, randomized, single-blind, clinical trial, randomizing 300 patients with de novo coronary artery lesions in a ratio of 3:1 to either EES or PES. The primary end point was in-stent late loss at 180 days.

RESULTS

At 3-year clinical follow-up cardiac death was numerically lower with EES than PES (0.5% vs. 4.3%, p = 0.056). The observed rate of myocardial infarction was 3.6% for EES and 7.2% for PES (p = 0.31). The rate of ischemia-driven target lesion revascularization was 4.6% and 10.1% for EES and PES, respectively (p = 0.14). Overall, there was a trend for lower major adverse cardiovascular events in the EES group compared with PES (7.2% vs. 15.9%, p = 0.053). The rate of stent thrombosis was low and comparable in both groups (EES 1.0% vs. PES 2.9%).

CONCLUSIONS

The present study reports the favorable 3-year clinical outcomes of the EES, which are consistent with the results from other studies of the EES with shorter follow-up.

Determining clinical benefits of drug-eluting coronary stents according to the population risk profile: a meta-regression from 31 randomized trials

BACKGROUND

The use of drug-eluting stents (DES) in unfavourable patients has been associated with higher rates of clinical complications and stent thrombosis, and because of that concerns about the use of DES in high-risk settings have been raised.

OBJECTIVE

This study sought to demonstrate that the clinical benefit of DES increases as the risk profile of the patients increases.

METHODS

A meta-regression analysis from 31 randomized trials that compared DES and bare-metal stents, including overall 12,035 patients, was performed. The relationship between the clinical benefit of using DES (number of patients to treat [NNT] to prevent one episode of target lesion revascularization [TLR]), and the risk profile of the population (rate of TLR in patients allocated to bare-metal stents) in each trial was evaluated.

RESULTS

The clinical benefit of DES increased as the risk profile of each study population increased: NNT for TLR=31.1-1.2 (TLR for bare-metal stents); p<0.001. The use of DES was safe regardless of the risk profile of each study population, since the effect of DES in mortality, myocardial infarction, and stent thrombosis, was not adversely affected by the risk profile of each study population (95% confidence interval for β value 0.09 to 0.11, -0.12 to 0.19, and -0.03 to-0.15 for mortality, myocardial infarction, and stent thrombosis, respectively).

CONCLUSIONS

The clinical benefit of DES increases as the risk profile of the patients increases, without affecting safety.

Novel drug eluting stent system for customised treatment of coronary lesions: CUSTOM I feasibility trial 24 month results

AIMS

The Custom NX 36 Drug Eluting Stent (DES) System is designed to treat coronary lesions via in situ stent length customisation. The stent evaluated in this study consists of nine interdigitated stent segments, each 4 mm in length, coated with a biodegradable formulation of Biolimus A9 and Poly-Lactic-Acid, a biodegradable drug carrier, and loaded into a unique sheath protected, integrated balloon delivery system.

METHODS AND RESULTS

The objective of this non-randomised prospective multicentre CUSTOM I Trial was to demonstrate the safety of in situ stent length customisation in 30 consecutive patients. Angiographic (QCA) and intravascular ultrasound (IVUS) follow-up was performed at two cohort time intervals: four (n=10) or eight (n=20) months. Mean lesion length and reference vessel diameters were 17.7 +/- 9.6 mm and 2.6 +/- 0.3 mm, respectively. Procedural success was 93%. There were three MACEs in the study population from enrollment through to twenty-four month follow-up. The in-hospital MACE rate was 2/30, with non-Q-wave myocardial infarctions events in two patients who recovered without further sequelae. At five months, one patient who had crossed over initially to PTCA required CABG surgery. Results from QCA and IVUS assessments at four and eight months showed no binary restenosis, mean in-stent late luminal loss of 0.25 +/- 0.23 mm and 0.26 +/- 0.23 mm.

CONCLUSIONS

This first evaluation of the new customisable Biolimus A9-eluting Custom NX stent suggests safety and efficacy through twenty-four month follow-up. Further evaluations are warranted to confirm the overall favourable outcomes.

Late stent malapposition risk is higher after drug-eluting stent compared with bare-metal stent implantation and associates with late stent thrombosis

AIMS

Late stent malapposition (LSM) may be acquired (LASM) or persistent. LSM may play a role in patients who develop late stent thrombosis (ST). Our objective was to compare the risk of LASM in bare metal stents (BMS) with drug-eluting stents (DES) and to investigate the possible association of both acquired and persistent LSM with (very) late ST.

METHODS AND RESULTS

We searched PubMed and relevant sources from January 2002 to December 2007. Inclusion criteria were: (a) intra-vascular ultrasonography (IVUS) at both post-stent implantation and follow-up; (b) 6-9-month-follow-up IVUS; (c) implantation of either BMS or the following DES: sirolimus, paclitaxel, everolimus, or zotarolimus; and (d) follow-up for LSM. Of 33 articles retrieved for detailed evaluation, 17 met the inclusion criteria. The risk of LASM in patients with DES was four times higher compared with BMS (OR = 4.36, CI 95% 1.74-10.94) in randomized clinical trials. The risk of (very) late ST in patients with LSM (five studies) was higher compared with those without LSM (OR = 6.51, CI 95% 1.34-34.91).

CONCLUSION

In our meta-analysis, the risk of LASM is strongly increased after DES implantation compared with BMS. Furthermore, LSM seems to be associated with late and very late ST.

Off-label use of stents: bare-metal versus drug-eluting stents

Drug-eluting stents (DES) became the default strategy for percutaneous revascularization due to their improved intermediate-term outcomes when compared with bare-metal stents (BMS) in the pivotal randomized, controlled trials. The excellent results of DES in on-label or US FDA-approved indications led to extrapolation of the results to more complex situations that were excluded from initial pivotal trials; such as off-label indications. Safety concerns began to grow after reports of increased late thrombosis and possibly associated increased death and myocardial infarction with DES, especially in the off-label situations. Recently, however, several important published registries have calmed some of those uncertainties and reassured the cardiology community of the safety and efficacy of DES compared with BMS. There is an overall poorer outcome with off-label use of any stent (BMS or DES) compared with standard or on-label use. This difference in outcome is most likely related to patient or specific coronary lesion characteristics or comorbidities that predispose an individual to adverse outcomes regardless of the stent type used. It is accepted now that DES use does result in a small increased risk of late thrombosis, but that risk is offset by a significant reduction in restenosis. Overall, the current data suggest that the use of DES in most lesion subsets is at least as safe as and clearly more efficacious than use of BMS in similar situations.

Systemic exposure of everolimus after stent implantation: a pharmacokinetic study

OBJECTIVES

We evaluated the pharmacokinetics of the eluted everolimus by assessing systemic drug release and distribution of everolimus-eluting stents.

BACKGROUND

Drugs eluted by a coronary stent might cause adverse events such as tumors, infections, or noncardiac death. The systemic exposure of the drugs is unknown because there are only limited data about pharmacokinetics of drug-eluting stents in humans.

METHODS

Venous blood samples in a subset of 39 patients were drawn just before implantation of the first stent (baseline, 0-minute time point) and at 10 and 30 minutes and 1, 2, 4, 6, 12, 24, 36, 48, 72, 168, and 720 hours (30 days) after completion of implantation of the last stent. Whole blood concentrations of everolimus were determined using a sensitive validated high-performance liquid chromatography mass spectrometry/mass spectrometry method.

RESULTS

The total dose of everolimus received by the patients ranged from 53 to 588 microg. The last time point up to which whole blood concentrations could be quantified ranged per patient from 4 to 720 hours after implantation of the last stent. Across all dose levels, individual T(max) values ranged from 0.13 and 2.17 hours; individual C(max) ranged from 0.14 to 2.79 ng/mL.

CONCLUSION

This study confirms the limited exposure to the systemic circulation of the eluted drug with the use of the XIENCE V Everolimus-Eluting Coronary Stent System (Abbott Vascular, Santa Clara, CA). Therefore, a systemic cause of adverse events is unlikely.

Next-generation drug-eluting stents in coronary artery disease: focus on everolimus-eluting stent (Xience V)

Percutaneous coronary revascularization has been a mainstay in the management of coronary artery disease since its introduction in the late 1970s. Bare-metal stents and, more recently, first-generation drug-eluting stents (DES), such as sirolimus-eluting (Cypher^®) and paclitaxel-eluting stents (Taxus^®), have further improved results of percutaneous coronary intervention (PCI) by improving early results and reducing the risk of restenosis. There is currently debate on the safety of these first-generation DES, given the potential for late stent thrombosis, especially after discontinuation of dual antiplatelet therapy. There are well known caveats on the performance of their respective metallic stent platforms, delivery, and dilation systems, and polymer coatings. Second-generation DES, such as zotarolimus-eluting (Endeavor^®) and everolimus-eluting stents (Xience V^®), have recently become available in the USA and/or Europe. The Xience V stent holds the promise of superior anti-restenotic efficacy as well as long-term safety. In addition, this stent is based on the Multi-link platform and delivery system. Recently available data already suggest the superiority of the Xience V stent in comparison to the Taxus stent in terms of prevention of restenosis, without significant untoward events. Nonetheless, the number of patients studied and the follow-up duration are still too limited to enable definitive conclusions. Only indirect meta-analyses can be used to date to compare the Xience V with the Cypher. This systematic review tries to provide a concise and critical appraisal of the data in support of the Xience V everolimus-eluting stent.

Pro-healing drug-eluting stents: a role for antioxidants?

Current strategies to lower the incidence of ISR (in-stent restenosis) following PCI (percutaneous coronary intervention) are aimed at modifying arterial healing after stent injury. This can impair endothelial recovery and render the vessel prone to acute thrombosis. As early restoration of endothelial integrity inhibits neointimal growth and thrombosis, alternative approaches which encourage this process may provide a more effective long-term result after PCI. Oxidative stress is enhanced after PCI and participates in the regulation of endothelial regeneration and neointimal growth. Moreover, evidence suggests antioxidants improve re-endothelialization and inhibit ISR. By promoting, rather than blocking, the healing process, antioxidant and other therapies may offer an alternative or additional approach over the antiproliferative approaches common to many current devices.

Drug-eluting stents - what should be improved?

Despite the success of drug-eluting stents (DES) in reducing restenosis and the need for target vessel revascularization, several deficiencies have been unraveled since their first clinical application including the risk of stent thrombosis, undesired effects due to the stent polymer as well as the stent itself, and incomplete inhibition of restenosis (especially in complex lesions). Several novel stent systems are being investigated in order to address these issues. In second-generation DES, the rapamycin analogues zotarolimus and everolimus (and more recently biolimus) have been most extensively studied. Furthermore, special stent-coatings to actively promote endothelial healing (in order to reduce the risk of stent thrombosis) and to further reduce restenosis have been employed. To avoid undesirable effects of currently applied (durable) polymers, biocompatible and bioabsorbable polymers as well as DES delivery systems without the need for a polymer have been developed. Bioabsorbable stents, both polymeric and metallic, were developed to decrease potential late complications after stent implantation. Although most of these innovative novel principles intuitively seem appealing and demonstrate good results in initial clinical evaluations, long-term large-scale studies are necessary in order to reliably assess whether these novel systems are truly superior to first-generation DES with respect to safety and efficacy.