Healing Achilles--sirolimus versus paclitaxel

Comparing a strategy of sirolimus-eluting balloon treatment to drug-eluting stent implantation in de novo coronary lesions in all-comers: Design and rationale of the SELUTION DeNovo Trial

BACKGROUND

Drug eluting stents (DES) are associated with a 2% to 4% annual rate of target lesion failure through 5-to-10-year follow-up. The presence of a metallic protheses is a trigger for neo-atherosclerosis and very late stent thrombosis. A "leave nothing behind" strategy using Drug Coated Balloons has been suggested; however, paclitaxel coated balloons are only recommended in selected indications. Recently a novel sirolimus eluting balloon, the SELUTION SLR ^TM 014 PTCA balloon (SEB) (M.A. MedAlliance SA, Nyon, Switzerland) has been developed.

HYPOTHESIS

A strategy of percutaneous coronary intervention (PCI) with SEB and provisional DES is non-inferior to a strategy of systematic DES on target vessel failure (TVF) at one and five years. If non-inferiority is met at 5 years, superiority will be tested.

DESIGN

SELUTION DeNovo is a multi-center international open-label randomized trial. Subjects meeting eligibility criteria are randomized 1:1 to treatment of all lesions with either SEB and provisional DES or systematic DES. Major inclusion criteria are PCI indicated for ≥1 lesion considered suitable for treatment by either SEB or DES and clinical presentation with chronic coronary syndrome, unstable angina or non-ST segment elevation myocardial infarction (NSTEMI). There is no limitation in the number of lesions to be treated. Target lesions diameters are between 2 and 5 mm. Major exclusion criteria are lesions in the left main artery, chronic total occlusions, ST segment elevation myocardial infarction and unstable non-ST segment elevation myocardial infarction. Three thousand three hundred twenty six patients will be included in 50 sites in Europe and Asia. TVF rates and their components will be determined at 30 days, 6 months and annually up to 5 years post-intervention. Among secondary endpoints, bleeding events, cost-effectiveness data and net clinical benefits will be assessed.

SUMMARY

SELUTION DeNovo trial is an open-label, multi-center international randomized trial comparing a strategy of PCI with SEB and provisional DES to a strategy of PCI with systematic DES on TVF at one and five years. Non-inferiority will be tested at one and five years. If non-inferiority is met at five years, superiority will be tested.

Drug-Eluting Stents: Technical and Clinical Progress

Drug-eluting stents (DES) demonstrated superior efficacy when compared to bare metal stents and plain-old balloon angioplasty and are nowadays used in almost all percutaneous revascularization procedures. The design of the stent platforms is constantly improving to maximize its efficacy and safety. Constant development of DES includes adoption of new materials used for scaffold production, new design types, improved overexpansion abilities, new polymers coating and, finally, improved antiproliferative agents. Especially nowadays, with the immense number of available DES platforms, it is crucial to understand how different aspects of stents impact the effect of their implantation, as subtle differences between various stent platforms could impact the most important issue-clinical outcomes. This review discusses the current status of coronary stents and the impact of stent material, strut design and coating techniques on cardiovascular outcomes.

Nanoparticles eluting stents for coronary intervention: Formulation, characterization and in vitro evaluation

Coronary artery disease (CAD) is currently a leading cause of death worldwide. In the history of percutaneous coronary intervention for the treatment of CAD, a drug-eluting stent (DES) is recognized as a revolutionary technology that has the unique ability to significantly reduce restenosis and provide both mechanical and biological solutions simultaneously to the target lesion. The aim of the research work was to design and fabricate DES coated with a nanoparticulate drug formulation. Sirolimus, an inhibitor of the smooth muscle cell (SMC) proliferation and migration, was encapsulated in polymeric nanoparticles. The nanoparticle formulation was characterized for various physicochemical parameters. Cell viability and cell uptake studies were performed using human coronary artery smooth muscle cells (HCASMCs). The developed nanoparticle formulation showed enhanced efficacy compared to plain drug solution and exhibited time-dependent uptake into the HCASMCs. The developed nanoparticle formulation was coated on the FlexinniumTM ultra-thin cobalt-chromium alloy coronary stent platform. The nanoparticle coated stents were characterized for morphology and residual solvent analysis. In-vitro drug release was also evaluated. Ex-vivo arterial permeation was carried out to evaluate the nanoparticle uptake from the surface of the stents. The characterization studies together corroborated that the developed nanoparticle coated stent can be a promising replacement of the current drug-eluting stents.

Meta-analysis of Duration of Continuous Dual Antiplatelet Therapy and Late Stent Thrombosis After Second-Generation Drug Stent Implantation

INTRODUCTION

The aim of the present study was to perform a systematic comparison of the incidence of late and extremely late stent thrombosis (ST) with short-term and long-term dual antiplatelet therapy (DAPT) after a second-generation drug-eluting stent (DES) implantation.

METHODS

Randomized controlled trials using short-term and long-term DAPT and reporting late ST (30 days-1 year) and extremely late ST (longer than 1 year) after a percutaneous coronary intervention (PCI) with DES were searched and compared in the Life Sciences and Biomedical Information Bibliographic Database (MEDLINE), EMBASE, Cochrane Central, and ClinicalTrials.com. ST was used as the primary endpoint of the therapeutic outcome, and the fixed-effects model (I² < 50%) or random-effects model (I² ≥ 50%) was adopted for the combined analysis. The odds ratio (OR) and 95% confidence interval (CIs) were used to represent the results. P < 0.05 in the combined result indicated that the difference was statistically significant.

RESULTS

A total of five randomized controlled trials consisting of 7142 patients were included, with 3556 cases of short-term DAPT (at most 6 months), and 3586 cases of long-term DAPT (at least 12 months). There was no significant difference between late ST and administration duration of DAPT (OR 0.98, 95% CI 0.30-3.18; P = 0.97, I² = 0%). There was also no significant difference between the incidence of extremely late ST and the duration of DAPT application (OR 0.30, 95% CI 0.03-2.95; P = 0.31).

CONCLUSION

The duration of continuous DAPT application had no effect on the occurrence of late and extremely late ST.

[Association of CMTM5 gene expression with the risk of in-stent restenosis in patients with coronary artery disease after drug-eluting stent implantation and the effects and mechanisms of CMTM5 on human vascular endothelial cells]

OBJECTIVE

To elucidate the correlation between CKLF-like marvel transmembrane domain containing member (CMTM5) gene and the risk of in-stent restenosis (ISR) with coronary artery disease (CAD) patients and to detect the effects and mechanisms of CMTM5-stimulated genes on human vascular endothelial cells (ECs) proliferation and migration.

METHODS

A total of 124 hospitalized patients in Shijitan Hospital were enrolled in this study. All the CAD patients were detected with platelet reactivity and grouped into two groups according to platelet reactivity; ISR was conformed by coronary angiography; RT-PCR method was used to detect CMTM5 gene expression; The CMTM5 over expression, reduction and control EC lines were established; Cell count, MTT, Brdu and flow cytometry methods were used to detect the proliferation of ECs, scratch and transwell experiments to test the migration of ECs, Western blot was used to detect signal path expressions.

RESULTS

CMTM5 gene expression in HAPR (High on aspirin platelet reactivity) group was 1.72 times compared with No-HAPR group, which was significantly higher than No-HAPR group. HAPR group ISR rate was 25.8% (8 cases), the incidence of No-HAPR ISR group was 9.7% (9 cases), and the results showed that in HAPR group, the incidence of ISR was significantly higher than that in No-HAPR group (P=0.04, OR=0.04, 95%CI=1.16－7.52), which showed that CMTM5 gene was significantly correlated with the risk of ISR. In HAPR group ISR rate was 25.8% (8 cases), the incidence of ISR in No-HAPR group was 9.7% (9 cases), and the results showed that the risk of ISR in HAPR group was significantly higher than that in No-HAPR group. All the results showed that CMTM5 was significantly correlated with the risk of ISR in CAD patients (P < 0.05). CMTM5 overexpression inhibited the proliferation and migration ability of ECs (P < 0.05), PI3K/Akt signaling pathways were involved in the role of regulation on ECs.

CONCLUSION

Our results revealed that CMTM5 gene was closely related with ISR, CMTM5 overexpression may repress ECs proliferation and migration through regulating PI3K-Akt signaling.

Heart team 2.0: A decision tree for minimally invasive and hybrid myocardial revascularization

Recent years have seen an important shift in the target population for myocardial revascularization. Patients are increasingly presenting with more complex coronary artery disease (CAD), but also with multiple comorbidities and frailty. At the same time, minimally invasive strategies such as Minimally Invasive Direct Coronary Artery Bypass Grafting (MIDCAB) and Percutaneous Coronary Interventions (PCI) have been developed, which might be more appealing for this group of patients. As a result, the landscape of options for myocardial revascularization is evolving while adequate use of all resources is required to ensure optimal patient care. Heart Teams are confronted with the challenge of incorporating the new minimally invasive strategies into the decision process, yet current guidelines do not fully address this challenge. In this review, the current evidence regarding outcomes, indications, benefits, and risks of off-pump coronary artery bypass grafting (OPCAB), MIDCAB, PCI, and hybrid coronary revascularization (HCR) are discussed. Based on this evidence and on experiences from Heart Team discussions, a new decision tree is proposed that incorporates recent advances in minimally invasive revascularization strategies, thereby optimizing adequate delivery of care for each individual patient's needs. Introducing all important considerations in a logical way, this tool facilitates the decision-making process and might ensure appropriate use of resources and optimal care for individual patients.

Magmaris resorbable magnesium scaffold for the treatment of coronary heart disease: overview of its safety and efficacy

Introduction: Bioresorbable scaffold technology provides transient vessel support with drug-delivery capability without the long-term limitations of the permanent metallic drug-eluting stents (DES). The technology has the potential to overcome many of the safety concerns associated with metallic DES, such as hypersensitivity reactions, late stent thrombosis and progression of atherosclerosis within the stented segment (i.e. neoatherosclerosis). Areas covered: The sirolimus-eluting resorbable magnesium scaffold Magmaris is the only metallic CE-marked resorbable scaffold currently available. This magnesium scaffold is designed for providing a short-term lumen support (up to 3 months) before being completely bioresorbed, eliminating the permanent caging typical of the metallic DES. This review will focus on the device development and characteristics, currently available clinical efficacy and safety data, and potential future perspectives. Expert opinion: The first clinical studies testing this device in a small number of patients have shown promising results with good clinical and safety outcomes up to 3 years' clinical follow-up, supporting the use of Magmaris in simple coronary artery disease.

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.

Organ transplantation and drug eluting stents: Perioperative challenges

Patients listed for organ transplant frequently have severe coronary artery disease (CAD), which may be treated with drug eluting stents (DES). Everolimus and zotarolimus eluting stents are commonly used. Newer generation biolimus and novolimus eluting biodegradable stents are becoming increasingly popular. Patients undergoing transplant surgery soon after the placement of DES are at increased risk of stent thrombosis (ST) in the perioperative period. Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor such as clopidogrel, prasugrel and ticagrelor is instated post stenting to decrease the incident of ST. Cangrelor has recently been approved by Food and Drug Administration and can be used as a bridging antiplatelet drug. The risk of ischemia vs bleeding must be considered when discontinuing or continuing DAPT for surgery. Though living donor transplant surgery is an elective procedure and can be optimally timed, cadaveric organ availability is unpredictable, therefore, discontinuation of antiplatelet medication cannot be optimally timed. The type of stent and timing of transplant surgery can be of utmost importance. Many platelet function point of care tests such as Light Transmittance Aggregrometry, Thromboelastography Platelet Mapping, VerifyNow, Multiple Electrode Aggregrometry are used to assess bleeding risk and guide perioperative platelet transfusion. Response to allogenic platelet transfusion to control severe intraoperative bleeding may differ with the antiplatelet drug. In stent thrombosis is an emergency where management with either a drug eluting balloon or a DES has shown superior outcomes. Post-transplant complications often involved stenosis of an important vessel that may need revascularization. DES are now used for endovascular interventions for transplant orthotropic heart CAD, hepatic artery stenosis post liver transplantation, transplant renal artery stenosis following kidney transplantation, etc. Several antiproliferative drugs used in the DES are inhibitors of mammalian target of rapamycin. Thus they are used for post-transplant immunosuppression to prevent acute rejection in recipients with heart, liver, lung and kidney transplantation. This article describes in detail the various perioperative challenges encountered in organ transplantation surgery and patients with drug eluting stents.

Secreted Matrix Metalloproteinase-9 of Proliferating Smooth Muscle Cells as a Trigger for Drug Release from Stent Surface Polymers in Coronary Arteries

Cardiovascular diseases are the leading causes of death in industrialized countries. Atherosclerotic coronary arteries are commonly treated with percutaneous transluminal coronary intervention followed by stent deployment. This treatment has significantly improved the clinical outcome. However, triggered vascular smooth muscle cell (SMC) proliferation leads to in-stent restenosis in bare metal stents. In addition, stent thrombosis is a severe side effect of drug eluting stents due to inhibition of endothelialization. The aim of this study was to develop and test a stent surface polymer, where cytotoxic drugs are covalently conjugated to the surface and released by proteases selectively secreted by proliferating smooth muscle cells. Resting and proliferating human coronary artery smooth muscle cells (HCASMC) and endothelial cells (HCAEC) were screened to identify an enzyme exclusively released by proliferating HCASMC. Expression analyses and enzyme activity assays verified selective and exclusive activity of the matrix metalloproteinase-9 (MMP-9) in proliferating HCASMC. The principle of drug release exclusively triggered by proliferating HCASMC was tested using the biodegradable stent surface polymer poly-l-lactic acid (PLLA) and the MMP-9 cleavable peptide linkers named SRL and AVR. The specific peptide cleavage by MMP-9 was verified by attachment of the model compound fluorescein. Fluorescein release was observed in the presence of MMP-9 secreting HCASMC but not of proliferating HCAEC. Our findings suggest that cytotoxic drug conjugated polymers can be designed to selectively release the attached compound triggered by MMP-9 secreting smooth muscle cells. This novel concept may be beneficial for stent endothelialization thereby reducing the risk of restenosis and thrombosis.

Biodegradable Metals for Cardiovascular Stents: from Clinical Concerns to Recent Zn-Alloys

Metallic stents are used to promote revascularization and maintain patency of plaqued or damaged arteries following balloon angioplasty. To mitigate the long-term side effects associated with corrosion-resistant stents (i.e., chronic inflammation and late stage thrombosis), a new generation of so-called "bioabsorbable" stents is currently being developed. The bioabsorbable coronary stents will corrode and be absorbed by the artery after completing their task as vascular scaffolding. Research spanning the last two decades has focused on biodegradable polymeric, iron-based, and magnesium-based stent materials. The inherent mechanical and surface properties of metals make them more attractive stent material candidates than their polymeric counterparts. A third class of metallic bioabsorbable materials that are based on zinc has been introduced in the last few years. This new zinc-based class of materials demonstrates the potential for an absorbable metallic stent with the mechanical and biodegradation characteristics required for optimal stent performance. This review compares bioabsorbable materials and summarizes progress towards bioabsorbable stents. It emphasizes the current understanding of physiological and biological benefits of zinc and its biocompatibility. Finally, the review provides an outlook on challenges in designing zinc-based stents of optimal mechanical properties and biodegradation rate.

Clinical utility of platinum chromium bare-metal stents in coronary heart disease

Coronary stents represent a key development for the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. While drug-eluting stents gained wide acceptance in contemporary percutaneous coronary intervention practice, further developments in bare-metal stents remain crucial for patients who are not candidates for drug-eluting stents, or to improve metallic platforms for drug elution. Initially, stent platforms used biologically inert stainless steel, restricting stent performance due to limitations in flexibility and strut thickness. Later, cobalt chromium stent alloys outperformed steel as the material of choice for stents, allowing latest generation stents to be designed with significantly thinner struts, while maintaining corrosion resistance and radial strength. Most recently, the introduction of the platinum chromium alloy refined stent architecture with thin struts, high radial strength, conformability, and improved radiopacity. This review will provide an overview of the novel platinum chromium bare-metal stent platforms available for coronary intervention. Mechanical properties, clinical utility, and device limitations will be summarized and put into perspective.

Propensity score matched lesion-based comparison of long-term clinical and angiographic outcomes after placement of sirolimus (Cypher Bx Velocity) and paclitaxel (TAXUS Express)-eluting stents for de novo native coronary stenosis

Long-term clinical and angiographic outcomes after sirolimus (SES: Cypher Bx Velocity) and paclitaxel (PES: TAXUS Express)-eluting stent implantation were firstly compared in Japan. During PES-available period from May 2007 to February 2009, 1068 nonrandomized consecutive de novo native coronary lesions treated either with a PES (682 lesions) or SES were enrolled in this study, and a retrospective examination was conducted in April 2013. During that interval, the use ratio of drug-eluting stent (i.e. SES plus PES) was 94.2 %. By adjusting the baselines with a propensity score matching analysis produced 383 lesions in each arm, the incidence of the clinical endpoint (1500-day cardiac death, nonfatal recurrent myocardial infarction, and definite stent thrombosis) after placement of SES (2.1 %; mean follow-up, 1400 ± 290 days) was not significantly different from that in the PES group (2.6 %; 1394 ± 325 days, p = 0.637). SES did not relate to the clinical endpoint (hazard ratio 1.04; 95 % CI 0.29-3.76; p = 0.949). In the baseline-adjusted angiographic followed up lesions (n = 234 in each arm), the incidence of binary restenosis (percent diameter stenosis [%DS] >50 %) in the SES group (12.0 %; mean follow-up, 477 ± 281 days) was not significantly different from that in the PES group (14.5 %; 497 ± 341 days, p = 0.431). SES did not relate to binary restenosis (Odds ratio 0.73; 95 % CI 0.40-1.32; p = 0.295). In conclusion, the present propensity score matched lesion-based analysis firstly showed the statistical equivalent long-term clinical and angiographic outcomes after either SES or PES placement for de novo native coronary lesion in Japanese patients in a daily practice environment.

Italian Diffuse/Multivessel Disease ABSORB Prospective Registry (IT-DISAPPEARS). Study design and rationale

BACKGROUND

The Absorb Bioresorbable Vascular Scaffold System (Absorb BVS) is an everolimus-eluting bioresorbable vascular scaffold able to provide temporary scaffolding and antiproliferative drug delivery for the treatment of coronary artery disease. This temporary scaffolding could be the true feature to overcome the limitations of the conventional metallic stents. A growing body of evidence worldwide is supporting its implementation into daily practice as being associated with comparable results as the second-generation everolimus-eluting stent. However, these pieces of evidence come from 'studies in which the majority of the patients had low-risk stenoses', whereas patients with more complex coronary artery disease could benefit the most from the Absorb BVS technology.

METHODS

The aim of the IT-DISAPPEARS is to investigate the procedural and clinical performance of the Absorb BVS in patients with long (>24 mm), single-vessel coronary disease or with multivessel disease. At least 50 centers across the Italian territory will enroll 1000 patients with either stable or acute coronary syndromes. Follow-up will end up at 5 years. Primary endpoint will be the cumulative hierarchical incidence of major adverse cardiac events at 1 year, defined as: cardiac death, nonfatal target vessel myocardial infarction, or clinically driven target lesion revascularization. The efficacy as well as safety parameters will be evaluated along with a detailed evaluation of the dual antiplatelet therapy duration/interruption.

CONCLUSION

The IT-DISAPPEARS could provide the first evidence worldwide concerning the performance of Absorb BVS in patients with high-risk diffuse coronary disease.

Microwave spectrometry for the evaluation of the structural integrity of metallic stents

PURPOSE

To assess the feasibility of a method based on microwave spectrometry to detect structural distortions of metallic stents in open air conditions and envisage the prospects of this approach toward possible medical applicability for the evaluation of implanted stents.

METHODS

Microwave absorbance spectra between 2.0 and 18.0 GHz were acquired in open air for the characterization of a set of commercial stents using a specifically design setup. Rotating each sample over 360°, 2D absorbance diagrams were generated as a function of frequency and rotation angle. To check our approach for detecting changes in stent length (fracture) and diameter (recoil), two specific tests were performed in open air. Finally, with a few adjustments, this same system provides 2D absorbance diagrams of stents immersed in a water-based phantom, this time over a bandwidth ranging from 0.2 to 1.8 GHz.

RESULTS

The authors show that metallic stents exhibit characteristic resonant frequencies in their microwave absorbance spectra in open air which depend on their length and, as a result, may reflect the occurrence of structural distortions. These resonances can be understood considering that such devices behave like dipole antennas in terms of microwave scattering. From fracture tests, the authors infer that microwave spectrometry provides signs of presence of Type I to Type IV stent fractures and allows in particular a quantitative evaluation of Type III and Type IV fractures. Recoil tests show that microwave spectrometry seems able to provide some quantitative assessment of diametrical shrinkage, but only if it involves longitudinal shortening. Finally, the authors observe that the resonant frequencies of stents placed inside the phantom shift down with respect to the corresponding open air frequencies, as it should be expected considering the increase of dielectric permittivity from air to water.

CONCLUSIONS

The evaluation of stent resonant frequencies provided by microwave spectrometry allows detection and some quantitative assessment of stent fracture and recoil in open air conditions. Resonances of stents immersed in water can be also detected and their characteristic frequencies are in good agreement with theoretical estimates. Although these are promising results, further verification in a more relevant phantom is required in order to foresee the real potential of this approach.

A novel platinum chromium everolimus-eluting stent for the treatment of coronary artery disease

The development of coronary stents represents a major step forward in the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. The initial enthusiasm for bare metal stents was, however, tempered by a significant incidence of in-stent restenosis, the manifestation of excessive neointima hyperplasia within the stented vessel segment, ultimately leading to target vessel revascularization. Later, drug-eluting stents, with controlled local release of antiproliferative agents, consistently reduced this need for repeat revascularization. In turn, the long-term safety of first-generation drug-eluting stents was brought into question with the observation of an increased incidence of late stent thrombosis, often presenting as myocardial infarction or sudden death. Since then, new drugs, polymers, and platforms for drug elution have been developed to improve stent safety and preserve efficacy. Development of a novel platinum chromium alloy with high radial strength and high radiopacity has enabled the design of a new, thin-strut, flexible, and highly trackable stent platform, while simultaneously improving stent visibility. Significant advances in polymer coating, serving as a drug carrier on the stent surface, and in antiproliferative agent technology have further improved the safety and clinical performance of newer-generation drug-eluting stents. This review will provide an overview of the novel platinum chromium everolimus-eluting stents that are currently available. The clinical data from major clinical trials with these devices will be summarized and put into perspective.

[Use of drug-eluting stents: impact of French recommendations on the rate of clinical restenosis at 2 years]

AIMS

The drug-eluting stents (DES) reduce restenosis rate compared to bare metal stents. The clinical efficacy is greater in some subgroups of patients at high risk of restenosis. The aim of this study is to evaluate the use of drug-eluting stent based on the recommendations of the French Society of Cardiology and its impact on the restenosis rate at 2 years.

METHODS

We included all patients who had coronary angioplasty with stenting in 2008. We evaluated the percentage of drug-eluting stent, the proportion of patients for which the French recommendations have been followed, and the rate of clinical restenosis at 2 years.

RESULTS

Four hundred and seventy-nine angioplasties were performed in 2008. The percentage of drug-eluting stents was 21.8%. Acute coronary syndrome with or without elevation of the ST segment were the main indications of angioplasty (67.9%). For the 115 drug-eluting stents implanted in 2008, French recommendations were followed in 93% of cases (107 stents). For 89 patients who received DES, these recommendations were followed in 91% of cases (81 patients). The clinical restenosis rate at 2 years evaluated in 89% of patients was 5.6%. The rate of in-stent restenosis in bare metal and drug-eluting stents were 5.9 and 3.7%.

CONCLUSION

The use of DES in our center is characterized by a small rate and a good compliance of the recommendations of the French Society of Cardiology. This strategy is associated with a low rate of restenosis at 2 years of follow-up.

Emerging applications of nanotechnology for the diagnosis and management of vulnerable atherosclerotic plaques

An estimated 16 million people in the United States have coronary artery disease (CAD), and approximately 325,000 people die annually from cardiac arrest. About two-thirds of unexpected cardiac deaths occur without prior recognition of cardiac disease. A vast majority of these deaths are attributable to the rupture of 'vulnerable atherosclerotic plaques'. Clinically, plaque vulnerability is typically assessed through imaging techniques, and ruptured plaques leading to acute myocardial infarction are treated through angioplasty or stenting. Despite significant advances, it is clear that current imaging methods are insufficiently capable for elucidating plaque composition--which is a key determinant of vulnerability. Further, the exciting improvement in the treatment of CAD afforded by stenting procedures has been buffered by significant undesirable host-implant effects, including restenosis and late thrombosis. Nanotechnology has led to some potential solutions to these problems by yielding constructs that interface with plaque cellular components at an unprecedented size scale. By leveraging the innate ability of macrophages to phagocytose nanoparticles, contrast agents can now be targeted to plaque inflammatory activity. Improvements in nano-patterning procedures have now led to increased ability to regenerate tissue isotropy directly on stents, enabling gradual regeneration of normal, physiologic vascular structures. Advancements in immunoassay technologies promise lower costs for biomarker measurements, and in the near future, may enable the addition of routine blood testing to the clinician's toolbox--decreasing the costs of atherosclerosis-related medical care. These are merely three examples among many stories of how nanotechnology continues to promise advances in the diagnosis and treatment of vulnerable atherosclerotic plaques.

Signaling pathways regulating vascular smooth muscle cell differentiation

Vascular smooth muscle cell (VSMC) differentiation is an essential component of vascular development. These cells perform biosynthetic, proliferative, and contractile roles in the vessel wall. VSMCs are not terminally differentiated and are able to modulate their phenotype in response to changing local environmental cues. There is clear evidence that alterations in the differentiated state of the VSMC play a critical role in the pathogenesis of atherosclerosis and intimal hyperplasia, as well as in a variety of other major human diseases, including hypertension, asthma, atherosclerosis and vascular aneurysms. The focus of this review is to provide an overview of the current state of knowledge of molecular mechanisms involved in controlling phenotypic switching of VSMCs, with particular focus on examination of the signaling pathways that regulate this process.

Sirolimus-Loaded Polyurethane Graft for Hemodialysis Access in Sheep

Intimal hyperplasia is the most common final pathway for hemoaccess occlusion in dialysis patients. Drug eluting stents have been shown to decrease intimal hyperplasia in coronary arteries and possibly in peripheral arteries. We evaluated the use of a sirolimus loaded polyurethane graft as prophylaxis in hemodialysis access. Grafts were loaded with sirolimus and elution curves were determined for the polyurethane material. The arteriovenous grafts were then placed in the neck of 20 sheep. A non-loaded graft was placed in the contralateral neck. Patency rates, ultrasound evaluation, angiography and histomorphometry were determined for each graft. At 30, 60 and 90 days the drug loaded graft had improved patency rates compared to the control, with a 25% improvement noted at 3 months. Life table analysis showed the drug loaded graft consistently better patency than the control (p = .136). The control graft had greater neointimal stenosis (14.5% vs 9.17%) over the course of the study (p = .157). Although none of these findings was statistically significant in this pilot study, the sirolimus coated graft out-performed the control in every measured parameter at each time point evaluated. Further work to asses the validity of drug coated materials to prevent intimal hyperplasia in hemodialysis access is warranted.

Coronary artery stents: Part I. Evolution of percutaneous coronary intervention

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.

Rapamycin Promotes Vascular Smooth Muscle Cell Differentiation through Insulin Receptor Substrate-1/Phosphatidylinositol 3-Kinase/Akt2 Feedback Signaling

The phenotypic plasticity of mature vascular smooth muscle cells (VSMCs) facilitates angiogenesis and wound healing, but VSCM dedifferentiation also contributes to vascular pathologies such as intimal hyperplasia. Insulin/insulin-like growth factor I (IGF-I) is unique among growth factors in promoting VSMC differentiation via preferential activation of phosphatidylinositol 3-kinase (PI3K) and Akt. We have previously reported that rapamycin promotes VSMC differentiation by inhibiting the mammalian target of rapamycin (mTOR) target S6K1. Here, we show that rapamycin activates Akt and induces contractile protein expression in human VSMC in an insulin-like growth factor I-dependent manner, by relieving S6K1-dependent negative regulation of insulin receptor substrate-1 (IRS-1). In skeletal muscle and adipocytes, rapamycin relieves mTOR/S6K1-dependent inhibitory phosphorylation of IRS-1, thus preventing IRS-1 degradation and enhancing PI3K activation. We report that this mechanism is functional in VSMCs and crucial for rapamycin-induced differentiation. Rapamycin inhibits S6K1-dependent IRS-1 serine phosphorylation, increases IRS-1 protein levels, and promotes association of tyrosine-phosphorylated IRS-1 with PI3K. A rapamycin-resistant S6K1 mutant prevents rapamycin-induced Akt activation and VSMC differentiation. Notably, we find that rapamycin selectively activates only the Akt2 isoform and that Akt2, but not Akt1, is sufficient to induce contractile protein expression. Akt2 is required for rapamycin-induced VSMC differentiation, whereas Akt1 appears to oppose contractile protein expression. The anti-restenotic effect of rapamycin in patients may be attributable to this unique pattern of PI3K effector regulation wherein anti-differentiation signals from S6K1 are inhibited, but pro-differentiation Akt2 activity is promoted through an IRS-1 feedback signaling mechanism.

Regulation of vascular smooth muscle cell differentiation

Vascular smooth muscle cell (VSMC) differentiation is an essential component of vascular development. These cells perform biosynthetic, proliferative, and contractile roles in the vessel wall. VSMCs are not terminally differentiated and are able to modulate their phenotype in response to changing local environmental cues. There is clear evidence that alterations in the differentiated state of the VSMC play a critical role in the pathogenesis of atherosclerosis and intimal hyperplasia, as well as in a variety of other major human diseases, including hypertension, asthma, and vascular aneurysms. The focus of this review is to provide an overview of the current state of knowledge of molecular mechanisms involved in controlling phenotypic switching of SMCs, with particular focus on examination of signaling pathway that regulate this process.

Intravascular ultrasound findings in patients with restenosis of sirolimus- and paclitaxel-eluting stents

OBJECTIVE

We used intravascular ultrasound (IVUS) to compare restenotic sirolimus-eluting (SES) vs paclitaxel-eluting (PES) stents.

BACKGROUND

Little is known about the IVUS pattern and mechanisms of restenosis, in the two widely available drug-eluting stent (DES) platforms.

METHODS

Volumetric IVUS analysis was performed in patients with clinical restenosis in DES (n=29 SES and 11 PES respectively).

RESULTS

Despite similar vessel volumes (347.5+/-155.6 vs 356.5+/-164.1 mm(3), p=0.84) and stent volumes (175.6+/-74.57 vs 179.7+/-84.24 mm(3), p=1.0), IVUS analysis showed that neointimal hyperplasia volume was significantly greater in PES restenoses than in SES restenoses (40.0+/-44.2 vs 19.3+/-11.4 mm(3), p=0.02) without any significant difference in distribution over the stent length. This leads to a higher percent of volume obstruction (intimal hyperplasia volume divided by stent volume: 18.5+/-13.7% vs 11.8+/-7.7%, p=0.045). Minimal stent area was smaller in SES than in PES (4.3+/-1.2 vs 5.6+/-1.2 mm(2), p=0.06) and stent underexpansion was more frequently observed in SES stents: minimal stent area <4.5 mm(2) (65% in SES vs 27% in PES, p=0.04). Stent edge restenosis occurred in 1/29 SES (3%) vs 3/11 PES (27%) stents, p=0.056.

CONCLUSION

The magnitude of neointimal hyperplasia was greater in PES than in SES while stent underexpansion appeared to be more common in SES.

Factors predictive of cardiac events and restenosis after sirolimus-eluting stent implantation in small coronary arteries

OBJECTIVES

Predictors of cardiac events and restenosis after sirolimus-eluting stent (SES) implantation in small coronary arteries were evaluated.

BACKGROUND

Although SES implantation has markedly reduced the risk of restenosis, small vessel disease remains a major cause of SES failure.

METHODS

We prospectively investigated the factors predictive of cardiac events and restenosis in 1,092 consecutive patients who received SES implantation for 1,269 lesions in small coronary arteries (< or = 2.8 mm). Follow-up angiography at 6 months was performed in 751 patients with 889 lesions (follow-up rate 70.3%).

RESULTS

Restenosis (diameter stenosis > or = 50%) was angiographically documented in 65 patients with 77 lesions (8.7%): 55 focal (71.4%), 8 diffuse (10.4%), 2 diffuse proliferative (2.6%), and 12 total (15.6%). Lesion length, stent length, reference artery size, and in-stent restenotic lesions were univariate predictors of restenosis. By multivariate analysis, lesion length (OR 1.04; 95% CI 1.02-1.05; P < 0.001) and in-stent restenotic lesions (OR 3.38; 95% CI 1.80-6.35; P < 0.001) were significant independent predictors of restenosis. During follow-up (23.2 +/- 7.9 months), there were 17 deaths (5 cardiac and 12 noncardiac), 5 nonfatal Q-wave myocardial infarctions, and 42 target lesion revascularizations. The cumulative probability of survival without major adverse cardiac events (MACE) was (96.6 +/- 0.6)% at 1 year and (95.1 +/- 0.7)% at 2 years. In multivariate analysis, lesion length (HR 1.04; 95% CI 1.01-1.07; P = 0.004) and in-stent restenotic lesions (HR 3.29; 95% CI 1.58-6.86; P = 0.001) were independently related to MACE.

CONCLUSIONS

SES implantation in small coronary arteries is safe and effective, with lesion length having a major impact on restenosis and MACE.

Network analysis of human in-stent restenosis

BACKGROUND

Recent successes in the treatment of in-stent restenosis (ISR) by drug-eluting stents belie the challenges still faced in certain lesions and patient groups. We analyzed human coronary atheroma in de novo and restenotic disease to identify targets of therapy that might avoid these limitations.

METHODS AND RESULTS

We recruited 89 patients who underwent coronary atherectomy for de novo atherosclerosis (n=55) or in-stent restenosis (ISR) of a bare metal stent (n=34). Samples were fixed for histology, and gene expression was assessed with a dual-dye 22,000 oligonucleotide microarray. Histological analysis revealed significantly greater cellularity and significantly fewer inflammatory infiltrates and lipid pools in the ISR group. Gene ontology analysis demonstrated the prominence of cell proliferation programs in ISR and inflammation/immune programs in de novo restenosis. Network analysis, which combines semantic mining of the published literature with the expression signature of ISR, revealed gene expression modules suggested as candidates for selective inhibition of restenotic disease. Two modules are presented in more detail, the procollagen type 1 alpha2 gene and the ADAM17/tumor necrosis factor-alpha converting enzyme gene. We tested our contention that this method is capable of identifying successful targets of therapy by comparing mean significance scores for networks generated from subsets of the published literature containing the terms "sirolimus" or "paclitaxel." In addition, we generated 2 large networks with sirolimus and paclitaxel at their centers. Both analyses revealed higher mean values for sirolimus, suggesting that this agent has a broader suppressive action against ISR than paclitaxel.

CONCLUSIONS

Comprehensive histological and gene network analysis of human ISR reveals potential targets for directed abrogation of restenotic disease and recapitulates the results of clinical trials of existing agents.

Brief review: Coronary drug-eluting stents and anesthesia

PURPOSE

Anesthesiologists managing patients with drug-eluting stents (DES) face the challenge of balancing the risks of bleeding vs perioperative stent thrombosis (ST). This article reviews DES and the influence of antiplatelet medications related to their use. A perioperative management algorithm is suggested. Novel P2Y12 antagonists currently under investigation, including cangrelor and prasugrel are considered, as well as their potential role in modification of perioperative cardiovascular risks and management of patients with DES.

SOURCE

A PubMed search of the relevant literature over the period 1985-2005 was undertaken using the terms "drug-eluting stent", "coronary artery stent", "bare metal stent", "antiplatelet medication", "aspirin", "clopidogrel."

PRINCIPAL FINDINGS

Delayed re-endothelialization may render both sirolimus-eluting and paclitaxel-eluting stents susceptible to thrombosis for a longer duration than bare metal stents. Stent thrombosis may be associated with resistance to antiplatelet medication. In patients with a DES, a preoperative cardiology consultation is essential. Elective surgery should be postponed if the duration between DES placement and noncardiac surgery is less than six months. For semi-emergent procedures, both aspirin and clopidogrel should be continued during surgery unless clearly contraindicated by the nature of the surgery. If the risk of bleeding is high, then modification of antiplatelet medications should be considered on a case-by-case basis.

CONCLUSION

A profound increase in the number of patients with DES requires anesthesiologists to be familiar with their associated antiplatelet medications, and strategies for risk modification of ST and possible hemorrhagic complications in the perioperative setting.

Comparison of zotarolimus-eluting and sirolimus-eluting stents in patients with native coronary artery disease: a randomized controlled trial

OBJECTIVES

This trial examined the relative clinical efficacy, angiographic outcomes, and safety of zotarolimus-eluting coronary stents (ZES) with a phosphorylcholine polymer versus sirolimus-eluting stents (SES).

BACKGROUND

Whether a cobalt-based alloy stent coated with the novel antiproliferative agent, zotarolimus, and a phosphorylcholine polymer may provide similar angiographic and clinical benefit compared with SES is undetermined.

METHODS

A prospective, multicenter, 3:1 randomized trial was conducted to evaluate the safety and efficacy of ZES (n = 323) relative to SES (n = 113) in 436 patients undergoing elective percutaneous revascularization of de novo native coronary lesions with reference vessel diameters between 2.5 mm and 3.5 mm and lesion length > or =14 mm and < or =27 mm. The primary end point was 8-month angiographic in-segment late lumen loss.

RESULTS

Angiographic in-segment late lumen loss was significantly higher among patients treated with ZES compared with SES (0.34 +/- 0.44 mm vs. 0.13 +/- 0.32 mm, respectively; p < 0.001). In-hospital major adverse cardiac events were significantly lower among patients treated with ZES (0.6% vs. 3.5%, p = 0.04). In-segment binary angiographic restenosis was also higher in the ZES cohort (11.7% vs. 4.3%, p = 0.04). Total (clinically and non-clinically driven) target lesion revascularization rates at 9 months were 9.8% and 3.5% for the ZES and SES groups, respectively (p = 0.04). However, neither clinically driven target lesion revascularization (6.3% zotarolimus vs. 3.5% sirolimus, p = 0.34) nor target vessel failure (12.0% zotarolimus vs. 11.5% sirolimus, p = 1.0) differed significantly.

CONCLUSIONS

Compared with SES, treatment with a phosphorylcholine polymer-based ZES is associated with significantly higher late lumen loss and binary restenosis at 8-month angiographic follow-up. (The Endeavor III CR; http://clinicaltrials.gov/ct/show/NCT00265668?order=1?).

mTOR-dependent synthesis of Bcl-3 controls the retraction of fibrin clots by activated human platelets

New activities of human platelets continue to emerge. One unexpected response is new synthesis of proteins from previously transcribed RNAs in response to activating signals. We previously reported that activated human platelets synthesize B-cell lymphoma-3 (Bcl-3) under translational control by mammalian target of rapamycin (mTOR). Characterization of the ontogeny and distribution of the mTOR signaling pathway in CD34+ stem cell-derived megakaryocytes now demonstrates that they transfer this regulatory system to developing proplatelets. We also found that Bcl-3 is required for condensation of fibrin by activated platelets, demonstrating functional significance for mTOR-regulated synthesis of the protein. Inhibition of mTOR by rapamycin blocks clot retraction by human platelets. Platelets from wild-type mice synthesize Bcl-3 in response to activation, as do human platelets, and platelets from mice with targeted deletion of Bcl-3 have defective retraction of fibrin in platelet-fibrin clots mimicking treatment of human platelets with rapamycin. In contrast, overexpression of Bcl-3 in a surrogate cell line enhanced clot retraction. These studies identify new features of post-transcriptional gene regulation and signal-dependant protein synthesis in activated platelets that may contribute to thrombus and wound remodeling and suggest that posttranscriptional pathways are targets for molecular intervention in thrombotic disorders.

Clinical Outcomes for Sirolimus-Eluting Stents and Polymer-Coated Paclitaxel-Eluting Stents in Daily Practice

OBJECTIVES

We compared the clinical outcome of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in a real-world scenario.

BACKGROUND

In selected patients, SES has been associated with lower late luminal loss than PES. Whether this emerging biological difference could translate into different clinical efficacy in daily practice is presently unknown.

METHODS

This analysis included 1,676 consecutive patients with de novo coronary lesions treated solely with drug-eluting stents (SES = 992; PES = 684). All patients were enrolled in a dynamic prospective registry comprising 13 hospitals. We assessed the cumulative incidence of major adverse cardiac events (MACE), defined as death, myocardial infarction (MI), and target vessel revascularization (TVR) during follow-up.

RESULTS

Overall, 29% of the patients had diabetes, 23% had prior MI, and 9% had poor left ventricular function. ST-segment elevation MI was diagnosed at admission in 12%. Multivessel intervention was performed in 16%. At 1-year follow-up, SES was associated with a reduced incidence of MACE (9.2% SES vs. 14.1% PES; p = 0.007) and TVR (5.0% SES vs. 10.0% PES; p = 0.0008) compared to PES. A propensity analysis with many clinical and angiographic variables was carried out to adjust for baseline differences. In this analysis, SES was associated with a 44% risk reduction of MACE (hazard ratio 0.56, 95% confidence interval 0.39 to 0.78) and a 55% reduction of TVR (hazard ratio 0.45, 95% confidence interval 0.29 to 0.70). This result was consistent across most subgroups tested. Similar rates of death and MI were observed in the 2 treatment groups.

CONCLUSIONS

In this large real-world population, SES improved 1-year clinical results as compared to PES.

The Paclitaxel-Eluting Stent in Percutaneous Coronary Intervention: Part II

The paclitaxel- and sirolimus-eluting stents are currently the only drug-eluting stents approved for use in the United States. These 2 stents differ in terms of mechanism of drug action, the construct of the stent itself, and the drug delivery polymer. Clinical trials have demonstrated superiority of both paclitaxel- and sirolimus-eluting stents when compared with bare-metal stents in terms of reducing restenosis and the need for target vessel revascularization. Recently published head-to-head trials have not conclusively shown 1 drug-eluting stent to be superior to the other, but have demonstrated more favorable angiographic results with the sirolimus-eluting stent compared with the paclitaxel-eluting stent; however, no significant difference has been demonstrated in clinical outcomes such as myocardial infarction or death. In terms of economics, the paclitaxel-eluting stent is substantially more expensive than the bare-metal stent. However, by significantly reducing the risk of restenosis and need for repeat revascularization, the higher direct cost of the paclitaxel-eluting stent may in theory be offset by lower overall healthcare costs, although economic analyses have yet to definitively establish that the paclitaxel-eluting stent is truly cost-effective. There is still much to be discovered regarding the paclitaxel-eluting stent, specifically the optimal stent design and drug release mechanism, the relative safety and efficacy of the paclitaxel-eluting stent compared with other drug-eluting stents, the long-term effects of the paclitaxel-eluting stent, the ideal antiplatelet regimen to use in patients with a paclitaxel-eluting stent, the safety and efficacy of the paclitaxel-eluting stent in various high-risk patient groups, and the ultimate cost-effectiveness of this device.

Is late luminal loss an accurate predictor of the clinical effectiveness of drug-eluting stents in the coronary arteries?

Late luminal loss after percutaneous coronary intervention, although not normally distributed, has been shown to be monotonically correlated with the probability of binary angiographic restenosis after drug-eluting stent implantation. A recently proposed method has been shown to predict the restenosis rate after sirolimus-eluting stent and paclitaxel-eluting stent implantation using a power transformation of the value of late loss obtained after implantation of the 2 stent types. We used the same method to compute and compare restenosis rates from late loss values observed in the "head-to-head" randomized sirolimus-eluting stent versus paclitaxel-eluting stent comparisons available thus far. Our results showed that the model proposed has a poor overall ability to predict the real incidence and relative risk of restenosis because the use of late loss as an end point tended to overestimate the difference in restenosis, and the derived effect estimate of 1 stent compared with that of the other seemed to be overemphasized with respect to the real risk. We thus believe that further investigations are needed to appraise the real clinical effect of late loss and its reliability as an end point in direct comparative drug-eluting stent trials before its use can be recommended as a clinical surrogate.

Role of drug eluting stents in diabetic patients

There is a clear need for a large multicentre trial comparing the efficacy of the two available drug eluting stents, sirolimus and paclitaxel, in diabetic patients with multivessel disease.

Restenosis related to percutaneous coronary intervention has been solved?

Percutaneous coronary intervention (PCI) has become the most important revascularization method in the treatment of coronary artery disease. The major problem in PCI has been renarrowing of the dilated vessel after the procedure (restenosis). The best results in the prevention of restenosis have been obtained by covering the stent with drugs that inhibit cellular growth, thus limiting excessive scar formation inside of the stent. With drug-eluting stents, restenosis has been reduced to one-tenth compared with balloon angioplasty and to one-fourth compared to bare metal stents. Due to drug-eluting stents, PCI is an alternative to bypass surgery. However, restenosis will remain a challenge due to the increased number of procedures and more difficult disease treated with PCI.

Incidence and predictors of recurrent restenosis following implantation of drug-eluting stents for in-stent restenosis

OBJECTIVES

We investigated the incidence and predictors of recurrent restenosis after drug-eluting stent (DES) implantation for in-stent restenosis (ISR) in routine clinical practice.

BACKGROUND

Although DESs have been increasingly used for treatment of ISR, little is known about the predictors of DES failure.

METHODS

We determined the incidence of recurrent restenosis and major adverse cardiac events (MACE) in 224 consecutive patients with 239 lesions treated with sirolimus-eluting (n=217 lesions) or paclitaxel-eluting (n=22 lesions) stents for the first episode of ISR.

RESULTS

The procedural success rate was 99.2%, and in-hospital complications did not occur in any patient. Follow-up angiography at 6 months was obtained in 73.7% of patients. Angiographic re-restenosis rate was 12.6%, and target lesion revascularization was required in 7.6% of patients. Of the 22 incidents of re-restenosis, 15 were focal (68.2%), 5 were diffuse (22.7%), and 2 were total (9.1%) restenosis. Univariate analysis showed that lesion length, use of paclitaxel-eluting stent, and number of stents per lesion were significant predictors of re-restenosis. In multivariate analysis, however, lesion length and use of paclitaxel-eluting stent were independent predictors of re-restenosis. During the follow-up (mean, 18.3+/-8.1 months), there were 4 deaths (1 cardiac, 3 noncardiac), but no nonfatal myocardial infarctions (MIs). MACE occurred in 18 patients. The cumulative probability of MACE-free survival was 92.9+/-1.8% at 1 year and 90.5+/-2.4% at 2 years.

CONCLUSIONS

DESs are highly effective for treatment of ISR, with recurrent restenosis related to lesion length and type of DES.