Time course of restenosis during the first year after emergency coronary stenting

Research progress of drug eluting balloon in arterial circulatory system

The arterial circulatory system diseases are common in clinical practice, and their treatment options have been of great interest due to their high morbidity and mortality. Drug-eluting balloons, as a new type of endovascular interventional treatment option, can avoid the long-term implantation of metal stents and is a new type of angioplasty without stents, so drug-eluting balloons have better therapeutic effects in some arterial circulatory diseases and have been initially used in clinical practice. In this review, we first describe the development, process, and mechanism of drug-eluting balloons. Then we summarize the current studies on the application of drug-eluting balloons in coronary artery lesions, in-stent restenosis, and peripheral vascular disease. As well as the technical difficulties and complications in the application of drug-eluting balloons and possible management options, in order to provide ideas and help for future in-depth studies and provide new strategies for the treatment of more arterial system diseases.

Treatment of In-stent Restenosis of the Internal Carotid Artery Using Drug-eluting Balloons

PURPOSE

In-stent restenosis (ISR) following internal carotid artery (ICA) stenting is relatively common with an estimated incidence of 5%. Treatment options include repeat angioplasty with conventional or drug-eluting balloons (DEB), repeat stent angioplasty and surgical intervention. Application of DEB in ISR of the coronary and peripheral arteries is an established method; however, data on DEB treatment of ICA ISR are sparse. In this work, results from a retrospective cohort of 45 patients harboring 46 ICA ISR lesions treated with DEB angioplasty are presented.

METHODS

Clinical, procedural and imaging data from DEB angioplasty treatment of 46 high-grade ICA ISR lesions in 45 patients, performed between 2013 and 2021 were collected. A single type of DEB (Elutax, Aachen Resonance, Aachen, Germany) was used in all procedures. Imaging follow-up was performed by regular Doppler ultrasound (DUS), verified by computed tomography angiography (CTA) in cases suspicious for a recurrent ISR.

RESULTS

Technical success was 100%. Intraprocedural and postprocedural complications were not encountered. Clinical follow-up was obtained in all patients. Recurrent stroke in the affected territory was not encountered. A recurrent ISR following DEB treatment was confirmed by DUS and CTA in 4/46 (8.7%) of the lesions and were retreated with DEB. A third recurrent ISR occurred in a single case (2%) and following a second DEB retreatment there were no signs of a fourth recurrence after 36 months follow-up.

CONCLUSION

The use of DEB angioplasty is a safe and effective treatment of ICA ISR lesions, yielding significantly better results compared to other modalities. Randomized multicenter studies are warranted.

Inflammatory Phenotype by OCT Coronary Imaging: Specific Features Among De Novo Lesions, In-Stent Neointima, and In-Stent Neo-Atherosclerosis

BACKGROUND

Coronary stenosis can be caused de novo atherosclerosis, in-stent restenosis, and in-stent neoatherosclerosis, three entities that develop from a diverse pathophysiological milieu.

OBJECTIVE

This study aims to investigate, using optical coherence tomography (OCT), whether or not coronary lesions related to these processes differ in their local inflammatory profile.

METHODS

Retrospective analysis of patients with diagnosed or suspected coronary lesions who had undergone OCT imaging for clinical reasons. Macrophage and intra-plaque neovascularization were assessed by OCT and used as surrogates of local inflammation. A significance level of < 0.05 was adopted as statistically significant.

RESULTS

From the 121 lesions, 74 were de novo, 29 were restenosis, and 18 were neoatherosclerosis. Neovascularization was found in 65.8% of de novo, 10.3% in restenosis, and 94.4% in neoatherosclerosis (p<0.01 for all). The volume of neovascularization was different among lesion types (950 vs. 0 vs. 6220, respectively [median values in 1000 x µm3/mm]; p<0.01 for all), which were significantly higher in neoatherosclerosis and lower in restenosis. The presence of macrophages differed among the lesions (95.9% in de novo vs. 6.9% in restenosis vs. 100% in neoatherosclerosis [p<0.01 for all]). Moreover, the intensity of macrophagic infiltration was different among lesion types (2.5 vs. 0.0 vs. 4.5, respectively [median values of macrophage score]; p<0.01 for all), significantly higher in neoatheroscleosis and lower in restenosis.

CONCLUSION

When compared using coronary OCT, de novo atherosclerosis, in-stent restenosis, and neoatherosclerosis presented markedly different inflammatory phenotypes.

Caffeic Acid-Grafted PLGA as a Novel Material for the Design of Fluvastatin-Eluting Nanoparticles for the Prevention of Neointimal Hyperplasia

Drug-eluting nanoparticles (NPs) administered by an eluting balloon represent a novel tool to prevent restenosis after angioplasty, even if the selection of the suitable drug and biodegradable material is still a matter of debate. Herein, we provide the proof of concept of the use of a novel material obtained by combining the grafting of caffeic acid or resveratrol on a poly(lactide-co-glycolide) backbone (g-CA-PLGA or g-RV-PLGA) and the pleiotropic effects of fluvastatin chosen because of its low lipophilic profile which is challenging for the encapsulation in NPs and delivery to the artery wall cells. NPs made of such materials are biocompatible with macrophages, human smooth muscle cells (SMCs), and endothelial cells (ECs). Their cellular uptake is demonstrated and quantified by confocal microscopy using fluorescent NPs, while their distribution in the cytoplasm is verified by TEM images using NPs stained with an Ag-PVP probe appositely synthetized. g-CA-PLGA assures the best control of the FLV release from NP sizing around 180 nm and the faster SMC uptake, as demonstrated by confocal analyses. Interestingly and surprisingly, g-CA-PLGA improves the FLV efficacy to inhibit the SMC migration, without altering its effects on EC proliferation and migration. The improved trophism of NPs toward SMCs, combined with the excellent biocompatibility and low modification of the microenvironment pH upon polymer degradation, makes g-CA-PLGA a suitable material for the design of drug-eluting balloons.

Management of in-stent restenosis

In-stent restenosis (ISR) remains the most common cause of stent failure after percutaneous coronary intervention (PCI). Recent data suggest that ISR-PCI accounts for 5-10% of all PCI procedures performed in current clinical practice. This State-of-the-Art review will primarily focus on the management of ISR but will begin by briefly discussing diagnosis and classification. We then move on to detail the evidence base underpinning the various therapeutic strategies for ISR before finishing with a proposed ISR management algorithm based on current scientific data.

Coronary In-Stent Restenosis–Predictors and Treatment

BACKGROUND

Despite the use of modern drug-eluting stents (DES), in-stent restenosis (ISR) may still occur in as many as 2-10% of percutaneous coronary interventions (PCI) in certain lesion/patient subsets. ISR causes increased morbidity after stent implantation; acute myocardial infarction is a frequent correlate to a clinical ISR, arising in 5-10% of cases. Compared to de novo stenosis, patients with ISR also present more frequently with symptoms of unstable angina pectoris (45% versus 61%). In this article, we discuss the risk factors for ISR and the corresponding diagnostic measures and effective treatment strategies.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, with special attention to current international guidelines and specialist society recommendations.

RESULTS

The type of implanted stent, the presence of diabetes mellitus, previous bypass surgery, and small vessel caliber are predictors for ISR. In their guidelines, the European specialist societies (ESC/EACTS) recommend repeated PCI with DES implantation or drug-coated balloon (DCB) angioplasty as the methods of choice for the treatment of ISR. This approach is supported by evidence from meta-analyses. The RIBS-IV trial showed that revascularization treatment of the target lesion is needed less often after everolimus-eluting stent (EES) implantation than after DCB dilatation (11 [7.1%] versus 24 [15.6%]; p = 0.015; hazard ratio: 0.43; 95% confidence interval: [0.21; 0.87]).

CONCLUSION

Because the pathogenesis of ISR is multifactorial, differentiated risk stratification is necessary. The identification of patient-, stent-, and lesion-related predictors is particularly important, as the most effective way to combat ISR is to prevent it.

Comparison of Drug-Coated Balloons to Bare Metal Stents in the Treatment of Symptomatic Vertebral Artery-Origin Stenosis: A Prospective Randomized Trial

OBJECTIVE

We sought to compare the angiographic and clinical outcomes of drug-coated balloon (DCB) with distal embolic protection devices (EPDs) versus bare metal stent (BMS) without EPD in the treatment of symptomatic vertebral artery origin stenosis (VAOS).

METHODS

Between January 2017 and December 2018, a prospective randomized trial was conducted involving 95 patients with symptomatic VAOS randomly assigned to treatment with DCB + EPD (n = 49) or BMS without EPD (n = 46). Target vessel restenosis (RS) >50% detected by computed tomography angiography was the primary endpoint. Technical success, clinical success, and signal intensity abnormalities on diffusion-weighted imaging within 3 days after operation were compared.

RESULTS

The 30-day technical success rate was 93.9% for DCB group versus 95.7% for the BMS group (P = 0.094). Diffusion-weighted imaging within 3 days postoperative showed asymptomatic embolization in 2 (4.1%) patients in the DCB group and 9 (19.6%) patients in the BMS group (P = 0.004). At a mean 16-month follow-up, the clinical success rate was 89.8% for the DCB group versus 91.3% (42/46) for the BMS group (P = 0.125). The RS was seen in 5/49 (10.2%) in the DCB group and 6/46 (13.0%) in the BMS group (P = 0.082). Target vessel revascularization was performed in 4 (8.7%) BMS group versus 3 (6.1%) in the DCB group (P = 0.091).

CONCLUSIONS

DCB with EPD in the treatment of symptomatic VAOS is technically feasible and safe and significantly reduced thromboembolic events on imaging when compared with BMS without EPD. There was no significant difference between the 2 groups in the rate of RS during 12 months after surgery.

Combining the Passeo-18 Lux Drug-Coated Balloon and the Pulsar-18 Bare Metal Stent: 12- and 24-Month Outcomes of the BIOLUX 4EVER Investigator-Initiated Trial

PURPOSE

To report the outcomes after treating stenotic or occluded femoropopliteal lesions with a drug-coated balloon (DCB) followed by the implantation of a thin-strut self-expanding bare metal stent in the BIOLUX 4EVER trial (ClinicalTrials.gov identifier NCT02211664).

MATERIALS AND METHODS

The prospective, multicenter, physician-initiated BIOLUX 4-EVER trial was conducted at 5 centers in Belgium and enrolled 120 patients (mean age 70.9±10.5 years; 79 men) with symptomatic stenotic or occluded de novo femoropopliteal lesions. A fifth of the patients had diabetes mellitus and nearly half had previous peripheral artery interventions. The lesions were a mean 83.3±49.5 mm long with a mean reference vessel diameter of 5.26±0.59 mm. Lesions were treated with a Passeo-18 Lux DCB followed by the implantation of a Pulsar-18 bare metal stent. Follow-up visits were conducted at 1, 6, 12, and 24 months postprocedure; the main outcome was primary patency at 12 months.

RESULTS

Technical success was obtained in all patients. Primary patency was observed in 89.9% of patients (95% CI 84.0% to 95.8%) at 12 months and in 83.5% at 24 months (95% CI 89.9% to 97.3%), and freedom from target lesion revascularization was 93.6% (95% CI 89.9% to 97.3%) and 86.1% (95% CI 79.9% to 92.3%), respectively. Ten patients died throughout the course of the trial (90.7% survival at 24 months), all of noncardiovascular causes. The ankle-brachial index improved from 0.68±0.09 at baseline to 0.93±0.11 and 0.93±0.12 at 12- and 24-month follow-up visits (p<0.001). An improvement of at least 1 Rutherford category was observed in 91 of 94 patients (96.8%) at 12 months and 78 of 83 patients (93.4%) at 24 months (p<0.001).

CONCLUSION

The combination of a Passeo-18 Lux DCB followed by a Pulsar-18 stent implantation produced safe and effective outcomes in the treatment of femoropopliteal lesions at up to 24 months. Adding paclitaxel to the bare nitinol stent platform by predilating with a Passeo-18 Lux DCB seems to increase efficacy at 1 and 2 years compared with the use of bare metal stents only, which were investigated in the precursor 4-EVER study.

Zilver PTX peripheral paclitaxel-eluting stent: a technology evaluation

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Durable polymer everolimus-eluting stents: history, current status and future prospects

INTRODUCTION

Coronary percutaneous interventions have evolved from plain old balloon angioplasty (POBA) to stent implantation, which itself evolved from bare-metal stents (BMS) to the new biodegradable stents which try to restore endothelial function. Currently, the most commonly used stent is the everolimus-eluting stent.

AREAS COVERED

This review will cover the current status of durable polymer everolimus-eluting stent, its history, and future perspectives. Nowadays, the everolimus-eluting stent is the most used device in the acute and chronic settings due to its safety and efficacy.

EXPERT OPINION

Durable polymer everolimus-eluting stent, supported by much evidence, has demonstrated its efficacy and safety, not only in de novo artery lesions, but in multiples scenarios, such as the acute setting and diabetic population, becoming one of the most polyvalent stents available. Nowadays, research is focused on the reduction of antiplatelet treatment duration. Similar rates of stent thrombosis with short dual antiplatelet treatment regimens of 1 to 3 months compared to pronged treatment have been observed. However, specific studies should be performed to evaluate this possibility.

Evaluation of Mechanical Performances of Stents with 38 mm Length in Long Lesion

Objective

Single stent with 38 mm length has emerged as a potential solution for long lesion treatment using PCI. However, long stents need to come over a longer lesion length combined with a higher incidence of tortuous calcification, requiring a stent to provide superior transport and compliance and reduce elastic retraction. Here, we evaluated the mechanical performances of the existing four types of drug eluting stents with 38 mm length, which could provide guidance for clinicians to choose the proper stents for the patients.

Methods

The stents with 38 mm length from XIENCE Xpedition (Abbott, US), SYNERGY (Boston Scientific, US), FIREHAWK (Microport, China), and HELIOS (HELIOS, China) were collected. Mechanical parameters of stents including crossing ability, compliance, elastic recoil, and longitudinal strength were performed.

Results

The resistance force of stents from XIENCE Xpedition was smaller than FIREHAWK (p < 0.05), which indicates that the stent from XIENCE Xpedition has better crossing ability. The ratio of stent diameter reduction from both XIENCE Xpedition and SYNERGY was less than 3% with no statistical difference. In addition, the elastic recoil percentage of stents from SYNERGY, XIENCE Xpedition, FIREHAWK, and HELIOS was 1.16%, 2.62%, 3.66%, and 4.19%, respectively, indicating that SYNERGY had better elastic recoil compared to FIREHAWK and HELIOS (p < 0.05), which indicates that the stent from XIENCE Xpedition has better crossing ability. The ratio of stent diameter reduction from both XIENCE Xpedition and SYNERGY was less than 3% with no statistical difference. In addition, the elastic recoil percentage of stents from SYNERGY, XIENCE Xpedition, FIREHAWK, and HELIOS was 1.16%, 2.62%, 3.66%, and 4.19%, respectively, indicating that SYNERGY had better elastic recoil compared to FIREHAWK and HELIOS (p < 0.05), which indicates that the stent from XIENCE Xpedition has better crossing ability. The ratio of stent diameter reduction from both XIENCE Xpedition and SYNERGY was less than 3% with no statistical difference. In addition, the elastic recoil percentage of stents from SYNERGY, XIENCE Xpedition, FIREHAWK, and HELIOS was 1.16%, 2.62%, 3.66%, and 4.19%, respectively, indicating that SYNERGY had better elastic recoil compared to FIREHAWK and HELIOS (

Conclusion

The evaluation of mechanical properties for the stent with 38 mm length including crossing ability, compliance, elastic recoil, and longitudinal strength could provide reference index for more accurately clinical application for long lesion treatment.

Swine model of in-stent stenosis in the iliac artery evaluating the serial time course

The aim of this study was to propose a new animal model evaluating the serial time course of in-stent stenosis by repeated carotid artery catheterization in the same animal. 16 bare-metal stents were implanted in the normal external and internal iliac artery of 8 miniature pigs. Repeated measurements were performed in the same animal every 2 weeks for 12 weeks through carotid artery catheterization. The time course and peak neointimal proliferation were evaluated by intravascular ultrasound. Health of all animals was assessed by clinical and hematological examinations. As a result, 7 times of carotid artery catheterization was performed per pig, but all animals remained healthy without both any complications and hematological inflammatory abnormalities. The time course of neointimal proliferation of each stent was observed from the stage of hyperplasia to partial regression. The peak neointimal proliferation varied from 6 to 12 weeks despite implantation of identical stents using the same deployment method. In conclusion, repeated carotid artery catheterization to the same animal is feasible without animal health deterioration. This model should be useful to evaluate the time course of neointimal proliferation after stent deployment in preclinical study.

Long-Term Follow-Up After Treatment of Drug-Eluting Stent Restenosis and De Novo Lesions Using SeQuent Please Paclitaxel-Coated Balloons

Managing patients with in-stent restenosis (ISR) remains an important clinical challenge. In particular, large, randomized trials assessing the effect of drug-eluting balloons (DEB) in patients with de novo lesions are warranted. We investigated the effect of DEB on procedural complications, target lesion revascularization (TLR), and major adverse cardiac and cerebrovascular events in patients with drug-eluting stent ISR and de novo lesions. The clinical profiles of 238 consecutive patients treated for coronary ISR (n = 174) and de novo lesions (n = 64) using SeQuent Please paclitaxel-coated balloon were analyzed. Study end points were major adverse cardiac events (MACEs). At 1-year follow-up, TLR and MACEs occurred with acceptably low rates (5.0% and 6.3%, respectively). At 2.00 (0.74) years of follow-up, there was a significant difference in the rates of TLR between the ISR and the de novo lesions groups (14.4% [ISR] vs 3.1% [de novo], P = .028), and the occurrence of MACEs distinctly increased in the ISR group compared to the de novo lesions group (21.8% vs 6.2%, P = .009). The long-term outcomes of the ISR group were inferior to those of the de novo group (TLR, log-rank P = .019; MACEs, log-rank P = .010). Drug-eluting balloon for ISR and de novo lesions of small coronary vessels is effective and safe.

Autoimmune Diseases May Increase Adverse Cardiovascular Events After Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

BACKGROUND

Outcomes of patients with autoimmune diseases after percutaneous coronary intervention (PCI), as compared to those without autoimmune disease, remain unclear.

METHODS

We searched Medline, EMBASE, and the Cochrane Library from their inception to 1 April 2017. All studies comparing the following outcomes of patients with and without autoimmune diseases after PCI were included: long-term mortality, major adverse cardiovascular events (MACE), repeat revascularisation, myocardial ischaemia or myocardial infarction (MI), restenosis, and in-hospital mortality. The Newcastle-Ottawa Quality Assessment Scale (NOS) and the quality assessment form of the Agency for Healthcare Research and Quality (USA) (AHRQ) were used for assessing the risk of bias, and the certainty of evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

A total of 11 studies were included in our analysis. Compared with patients without autoimmune diseases, those with autoimmune diseases carried an increased risk of MACEs (relative risk (RR): 2.24, 95% confidence interval (CI): 1.20-4.16; heterogeneity: p=0.128, I²=56.9%), repeat revascularisation (RR: 1.66, 95% CI 95%: 1.01-2.72; heterogeneity: p=0.057, I²=65.1%), ischaemia or MI (RR: 2.80, 95% CI: 1.38-5.65; heterogeneity: p=0.871, I²=0.0%), and restenosis (RR: 2.06, 95% CI: 1.39-3.07; heterogeneity: p=0.665, I²=0.0%) during the one-year follow-up after PCI, and carried an increased risk of MACEs (RR: 1.10, 95% CI: 1.04-1.17) and death (RR: 1.38, 95% CI: 1.25-1.51) during the 11-year follow-up after PCI.

CONCLUSIONS

Evidence of very low quality showed that during the one-year follow-up period, patients with autoimmune diseases after PCI were more likely to experience MACEs, repeat revascularisation, myocardial ischaemia or MI, and restenosis. During the 11-year follow-up period, patients with autoimmune diseases after PCI were more likely to die. It is therefore important to watch for restenosis, repeat ischaemia or MI and other adverse events more carefully in patients with autoimmune diseases after PCI.

Identification of genomic differences among peripheral arterial beds in atherosclerotic and healthy arteries

Calcification is independently associated with cardiovascular events and morbidity. The calcification burden in atherosclerotic lesions quantitatively and qualitatively differs between arterial beds. Cardiovascular risk factors (CVRF) differentially affect plaque development between arterial beds. The aim of this study was to evaluate the impact of CVRF on atherosclerotic plaque calcification and to further study the molecular arterial heterogeneity that could account for these differences. Histological analysis was performed on atherosclerotic plaques from 153 carotid, 97 femoral and 28 infrapopliteal arteries. CVRF showed minor associations with plaque calcification: age and hypertension affected only the overall presence of calcification but not the type of the calcification, which significantly differed between arterial beds. Transcriptome analysis revealed distinct gene expression profiles associated with each territory in atherosclerotic and healthy arteries. Canonical pathway analysis showed the preferential involvement of immune system-related processes in both atherosclerotic and healthy carotid arteries. Bone development-related genes were among those mostly enriched in atherosclerotic and healthy femoral arteries, which are more prone to developing endochondral calcification. This study highlights the heterogeneous nature of arteries from different peripheral vascular beds and contributes to a better understanding of atherosclerosis formation and evolution.

Drug-eluting balloons versus drug-eluting stents for the management of in-stent restenosis: A meta-analysis of randomized and observational studies

OBJECTIVES

The aim of this study was to evaluate the efficacy of drug-eluting balloons (DEB) with drug-eluting stents (DES) in patients with in-stent restenosis (ISR).

BACKGROUND

DES implantation and DEB were available strategies in percutaneous coronary intervention (PCI) for ISR, but the optimal management for ISR lesions remains controversial.

METHODS

Electronic databases were searched for randomized controlled trials and observational cohort studies which reported the clinical outcomes of using DEB comparing with DES implantation in patients with ISR. Clinical endpoints such as major adverse cardiovascular events (MACE), death, and myocardial infarction were assessed.

RESULTS

Five randomized controlled trials and five observational cohort studies with 962 patients in the DEB group and 908 patients in the DES group met inclusion criteria. There was no significant difference between DEB and DES in major clinical outcomes, such as MACE (OR 1.01; 95% CI: 0.64-1.58; p=0.97; I²=0%), all-cause death (OR 1.04; 95% CI: 0.54-1.98; p=0.91; I²=0%), cardiovascular death (OR 1.44; 95% CI: 0.57-3.65; p=0.44; I²=0%), stent thrombosis (OR 0.61; 95% CI: 0.16-2.33; p=0.47; I²=0%), and myocardial infarction (OR 1.02; 95% CI: 0.53-1.94; p=0.96; I²=0%). DEB was associated with a significant increase in target lesion revascularization (OR 1.54; 95% CI: 1.10-2.15; p=0.01; I²=57%).

CONCLUSION

Treatment of ISR using DEB led to comparable clinical outcomes with DES implantation.

Stent thrombosis and restenosis: what have we learned and where are we going? The Andreas Grüntzig Lecture ESC 2014

Modern-day stenting procedures leverage advances in pharmacotherapy and device innovation. Patients treated with contemporary antiplatelet agents, peri-procedural antithrombin therapy and new-generation drug-eluting stents (DES) have excellent outcomes over the short to medium term. Indeed, coupled with the reducing costs of these devices in most countries there remain very few indications where patients should be denied treatment with standard-of-care DES therapy. The two major causes of stent failure are stent thrombosis (ST) and in-stent restenosis (ISR). The incidence of both has reduced considerably in recent years. Current clinical registries and randomized trials with broad inclusion criteria show rates of ST at or <1% after 1 year and ∼0.2-0.4% per year thereafter; rates of clinical ISR are 5% respectively. Angiographic surveillance studies in large cohorts show rates of angiographic ISR of ∼10% with new-generation DES. The advent of high-resolution intracoronary imaging has shown that in many cases of late stent failure neoatherosclerotic change within the stented segment represents a final common pathway for both thrombotic and restenotic events. In future, a better understanding of the pathogenesis of this process may translate into improved late outcomes. Moreover, the predominance of non-stent-related disease as a cause of subsequent myocardial infarction during follow-up highlights the importance of lifestyle and pharmacological interventions targeted at modification of the underlying disease process. Finally, although recent developments focus on strategies which circumvent the need for chronically indwelling stents--such as drug-coated balloons or fully bioresorbable stents-more data are needed before the wider use of these therapies can be advocated.

Value of C-Arm Computed Tomography to Evaluate Stent Deployment During Femoro-Popliteal Revascularization

PURPOSE

To compare the accuracy of C-arm computed tomography (CT) and digital subtraction angiography (DSA) in detecting incomplete stent expansion (ISE) after superficial femoral artery (SFA) stenting using intravascular ultrasound (IVUS) as a gold standard.

MATERIALS

Fifty patients with symptomatic SFA occlusive disease requiring angioplasty were prospectively included. Once technical success (<30 % residual stenosis) was obtained on post-procedural DSA, C-arm CT and IVUS were acquired. DSA and C-arm CT examinations were reviewed by 2 investigators and correlated with IVUS. C-arm CT image quality was rated on a four-point scale. Doppler ultrasound was performed at 1-year follow-up.

RESULTS

The ankle-brachial index was 0.69 ± 0.10 and 0.99 ± 0.40, respectively, pre- and post-procedure. C-arm CT imaging quality was rated as good or excellent in 80%. In-stent minimal luminal diameter (MLD) was evaluated at 4.71 ± 0.7 mm on DSA, 3.39 ± 0.6 mm on IVUS, and 3.12 ± 0.9 mm on C-arm CT. Compared to IVUS, DSA demonstrated an overestimation of MLD (p = 0.0001), an underestimation of ISE (DSA = 18.8% ± 7.6; IVUS = 29.8% ± 9) (p < 0.0001), and a poor inter-technique intra-class correlation coefficient (ICC = 0.24). No difference was observed between IVUS and C-arm CT in ISE as calculated by diameter (29.8 ± 9 vs. 28.2 ± 12.5%, p = 0.5) and area (30.2 ± 8.4 vs. 33.3 ± 9.5%, p = 0.2). Inter-technique ICC between C-arm CT and IVUS was 0.72 [95%CI 0.49; 0.85] for MLA measurements. The inter-observer ICC for MLD and MLA measurements on C-arm CT were, respectively, estimated at 0.75 [95% CI 0.40, 0.89] and 0.77 [95% CI 0.43, 0.90)].

CONCLUSIONS

C-arm CT presents a better correlation with IVUS than DSA to determine lumen diameter and ISE immediately after percutaneous revascularization.

Surface modification with dopamine and heparin/poly-L-lysine nanoparticles provides a favorable release behavior for the healing of vascular stent lesions

Surface biofunctional modification of coronary artery stents to prevent thrombosis and restenosis formation, as well as accelerate endothelialization, has become a new hot spot. However, bioactive coatings on implants are not yet sufficiently developed for long-term activity, as they quickly lose efficiency in vivo and finally fail. On the basis of a novel time-ordered concept of biofunctionality for vascular stents, heparin/poly l-lysine nanoparticle (NP) was developed and immobilized on a polydopamine-coated titanium surface, with the aim of regulating and maintaining the intravascular biological response within the normal range after biomaterial implantation. An in vitro dynamic release model was established to mimic the blood flow condition in vivo with three phases: (1) An early phase (1-7 days) with release of predominantly anticoagulant and anti-inflammatory substances and to a minor degree antiproliferative effects against smooth muscle cells (SMCs); (2) this is followed by a phase (7-14 days) of supported endothelial cell (ECs) proliferation and suppressed SMC proliferation with persisting high antithrombogenicity and anti-inflammatory properties of the surface. (3) Finally, a stable stage (14-28 days) with adequate biomolecules on the surface that maintain hemocompatibility and anti inflammation as well as inhibit SMCs proliferation and promote ECs growth. In vivo animal tests further confirmed that the NP-modified surface provides a favorable release behavior to apply a stage-adjusted remedy. We suggested that these observations provide important guidance and potential means for reasonable and suitable platform construction on a stent surface.

The formation of an anti-restenotic/anti-thrombotic surface by immobilization of nitric oxide synthase on a metallic carrier

Coronary stenosis due to atherosclerosis, the primary cause of coronary artery disease, is generally treated by balloon dilatation and stent implantation, which can result in damage to the endothelial lining of blood vessels. This leads to the restenosis of the lumen as a consequence of migration and proliferation of smooth muscle cells (SMCs). Nitric oxide (NO), which is produced and secreted by vascular endothelial cells (ECs), is a central anti-inflammatory and anti-atherogenic player in the vasculature. The goal of the present study was to develop an enzymatically active surface capable of converting the prodrug l-arginine, to the active drug, NO, thus providing a targeted drug delivery interface. NO synthase (NOS) was chemically immobilized on the surface of a stainless steel carrier with preservation of its activity. The ability of this functionalized NO-producing surface to prevent or delay processes involved in restenosis and thrombus formation was tested. This surface was found to significantly promote EC adhesion and proliferation while inhibiting that of SMCs. Furthermore, platelet adherence to this surface was markedly inhibited. Beyond the application considered here, this approach can be implemented for the local conversion of any systemically administered prodrug to the active drug, using catalysts attached to the surface of the implant.

Vascular injury post stent implantation: different gene expression modulation in human umbilical vein endothelial cells (HUVECs) model

To explore whether stent procedure may influence transcriptional response of endothelium, we applied different physical (flow changes) and/or mechanical (stent application) stimuli to human endothelial cells in a laminar flow bioreactor (LFB) system. Gene expression analysis was then evaluated in each experimental condition. Human umbilical vein endothelial cells (HUVECs) were submitted to low and physiological (1 and 10 dyne/cm(2)) shear stress in absence (AS) or presence (PS) of stent positioning in a LFB system for 24 h. Different expressed genes, coming from Affymetrix results, were identified based on one-way ANOVA analysis with p values <0.01 and a fold changed >3 in modulus. Low shear stress was compared with physiological one in AS and PS conditions. Two major groups include 32 probes commonly expressed in both 1AS versus 10AS and 1PS versus 10PS comparison, and 115 probes consisting of 83 in addition to the previous 32, expressed only in 1PS versus 10PS comparison. Genes related to cytoskeleton, extracellular matrix, and cholesterol transport/metabolism are differently regulated in 1PS versus 10PS condition. Inflammatory and apoptotic mediators seems to be, instead, closely modulated by changes in flow (1 versus 10), independently of stent application. Low shear stress together with stent procedure are the experimental conditions that mainly modulate the highest number of genes in our human endothelial model. Those genes belong to pathways specifically involved in the endothelial dysfunction.

Increase of ADAM10 level in coronary artery in-stent restenosis segments in diabetic minipigs: high ADAM10 expression promoting growth and migration in human vascular smooth muscle cells via Notch 1 and 3

Background

This study aimed to identify major proteins in the pathogenesis of coronary artery in-stent restenosis (ISR) in diabetic minipigs with sirolimus-eluting stenting, and to investigate the roles of key candidate molecules, particularly ADAM10, in human arterial smooth muscle cells (HASMCs).

Methods and Results

The stents were implanted in the coronary arteries of 15 diabetic and 26 non-diabetic minipigs, and angiography was repeated at six months. The intima of one vascular segment with significant ISR and one with non-ISR in diabetic minipigs were isolated and cultured in conditioned medium (CM). The CM was analyzed by LC-MS/MS to uncover proteins whose levels were significantly increased (≥1.5-fold) in ISR than in non-ISR tissues. After literature searching, we focused on the identified proteins, whose biological functions were most potentially related to ISR pathophysiology. Among them, ADAM10 was significantly increased in diabetic and non-diabetic ISR tissues as compared with non-ISR controls. In cell experiments, retrovirus-mediated overexpression of ADAM10 promoted growth and migration of HASMCs. The effects of ADAM10 were more remarkable in high-glucose culture than in low-glucose culture. Using shRNA and an inhibitor of γ-secretase (GSI), we found that the influences of ADAM10 were in part mediated by Notch1 and notch 3 pathway, which up-regulated Notch downstream genes and enhanced nuclear translocation of the small intracellular component of Notch1 and Notch3.

Conclusions

This study has identified significantly increased expression of ADAM10 in the ISR versus non-ISR segment in diabetic minipigs and implicates ADAM10 in the enhanced neointimal formation observed in diabetes after vascular injury.

Incidence, time course and predictors of early vs. late target lesion revascularisation after everolimus-eluting stent implantation: a SPIRIT V substudy

AIMS

To evaluate the incidence, time course and predictors of late target lesion revascularisation (TLR) (between one and two years) as compared to early TLR (<1 year) following everolimus-eluting stent implantation in patients enrolled in the SPIRIT V study.

METHODS AND RESULTS

The SPIRIT V single-arm study enrolled a total of 2,700 patients (n=2,663 intent-to-treat) with de novo coronary artery lesions undergoing EES implantation. Patients were evaluated at 30 days, one year and two years following the index procedure. All patients who had a clinically driven TLR (not associated with stent thrombosis) were allocated to either the early or the late group. Clinical, angiographic and procedural data were recorded and predictors of early vs. late TLR were assessed by logistic regression analysis. There were no significant differences in baseline demographics and risk factors between the two groups with the exception that patients in the late TLR group were significantly older (68.5 ± 8.5 years vs. 63.5 ± 8.9 years, p=0.022). At two years, only 2.7% (70/2,562) experienced a TLR unrelated to a stent thrombosis event with 1.6% (43/2,627) occurring within one year of the index procedure and 1.1% (27/2,562) occurring between one and two years. There were no differences between the groups in terms of clinical outcomes. Age ≥70 years was the only variable which independently predicted late TLR (OR=4.80 [1.69-13.63], p=0.0032).

CONCLUSIONS

In this large registry without angiographic follow-up, early (<1 year) and late (>1 year) TLR rates were exceedingly low and thereby confirm the previous findings of randomised controlled studies. Age (>70 years) emerged as the only predictor of late TLR.

[Arterial heterogeneity]

More and more clinical observations and trials support the concept of heterogeneity of atheroma according to the arterial bed. In a pilot study named "Étude Comparative des Lésions Athéromateuses" (ECLA), we have shown that carotid and femoral plaques possess different characteristics. Carotid arteries display increased lipid content compared to femoral arteries whereas femoral arteries are more prone to calcify and to develop osteoid metaplasia. These observations should lead the researcher and the clinician to look at the cellular and molecular mechanisms governing the heterogeneity of atheromas. At last, a better understanding of the characteristics of plaques should help us to determine plaque stability, to prevent cardiovascular events and to choose the best medical, endovascular or surgical option.

Mobilization of CD34+ KDR+ endothelial progenitor cells predicts target lesion revascularization

BACKGROUND

Endothelial lesion and regeneration are critical events in the process leading to in-stent restenosis (ISR) after bare metal stent (BMS) percutaneous coronary intervention (PCI).

OBJECTIVES

To prospectively investigate the relationship between biomarkers reflecting endothelial turnover and the occurrence of ISR.

METHODS

We performed a multicenter prospective observational study that included 156 patients undergoing elective PCI with BMS. Endothelial lesion was assessed by the enumeration of circulating endothelial cells (CECs). Endothelial regeneration was evaluated by enumeration of circulating CD34+ progenitor cells (CD34+ PCs) and CD34+ KDR+ endothelial progenitor cells (EPCs). Measurements were performed before PCI, and 6 and 24 h after PCI. Dynamic changes were evaluated by calculating the delta value of each marker. The primary and secondary endpoints of the study were clinical target lesion revascularizations (TLRs) and major adverse cardiovascular events (MACEs) after 6 months of follow-up.

RESULTS

During follow-up, 28 MACEs were recorded, including 27 TLRs. PCI induced a significant rise in the numbers of CECs, CD34+ PCs, and CD34+ KDR+ EPCs. Baseline, 6-h and 24-h levels of these markers did not differ between patients with and without TLR. The delta percentage of CD34+ KDR+ EPCs was significantly reduced in patients with TLR as compared with patients without TLR (- 0.56 ± 8.1 vs. 2.91 ± 6.2; P = 0.015). In multivariate analysis, the delta percentage of CD34+ KDR+ EPCs independently predicted the occurrence of TLR and MACEs (P = 0.02 and P = 0.014, respectively).

CONCLUSION

The endothelial regenerative response to injury induced by PCI, assessed by CD34+ KDR+ EPCs mobilized among progenitor cells, determines the risk of TLR and MACEs in stable coronary artery disease patients.

Effects of thiazolidinediones on cardiovascular events in patients with type 2 diabetes mellitus after drug-eluting stent implantation: a retrospective cohort study using the national health insurance database in Taiwan

BACKGROUND

Thiazolidinediones (TZDs) may reduce in-stent restenosis and improve clinical outcomes in type 2 diabetic patients after bare-metal stent implantation. However, it is still unknown whether diabetic patients with drug-eluting stents (DESs) could benefit from treatment with TZDs.

OBJECTIVE

The objective was to evaluate the clinical outcomes of TZDs in type 2 diabetic patients within 1 year of receiving DESs.

METHODS

This retrospective cohort study was performed in 1743 Taiwanese type 2 diabetic patients (1137 men; 606 women) who received DESs between December 1, 2006 and December 31, 2007. Patients were classified into TZD (n = 268) or non-TZD groups (n = 1,475) using medication records within 3 months of the index hospitalization. Follow-up data were available through December 31, 2008. Clinical outcome measurements included death, myocardial infarction (MI), and repeat revascularization within 1 year after the index date of hospitalization. Cox proportional hazards model and other analyses were performed for the study.

RESULTS

For the TZD and non-TZD groups, the mean ages were 65.07 and 66.09 years, respectively, for those with limus-eluting stents (LESs) and 65.61 and 65.81 years, respectively, for those with paclitaxel-eluting stents (PESs). With or without TZD medication, there were no significant differences in the adjusted hazard ratios of death, MI, or repeat revascularization for diabetic patients who received LESs or PESs. TZD treatment in patients who received LESs and had a history of MI was associated with a higher risk of MI (hazard ratio = 5.292; 95% CI, 1.028-27.232).

CONCLUSIONS

TZDs did not improve the clinical outcomes in Taiwanese type 2 diabetes patients who received DESs. TZDs might have been a contributor to higher risk of MI in patients with LESs and a history of MI. Larger clinical trials are still needed to study this issue further.

Eight-year clinical outcome after radioactive stent implantation: a treatment failure without irreversible long-term clinical sequelae

AIMS

To assess the long-term outcome of patients who underwent radioactive stent (RS) implantation.

METHODS AND RESULTS

The RS study population consisted of 133 consecutive patients who underwent RS implantation between November 1997 and July 2000. They were matched using the propensity score method with 266 patients who underwent bare metal stenting (BMS) in the same span. Long-term survival status and information on MACE (death, non-fatal myocardial infarction or any re-intervention) was retrospectively obtained. Eight-year cumulative survival (90.2% vs. 87.4%, p = 0.57) was similar between the RS and BMS group respectively, while 8-year cumulative MACE-free survival was significantly lower in RS patients (42.1% vs. 64.3%, p < 0.001) due to the difference in events (mainly target lesion revascularisations [TLRs]) during the first year of follow-up (cumulative 1-year MACE-free survival: 59.4% vs. 86.7%, p < 0.001); there was no difference in the MACE rate after the first year (p = 0.71). The TLR rate at six months in the RS group was 29.3%, mainly due to edge restenosis and at one year 36.2% (control group: 9.5%, p < 0.001).

CONCLUSIONS

A high incidence of MACE and re-intervention was observed during the first year following RS implantation, mainly related to TLR for edge restenosis. After the first year, the clinical outcome of RS patients was similar to the control group indicating that there are no late adverse effects related to low dose-rate intracoronary radiation therapy.

Experiences of neuroform stent applications for ruptured anterior communicating artery aneurysms with small parent vessel

OBJECTIVE

The purpose of this study was to review the safety and durability of aneurysms treated with stent-assisted coiling of ruptured anterior communicating artery aneurysms with small parent vessels (< 2.0 mm).

METHODS

Retrospective review of all ruptured aneurysm treated with stent assisted endovascular coiling between March 2005 and March 2009 at our institution was conducted. We report 11 cases of the Neuroform stent placement into cerebral vessels measuring less than 2.0 mm in diameter (range, 1.3-1.9 mm) in anterior cerebral artery. Clinical follow-up ranged from 3 to 12 months and imaging follow-up was performed with cerebral angiography at 6 months and 12 months after discharge.

RESULTS

Complete occlusion was achieved in 10 patients, and a remnant neck was evident in one. No stent displacement or no dislodgement occurred during stent placement. There was no evidence of thromboembolic complication, arterial dissection and spasm during procedure. We performed follow-up angiography in all patients at 6 months and/or 12 months from the first procedure. The follow-up angiographic data showed successfully results except one in-stent stenosis case. All patients improved clinical performances except one patient with severe vasospasm who showed poor clinical condition initially.

CONCLUSION

We have safely and successfully treated 11 vessels smaller than 2.0 mm in diameter with self-expanding stents with good short and intermediate term results. More clinical data with longer follow-ups are needed to establish the role of stent-assisted coiling in ruptured aneurysms with small parent vessels.

In-stent restenosis

The introduction of coronary stents marked a major turning point in the practice of interventional cardiology. Whereas the efficacy of balloon angioplasty was challenged both by immediate mechanical complications and by a high incidence of restenosis, coronary stents offered cardiologists a means by which to not only augment immediate procedural success, but also to reduce the incidence of restenosis following coronary intervention. However, despite technological advances and an improved understanding of the restenotic process, the overall rate of in-stent restenosis following bare metal stent implantation remains high. Although the introduction of drug-eluting stents has further reduced the incidence of restenosis, the "real-world" application of drug-eluting stents in increasingly complex lesion and patient subsets has given way to the even greater clinical challenge of managing drug-eluting stent restenosis. Although the standard treatment of bare metal stent restenosis typically involves placement of a drug-eluting stent, the optimal therapeutic approach to drug-eluting stent restenosis remains less defined. The issue of in-stent restenosis (especially following implantation of a drug-eluting stent) remains a clinical challenge, and investigation into therapeutic options remains ongoing. As technology evolves, such investigation will likely incorporate novel approaches including drug-coated balloons novel stent designs.

Durability of antirestenotic efficacy in drug-eluting stents with and without permanent polymer

OBJECTIVES

We sought to assess changes in antirestenotic efficacy of drug-eluting stents (DES) by restudying subjects at 2 time points after coronary stenting (6 to 8 months and 2 years) and to compare differences in time courses of late luminal loss (LLL) between 3 different DES platforms in use at our institution.

BACKGROUND

DES therapy is associated with low levels of LLL at 6 to 8 months. The temporal course of neointimal formation after this time point remains unclear.

METHODS

This prospective, observational, systematic angiographic follow-up study was conducted at 2 centers in Munich, Germany. Patients underwent stenting with permanent-polymer rapamycin-eluting stents (RES), polymer-free RES, or permanent-polymer paclitaxel-eluting stents (PES). The primary end point was delayed LLL (the difference in in-stent LLL between 6 to 8 months and 2 years).

RESULTS

Of 2,588 patients undergoing stenting, 2,030 patients (78.4%) had 6- to 8-month angiographic follow-up and were enrolled in the study. Target lesion revascularization was performed in 259 patients; these patients were not considered for further angiographic analysis. Of 1,771 remaining patients, 1,331 had available 2-year reangiographic data (75.2%). Overall mean (SD) delayed LLL was 0.12 +/- 0.49 mm (0.17 +/- 0.50 mm, 0.01 +/- 0.42 mm, and 0.13 +/- 0.50 mm in permanent-polymer RES, polymer-free RES, and permanent-polymer PES groups, respectively [p < 0.001]). In multivariate analysis, only stent type (in favor of polymer-free RES) predicted delayed LLL.

CONCLUSIONS

Ongoing erosion of luminal caliber beyond 6 to 8 months after the index procedure is observed following DES implantation. Absence of permanent polymer from the DES platform seems to militate against this effect.

Neuroform Stent Applications in Ruptured Intracranial Aneurysms with Small Parent Vessels

The Neuroform stent is a device specifically designed for use in cerebral vessels and is increasingly being used in the embolization of broad-necked aneurysms, but long-term results are unsatisfactory. Reconstructive treatments using stents improve the occlusion rate and protect parent vessels. Stent-assisted coiling of broad-necked cerebral aneurysms is a technique that has rendered most aneurysms amenable to coiling. Recently, the use of stent-assisted coiling with preservation of the parent vessel lumen has been described in some series. Several studies have shown that with the advances in device technology intracranial stenting is feasible even in the distal part of the ICA. But, endovascular treatment of these aneurysms (small parent vessel less than 2.0 mm) in Neuroform stent-assisted coiling has no clinical applications. These lesions have seemed more difficult to treat than other aneurysms because of subsequent thrombus formation and vessel trauma after stent deployment and navigation. The purpose of this study was to review the safety and durability of our aneurysms treated with stent-assisted coiling of ruptured aneurysms with small parent vessesl.

Is there delayed restenosis in patients with coronary artery disease treated with sirolimus-eluting stent?

BACKGROUND

Although long-term follow-up after sirolimus-eluting stent implantation shows a sustained clinical benefit in several randomized and registered trials, little is known about the pattern of neointimal growth beyond the first 6 to 9 months. In this study, we therefore evaluated the possible delayed restenosis in patients with coronary artery disease treated with sirolimus-eluting stent.

METHODS

A total of consecutive 333 patients with 453 lesions were enrolled in this study (among 782 consecutive patients with 1023 lesions). Lesions were subjected to follow-up by quantitative coronary angiography, and patients were divided into two groups according to the time of follow-up by quantitative coronary angiography: early group (< or =270 days, n=270 with 369 lesions) and late group (>270 days, n=63 with 84 lesions). Binary restenosis was defined as stenosis of more than 50% of the lumen diameter in the target lesion.

RESULTS

Baseline clinical, demographic or angiographic characteristics were well balanced between the two groups. The in-stent restenosis rate was not significant between the early group and the late group (3.5 vs. 6.0%; P>0.05). The late loss and target lesion revascularization appeared higher in late group but there were no significant differences (0.15+/-0.38 mm vs. 0.24+/-0.44 mm; and 4.9 vs. 9.5%, P>0.05, respectively). Similarly, overall thrombosis rate was also same in both groups. In-segment restenosis was, however, higher in late group compared with that in early group (7.9 vs. 16.7%, P=0.013).

CONCLUSION

In this unrestricted population, the beneficial effects of sirolimus-eluting stent implantation extend out more than 1 year in real world practice, that has been confirmed by the results of the large randomized clinical trials. The late in-segment restenosis could, however, be found, suggesting that a prolonged clinical and angiographic surveillance in this subset of patients seems to be warranted.

Late restenosis following sirolimus-eluting stent implantation

Despite encouraging results from randomized trials, concerns exist about long-term results of sirolimus-eluting stent implantation. We sought to determine whether in-stent restenosis occurring >1 year ("late") after sirolimus-eluting stent implantation is a real clinical entity. We analyzed data on all sirolimus-eluting stents implanted in our institution before March 2003. During the study period 928 lesions in 433 patients were treated. Angiographic follow-up was performed in 306 patients (70.6%) with 679 lesions (73.2%). Angiography after 1 year was performed only in symptomatic patients. We considered restenosis "early" if it occurred during the first year and late if after 1 year. Late restenosis required demonstration of a widely patent stent at 6 to 9 months, with repeat angiography after 1 year demonstrating restenosis. Restenosis occurred in 160 lesions overall (23.5%). Of the 31 (4.6%) that were documented after 1 year, 13 were excluded from analysis due to absence of 6- to 9-month angiography; the remaining 18 (2.6%, 1.7 to 4.2) fulfilled our criteria for late restenosis (median time of documentation 607 days, interquartile range 511 to 923). In conclusion, late restenosis is an infrequent but real entity; its existence implies we should not discount the possibility of restenosis as the cause of symptoms that develop >1 year after sirolimus-eluting stent implantation.

Primary stent therapy for symptomatic intracranial atherosclerotic stenosis: 1-year follow-up angiographic and midterm clinical outcomes

OBJECT

The aim of this study was to report 1-year angiographic follow-up results and midterm clinical outcomes in patients with symptomatic intracranial atherosclerotic lesions treated with stent placement.

METHODS

Ten patients with ischemic symptoms referable to stenotic intracranial atherosclerotic arteries, with greater than 60% stenosis, underwent elective surgery in which a primary stent was placed. All patients underwent pretreatment (> or =1 week) combination oral antiplatelet (clopidogrel and aspirin) therapy and long-term (6-month) combination oral antiplatelet (clopidogrel and aspirin) therapy after stents were placed. The procedure involved selecting stents of the same size as the diameter of the target vessel and slowly inflating the balloon to its nominal pressure. One-year angiography and midterm clinical follow-up data were obtained. The stents were successfully placed in all patients without any perioperative complication. The mean preoperative stenosis rate of 81% decreased to 4% after the stent was placed. Nine patients who underwent follow-up angiography (one patient refused) at a mean of 12.3 months (range 10-19 months) had no changes in luminal diameter compared with the immediate postoperative luminal diameter. Luminal narrowing increased, from 15 to 38%, in one case in which there was comparatively greater residual stenosis (15%). No patient suffered new ischemic symptoms during a mean clinical follow-up period of 21 months (range 12-36 months).

CONCLUSIONS

Elective stent surgery can provide good angiographic and clinical midterm outcomes in patients with symptomatic intracranial atherosclerotic stenosis, and the procedure is associated with a high degree of technical success. Reassessment of these promising results is needed in a larger population and in a randomized prospective comparison study.

Treatment of intracranial stenoses using the Neuroform stent system: initial experience in five cases

INTRODUCTION

We assessed the technical feasibility of balloon-assisted angioplasty with consecutive stenting using a flexible, self-expanding neurovascular stent for the treatment of intracranial arteriosclerotic vascular stenoses.

METHODS

Five consecutive patients with symptomatic drug-resistant stenoses of the intracranial internal carotid artery (ICA) or the main stem of the middle cerebral artery (MCA) were treated by balloon-assisted angioplasty with consecutive stenting using the Neuroform stent system.

RESULTS

Balloon dilatation of the stenoses and consecutive stent placement with complete coverage of the stenoses was feasible in all patients. One patient suffered acute thrombosis distally to the stented vessel segment which was successfully treated by fibrinolysis, and one patient suffered acute subarachnoid and parenchymal hemorrhage probably due to vessel perforation. In the other three patients, no complications occurred during or immediately after angioplasty. All patients were free of further ischemic events up to the 6-month follow-up.

CONCLUSION

Our findings demonstrate that the Neuroform stent system can used successfully for the treatment of intracranial stenoses of the ICA and the main stem of the MCA. Although immediate angiographic results are promising, long-term angiographic and clinical follow-up is essential to demonstrate long-term outcome.

Current understanding of coronary in-stent restenosis. Pathophysiology, clinical presentation, diagnostic work-up, and management

In-stent restenosis is the limiting entity following coronary stent implantation. It is associated with significant morbidity and cost and thus represents a major clinical and economical problem. Worldwide, approximately 250 000 in-stent restenotic lesions per year have to be dealt with. The pathophysiology of instent restenosis is multifactorial and comprises inflammation, smooth muscle cell migration and proliferation and extracellular matrix formation, all mediated by distinct molecular pathways. Instent restenosis has been recognised as very difficult to manage, with a repeat restenosis rate of 50% regardless of the mechanical angioplasty device used. Much more favourable results were reported for the adjunctive irradiation of the in-stent restenotic lesion, with a consistent reduction of the incidence of repeat in-stent restenosis by 50%. Data from the first clinical trials on drug-eluting stents for the treatment of in-stent restenosis have shown very much promise yielding this strategy likely to become the treatment of choice. This review outlines the histological and molecular findings of the pathophysiology, the epidemiology, the predictors and the diagnostic work-up of in-stent restenosis and puts emphasis on the various treatment options for its prevention and therapy.

Primary Stenting of Intracranial Atherosclerotic Stenoses

PURPOSE

To determine the feasibility and safety of stenting intracranial atherosclerotic stenoses.

METHODS

In 12 patients the results of primary intracranial stenting were evaluated retrospectively. Patient ages ranged from 49 to 79 years (mean 64 years). Six patients presented with stenoses in the anterior circulation, and six had stenosis in the posterior circulation. One patient presented with extra- and intracranial tandem stenosis of the left internal carotid artery. Three patients presented with acute basilar thrombosis, caused by high-grade basilar stenoses.

RESULTS

Intracranial stenoses were successfully stented in 11 of 12 patients. In one patient the stent could not be advanced over the carotid siphon to reach the stenosis of the ophthalmic internal carotid artery. Follow-up digital subtraction angiographic studies were obtained in two patients who had presented with new neurologic signs or symptoms. In both cases the angiogram did not show any relevant stenotic endothelial hyperplasia. In one patient, after local thrombolysis the stenosis turned out to be so narrow that balloon angioplasty had to be performed before stent deployment. All three patients treated for stenosis-related basilar thrombosis died due to brainstem infarction that had ensued before the intervention.

CONCLUSIONS

Prophylactic primary stenting of intracranial stenoses of the anterior or posterior cerebral circulation can be performed with a low complication rate; technical problems such as stent flexibility must still be solved. Local thrombolysis followed by stenting in stenosis-related thrombotic occlusion is technically possible.

Trends in coronary artery revascularisation procedures in Western Australia, 1980-2001

OBJECTIVES

To describe trends in the use of coronary artery revascularisation procedures (CARPs) and to determine whether or when CARP rates will stabilise.

SETTING

State of Western Australia.

PATIENTS

All patients treated by coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) between 1980 and 2001.

DESIGN

Descriptive study.

MAIN OUTCOME MEASURES

Age standardised rates of first and total CARPs, CABGs, and PCIs.

RESULTS

Overall rates for both total and first CARPs among men and women rose steeply from 1980 to 1993, when they abruptly stabilised or actually started to decline. Rates in age groups under 65 years tended to rise earlier in the period and remained relatively flat, while rates for people over the age of 75 years started to rise later and were still increasing at the end of the study.

CONCLUSIONS

Despite continuing increases in capacity to perform both CABG and PCI in Western Australia and evidence of continuing increases in the use of CARPs in the elderly population, rates appear to have stabilised for the first time since they were introduced.

The Canadian study of the sirolimus-eluting stent in the treatment of patients with long de novo lesions in small native coronary arteries (C-SIRIUS)

OBJECTIVES

We assessed the safety and effectiveness of the sirolimus-eluting stent (SES) in treating single de novo long lesions in small native coronary arteries compared to an identical bare metal stent (BMS).

BACKGROUND

The SES was previously demonstrated to reduce restenosis significantly. However, patients with long lesions in small vessels have not been well studied and may define a group at very high risk.

METHODS

The Canadian Study of the Sirolimus-Eluting Stent in the Treatment of Patients With Long De Novo Lesions in Small Native Coronary Arteries (C-SIRIUS) was a multicenter, randomized, double-blind trial comparing SES versus identical BMS. The primary end point was in-stent minimal lumen diameter (MLD) at eight months. Secondary end points included angiographic restenosis at 8 months, target lesion revascularization (TLR), and major adverse cardiac events (MACE) at 270 days.

RESULTS

A total of 100 patients were enrolled at eight Canadian sites. The in-stent MLD at eight months was 2.46 +/- 0.37 mm in the SES compared with 1.49 +/- 0.75 mm in the BMS (a 65% increase, p < 0.001). Angiographic restenosis occurred in 1 of 44 SES patients (2.3%, with no in-stent restenosis) and in 23 of 44 BMS patients (52.3%, p < 0.001). At 270 days, there were two clinically driven TLRs in the SES (4%) and nine in the BMS (18%, p = 0.05). The Kaplan-Meier estimate of freedom from MACE at 270 days was 96.0% for SES patients and 81.7% for BMS patients (p = 0.029).

CONCLUSIONS

Patients with long lesions in small vessels are at very high risk of restenosis. In these patients, the SES dramatically reduces the risk of restenosis at eight months, translating into an excellent clinical outcome at nine months.

Stent restenosis and the use of drug-eluting stents in patients with diabetes mellitus

Stents have become the technique of choice for percutaneous revascularization, but in-stent restenosis has remained a clinical challenge. This brief article summarizes the incidence, patterns, and proposed mechanisms of restenosis and outlines its contemporary management with specific focus on the diabetic patient. It includes a synopsis of the strategy of drug-eluting stents, which is the most recent and major advance in percutaneous coronary intervention.

The Glu298Asp polymorphism in endothelial nitric oxide synthase gene is associated with coronary in-stent restenosis

BACKGROUND

Reduced or impaired synthesis of nitric oxide promotes the proliferation of vascular smooth muscle cells, and thus may induce the neointimal formation leading to coronary in-stent restenosis. Recent reports have suggested that the Glu298Asp polymorphism in exon 7 of the endothelial nitric oxide synthase gene is associated with coronary spasm and acute myocardial infarction. In this study, we have examined the implication of this polymorphism with regard to coronary restenosis after Palmaz-Schatz stent deployment.

METHODS

Eighty-nine lesions in 85 consecutive patients were treated with Palmaz-Schatz stents, and were prospectively followed up for 6 months. The lesions were classified into a restenosis group (% diameter stenosis=50%) and a non-restenosis group. Assessment was made using an automated quantitative angiographic system. We performed polymerase chain reaction-restriction fragment length polymorphism analysis to detect the missense Glu298Asp variant in exon 7 of the endothelial nitric oxide synthase gene.

RESULTS

Coronary risk factors and angiographic findings of stenotic lesions did not differ between the groups. Univariate analyses showed that the missense Glu298Asp variant was the only statistically significant predictor of restenosis (odds ratio, 4.27; P=0.025). In addition, multiple logistic regression analysis revealed the missense Glu298Asp variant as the only independent predictor for in-stent restenosis (odds ratio, 3.90; P=0.036).

CONCLUSIONS

The missense Glu298Asp variant may be an independent risk factor for in-stent restenosis.