Histopathology of in-stent restenosis in patients with peripheral artery disease

Network Meta-Analysis of All Available Regimens Based on Drug-Coated Balloon Angioplasty and Laser Atherectomy for Femoropopliteal In-Stent Restenosis

PURPOSE

Drug-coated balloon (DCB) angioplasty and laser atherectomy (LA) have been frequently utilized to treat femoropopliteal in-stent restenosis (ISR); however, no studies have concurrently compared available regimens, including DCB, LA+DCB, and LA + plain balloon angioplasty (PB). Therefore, we conducted this network meta-analysis to determine whether there were significant differences in outcomes among these regimens.

MATERIALS AND METHODS

A comprehensive search was conducted in PubMed, EMBASE, and the Cochrane library to identify all randomized controlled trials comparing DCB or LA-based regimes with POBA or each other for treating femoropopliteal in-stent restenosis (ISR) from their inception until March 2021. The primary outcome measure was binary restenosis, and secondary outcome measures were target lesion revascularization (TLR) and mortality, evaluated at 6 and 12 months, respectively. Statistical analysis was performed using Aggregate Data Drug Information System (ADDIS) 1.4 software, and all data were graphically summarized using Microsoft Excel software.

RESULTS

The final analysis included 11 studies, of which 6 studies compared DCB with PB, 2 studies compared PB vs LA+PB, 2 studies compared DCB vs LA+DCB, and 1 study compared LA+DCB with LA+PB. DCB was better than PB in decreasing binary restenosis at 6 (odds ratio [OR]: 0.22, 95% credible interval [CrI]: 0.04-0.91) and 12 (OR: 0.26, 95% CrI: 0.12-0.50) months. DCB was associated with lower TLR than PB at 6 months (OR: 0.31, 95% CrI: 0.13-0.69). LA+DCB was also superior to PB in treating binary restenosis at 12 months (OR: 6.10, 95% CrI: 1.94-24.41) and TLR at 6 months (OR: 5.32, 95% CrI: 1.43-28.06). There was no statistical difference in mortality between PB, DCB, and LA+PB. DCB and LA+DCB were the first 2 options for reducing binary restenosis and TLR.

CONCLUSION

The current network meta-analysis demonstrates that both DCB and LA+DCB are superior to PB alone, and that DCB and LA+DCB may be the preferred treatment options for reducing binary restenosis and TLR.

CLINICAL IMPACT

The treatment for femoropopliteal in-stent restenosis (ISR) remains challenging clinical practice. One important reason is that no optimal treatment strategy was available. Drug-coated balloon angioplasty (DCB) and laser atherectomy (LA) have been extensively utilized to treat ISR; however, different combinations of these treatments further confused the clinicians' choices. This network meta-analysis systematically investigated the difference between the currently available treatments regarding therapeutic effects and safety, indicating that DCB and LA+DCB may be the optimal treatment for decreasing the risk of binary restenosis and target lesion revascularization. The results of the current network meta-analysis help to resolve the confusion of clinicians in making the decision.

Impact of Tissue Damage and Hemodynamics on Restenosis Following Percutaneous Transluminal Angioplasty: A Patient-Specific Multiscale Model

Multiscale agent-based modeling frameworks have recently emerged as promising mechanobiological models to capture the interplay between biomechanical forces, cellular behavior, and molecular pathways underlying restenosis following percutaneous transluminal angioplasty (PTA). However, their applications are mainly limited to idealized scenarios. Herein, a multiscale agent-based modeling framework for investigating restenosis following PTA in a patient-specific superficial femoral artery (SFA) is proposed. The framework replicates the 2-month arterial wall remodeling in response to the PTA-induced injury and altered hemodynamics, by combining three modules: (i) the PTA module, consisting in a finite element structural mechanics simulation of PTA, featuring anisotropic hyperelastic material models coupled with a damage formulation for fibrous soft tissue and the element deletion strategy, providing the arterial wall damage and post-intervention configuration, (ii) the hemodynamics module, quantifying the post-intervention hemodynamics through computational fluid dynamics simulations, and (iii) the tissue remodeling module, based on an agent-based model of cellular dynamics. Two scenarios were explored, considering balloon expansion diameters of 5.2 and 6.2 mm. The framework captured PTA-induced arterial tissue lacerations and the post-PTA arterial wall remodeling. This remodeling process involved rapid cellular migration to the PTA-damaged regions, exacerbated cell proliferation and extracellular matrix production, resulting in lumen area reduction up to 1-month follow-up. After this initial reduction, the growth stabilized, due to the resolution of the inflammatory state and changes in hemodynamics. The similarity of the obtained results to clinical observations in treated SFAs suggests the potential of the framework for capturing patient-specific mechanobiological events occurring after PTA intervention.

Rivaroxaban plus aspirin vs. dual antiplatelet therapy in endovascular treatment in peripheral artery disease and analysis of medication utilization of different lesioned vascular regions

Background

In the management of Peripheral Arterial Disease (PAD), the administration of anticoagulant or antiplatelet agents is imperative. The use of Dual Antiplatelet Therapy (DAPT) in conjunction with rivaroxaban has shown potential in mitigating adverse outcomes. Given the heterogeneity in the pathology of lower limb arteries, there is a compelling case for individualized treatment strategies.

Methods

In a single-center retrospective study on pharmacotherapy for peripheral artery disease, patients were treated with either aspirin combined with rivaroxaban or aspirin coupled with clopidogrel. The primary efficacy outcome encompassed a composite of increases in the Rutherford classification, acute limb ischemia, amputations due to vascular causes, target lesion revascularization, myocardial infarction, ischemic stroke, and cardiovascular death. The primary safety outcome was major bleeding, as defined by the Thrombolysis in Myocardial Infarction (TIMI) criteria; meanwhile, major bleeding as categorized by the International Society on Thrombosis and Haemostasis (ISTH) served as a secondary safety outcome. The study differentiated between two subgroups: patients with only above-the-knee and below-the-knee arterial lesions.

Results

From January 2016 to December 2021, 455 patients received either clopidogrel plus aspirin or rivaroxaban plus aspirin following endovascular treatment (EVT). The rivaroxaban group (n = 220) exhibited a lower incidence of primary efficacy outcomes [49.1% vs. 60.4%, hazard ratio (HR) 0.77, P = 0.006] but had more TIMI major bleeding events (5.9% vs. 2.1%, HR 2.6, P = 0.04). ISTH major bleeding events did not show a significant difference, though a higher percentage of rivaroxaban patients discontinued medication due to bleeding (10% vs. 4.7%, HR 2.2, P = 0.03). In the above-the-knee arterial disease subgroup, the rivaroxaban group demonstrated a lower incidence of primary efficacy outcomes (28.2% vs. 45.2%, HR 0.55, P = 0.02). In the below-the-knee arterial disease subgroup, no significant difference was observed in the occurrence of primary efficacy events between the two groups (58.7% vs. 64.8%, HR 0.76, P = 0.14).

Conclusion

Rivaroxaban plus aspirin improved outcomes compared to DAPT in patients with lower extremity artery disease. Similar findings were observed in the above-the-knee artery lesion-only group. However, in the below-the-knee artery lesion-only group, rivaroxaban plus aspirin did not surpass DAPT in efficacy. Regarding safety, rivaroxaban plus aspirin exhibited higher bleeding risks and more frequent treatment discontinuation than aspirin combined with clopidogrel.

Meta-analysis of outcomes from drug-eluting stent implantation in femoropopliteal arteries

OBJECTIVE

In recent years, studies of drug-eluting stent (DES) for femoropopliteal artery diseases (FPADs) have been gradually published. To explore whether this type of stent is superior to the traditional bare metal stent (BMS), we performed this study.

METHODS

A systematic search for randomized controlled trials (RCTs) in Excerpta Medica Database (Embase), PubMed, Web of Science (WOS), and Cochrane Library was performed on November 29, 2022. We innovatively adopted the hazard ratio (HR), the most appropriate indicator, as a measure of the outcomes that fall under the category of time-to-event data. The HRs was extracted directly or indirectly. Then, the meta-analyses using random effects model were performed. The bias risks of included papers were assessed by the Cochrane Risk of Bias 2.0 tool. This study was registered on the PROSPER platform (CRD42023391944) and not funded.

RESULTS

Seven RCTs involving 1,889 participants were found. After pooled analyses, we obtained results without propensity on each of the following 3 outcomes of interest: in-stent restenosis (ISR) -free survival, primary patency (PP) survival, and target lesion revascularization (TLR) -free survival (P >0.05, respectively). Because the results of pooled analyses of the other two outcomes of interest (all-cause death free survival and clinical benefit survival) had high heterogeneity both, they were not accepted by us.

CONCLUSION

For FPADs, the DES has not yet demonstrated superiority or inferiority to BMS, in the ability to maintain PP, avoid ISR and TLR.

Stent failure: the diagnosis and management of intracoronary stent restenosis

INTRODUCTION

Despite advances in stent technology for percutaneous coronary intervention (PCI) in the treatment of coronary disease, these procedures can be complicated by stent failure manifesting as intracoronary stent restenosis (ISR). Even with advances of stent technology and medical therapy this complication is reported to affect around 10% of all percutaneous coronary intervention (PCI) procedures. Depending on stent type (drug-eluting versus bare metal), ISR have subtle differences in mechanism and timing and offer different challenges in diagnosing the etiology and subsequent treatment options.

AREAS COVERED

This review will be visiting the definition, pathophysiology and risk factors of ISR.

EXPERT OPINION

The evidence behind management options has been illustrated with the aid of real life clinical cases and summarized in a proposed management algorithm.

An extracellular matrix-mimetic coating with dual bionics for cardiovascular stents

Anti-inflammation and anti-coagulation are the primary requirements for cardiovascular stents and also the widely accepted trajectory for multi-functional modification. In this work, we proposed an extracellular matrix (ECM)-mimetic coating for cardiovascular stents with the amplified functionalization of recombinant humanized collagen type III (rhCOL III), where the biomimetics were driven by structure mimicry and component/function mimicry. Briefly, the structure-mimic was constructed by the formation of a nanofiber (NF) structure via the polymerization of polysiloxane with a further introduction of amine groups as the nanofibrous layer. The fiber network could function as a three-dimensional reservoir to support the amplified immobilization of rhCoL III. The rhCOL III was tailored for anti-coagulant, anti-inflammatory and endothelialization promotion properties, which endows the ECM-mimetic coating with desired surface functionalities. Stent implantation in the abdominal aorta of rabbits was conducted to validate the in vivo re-endothelialization of the ECM-mimetic coating. The mild inflammatory responses, anti-thrombotic property, promotion of endothelialization and suppression of excessive neointimal hyperplasia confirmed that the ECM-mimetic coating provided a promising approach for the modification of vascular implants.

Predicting 1-year in-stent restenosis in superficial femoral arteries through multiscale computational modelling

In-stent restenosis in superficial femoral arteries (SFAs) is a complex, multi-factorial and multiscale vascular adaptation process whose thorough understanding is still lacking. Multiscale computational agent-based modelling has recently emerged as a promising approach to decipher mechanobiological mechanisms driving the arterial response to the endovascular intervention. However, the long-term arterial response has never been investigated with this approach, although being of fundamental relevance. In this context, this study investigates the 1-year post-operative arterial wall remodelling in three patient-specific stented SFA lesions through a fully coupled multiscale agent-based modelling framework. The framework integrates the effects of local haemodynamics and monocyte gene expression data on cellular dynamics through a bi-directional coupling of computational fluid dynamics simulations with an agent-based model of cellular activities. The framework was calibrated on the follow-up data at 1 month and 6 months of one stented SFA lesion and then applied to the other two lesions. The calibrated framework successfully captured (i) the high lumen area reduction occurring within the first post-operative month and (ii) the stabilization of the median lumen area from 1-month to 1-year follow-ups in all the stented lesions, demonstrating the potentialities of the proposed approach for investigating patient-specific short- and long-term responses to endovascular interventions.

A method of assessing peripheral stent abrasiveness under cyclic deformations experienced during limb movement

Poor outcomes of peripheral arterial disease stenting are often attributed to the inability of stents to accommodate the complex biomechanics of the flexed lower limb. Abrasion damage caused by rubbing of the stent against the artery wall during limb movement plays a significant role in reconstruction failure but has not been characterized. Our goals were to develop a method of assessing the abrasiveness of peripheral nitinol stents and apply it to several commercial devices. Misago, AbsolutePro, Innova, Zilver, SmartControl, SmartFlex, and Supera stents were deployed inside electrospun nanofibrillar tubes with femoropopliteal artery-mimicking mechanical properties and subjected to cyclic axial compression (25%), bending (90°), and torsion (26°/cm) equivalent to five life-years of severe limb flexions. Abrasion was assessed using an abrasion damage score (ADS, range 1-7) for each deformation mode. Misago produced the least abrasion and no stent fractures (ADS 3). Innova caused small abrasion under compression and torsion but large damage under bending (ADS 7). Supera performed well under bending and compression but caused damage under torsion (ADS 8). AbsolutePro produced significant abrasion under bending and compression but less damage under torsion (ADS 12). Zilver fractured under all three deformations and severely abraded the tube under bending and compression (ADS 15). SmartControl and SmartFlex fractured under all three deformations and produced significant abrasion due to strut penetration (ADS 20 and 21). ADS strongly correlated with clinical 12-month primary patency and target lesion revascularization rates, and the described method of assessing peripheral stent abrasiveness can guide device selection and development. STATEMENT OF SIGNIFICANCE: Poor outcomes of peripheral arterial disease stenting are related to the inability of stents to accommodate the complex biomechanics of the flexed lower limb. Abrasion damage caused by rubbing of the stent against the artery wall during limb movement plays a significant role in reconstruction failure but has not been characterized. Our study presents the first attempt at assessing peripheral stent abrasiveness, and the proposed method is applied to compare the abrasion damage caused by Misago, AbsolutePro, Innova, Zilver, SmartControl, SmartFlex, and Supera peripheral stents using artery-mimicking synthetic tubes and cyclic deformations equivalent to five life-years of severe limb flexions. The abrasion damage caused by stents strongly correlates with their clinical 12-month primary patency and target lesion revascularization rates, and the described methodology can be used as a cost-effective and controlled way of assessing stent performance, which can guide device selection and development.

Bifurcated Aneurysm Location Predicts In-Stent Stenosis After Neuroform-EZ Stent-Assisted Coiling for Intracranial Aneurysm

Background and Purpose

The Neuroform EZ stent system (Boston Scientific Corporation, Fremont, CA, United States) is a fourth-generation intracranial aneurysm stent designed specifically for the cerebrovasculature to support aneurysm treatment. In this study, we analyzed our consecutive series of patients with aneurysm treated with the Neuroform EZ stent, with special attention to the occurrence of in-stent stenosis (ISS).

Methods

A retrospective review of our center's electronic database was conducted to identify all patients with intracranial aneurysms who underwent aneurysm treatment with the Neuroform EZ stent between January 2016 and October 2018. Patients with at least one digital subtraction angiography (DSA) follow-up in our hospital were enrolled in this study. In-stent stenosis (ISS) was graded as mild (<2–5%), moderate (25–50%), or severe (>50%).

Results

The study included 114 patients (78 women, 68.4%; median age 57.2 ± 9 years) with a total of 116 aneurysms. Of the 116 lesions, 20 were identified with ISS (17.2%) at a mean follow-up of 6.9 ± 1.7 months, and ISS was mild in 30% (6/20), moderate in 50% (10/20), and severe in 20% (4/20). No patients were symptomatic or required further intervention. Patients who developed ISS were younger than those without ISS (52.6 ± 7.8 vs. 57.9 ± 9; p = 0.016). The proportion of aneurysms located at the artery bifurcation was significantly higher in patients with stenosis than located at the sidewall artery (37.9 vs. 10.3%; p = 0.002). In the multivariable analysis, the patients' age (OR = 0.94; 95% CI 0.88–0.998; p = 0.02) and bifurcated aneurysm location (OR = 4.59; 95% CI 1.54–13.67; p = 0.006) were independent predictors of ISS.

Conclusions

In this retrospective study, the incidence of ISS after Neuroform EZ stent placement was 17.2%, and all the ISS cases were asymptomatic. Patients with younger age and bifurcated aneurysm location are more likely to develop ISS. Although Neuroform EZ stent is particularly suitable for bifurcated aneurysms, the ISS for this location should be focused upon.

A predictive multiscale model of in-stent restenosis in femoral arteries: linking haemodynamics and gene expression with an agent-based model of cellular dynamics

In-stent restenosis (ISR) is a maladaptive inflammatory-driven response of femoral arteries to percutaneous transluminal angioplasty and stent deployment, leading to lumen re-narrowing as consequence of excessive cellular proliferative and synthetic activities. A thorough understanding of the underlying mechanobiological factors contributing to ISR is still lacking. Computational multiscale models integrating both continuous- and agent-based approaches have been identified as promising tools to capture key aspects of the complex network of events encompassing molecular, cellular and tissue response to the intervention. In this regard, this work presents a multiscale framework integrating the effects of local haemodynamics and monocyte gene expression data on cellular dynamics to simulate ISR mechanobiological processes in a patient-specific model of stented superficial femoral artery. The framework is based on the coupling of computational fluid dynamics simulations (haemodynamics module) with an agent-based model (ABM) of cellular activities (tissue remodelling module). Sensitivity analysis and surrogate modelling combined with genetic algorithm optimization were adopted to explore the model behaviour and calibrate the ABM parameters. The proposed framework successfully described the patient lumen area reduction from baseline to one-month follow-up, demonstrating the potential capabilities of this approach in predicting the short-term arterial response to the endovascular procedure.

Roles of MicroRNAs in Peripheral Artery In-Stent Restenosis after Endovascular Treatment

Endovascular repair including percutaneous transluminal angioplasty (PTA) and stent implantation has become the standard approach for the treatment of peripheral arterial disease; however, restenosis is still the main limited complication for the long-term success of the endovascular repair. Endothelial denudation and regeneration, inflammatory response, and neointimal hyperplasia are major pathological processes occurring during in-stent restenosis (ISR). MicroRNAs exhibit great potential in regulating several vascular biological events in different cell types and have been identified as novel therapeutic targets as well as biomarkers for ISR prevention. This review summarized recent experimental and clinical studies on the role of miRNAs in ISR modification, with the aim of unraveling the underlying mechanism and potential therapeutic strategy of ISR.

Photoablative atherectomy followed by a paclitaxel-coated balloon to inhibit restenosis in instent femoro-popliteal obstructions (PHOTOPAC)

Background: To evaluate the safety and effectiveness of preparing instent femoropopliteal lesion with photoablative laser atherectomy or plain balloon angioplasty (POBA) prior to drug-coated balloon (DCB) angioplasty. Patients and methods: The prospective, multicenter, randomized study enrolled patients with Rutherford-Becker-class (RBC) 1 to 5 and instent lesions located in superficial femoral artery and/or popliteal artery above the knee joint. Primary endpoint was target lesion percent stenosis at 1 year as determined by the angiographic core-laboratory. Secondary endpoints included procedural success, major adverse event rate, clinical improvement and improvement in ankle-brachial index (ABI), clinically-driven target lesion revascularization (CD-TLR), and primary patency rate at until 2-year follow-up. Results: The study was terminated prior to the enrollment goal due to slow enrollment. Thirty patients were included in the laser plus DCB cohort and 31 patients in the control cohort. Primary endpoint was not significantly different (p=0.331). Procedural success was 83.3% and 87.1% for the laser plus DCB and the control cohort, respectively. Serious adverse events at 30 days and 1-year were not statistically different between the two cohorts. For the ABI, significant improvements were present at discharge as well as at the follow-up visits. This was also evident for the RBC at the follow-up visits. One- and two-year freedom from CD-TLR was 86.7% vs. 87.1%, and 63.6% vs. 72%, respectively. Duplex derived primary patency was 90% at 6-months, 65.5% at one year and 56.5% at two year for the laser cohort and 90.3%, 75.9% and 53.8% for the control cohort. Conclusions: Safety of instent photoablative laser atherectomy followed by DCB angioplasty is confirmed by this study. Due to the small sample size, no benefit over POBA as vessel preparation could be shown.

Usefulness of black-blood magnetic resonance angiography generated from vessel wall imaging after the stent-assisted treatment of intracranial arterial diseases

PURPOSE

After stent-assisted treatment for intracranial diseases, three-dimensional time-of-flight magnetic resonance angiography is a noninvasive follow-up method, but susceptibility artifacts prevent accurate evaluations of stented arteries. Sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) sequence often used for vessel wall imaging is less susceptible to susceptibility artifacts, since it is a spin-echo sequence. Hence, we evaluated the feasibility of black-blood magnetic resonance angiography generated from vessel wall imaging data obtained using the SPACE sequence in the depiction of stented arteries by comparing with three-dimensional time-of-flight magnetic resonance angiography and digital subtraction angiography.

METHODS

Our study group comprised 11 consecutive patients. For both three-dimensional time-of-flight magnetic resonance angiography and black-blood magnetic resonance angiography, the contrast ratio obtained from the stented artery and the normal artery proximal to the stent were calculated. And the depiction of stented arteries was visually evaluated. Additionally, the relative diameter index obtained from the stented artery and the normal artery proximal to the stent were calculated for three-dimensional time-of-flight magnetic resonance angiography, black-blood magnetic resonance angiography and digital subtraction angiography.

RESULTS

The contrast ratio of the stented artery was significantly lower than that of the normal artery on three-dimensional time-of-flight magnetic resonance angiography, but no significant difference was seen using black-blood magnetic resonance angiography. Regarding both the diameter index and the visual assessment score, black-blood magnetic resonance angiography was significantly better than three-dimensional time-of-flight magnetic resonance angiography. On black-blood magnetic resonance angiography, the diameter index was equal to that of digital subtraction angiography, and the flow signal was homogeneous and continuous in most the cases.

Etosis, rather than apoptosis or cell proliferation, typifies thrombus progression - An immunohistochemical study of coronary aspirates

Background

Coronary thrombosis is a process with unpredictable clinical outcome. Changes of thrombus composition overtime influence tissue repair and stabilization. We investigated rates of cell deaths and cell proliferation at different time points after initiation of thrombosis.

Methods

Thrombectomy aspirates of 55 myocardial infarction patients were selected and histomorphologically classified as fresh (25), lytic (25), partially fibrocellular (10), completely fibrocellular (10). Paraffin sections were immunostained with anti-(cleaved) caspase-3/Casp3 (apoptosis), Citrullinated histone/CitH 3 (etosis), C-reactive protein/CRP and Ki67 (proliferation) in combination with either Feulgen counterstaining (DNA) or cell markers for granulocytes, macrophages, SMCs, platelets and endothelium. Rates of apoptosis, etosis and proliferation were measured as a percentage of total number of immunopositive pixels versus total number of DNA positive pixels, while co-localization with cell markers was assessed by digital image analysis.

Results

Positive staining of CitH3 was observed more frequently (93%) than Casp3 (70%), Ki67 (79%) or CRP (59%) (p < 0.05). Moreover, rate of etosis, found in granulocytes and macrophages, differed significantly among thrombi of different age, being higher in lytic (12.82) than in fresh (8.52) and late-organized (2.75) (p < 0.05). Such differences were not observed for the rates of apoptosis or cell proliferation related to thrombus age. CRP staining was present in fresh, lytic and organized thrombi, but did not reliably identify necrotic areas.

Conclusions

Different patterns of cell death and cell proliferation are noticed during progression of coronary thrombus overtime, but with significant differences for only etosis. Etosis could potentially serve as a biomarker for thrombus instability with clinical significance.

Edoxaban Plus Aspirin vs Dual Antiplatelet Therapy in Endovascular Treatment of Patients With Peripheral Artery Disease: Results of the ePAD Trial

Purpose: To report a randomized study that investigated the safety (risk of major bleeds) and potential efficacy of edoxaban, an oral anticoagulant that targets the major components of arterial thrombi, to prevent loss of patency following endovascular treatment (EVT). Methods: Between February 2012 and June 2014, 203 patients who underwent femoropopliteal EVT were randomized to receive aspirin plus edoxaban or aspirin plus clopidogrel for 3 months in the Edoxaban in Peripheral Arterial Disease (ePAD) study (ClinicalTrials.gov identifier NCT01802775). Randomization assigned 101 patients (mean age 68.0±10.4 years; 67 men) to the edoxaban group and 102 patients (mean age 66.7±8.6 years; 78 men) to the clopidogrel group. The primary safety endpoint was bleeding as classified by the TIMI (Thrombolysis in Myocardial Infarction) criteria and ISTH (International Society of Thrombosis and Hemostasis) criteria; the efficacy endpoint was the rate of restenosis/reocclusion. Results: There were no major or life-threatening bleeding events in the edoxaban group, while there were 2 major and 2 life-threatening bleeding events in the clopidogrel group by the TIMI criteria. By the ISTH classification, there was 1 major and 1 life-threatening bleeding event vs 5 major and 2 life-threatening bleeding events, respectively [relative risk (RR) 0.20, 95% confidence interval (CI) 0.02 to 1.70]. The bleeding risk was not statistically different with either treatment when assessed by TIMI or ISTH. Following 6 months of observation, there was a lower incidence of restenosis/reocclusion with edoxaban compared with clopidogrel (30.9% vs 34.7%; RR 0.89, 95% CI 0.59 to 1.34, p=0.643). Conclusion: These results suggest that patients who have undergone EVT have similar risks for major and life-threatening bleeding events with edoxaban and aspirin compared with clopidogrel and aspirin. The incidence of restenosis/reocclusion events, while not statistically different, was lower with edoxaban and aspirin, but an adequately sized trial will be needed to confirm these findings.

Contribution of transcription factor EB to adipoRon-induced inhibition of arterial smooth muscle cell proliferation and migration

Abnormal vascular smooth muscle cell (SMC) dedifferentiation with increased proliferation and migration during pathological vascular remodeling is associated with vascular disorders, such as atherosclerosis and in-stent restenosis. AdipoRon, a selective agonist of adiponectin receptor, has been shown to protect against vascular remodeling by preventing SMC dedifferentiation. However, the molecular mechanisms that mediate adipoRon-induced SMC differentiation are not well understood. The present study aimed to elucidate the role of transcription factor EB (TFEB), a master regulator of autophagy, in mediating adipoRon's effect on SMCs. In cultured arterial SMCs, adipoRon dose-dependently increased TFEB activation, which is accompanied by upregulated transcription of genes involved in autophagy pathway and enhanced autophagic flux. In parallel, adipoRon suppressed serum-induced cell proliferation and caused cell cycle arrest. Moreover, adipoRon inhibited SMC migration as characterized by wound-healing retardation, F-actin reorganization, and matrix metalloproteinase-9 downregulation. These inhibitory effects of adipoRon on proliferation and migration were attenuated by TFEB gene silencing. Mechanistically, activation of TFEB by adipoRon is dependent on intracellular calcium, but it is not associated with changes in AMPK, ERK1/2, Akt, or molecular target of rapamycin complex 1 activation. Using ex vivo aortic explants, we demonstrated that adipoRon inhibited sprouts that had outgrown from aortic rings, whereas lentiviral TFEB shRNA transduction significantly reversed this effect of adipoRon on aortic rings. Taken together, our results indicate that adipoRon activates TFEB signaling that helps maintain the quiescent and differentiated status of arterial SMCs, preventing abnormal SMC dedifferentiation. This study provides novel mechanistic insights into understanding the therapeutic effects of adipoRon on TFEB signaling and pathological vascular remodeling.

Activation of TFEB ameliorates dedifferentiation of arterial smooth muscle cells and neointima formation in mice with high-fat diet

Autophagy is recently implicated in regulating vascular smooth muscle cell (SMC) homeostasis and in the pathogenesis of vascular remodeling. Transcription factor EB (TFEB) is a master regulator of autophagy signaling pathways. However, the molecular mechanisms and functional roles of TFEB in SMC homeostasis have not been elucidated. Here, we surveyed the ability of TFEB to regulate autophagy pathway in SMCs, and whether pharmacological activation of TFEB favors SMC homeostasis preventing dedifferentiation and pathogenic vascular remodeling. In primary cultured SMCs, TFEB activator trehalose induced nuclear translocation of TFEB and upregulation of TFEB-controlled autophagy genes leading to enhanced autophagy signaling. Moreover, trehalose suppressed serum-induced SMC dedifferentiation to synthetic phenotypes as characterized by inhibited proliferation and migration. These effects of trehalose were mimicked by ectopic upregulation of TFEB and inhibited by TFEB gene silencing. In animal experiments, partial ligation of carotid arteries induced downregulation of TFEB pathway in the media layer of these arteries. Such TFEB suppression was correlated with increased SMC dedifferentiation and aggravated high-fat diet (HFD)-induced neointima formation. Treatment of mice with trehalose reversed this TFEB pathway suppression, and prevented SMC dedifferentiation and HFD-induced neointima formation. In conclusion, our findings have identified TFEB as a novel positive regulator for autophagy pathway and cellular homeostasis in SMCs. Our data suggest that suppression of TFEB may be an initiating mechanism that promotes SMC dedifferentiation leading to accelerated neointima formation in vascular disorders associated with metabolic stress, whereas trehalose reverses these changes. These findings warrant further evaluation of trehalose in the clinical settings.

Histological features of restenosis associated with paclitaxel drug-coated balloon: implications for therapy

PURPOSE

To investigate the cellular and extracellular changes induced by drug-coated balloons (DCB) in the treatment of superficial femoral artery (SFA) restenosis, and to compare histopathological features with those observed after plain old balloon angioplasty (POBA) from the same patients.

METHODS AND RESULTS

Plaque samples for five patients with SFA restenosis (first-time) after POBA were collected using atherectomy and DCB. These samples constitute the POBA restenosis group. The same five patients developed recurrent restenosis (RR) after DCB, at the same intervention site. These SFA-RR lesions were again treated using atherectomy and POBA. These samples constitute the DCB restenosis group. DCB restenosis group plaques showed significant reduction in neointima, smooth muscle cells, fibroblast densities, and Ki67 index; and increase in caspase 3, features of apoptosis and type III collagen deposition in comparison to the POBA restenosis group.

CONCLUSION

Plaque tissue from the DCB restenosis group show reductions in neointimal thickness, cellularity, and cellular proliferation, along with increased apoptosis, and Type III collagen content. These results suggest a different mechanistic pathway for DCB restenosis, in which neointimal proliferation is reduced but reparative fibrosis is increased. The treatment for SFA-RR after DCB may therefore benefit from different forms of therapy including scaffolding, rather than recurrent anti-proliferative therapy.

Tumor Necrosis Factor Receptor-Associated Factor 5 Promotes Arterial Neointima Formation through Smooth Muscle Cell Proliferation

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are cytoplasmic adaptor proteins of the TNF/interleukin (IL)-1/Toll-like receptor superfamily. Ligands of this family such as TNFα, CD40L, and IL-1β promote chronic inflammatory processes such as atherosclerosis and restenosis, the latter being a common adverse reaction after vascular interventions. We previously reported overexpression of TRAF5 in murine and human atheromata and TRAF5-dependent proinflammatory functions in vitro. However, the role of TRAF5 in restenosis remains unsettled. To evaluate whether TRAF5 affects neointima formation, TRAF5-/-LDLR-/- and TRAF5+/+LDLR-/- mice consuming a high cholesterol diet (HCD) received wire-induced injury of the carotid artery. After 28 days, TRAF5-deficient mice showed a 45% decrease in neointimal area formation compared with TRAF5-compentent mice. Furthermore, neointimal vascular smooth muscle cells (vSMC) and macrophages decreased whereas collagen increased in TRAF5-deficient mice. Mechanistically, the latter expressed lower transcript levels of the matrix metalloproteinases 2 and 9, both instrumental in extracellular matrix degradation and vSMC mobilization. Additionally, TRAF5-specific siRNA interference rendered murine vSMC less proliferative upon CD40L stimulation. In accordance with these findings, fewer vSMC isolated from TRAF5-deficient aortas were in a proliferative state as assessed by Ki67 and cyclin B1 expression. In conclusion, TRAF5 deficiency mitigates neointima formation in mice, likely through a TRAF5-dependent decrease in vSMC proliferation.

Association study of matrix metalloproteinase 3 5A/6A polymorphism with in-stent restenosis after percutaneous coronary interventions in a Han Chinese population

Objective

We aimed to investigate the association between the 5A/6A promoter polymorphism in the matrix metalloproteinase 3 (MMP3) gene and in-stent restenosis (ISR) in a regional Chinese population.

Methods

A total of 818 patients who underwent primary implantation of drug-eluting stents were enrolled and received a 6-month follow-up angiography and DNA genotyping of the 5A/6A polymorphism.

Results

ISR was found in 36.9% of all patients (302 ISR vs. 516 no ISR). The genotype proportion of 6A6A was significantly increased in ISRs (74.2% ISR vs. 66.8% no ISR), whereas the allele frequency of 5A was significantly decreased in ISR patients (25.8%) compared with controls who did not undergo ISR (33.1%).

Conclusions

Our data indicate that the MMP3 6A6A genotype is a genetic susceptibility factor for ISR after coronary stent placement, but the 5A allele can lower the risk for patients within 6 months after stenting. Therefore, genotyping 5A/6A in the MMP3 promoter is suggested for patients who undergo coronary stent implantation.

Vascular smooth muscle-MAPK14 is required for neointimal hyperplasia by suppressing VSMC differentiation and inducing proliferation and inflammation

Injury-induced stenosis is a serious vascular complication. We previously reported that p38α (MAPK14), a redox-regulated p38MAPK family member was a negative regulator of the VSMC contractile phenotype in vitro. Here we evaluated the function of VSMC-MAPK14 in vivo in injury-induced neointima hyperplasia and the underlying mechanism using an inducible SMC-MAPK14 knockout mouse line (iSMC-MAPK14^-/-). We show that MAPK14 expression and activity were induced in VSMCs after carotid artery ligation injury in mice and ex vivo cultured human saphenous veins. While the vasculature from iSMC-MAPK14^-/- mice was indistinguishable from wildtype littermate controls at baseline, these mice exhibited reduced neointima formation following carotid artery ligation injury. Concomitantly, there was an increased VSMC contractile protein expression in the injured vessels and a decrease in proliferating cells. Blockade of MAPK14 through a selective inhibitor suppressed, while activation of MAPK14 by forced expression of an upstream MAPK14 kinase promoted VSMC proliferation in cultured VSMCs. Genome wide RNA array combined with VSMC lineage tracing studies uncovered that vascular injury evoked robust inflammatory responses including the activation of proinflammatory gene expression and accumulation of CD45 positive inflammatory cells, which were attenuated in iSMC-MAPK14^-/- mice. Using multiple pharmacological and molecular approaches to manipulate MAPK14 pathway, we further confirmed the critical role of MAPK14 in activating proinflammatory gene expression in cultured VSMCs, which occurs in a p65/NFkB-dependent pathway. Finally, we found that NOX4 contributes to MAPK14 suppression of the VSMC contractile phenotype. Our results revealed that VSMC-MAPK14 is required for injury-induced neointima formation, likely through suppressing VSMC differentiation and promoting VSMC proliferation and inflammation. Our study will provide mechanistic insights into therapeutic strategies for mitigation of vascular stenosis.

Niclosamide inhibits vascular smooth muscle cell proliferation and migration and attenuates neointimal hyperplasia in injured rat carotid arteries

BACKGROUND AND PURPOSE

The anti-helminthic drug niclosamide regulates multiple cellular signals including STAT3, AMP-activated protein kinase (AMPK), Akt, Wnt/β-catenin and mitochondrial uncoupling which are involved in neointimal hyperplasia. Here we have examined the effects of niclosamide on vascular smooth muscle cell proliferation, migration and neointimal hyperplasia and assessed the potential mechanisms.

EXPERIMENTAL APPROACH

Cell migration was measured by using wound-induced migration assay and Boyden chamber assay. Protein levels were measured by using Western blot technique. Neointimal hyperplasia in vivo was induced in rats by balloon injury to the carotid artery.

KEY RESULTS

Niclosamide treatment inhibited serum-induced (15% FBS) and PDGF-BB-induced proliferation and migration of vascular smooth muscle cells (A10 cells). Niclosamide showed no cytotoxicity at anti-proliferative concentrations, but induced cell apoptosis at higher concentrations. Niclosamide treatment inhibited serum-induced (15% FBS) and PDGF-BB-induced STAT3 activation (increased protein levels of p-STAT3 at Tyr⁷⁰⁵ ) but activated AMPK, in A10 cells. Niclosamide exerted no significant effects on β-catenin expression and the activities of ERK1/2 and Akt in A10 cells. Injection (i.p.) of soluble pegylated niclosamide (PEG5000-niclosamide) (equivalent to niclosamide 25 mg·kg^-1 ) attenuated neointimal hyperplasia following balloon-injury in rat carotid arteries in vivo.

CONCLUSIONS AND IMPLICATIONS

Niclosamide inhibited vascular smooth muscle cell proliferation and migration and attenuated neointimal hyperplasia in balloon-injured rat carotid arteries through a mechanism involving inhibition of STAT3.

An Atelocollagen Coating for Efficient Local Gene Silencing by Using Small Interfering RNA

In the last decades, many efforts have been made to counteract adverse effects after stenting atherosclerotic coronary arteries. A breakthrough in better vascular wall regeneration was noted in the new era of drug-eluting stents. A novel personalized approach is the development of gene-eluting stents promising an alteration in gene expression involved in regeneration. We investigated a coating system consisting of the polymer atelocollagen (ATCOL) and a specific small interfering RNA (siRNA) for intercellular adhesion molecule-1 (ICAM-1) found on the surface of defective endothelial cells (ECs). We demonstrated very high cell viability, in which EA.hy926 grew on 0.008% or 0.032% ATCOL layers. Additionally, hemocompatibility assays proved the biocompatibility of this coating. The highest transfection efficiency with EA.hy926 was achieved with 5 μg siRNA immobilized in ATCOL after 2 days. The release of fluorescent-labeled siRNA was about 9 days. Long-term knockdown of ICAM-1 was analyzed by flow cytometry, revealing that the coating with 0.008% ATCOL and 5 μg siICAM-1 provoked gene silencing up to 8 days. 5′-RNA ligase-mediated rapid amplification of cDNA ends PCR (RLM-RACE-PCR) demonstrated the specificity of our established ATCOL gene-silencing coating, meaning that our coating is well suited for further investigations in in vivo studies. Herein, we would like to demonstrate that our ATCOL is well-suited for better artery wall regeneration after stent implantation.

Responses of adventitial CD34+ vascular wall-resident stem/progenitor cells and medial smooth muscle cells to carotid injury in rats

Cell culture and carotid injury studies with SD rats were performed to investigate the roles of CD34⁺ vascular wall-resident stem/progenitor cells (VRS/Pcs) and vascular smooth muscle cells (SMCs) in neointimal formation. In vitro, the media-isolated SM MHC⁺ SMCs occupied 93.92±8.62% of total BrdU⁺ cells, whereas the CD34⁺ cells, only 2.61±0.82%, indicating that the cell expansion in SMC culture was attributed to SM MHC⁺ SMCs. The adventitia-isolated CD34⁺ VRS/Pcs responded to PDGF-BB by differentiating into SMC-like cells which expressed SM22α (an early stage SMC marker), but seldom SM MHC (a late stage SMC marker). In carotid injury model, the CD34⁺ VRS/Pcs differentiated SMC-like cells migrated in very few numbers into only the outer layer of the media, and this was further confirmed by a cell tracking analysis. While the neointimal cells were consistently SM MHC⁺ and CD34^- SMCs during whole course of the post-injury remodeling. Thus it is speculated that the adventitial CD34⁺ VRS/Pcs, at least in rat model, do not directly participate in neointimal formation, but function to maintain homeostasis of the media during injury-induced vascular wall remodeling.

Distinct Differences on Neointima Formation in Immunodeficient and Humanized Mice after Carotid or Femoral Arterial Injury

Percutaneous coronary intervention is widely adopted to treat patients with coronary artery disease. However, restenosis remains an unsolved clinical problem after vascular interventions. The role of the systemic and local immune response in the development of restenosis is not fully understood. Hence, the aim of the current study was to investigate the role of the human immune system on subsequent neointima formation elicited by vascular injury in a humanized mouse model. Immunodeficient NOD.Cg-Prkdc^scidIL2rg^tm1Wjl(NSG) mice were reconstituted with human (h)PBMCs immediately after both carotid wire and femoral cuff injury were induced in order to identify how differences in the severity of injury influenced endothelial regeneration, neointima formation, and homing of human inflammatory and progenitor cells. In contrast to non-reconstituted mice, hPBMC reconstitution reduced neointima formation after femoral cuff injury whereas hPBMCs promoted neointima formation after carotid wire injury 4 weeks after induction of injury. Neointimal endothelium and smooth muscle cells in the injured arteries were of mouse origin. Our results indicate that the immune system may differentially respond to arterial injury depending on the severity of injury, which may also be influenced by the intrinsic properties of the arteries themselves, resulting in either minimal or aggravated neointima formation.

The History of Coronary Stenting

The history of coronary angioplasty began with the groundbreaking work of Andreas Grüntzig, who was the first to use balloon-expandable catheters for the treatment of flow-limiting atherosclerotic coronary artery lesions. Thereafter, early investigators tested self-expanding springs as a solution to abrupt closure and restenosis seen with balloon angioplasty but these devices suffered from difficult delivery and a high complication rate. Julio Palmaz and Richard Schatz introduced the first balloon-expandable stent as a mechanical support to improve vessel patency. Their pioneering work launched a new era in the treatment of coronary artery disease.

Pathology of Endovascular Stents

Contemporary endovascular stents are the product of an iterative design and development process that leverages evolving concepts in vascular biology and engineering. This article reviews how insights into vascular pathophysiology, materials science, and design mechanics drive stent design and explain modes of stent failure. Current knowledge of pathologic processes is providing a more complete picture of the factors mediating stent failure. Further evolution of endovascular stents includes bioresorbable platforms tailored to treat plaques acutely and to then disappear after lesion pacification. Ongoing refinement of stent technology will continue to require insights from pathology to understand adverse events, refine clinical protocols, and drive innovation.

Cyclic nucleotide phosphodiesterases in heart and vessels: A therapeutic perspective

Cyclic nucleotide phosphodiesterases (PDEs) degrade the second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), thereby regulating multiple aspects of cardiac and vascular muscle functions. This highly diverse class of enzymes encoded by 21 genes encompasses 11 families that are not only responsible for the termination of cyclic nucleotide signalling, but are also involved in the generation of dynamic microdomains of cAMP and cGMP, controlling specific cell functions in response to various neurohormonal stimuli. In the myocardium and vascular smooth muscle, the PDE3 and PDE4 families predominate, degrading cAMP and thereby regulating cardiac excitation-contraction coupling and smooth muscle contractile tone. PDE3 inhibitors are positive inotropes and vasodilators in humans, but their use is limited to acute heart failure and intermittent claudication. PDE5 is particularly important for the degradation of cGMP in vascular smooth muscle, and PDE5 inhibitors are used to treat erectile dysfunction and pulmonary hypertension. There is experimental evidence that these PDEs, as well as other PDE families, including PDE1, PDE2 and PDE9, may play important roles in cardiac diseases, such as hypertrophy and heart failure, as well as several vascular diseases. After a brief presentation of the cyclic nucleotide pathways in cardiac and vascular cells, and the major characteristics of the PDE superfamily, this review will focus on the current use of PDE inhibitors in cardiovascular diseases, and the recent research developments that could lead to better exploitation of the therapeutic potential of these enzymes in the future.

The Many Faces of the A2b Adenosine Receptor in Cardiovascular and Metabolic Diseases

Modulation of the low affinity adenosine receptor subtype, the A2b adenosine receptor (A2bAR), has gained interest as a therapeutic target in various pathologic areas associated with cardiovascular disease. The actions of the A2bAR are diverse and at times conflicting depending on cell and tissue type and the timing of activation or inhibition of the receptor. The A2bAR is a promising and exciting pharmacologic target, however, a thorough understanding of A2bAR action is necessary to reach the therapeutic potential of this receptor. This review will focus on the role of the A2bAR in various cardiovascular and metabolic pathologies in which the receptor is currently being studied. We will illustrate the complexities of A2bAR signaling and highlight areas of research with potential for therapeutic development.

A Review of Antithrombotic Therapy and the Rationale and Design of the Randomized Edoxaban in Patients With Peripheral Artery Disease (ePAD) Trial Adding Edoxaban or Clopidogrel to Aspirin After Femoropopliteal Endovascular Intervention

Compared with the coronary setting, knowledge about antithrombotic therapies after endovascular treatment (EVT) is inadequate in patients with peripheral artery disease (PAD). Based on a review of trials and guidelines, which is summarized in this article, there is scant evidence that antithrombotic drugs improve outcome after peripheral EVT. To address this knowledge gap, the randomized, open-label, multinational edoxaban in patients with Peripheral Artery Disease (ePAD) study ( ClinicalTrials.gov identifier NCT01802775) was designed to explore the safety and efficacy of a combined regimen of antiplatelet therapy with clopidogrel and anticoagulation with edoxaban, a selective and direct factor Xa inhibitor, both combined with aspirin. As of July 2014, 203 patients (144 men; mean age 67 years) from 7 countries have been enrolled. These patients have been allocated to once-daily edoxaban [60 mg for 3 months (or 30 mg in the presence of factors associated with increased exposure)] or clopidogrel (75 mg/d for 3 months). All patients received aspirin (100 mg/d) for the 6-month duration of the study. The primary safety endpoint is major or clinically relevant nonmajor bleeding; the primary efficacy endpoint is restenosis or reocclusion at the treated segment(s) measured at 1, 3, and 6 months using duplex ultrasound scanning. All outcomes will be assessed and adjudicated centrally in a masked fashion. The ePAD study is the first of its kind to investigate a combined regimen of antiplatelet therapy and anticoagulation through factor Xa inhibition with edoxaban.

Role of cAMP-phosphodiesterase 1C signaling in regulating growth factor receptor stability, vascular smooth muscle cell growth, migration, and neointimal hyperplasia

RATIONALE

Neointimal hyperplasia characterized by abnormal accumulation of vascular smooth muscle cells (SMCs) is a hallmark of occlusive disorders such as atherosclerosis, postangioplasty restenosis, vein graft stenosis, and allograft vasculopathy. Cyclic nucleotides are vital in SMC proliferation and migration, which are regulated by cyclic nucleotide phosphodiesterases (PDEs).

OBJECTIVE

Our goal is to understand the regulation and function of PDEs in SMC pathogenesis of vascular diseases.

METHODS AND RESULTS

We performed screening for genes differentially expressed in normal contractile versus proliferating synthetic SMCs. We observed that PDE1C expression was low in contractile SMCs but drastically elevated in synthetic SMCs in vitro and in various mouse vascular injury models in vivo. In addition, PDE1C was highly induced in neointimal SMCs of human coronary arteries. More importantly, injury-induced neointimal formation was significantly attenuated by PDE1C deficiency or PDE1 inhibition in vivo. PDE1 inhibition suppressed vascular remodeling of human saphenous vein explants ex vivo. In cultured SMCs, PDE1C deficiency or PDE1 inhibition attenuated SMC proliferation and migration. Mechanistic studies revealed that PDE1C plays a critical role in regulating the stability of growth factor receptors, such as PDGF receptor β (PDGFRβ) known to be important in pathological vascular remodeling. PDE1C interacts with low-density lipoprotein receptor-related protein-1 and PDGFRβ, thus regulating PDGFRβ endocytosis and lysosome-dependent degradation in an low-density lipoprotein receptor-related protein-1-dependent manner. A transmembrane adenylyl cyclase cAMP-dependent protein kinase cascade modulated by PDE1C is critical in regulating PDGFRβ degradation.

CONCLUSIONS

These findings demonstrated that PDE1C is an important regulator of SMC proliferation, migration, and neointimal hyperplasia, in part through modulating endosome/lysosome-dependent PDGFRβ protein degradation via low-density lipoprotein receptor-related protein-1.

Chronic treatment with trimetazidine after discharge reduces the incidence of restenosis in patients who received coronary stent implantation: a 1-year prospective follow-up study

BACKGROUND

The incidence of stent restenosis (SR) has risen with as more patients are being treated with drug-eluting stents (DESs). Trimetazidine has multiple favorable effects on the cardiovascular system. Here, we aimed to evaluate whether chronic treatment with trimetazidine reduced the incidence of SR.

METHODS

From January 2009 to December 2011 at Chinese PLA General Hospital, 768 patients were enrolled and randomized into the trimetazidine treatment group (TG, n = 384) and control group (CG, n = 384). After DES implantation, all patients were treated with regular medication. In the TG, trimetazidine was administrated at 20mg tid for at least 30days. All patients received follow-up angiography 9-13 months after discharge. Major adverse cardiac and cerebrovascular events (MACCEs) were recorded.

RESULTS

Six hundred thirty-five patients were included in the final analysis (TG, n = 312; CG, n = 323). SR occurred in 49 (7.7%) patients. The TG had a lower incidence of SR compared to the CG (4.2% vs. 11.1%, p = 0.001). At the 30-day follow-up, the TG exhibited a higher left ventricular ejection fraction than the CG (65.4 ± 10.7 vs. 63.1 ± 10.4, p = 0.006). The incidence of MACCEs was also lower in the TG at the 1-year follow-up (6.1% vs. 10.8%, p = 0.032). Further multivariate analysis revealed that trimetazidine treatment was a predictor for SR (OR: 0.376; 95% CI: 0.196-0.721; p = 0.003).

CONCLUSIONS

Trimetazidine treatment effectively reduced the incidence of SR and MACCEs after DES implantation at the 1-year follow-up.

The LIM-only protein FHL2 reduces vascular lesion formation involving inhibition of proliferation and migration of smooth muscle cells

The LIM-only protein FHL2, also known as DRAL or SLIM3, has a function in fine-tuning multiple physiological processes. FHL2 is expressed in the vessel wall in smooth muscle cells (SMCs) and endothelial cells and conflicting data have been reported on the regulatory function of FHL2 in SMC phenotype transition. At present the function of FHL2 in SMCs in vascular injury is unknown. Therefore, we studied the role of FHL2 in SMC-rich lesion formation. In response to carotid artery ligation FHL2-deficient (FHL2-KO) mice showed accelerated lesion formation with enhanced Ki67 expression compared with wild-type (WT)-mice. Consistent with these findings, cultured SMCs from FHL2-KO mice showed increased proliferation through enhanced phosphorylation of extracellular-regulated kinase-1/2 (ERK1/2) and induction of CyclinD1 expression. Overexpression of FHL2 in SMCs inhibited CyclinD1 expression and CyclinD1-knockdown blocked the enhanced proliferation of FHL2-KO SMCs. We also observed increased CyclinD1 promoter activity in FHL2-KO SMCs, which was reduced upon ERK1/2 inhibition. Furthermore, FHL2-KO SMCs showed enhanced migration compared with WT SMCs. In conclusion, FHL2 deficiency in mice results in exacerbated SMC-rich lesion formation involving increased proliferation and migration of SMCs via enhanced activation of the ERK1/2-CyclinD1 signaling pathway.

Finite element modeling of a novel self-expanding endovascular stent method in treatment of aortic aneurysms

A novel large self-expanding endovascular stent was designed with strut thickness of 70 μm × 70 μm width. The method was developed and investigated to identify a novel simpler technique in aortic aneurysm therapy. Stage 1 analysis was performed after deploying it in a virtual aneurysm model of 6 cm wide × 6 cm long fusiform hyper-elastic anisotropic design. At cell width of 9 mm, there was no buckling or migration of the stent at 180 Hg. Radial force of the stents was estimated after parametric variations. In stage 2 analysis, a prototype 300 μm × 150 μm stent with a cell width of 9 mm was chosen, and it was evaluated similarly after embedding in the aortic wall, and also with a tissue overgrowth of 1 mm over the stent. The 300/150 μm stent reduced the peak wall stress by 70% in the aneurysm and 50% reduction in compliance after embedding. Stage 3 analysis was performed to study the efficacy of stents with struts (thickness/width) 70/70, 180/100 and 300/150 μm after embedding and tissue overgrowth. The adjacent wall stresses were very minimal in stents with 180/100 and 70/70 μm struts after embedding. There is potential for a novel stent method in aortic aneurysm therapy.

Incidence and risk factors for medical complications and 30-day end points after carotid artery stenting

With the extensive use of carotid artery stenting (CAS) surgeries, scholars are paying more attention to the safety and efficiency of CAS. Our study aims to analyze the clinical efficiency, safety, and technical feasibility of CAS surgery in the treatment of carotid artery stenosis. A total of 379 cases of CAS were collected and retrospectively analyzed. The outcomes were summarized according to decrease in stenosis extent, incidence of early complications after procedure, 30-day end point events, and the follow-up data. Logistic regression was employed to analyze the correlations between risk factors and complications within 30 days and 30-day end points of stroke, myocardial infarctions (MIs), and mortality. The average extent of stenosis reduced from preoperative (81% ± 17%) to postoperative (26% ± 17%). In all, 53 patients had 72 medical complications, including 6 (1.58%) cerebral hemorrhage, 7 (1.85%) cerebral infarction, 5 (1.32%) transient ischemic attack (TIA), 5 (1.32%) heart failure, 10 (2.63%) symptomatic hypertension, 21 (5.54%) symptomatic hypotension, 10 (2.63%) symptomatic bradycardia, and 8 other complications; 15 patients had at least 2 complications. Advanced age, diabetes, and heart failure were associated with the high incidence of early complications (P < .05). Asymptomatic stenosis (odds ratio [OR] = 0.39, 95% confidence interval [CI]: 0.131-1.131, P = .0426) and diabetes (OR = 3.38, 95% CI: 1.340-8.574, P = .0099) were correlated with the incidence of 30-day end point events. Diabetes and symptomatic stenosis are independent risk factors for 30-day end point events of CAS. Advanced age, hypertension, and vascular unstable plaque will increase the risk of postoperative complications.

Disappearance of a small intracranial aneurysm as a result of vessel straightening and in-stent stenosis following use of an Enterprise vascular reconstruction device

In-stent stenosis after stent-assisted coil embolization is a rare but well-known complication. A 32-year-old woman with an unruptured wide-necked left internal carotid artery (ICA) terminus aneurysm and an ipsilateral very small anterior choroidal artery aneurysm underwent stent-assisted coil embolization for the ICA terminus aneurysm. The 4-month follow-up angiography revealed diffuse in-stent stenosis and disappearance of the untreated anterior choroidal artery aneurysm, retaining the patency of the anterior choroidal artery. To our knowledge, this is the first report to demonstrate the course of in-stent stenosis and disappearance of an untreated small intracranial aneurysm as a result. We report this unique case and discuss the interesting mechanism underlying this phenomenon, and also provide a review of the relevant literature.