Liquid Drug Delivery Approaches for the Treatment of Occlusive Arterial Disease: A Systematic Review

OBJECTIVE

Local Liquid drug (LLD) delivery devices have recently emerged as a novel approach to treat peripheral arterial disease. This systemic review aims to identify and evaluate the clinical utility of the most commonly used delivery devices.

METHODS

A systemic review was performed using the Medical Subjects Heading terms of "drug delivery," "liquid," "local," and "cardiovascular disease" in PubMed, Google Scholar, and Scopus.

RESULTS

Four commonly used delivery devices were identified, including (1) the Bullfrog Micro-Infusion Device, (2) the ClearWay RX Catheter, (3) the Occlusion Perfusion Catheter, and (4) the Targeted Adjustable Pharmaceutical Administration. All have shown to successfully deliver liquid therapeutic into the target lesion and have exhibited favorable safety and efficacy profiles in preclinical and clinical trials. The LLD devices have the ability to treat very long or multiple lesions with a single device, providing a more economical option. The safety profile in LLD clinical studies is also favorable in view of recent concerns regarding adverse events with crystalline-paclitaxel-coated devices.

CONCLUSION

There is clear clinical evidence to support the concept of local liquid delivery to treat occlusive arterial disease.

CLINICAL IMPACT

The 'leave nothing behind' strategy has been at the forefront of the most recent innovations in the field of interventional cardiology and vascular interventions. Although drug coated balloons have overcome limitations associated with plain old balloon angioplasty and peripheral stents, recent safety concerns and cost considerations have impacted their usage. In this review, various liquid drug delivery devices are presented, showcasing their capabilities and success in both preclinical and clinical settings. These innovative liquid delivery devices, capable of targeted delivery and their ability to be re-used for multiple treatment sites, may provide solutions for current unmet clinical needs.

In-stent Restenosis After Stenting for Superior Mesenteric Artery Dissection Is Associated With Stent Landing Zone: From Clinical Prediction to Hemodynamic Mechanisms

OBJECTIVE

To identify risk factors for in-stent restenosis (ISR) in patients undergoing stent placement for superior mesenteric artery dissection (SMAD) and to determine the hemodynamic mechanism underlying ISR.

METHODS

For this retrospective study, patients with SMAD who had ISR after stent placement were included in the ISR group, and age- and sex-matched patients with SMAD who did not experience ISR after stent placement were included in the control group. Clinical, imaging, and hemodynamic data were assessed. Multivariable regression was used to identify independent ISR risk factors. Structural and fluid dynamics simulations were applied to determine the hemodynamic mechanism underlying the occurrence of ISR.

RESULTS

The study population included 26 patients with ISR and 26 control patients. Multivariate analysis demonstrated that stent-to-vascular (S/V) ratio (odds ratio [OR], 1.14; 95% confidence interval [CI]: 1.00-1.29; p=0.045), stent proximal position >10 mm away from the SMA root (OR, 108.67; 95% CI: 3.09-3816.42; p=0.010), and high oscillatory shear index (OSI) area (OR, 1.25; 95% CI: 1.02-1.52; p=0.029) were predictors of ISR. In structural and fluid dynamics simulations, a stent proximal position near the abdominal aorta (AA) or entering into the AA reduced the contact area between the proximal struts of the stent and the vascular wall, and alleviated the distal lumen overdilation.

CONCLUSION

The S/V ratio, stent proximal position away from the SMA root (>10 mm), and high OSI area are independent risk factors for ISR in patients with SMAD undergoing stent placement. Deploying the proximal end of the stent near the AA or entering into the AA appears to improve the hemodynamic environment in the SMA lumen and ultimately reduce the risk of ISR.

CLINICAL IMPACT

In-stent restenosis is an uncommon but potentially catastrophic complication after stent placement for the management of superior mesenteric artery dissection. This study identified risk factors for in-stent restenosis and demonstrated that, as long as the stent can fully cover the dissection range, deploying the proximal end of the stent near the abdominal aorta or less entering into the abdominal aorta may reduce the risk of in-stent restenosis in this patient population.

Drug-Coated Balloon Angioplasty for Carotid Artery In-Stent Restenosis: Case Series

OBJECTIVES

Few case reports have demonstrated promising results of drug-coated balloons (DCBs) as an emerging management for carotid artery in-stent restenosis (CAISR). Herein, we report 6 cases of CAISR which were treated with a DCB with or without new stent deployment.

BACKGROUND

Carotid artery in-stent restenosis is a high-risk condition with an estimated incidence rate that varies widely from 6% to 40%. Several strategies are available now for the management of the CAISR including conventional balloon angioplasty, plaque modification balloon angioplasty, and new stent placement.

METHODS

A retrospective review of consecutive patients with a diagnosis of severe CAISR at Baylor Scott & White The Heart Hospital Plano from 2011 to 2021 was performed. This study was approved by the Baylor Scott & White Research Institute institutional review board.

RESULTS

Six patients underwent DCB angioplasty with or without stent placement under an embolic protection device. Resolution of CAISR was achieved in all cases with 0% to 10% residual stenosis in all cases. Following the procedure, 1 patient had a brief episode of syncope with balloon inflation with immediate recovery on deflation of the balloon. There were otherwise no significant neurological or cardiac events prior to discharge. All patients were asymptomatic at their follow-up visit with no neurological or cardiac events reported at 12, 24, and 36 months following the procedure.

CONCLUSION

While CAISR treatment remains a challenging condition, our study shows that the use of DCB with or without stent placement is a feasible and promising treatment option when compared with other conventional treatment options.

CLINICAL IMPACT

Carotid artery in-stent restenosis treatment remains a challenging condition. Our study shows that the use of drug coated balloon with or without stent placement is a feasible and promising treatment option when compared with current conventional treatment options.

Has collateral blood flow any effect on restenosis rate? Our experience

Objectives

Restenosis is one of the important factors affecting the effectiveness of percutaneous transluminal angioplasty and stenting in the treatment of intracranial atherosclerotic stenosis. We aimed to clarify whether recruitable collateral flow could cause restenosis in patients treated with percutaneous transluminal angioplasty and stenting.

Material and methods

Our study retrospectively analyzed patients with symptomatic severe intracranial atherosclerotic stenosis (≥70%) who underwent percutaneous transluminal angioplasty and stenting. We enrolled 28 patients with restenosis and 71 patients without restenosis. We analyzed baseline data, perioperative events, and follow-up results of patients in the two groups. Binary logistic regression analysis was used to identify restenosis predictors.

Results

For preoperative stroke, the restenosis group had a greater likelihood of having a previous stroke (89.3%), which was less prevalent in the non-restenosis group (66.2%) (P = 0.020). The restenosis group had a higher rate of re-stroke (21.4 vs. 4.2%, P = 0.022). After binary logistic regression analysis, collateral circulation and residual stenosis were independent risk factors of restenosis, with overall risk (95% confidence intervals) of 5.034 (1.484-4.066, P < 0.001) and 1.064 (1.006-1.125, P = 0.030), respectively. Restenosis risk increased 1.456-fold for each collateral circulation grade increase. However, for each 1% increase in residual stenosis, restenosis risk increased by 5.9% (P = 0.03). The chance of restenosis is minimal when the residual stenosis rate after percutaneous transluminal angioplasty and stent implantation is 15.85%.

Conclusions

Good collateral circulation was significantly associated with restenosis in patients undergoing intracranial angioplasty, the residual stenosis rate tends to be 15.85% to reduce restenosis risk. Compared to patients with restenosis, those without restenosis have a low stroke risk during follow-up.

Detection of Blood Clots Using a Whole Stent as an Active Implantable Biosensor

Many cardiovascular problems stem from blockages that form within the vasculature and often treatment includes fitting a stent through percutaneous coronary intervention. This offers a minimally invasive therapy but re-occlusion through restenosis or thrombosis formation often occurs post-deployment. Research is ongoing into the creation of smart stents that can detect the occurrence of further problems. In this study, it is shown that selectively metalizing a non-conductive stent can create a set of electrodes that are capable of detecting a build-up of material around the stent. The associated increase in electrical impedance across the electrodes is measured, testing the stent with blood clot to mimic thrombosis. It is shown that the device is capable of sensing different amounts of occlusion. The stent can reproducibly sense the presence of clot showing a 16% +/-3% increase in impedance which is sufficient to reliably detect the clot when surrounded by explanted aorta (one sample t-test, p = 0.009, n = 9). It is demonstrated that this approach can be extended beyond the 3D printed prototypes by showing that it can be applied to a commercially available stent and it is believed that it can be further utilized by other types of medical implants.

Nanocarrier Design for Dual-Targeted Therapy of In-Stent Restenosis

The injury-triggered reocclusion (restenosis) of arteries treated with angioplasty to relieve atherosclerotic obstruction remains a challenge due to limitations of existing therapies. A combination of magnetic guidance and affinity-mediated arterial binding can pave the way to a new approach for treating restenosis by enabling efficient site-specific localization of therapeutic agents formulated in magnetizable nanoparticles (MNPs) and by maintaining their presence at the site of arterial injury throughout the vulnerability period of the disease. In these studies, we investigated a dual-targeted antirestenotic strategy using drug-loaded biodegradable MNPs, surface-modified with a fibrin-avid peptide to provide affinity for the injured arterial wall. The MNPs were characterized with regard to their magnetic properties, efficiency of surface functionalization, disassembly kinetics, and interaction with fibrin-coated substrates. The antiproliferative effects of MNPs formulated with paclitaxel were studied in vitro using a fetal cell line (A10) exhibiting the defining characteristics of neointimal smooth muscle cells. Animal studies examined the efficiency of combined (physical/affinity) MNP targeting to stented arteries in Sprague Dawley rats using fluorimetric analysis and fluorescent in vivo imaging. The antirestenotic effect of the dual-targeted therapy was determined in a rat model of in-stent restenosis 28 days post-treatment. The results showed that MNPs can be efficiently functionalized to exhibit a strong binding affinity using a simple two-step chemical process, without adversely affecting their size distribution, magnetic properties, or antiproliferative potency. Dual-targeted delivery strongly enhanced the localization and retention of MNPs in stented carotid arteries up to 7 days post-treatment, while minimizing redistribution of the carrier particles to peripheral tissues. Of the two targeting elements, the effect of magnetic guidance was shown to dominate arterial localization (p = 0.004 vs. 0.084 for magnetic targeting and peptide modification, respectively), consistent with the magnetically driven MNP accumulation step defining the extent of the ultimate affinity-mediated arterial binding and subsequent retention of the carrier particles. The enhanced arterial uptake and sustained presence of paclitaxel-loaded MNPs at the site of stent deployment were associated with a strong inhibition of restenosis in the rat carotid stenting model, with both the neointima-to-media ratio (N/M) and % stenosis markedly reduced in the dual-targeted treatment group (1.62 ± 0.2 and 21 ± 3 vs. 2.17 ± 0.40 and 29 ± 6 in the control animals; p < 0.05). We conclude that the dual-targeted delivery of antirestenotic agents formulated in fibrin-avid MNPs can provide a new platform for the safe and effective treatment of in-stent restenosis.

Self-expanding versus balloon expandable stent for intracranial arterial stenosis: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

There are limited data regarding the comparison of balloon expandable stents (BES) and self-expanding stents (SES) for the treatment of intracranial arterial stenosis.

METHODS

We conducted a systematic review to identify studies that compared SES and BES in patients with symptomatic intracranial arterial stenosis. Data were extracted from relevant studies found through a search of PubMed, Scopus, and Web of Science until from January 1, 2010 to September 28, 2023. Statistical pooling with random-effects meta-analysis was undertaken to compare the rates/severity of postprocedure stenosis, technical success, 30-day stroke and/or death, cumulative clinical endpoints, and restenosis rates.

RESULTS

A total of 20 studies were included. The standardized mean difference (SMD) for postprocedure stenosis (%) was significantly lower (SMD: -0.52, 95% confidence interval [CI]: -0.79 to -0.24, p < .001, 10 studies involving 1515 patients) with BES. The odds for 30-day stroke and/or death were significantly lower (odds ratio [OR] 0.68, 95% CI: 0.50-0.94, p = .019, 15 studies involving 2431 patients), and cumulative clinical endpoints on follow-up were nonsignificantly lower (OR 0.64, 95% CI: 0.30-1.37, p = .250, 10 studies involving 947 patients) with BES. The odds for restenosis during follow-up were significantly lower (OR 0.50, 95% CI: 0.31-0.80, p = .004, 13 studies involving 1115 patients) with BES.

CONCLUSIONS

Compared with SES, BES were associated with lower rates of postprocedure 30-day stroke and/or death with lower rates of restenosis during follow up and the treatment of symptomatic intracranial arterial stenosis.

Identification of important genes related to HVSMC proliferation and migration in graft restenosis based on WGCNA

The great saphenous vein is the most commonly used vessel for coronary artery bypass grafting (CABG), but its use has been associated with a high restenosis rate at 10-year follow-up. This study sought to determine the key genes associated with vein graft restenosis that could serve as novel therapeutic targets. A total of 3075 upregulated and 1404 downregulated genes were identified after transcriptome sequencing of three pairs of restenosed vein grafts and intraoperative spare great saphenous veins. Weighted gene co-expression network analysis showed that the floralwhite module had the highest correlation with vein graft restenosis. The intersection of the floralwhite module gene set and the upregulated gene set contained 615 upregulated genes strongly correlated with vein graft restenosis. Protein-protein interaction network analysis identified six hub genes (ITGAM, PTPRC, TLR4, TYROBP, ITGB2 and CD4), which were obtained using the STRING database and CytoHubba. Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses showed that the common hub genes were mainly involved in the composition of the cell membrane; in biological processes such as neutrophil degranulation, receptor binding and intercellular adhesion, innate immune deficiency; and other signaling pathways. Finally, ITGB2 was selected as the target gene, and its expression was verified in tissues. The results showed that ITGB2 was significantly overexpressed in occluded vein grafts. To study the function of ITGB2 in HVSMCs, primary HVSMCs were cultured and successfully identified. EdU incorporation, wound healing and transwell assays showed that ITGB2 silencing significantly inhibited the proliferation and migration of HVSMCs stimulated by PDGF-BB. Overall, our study provides a basis for future studies on preventing restenosis following CABG.

SGLT2 inhibitor improves the prognosis of patients with coronary heart disease and prevents in-stent restenosis

Coronary heart disease is a narrowing or obstruction of the vascular cavity caused by atherosclerosis of the coronary arteries, which leads to myocardial ischemia and hypoxia. At present, percutaneous coronary intervention (PCI) is an effective treatment for coronary atherosclerotic heart disease. Restenosis is the main limiting factor of the long-term success of PCI, and it is also a difficult problem in the field of intervention. Sodium-glucose cotransporter 2 (SGLT2) inhibitor is a new oral glucose-lowering agent used in the treatment of diabetes in recent years. Recent studies have shown that SGLT2 inhibitors can effectively improve the prognosis of patients after PCI and reduce the occurrence of restenosis. This review provides an overview of the clinical studies and mechanisms of SGLT2 inhibitors in the prevention of restenosis, providing a new option for improving the clinical prognosis of patients after PCI.

Comparative efficacy of different Chinese patent medicines in preventing restenosis after percutaneous coronary intervention: a systematic review and Bayesian network meta-analysis of randomized clinical trials

Background: Chinese patent medicines (CMPs) have curative effectiveness in preventing coronary restenosis. However, the relative efficacy between different CPMs has not been sufficiently investigated. Methods: Randomized clinical trials were searched from electronic databases including PubMed, Web of Science, Cochrane Library, Embase, CNKI, VIP, WanFang, SinoMed, Chinese Clinical Trial Registry, and ClinicalTrials.gov. Bayesian network meta-analysis was performed to analyze CPMs' efficacy in preventing angiographic restenosis, recurrence angina, acute myocardial infarction, and target lesion revascularization after percutaneous coronary intervention. Results: This network meta-analysis included 47 trials with 5,077 patients evaluating 11 interventions. Regarding angiographic restenosis, the efficacy of CPMs (except Xuezhikang capsule) combined with standard treatment (Std) was superior to Std alone, and Guanxin Shutong capsule plus Std reduced the risk of angiographic restenosis by 76% (relative risk 0.24, 95% confidence interval 0.11-0.45, and very low to moderate certainty of evidence), most likely the best intervention. Fufang Danshen dripping pill combined with Std showed superiority over other interventions for relieving recurrence angina, which can reduce the risk by 83% (RR 0.17, 95% CI 0.04-0.51, very low to moderate certainty of evidence) compared to Std alone. In acute myocardial infarction after percutaneous coronary intervention, compared with Std alone, Danhong injection plus Std displayed a significant effect (RR 0.11, 95% CI 0.00-0.69, very low to moderate certainty of evidence) and was the best treatment probably. Chuanxiongqin tablet plus Std was the most effective treatment for reducing target lesion revascularization by 90% (RR 0.10, 95% CI 0.00-0.60, very low to moderate certainty of evidence) compared with Std alone. Conclusion: The results indicated that CPMs combined with Std reduced the risk of coronary restenosis after percutaneous coronary intervention. However, the results should be interpreted cautiously due to significant data limitations.

Resveratrol Inhibits Restenosis through Suppressing Proliferation, Migration and Trans-differentiation of Vascular Adventitia Fibroblasts via Activating SIRT1

AIM

After the balloon angioplasty, vascular adventitia fibroblasts (VAFs), which proliferate, trans-differentiate to myofibroblasts and migrate to neointima, are crucial in restenosis. Resveratrol (RSV) has been reported to protect the cardiovascular by reducing restenosis and the mechanism remains unclear.

METHODS

This study was dedicated to investigate the effect of RSV on VAFs in injured arteries and explore the potential mechanism. In this work, carotid artery balloon angioplasty was performed on male SD rats to ensure the injury of intima and VAFs were isolated to explore the effects in vitro. The functional and morphological results showed the peripheral delivery of RSV decreased restenosis of the injured arteries and suppressed the expression of proliferation, migration and transformation related genes. Moreover, after being treated with RSV, the proliferation, migration and trans-differentiation of VAFs were significantly suppressed and exogenous TGF-β1 can reverse this effect.

RESULT

Mechanistically, RSV administration activated SIRT1 and decreased the translation and expression of TGF-β1, SMAD3 and NOX4, and reactive oxygen species (ROS) decreased significantly after VAFs treated with RSV.

CONCLUSION

Above results indicated RSV inhibited restenosis after balloon angioplasty through suppressing proliferation, migration and trans-differentiation of VAFs via regulating SIRT1- TGF-β1-SMAD3-NOX4 to decrease ROS.

Implantable Self-Reporting Stents for Detecting In-Stent Restenosis and Cardiac Functional Dynamics

Despite the increasing number of stents implanted each year worldwide, patients remain at high risk for developing in-stent restenosis. Various self-reporting stents have been developed to address this challenge, but their practical utility has been limited by low sensitivity and limited data collection. Herein, we propose a next-generation self-reporting stent that can monitor blood pressure and blood flow inside the blood arteries. This proposed self-reporting stent utilizes a larger inductor coil encapsulated on the entire surface of the stent strut, resulting in a 2-fold increase in the sensing resolution and coupling distance between the sensor and external antenna. The dual-pressure sensors enable the detection of blood flow in situ. The feasibility of the proposed self-reporting stent is successfully demonstrated through in vivo analysis in rats, verifying its biocompatibility and multifunctional utilities. This multifunctional self-reporting stent has the potential to greatly improve cardiovascular care by providing real-time monitoring and unprecedented insight into the functional dynamics of the heart.

Three-dimensional optical coherence tomography to decide on reverse wire technique in bifurcation interventions

A 79-year-old male with effort angina was admitted to receive optical coherence tomography (OCT)-guided percutaneous coronary intervention for restenosis of an everolimus-eluting stent implanted to the left anterior descending artery (LAD) eight years ago.

Resolute onyx stent more effective than wingspan stent at preventing procedural complications and long-term restenosis

BACKGROUND AND PURPOSE

Angioplasty and stenting is a treatment option for patients with medically refractory symptomatic intracranial atherosclerotic disease (sICAD). Currently the Wingspan Stent System (WSS) is the only FDA approved device for this indication. We find the Resolute (R) Onyx Stent, a drug-eluting balloon mounted stent (DES), a better alternative to the WSS for treatment of sICAD. Herein, we present our findings comparing the two stents based on our single center experience.

METHODS

A prospectively maintained neuro-endovascular databased was queried for patients between January 2013 to June 2021. Inclusion criteria for patients included sICAD with failed medical management, and intracranial stenting with either R-Onyx DES or WSS, including patients treated within 7 days of their last stroke. Primary outcomes were assessed via the occurrence of ischemic or hemorrhagic stroke or death within 72 h of the procedure. Secondary outcomes consisted of recurrent stroke or significant in-stent restenosis evaluated by a clinical or angiographic follow-up at 6 months.

RESULTS

A total of 184 patients, average age 61.26 (SD = 12.53) (44% women), were eligible for analysis with 58 having R-onyx DES and 126 having WSS. Within 72 h, the primary outcome was observed in 1.7% (n = 1) of patients in the R-onyx DES group and 6.3% (n = 8) of patients in the WSS group (p = 0.089). Among 41 angiographic and clinical follow-ups in the R-onyx DES group, none had a recurrent stroke, while among 101 patients who had follow-up in the WSS group, 8.9% (n = 9) had a stroke (p = 0.024). At a 6-month angiographic follow-up, there was a significantly lower rate of symptomatic in-stent restenosis among the R-onyx DES group with 1.7% (n = 1) compared with 21.4% (n = 27) in the WSS group (p = 0.0003).

CONCLUSION

R-onyx DES is more effective than WSS in treating sICAD with low rates of periprocedural complications and long-term strokes and symptomatic in-stent restenosis. Future prospective randomized multicenter trials are needed.

Drug-Coated Balloon Angioplasty for Thoracic Great Vessel Stenosis Due to Takayasu Arteritis With 1-Year Follow-up

PURPOSE

Takayasu arteritis is a large-vessel vasculitis in women of childbearing age that affects large vessels including the aorta and its main branches. Inflammation of arteries can produce lesions that lead to occlusion, stenosis, or aneurysms which can lead to complications. If signs of organ dysfunction are present, vascular intervention may be necessary.

CASE REPORT

In this article, we present a case of Takayasu arteritis with high-grade stenosis of all the great vessels of the thoracic aorta treated with drug-coated balloon (DCB) angioplasty and stenting requiring multiple follow-up interventions over a 1-year follow-up.

CONCLUSION

The DCB angioplasty is a potential endovascular treatment for thoracic great artery stenosis in Takayasu arteritis that could be further explored.

Effect of High-Dose Drug-Coated Balloon Repetition After Drug-Coated Balloon Failure

PURPOSE

Although the optimal treatment for femoropopliteal (FP) drug-coated balloon (DCB) restenosis lesions remains debatable, the effectiveness of DCB repetition for DCB restenosis has been reported. However, the optimal DCB repetition strategy is not yet established. Thus, this study aimed to compare the clinical outcomes of high-dose DCB repetition with those of low-dose DCB repetition for FP DCB restenosis lesions.

MATERIALS AND METHODS

This single-center, observational study used a clinical database of 677 consecutive patients undergoing FP endovascular intervention for symptomatic peripheral artery disease between December 2018 and December 2021. Of these patients, 89 cases treated with DCB repetition for FP DCB restenosis lesions were analyzed. The primary endpoint was recurrent restenosis (re-restenosis) and the secondary endpoints were recurrent target-lesion revascularization (TLR), re-occlusion, and major adverse limb events (MALE) obtained using propensity score matching. Interaction analysis was also performed to explore the effects of the baseline characteristics on the association between high- and low-dose DCB with restenosis risk.

RESULTS

After propensity score matching, high-dose DCB demonstrated a significantly higher freedom from re-restenosis compared with low-dose DCB repetition at 1 year (90.4% vs 40.9%, p=0.034). In addition, freedom from re-TLR and MALE at 1 year was significantly higher in the high-dose DCB group (95.0% vs 53.3%, p=0.025; 95.0% vs 54.7%, p=0.025, respectively). Conversely, freedom rates from re-occlusion were not significantly different between the 2 groups (100.0% vs 84.0%, p=0.99). No baseline characteristics or perioperative outcomes had any significant interaction effect on the association of high-dose DCB versus low-dose DCB with restenosis risk.

CONCLUSION

For FP DCB restenosis lesions, high-dose DCB repetition offered more favorable outcomes than low-dose DCB repetition.

CLINICAL IMPACT

This study revealed that for femoropopliteal drug-coated balloon (DCB) restenosis lesions, high-dose DCB repetition obtained more favorable outcomes than low-dose DCB repetition. In addition, there was no significant interaction effect on the association of high- versus low-dose DCB with re-restenosis risk for the baseline characteristics and perioperative outcomes. This finding might be also a reason for choosing high-dose DCB repetition for FP DCB restenosis lesions in daily clinical practice.

Chitosan-salvianolic acid B coating on the surface of nickel-titanium alloy inhibits proliferation of smooth muscle cells and promote endothelialization

Introduction: Intracranial stents are of paramount importance in managing cerebrovascular disorders. Nevertheless, the currently employed drug-eluting stents, although effective in decreasing in-stent restenosis, might impede the re-endothelialization process within blood vessels, potentially leading to prolonged thrombosis development and restenosis over time. Methods: This study aims to construct a multifunctional bioactive coating to enhance the biocompatibility of the stents. Salvianolic acid B (SALB), a bioactive compound extracted from Salvia miltiorrhiza, exhibits potential for improving cardiovascular health. We utilized dopamine as the base and adhered chitosan-coated SALB microspheres onto nickel-titanium alloy flat plates, resulting in a multifunctional drug coating. Results: By encapsulating SALB within chitosan, the release period of SALB was effectively prolonged, as evidenced by the in vitro drug release curve showing sustained release over 28 days. The interaction between the drug coating and blood was examined through experiments on water contact angle, clotting time, and protein adsorption. Cellular experiments showed that the drug coating stimulates the proliferation, adhesion, and migration of human umbilical vein endothelial cells. Discussion: These findings indicate its potential to promote re-endothelialization. In addition, the bioactive coating effectively suppressed smooth muscle cells proliferation, adhesion, and migration, potentially reducing the occurrence of neointimal hyperplasia and restenosis. These findings emphasize the exceptional biocompatibility of the newly developed bioactive coating and demonstrate its potential clinical application as an innovative strategy to improve stent therapy efficacy. Thus, this coating holds great promise for the treatment of cerebrovascular disease.

Increased prescription dose for large vessel intravascular brachytherapy

BACKGROUND

Most randomized studies testing the effectiveness of IVBT were limited to vessels less than 4 mm diameter. In fact, it is now common to treat vessels larger than 4 mm. Accordingly, the authors instituted a prescription dose increase to 34 Gy at 2 mm from source center for vessels greater than 4.0 mm. The increase in prescription dose to 34 Gy at 2 mm from center is substantial, being 50% higher than the conventional maximum of 23 Gy.

AIM

To take a close look at group of patients treated to 34 Gy, and for whom follow-up angiograms are available.

METHODS

Ten patients treated for ISR with a prescription dose of 34 Gy and for whom follow-up angiograms were available were studied. Beta-radiation brachytherapy was performed with a Novoste Beta-Cath System using a strontium-90 (beta) source (Best Vascular, Springfield, VA). Source lengths of 40 or 60 mm were used. A dose of 34 Gy was prescribed at 2 mm from the source center.

RESULTS

Patients were re-catheterized from 2 to 21 months (median: 16 months) following IVBT, all for symptoms suggested of restenosis. All patients had some degree of ISR of the target vessel, but no IVBT-treated vascular segment showed angiographic signs of degeneration, dissection or aneurysm.

CONCLUSION

The authors' clinical impression, along with detailed review of the 10 cases, suggest that using a 34 Gy prescription dose at 2 mm from source center does not result in increased toxicity.

T-Remodeling of the Pulmonary Artery Bifurcation for Pulmonary Artery Origin Stenosis

BACKGROUND

Various surgical techniques are utilized for reconstructing hypoplastic pulmonary arteries (PAs) in patients with conotruncal anomalies and at times, may be susceptible to restenosis and reoperation. We reviewed our experience with a simple technique of T-shaped remodeling of the PA bifurcation.

METHODS

Between 2005 and 2019, 31 patients underwent T-remodeling of central PAs by a single cardiac surgeon. The PA bifurcation was opened cranially, and the opening was augmented with an oval-shaped patch effectively transforming the V-shaped bifurcation into a T-shaped bifurcation. Both origins of the PAs were enlarged, even in the instance of single PA origin stenosis.

RESULTS

Median age at time of T-remodeling was 17 months (range: 7 weeks to 14 years). The following cardiac morphologies were observed: tetralogy of Fallot (n = 12, 39%), pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (n = 8, 26%), truncus arteriosus (n = 6, 19%), pulmonary atresia with VSD (n = 3, 9.7%), and transposition of the great arteries (n = 2, 6.5%). Thirteen patients (42%) had previous central shunt, and eight patients (26%) had previous modified Blalock-Taussig shunt. There were no operative mortalities. Immediately after T-remodeling, echocardiographic estimates of right ventricle to PA gradient decreased from 42 [interquartile range 28-58] mm Hg to 20 [12-36] mm Hg (P = .03). Freedom from reoperation on the PA bifurcation for the entire cohort was 100% at one year, 88% (95% CI 68%-96%) at five years and 82% (57%-93%) at ten years.

CONCLUSIONS

T-remodeling for PA origin stenosis is a safe procedure with excellent freedom from reoperation that is easily reproducible and applicable to patients with all cardiac morphologies.

Apelin is expressed in intimal smooth muscle cells and promotes their phenotypic transition

During atherosclerotic plaque formation, smooth muscle cells (SMCs) switch from a contractile/differentiated to a synthetic/dedifferentiated phenotype. We previously isolated differentiated spindle-shaped (S) and dedifferentiated rhomboid (R) SMCs from porcine coronary artery. R-SMCs express S100A4, a calcium-binding protein. We investigated the role of apelin in this phenotypic conversion, as well as its relationship with S100A4. We found that apelin was highly expressed in R-SMCs compared with S-SMCs. We observed a nuclear expression of apelin in SMCs within experimentally-induced intimal thickening of the porcine coronary artery and rat aorta. Plasmids targeting apelin to the nucleus (N. Ap) and to the secretory vesicles (S. Ap) were transfected into S-SMCs where apelin was barely detectable. Both plasmids induced the SMC transition towards a R-phenotype. Overexpression of N. Ap, and to a lesser degree S. Ap, led to a nuclear localization of S100A4. Stimulation of S-SMCs with platelet-derived growth factor-BB, known to induce the transition toward the R-phenotype, yielded the direct interaction and nuclear expression of both apelin and S100A4. In conclusion, apelin induces a SMC phenotypic transition towards the synthetic phenotype. These results suggest that apelin acts via nuclear re-localization of S100A4, raising the possibility of a new pro-atherogenic relationship between apelin and S100A4.

[Transcriptome sequencing for identification of the genes associated with restenosis of venous grafts in rabbits]

OBJECTIVE

To identify the genes associated with venous graft restenosis in rabbits using transcriptome sequencing.

METHODS

Forty New Zealand rabbits were randomly divided into experimental group and control group, and in the experimental group, the left external jugular veins of the rabbits were engrafted to the left common carotid artery with continuous running suture; the rabbits in the control group received no operation. At 2 and 4 weeks after the operation, 10 rabbits from each group were euthanized and the venous grafts (in experimental group) or left external jugular vein (in control group) were harvested for measurement of the intima-media thickness using HE staining. RNA high-throughput sequencing (RNA-seq) was performed to identify the differentially expressed genes (DEGs) between the venous grafts and the control veins, and the biological functions of the DEGs were analyzed using GO and KEEG databases.

RESULTS

In the experimental group, intima-media thickening with increased extracellular matrix and vascular smooth muscle cell proliferation occurred in the venous grafts at 2 weeks and aggravated at 4 weeks after the operation. RNA high-throughput sequencing identified 1583 up-regulated genes and 608 down-regulated genes in the venous grafts in the experimental group, and GO and KEGG analysis of the DEGs pinpointed 10 hub genes, namely CD4, ZAP70, SYK, CD28, PIK3CD, CXCR4, CCR5, ITK, CCL5 and BTK.

CONCLUSION

CD4, ZAP70, SYK, CD28, PIK3CD, CXCR4, CCR5, ITK, CCL5 and BTK are probably the key genes associated with vein graft restenosis in rabbits.

Effect of down-regulation of let-7c/g on triggering a double-negative feedback loop and promoting restenosis

BACKGROUND

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) are the main causes of restenosis (RS) in diabetic lower extremity arterial disease (LEAD). However, the relevant pathogenic mechanisms are poorly understood.

METHODS

In this study, we introduced a "two-step injury protocol" rat RS model, which started with the induction of atherosclerosis (AS) and was followed by percutaneous transluminal angioplasty (PTA). Hematoxylin-eosin (HE) staining and immunohistochemistry staining were used to verify the form of RS. Two-step transfection was performed, with the first transfection of Lin28a followed by a second transfection of let-7c and let-7g, to explore the possible mechanism by which Lin28a exerted effects. 5-ethynyl-2΄-deoxyuridine (EdU) and Transwell assay were performed to evaluate the ability of proliferation and migration of VSMCs. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect the expression of Lin28a protein and let-7 family members.

RESULTS

Using a combination of in vitro and in vivo experiments, we discovered that let-7c, let-7g, and microRNA98 (miR98) were downstream targets of Lin28a. More importantly, decreased expression of let-7c/let-7g increased Lin28a, leading to further inhibition of let-7c/let-7g. We also found an increased level of let-7d in the RS pathological condition, suggesting that it may function as a protective regulator of the Lin28a/let-7 loop by inhibiting the proliferation and migration of VSMCs.

CONCLUSION

These findings indicated the presence of a double-negative feedback loop consisting of Lin28a and let-7c/let-7g, which may be responsible for the vicious behavior of VSMCs in RS.

Anemia as a risk factor for restenosis in femoropopliteal arterial disease after drug-coated balloon angioplasty

OBJECTIVE

This study aimed to investigate the relationship between anemia and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty.

METHODS

194 patients treated with DCB for femoropopliteal lesions were retrospectively analyzed for up to 12 months of follow-up between January 2017 and September 2020. Baseline clinical and procedural characteristics were compared between the anemia and non-anemia patients, and predictors of restenosis were identified using logistic regression.

RESULTS

32.5% of the patients undergoing DCB angioplasty had anemia. Patients with anemia were significantly older, with higher rates of hypertension, coronary artery disease, chronic renal insufficiency, and diabetes, and with lower rates of smoking and male gender. In the multivariate analysis, anemia was independently and significantly associated with a higher risk of restenosis (OR, 3.872; 95% CI, 1.556-9.638; P = 0.004).

CONCLUSION

Anemia is independently associated with restenosis in patients treated with DCB for femoropopliteal arterial disease. Patients with lower baseline hemoglobin might have more chances to develop restenosis at follow-up.

Impact of postprocedural minimum lumen area on clinical outcome after femoropopliteal drug-eluting stent implantation

INTRODUCTION

Although favorable results of fluoropolymer-based drug-eluting stent (FP-DES) treatment for femoropopliteal lesions have been reported, it is unclear whether minimal lumen area (MLA) after FP-DES implantation affects clinical outcomes. This study aimed to reveal the association between intravascular ultrasound (IVUS)-evaluated MLA and the 1-year risk of restenosis and aneurysmal degeneration after FP-DES implantation for femoropopliteal lesions.

METHODS

A subanalysis of the CAPSICUM (Contemporary outcomes After Paclitaxel-eluting peripheral Stent implantation for symptomatic lower limb IsChemia with sUperficial feMoral or proximal popliteal lesion) study analyzed 718 limbs in 686 patients with available IVUS-evaluated MLA data. The association of MLA with the 1-year risk of restenosis and aneurysmal degeneration was analyzed using the generalized propensity score method.

RESULTS

The 1-year incidence rate of restenosis was estimated to be 8.8% (95% CI, 6.1% to 12.5%) for the upper quartile of MLA (21.1 mm2) versus 14.3% (95% CI, 10.7% to 18.7%) for the lower quartile of MLA (15.2 mm2), with an odds ratio of 0.58 (95% CI, 0.36 to 0.93; p = 0.024), whereas the 1-year incidence rate of aneurysmal degeneration was 23.8% (95% CI, 19.5% to 28.8%) for the upper quartile versus 16.8% (95% CI, 12.6% to 22.0%) for the lower quartile, with an odds ratio of 1.55 (95% CI, 1.04 to 2.32; p = 0.031).

CONCLUSION

A large MLA after FP-DES implantation for femoropopliteal lesions was associated with decreased restenosis risk but increased aneurysmal degeneration risk. These findings suggest that MLA is a valuable predictor of clinical outcomes.

Foraminal Restenosis After Posterior Cervical Foraminotomy for the Treatment of Cervical Radiculopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To elucidate incidence, risk factor, and clinical effect of bone regrowth after posterior cervical foraminotomy (PCF).

METHODS

Ninety-eight patients who underwent PCF for the treatment of cervical radiculopathy and were followed up for >2 years were retrospectively reviewed. Foraminal dimension, sagittal gap at resected area, facet thickness, lamina length, and cervical range of motion (ROM) were measured. Neck pain visual analogue scale (VAS), arm pain VAS, and neck disability index (NDI) were recorded. Radiographic measures were compared between segments with foraminal narrowing of ≥20% at the 2-years follow-up (restenosis segments) and foraminal narrowing of <20% (patent segments).

RESULTS

Sixty-nine patients with 109 segments were included. 73.4% (80/109) of foramens demonstrated foraminal narrowing and decrease of foraminal dimension of ≥20% occurred in 30.3% (30/109). Foraminal dimension at postoperative 2-days was significantly higher in the restenosis segments (P = .047). Furthermore, increase of foraminal dimension was significantly associated with foraminal restenosis of ≥20% (P = .018). Facet thickness was significantly higher in the restenosis segments compared to patent segments at postoperative 2-years follow-up (P = .038). Neck pain VAS was significantly aggravated only in the restenosis group at postoperative 2-years follow-up (P < .001).

CONCLUSIONS

Foraminal narrowing commonly occurs after PCF due to bone healing. Bone growth occurs in all directions while medial facet growth contributes more to foraminal restenosis. Greater widening of foramen during PCF is a risk factor for postoperative foramen restenosis. Therefore, amount of bone resection should be kept optimal and excessive resection should be avoided to prevent foramen restenosis.

A randomized control trial to assess optical coherence tomography parameters of the Xlimus drug-eluting stent: the XLIMIT trial

Background

Third generation drug-eluting stents (DES) potentially offer better technical performance and reduced neointimal proliferation than previous generation DES. The XLIMIT non-inferiority trial evaluated the performance of the Xlimus (a novel sirolimus-eluting coronary stent system) in terms of endothelialization and tissue healing compared to the bioresorbable polymer Synergy DES.

Methods

A total of 177 patients undergoing percutaneous coronary intervention (PCI) were randomized in a 2:1 ratio (2 Xlimus: 1 Synergy). The primary endpoints, defined as the in-stent neointimal volume weighted by the sum of the lengths of the implanted stent (ISNV) and the in-stent neointimal percent volume obstruction (%VO) were evaluated at 6-9 months by means of optical coherence tomography (OCT). Additional OCT parameters as well as clinical endpoints were also collected.

Results

Most of the patients were males (77.4%), and the mean age was 64 years. One third of the population had stable angina/silent ischemia. A total of 300 stents (237 lesions) were analyzed: 198 (152 lesions) were in the Xlimus group, and 102 (85 lesions) in the Synergy group. The ISNV in the Xlimus group was 30.7 ± 24.5 mm3 while in the Synergy group it was 26.5 ± 26.7 mm3: the difference between the two means was 0.08 (-0, 04-0, 45), p = 0.018, thus meeting the non-inferiority hypothesis. The %VO was 16.3% ± 10.4% and 13.3% ± 10.8% in the Xlimus and Synergy groups, respectively: the difference between the two means was 3.0 (-0, 06-4, 2), (p = 0.01), thus meeting the non-inferiority hypothesis. No difference was found with respect to the secondary OCT endpoints as well as for clinical endpoints.

Conclusions

The study results confirm that the biological interaction of the Xlimus and Synergy DES with the coronary artery is comparable, and that translates in very reassuring OCT parameters at follow-up: as such, the Xlimus is non-inferior to the Synergy.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT03745053).

Cathepsin S inhibition in dendritic cells prevents Th17 cell differentiation in perivascular adipose tissues following vascular injury in diabetic rats

In the context of diabetes mellitus (DM), the circulating cathepsin S (CTSS) level is significantly higher in the cardiovascular disease group. Therefore, this study was designed to investigate the role of CTSS in restenosis following carotid injury in diabetic rats. To induce DM, 60 mg/kg of streptozotocin (STZ) in citrate buffer was injected intraperitoneally into Sprague-Dawley rats. After successful modeling of DM, wire injury of the rat carotid artery was performed, followed by adenovirus transduction. Levels of blood glucose and Th17 cell surface antigens including ROR-γt, IL-17A, IL-17F, IL-22, and IL-23 in perivascular adipose tissues (PVAT) were evaluated. For in vitro analysis, human dendritic cells (DCs) were treated with 5.6-25 mM glucose for 24 h. The morphology of DCs was observed using an optical microscope. CD4+ T cells derived from human peripheral blood mononuclear cells were cocultured with DCs for 5 days. Levels of IL-6, CTSS, ROR-γt, IL-17A, IL-17F, IL-22 and IL-23 were measured. Flow cytometry was conducted to detect DC surface biomarkers (CD1a, CD83, and CD86) and Th17 cell differentiation. The collected DCs presented a treelike shape and were positive for CD1a, CD83, and CD86. Glucose impaired DC viability at the dose of 35 mM. Glucose treatment led to an increase in CTSS and IL-6 expression in DCs. Glucose-treated DCs promoted the differentiation of Th17 cells. CTSS depletion downregulated IL-6 expression and inhibited Th17 cell differentiation in vitro and in vivo. CTSS inhibition in DCs inhibits Th17 cell differentiation in PVAT tissues from diabetic rats following vascular injury.

Endovascular treatment of re-stenotic iliac artery stents with drug-eluting balloons

AIM

To evaluate the results of revascularization of stenotic iliac stents using drug-eluting balloons (DEBs).

MATERIAL AND METHODS

Seventy-four patients with various levels of iliac stent restenosis were enrolled to study. All restenotic stents were treated using paclitaxel-coated balloons.

RESULTS

Through a follow-up median period of 24 months (4-24 months), there were no in-stent re-restenosis in 55 patients (74.3%) and there was one in class 1 (1.4%), four in class 2 (5.4%), and fourteen in class 3 (18.9%).

CONCLUSION

We conclude that; DEBs can be used for restenotic iliac artery stents for some Type C and D lesions, in addition to Types A and B with satisfacting results.

Factors Associated With Early and Late Restenosis Following Drug-Coated Balloon Treatment for Patients With Femoropopliteal Lesions

PURPOSE

Clinical trials have demonstrated the superiority of drug-coated balloon (DCB) to noncoated balloon angioplasty for the treatment of femoropopliteal (FP) lesions. In those trials, the difference of primary patency between DCB and noncoated angioplasty widens especially after 6 months, speculating that the antirestenosis effect of paclitaxel is manifested after 6 months. Factors associated with restenosis after 6 months differ from those associated with restenosis within 6 months. This study aimed to elucidate the prognostic factors associated with early (within 6 months) and late (after 6 months) restenosis following DCB treatment in real-world FP practice.

MATERIALS AND METHODS

This multicenter, retrospective study analyzed 486 FP lesions (mean lesion length, 11.9±10.1 cm; chronic total occlusion, 21.0%) in 423 patients (diabetes mellitus, 59.3%; hemodialysis, 37.1%; chronic limb-threatening ischemia, 41.6%) who underwent successful DCB treatment between January 2018 and December 2019. The outcome measure was restenosis which is defined as a peak systolic velocity ratio >2.4 based on duplex ultrasound findings. Early and late restenosis were classified by the cutoff period of 6 months after the procedure. The associations of baseline and procedural characteristics with early and late restenosis were explored using Cox proportional hazards regression analysis.

RESULTS

The mean follow-up period was 25.3±12.1 months. The 6, 12, 18, and 24 month cumulative incidences of restenosis were 7.4%±2.4%, 20.9%±3.9%, 29.9%±4.5%, and 38.4%±5.1%, respectively. During the follow-up period, early and late restenosis was evident in a total of 31 lesions and 138 lesions, respectively. Multivariate analysis revealed that chronic total occlusion (hazard ratio [HR], 2.29; 95% confidence interval [CI], 1.07-4.92; p=0.033) and superficial femoral artery ostial lesion (HR, 2.73; 95% CI, 1.28-5.80; p=0.009) were significantly associated with early restenosis. On the other hand, calcification circumference over 270° (HR, 1.67; 95% CI, 1.17-2.37; p=0.004), distal external elastic membrane diameter under 5 mm assessed by intravascular ultrasound (HR, 1.90; 95% CI, 1.29-2.79; p=0.001), and involving popliteal arterial lesion (HR, 1.54; 95% CI, 1.08-2.21; p=0.017) were significantly associated with late restenosis.

CONCLUSION

The prognostic factors associated with late restenosis differed from those associated with early restenosis in the real-world FP-DCB practice.

CLINICAL IMPACT

The current multicenter, retrospective study revealed that factors associated with early restenosis differed from those with late restenosis in the real-world FP-DCB practice. CTO and SFA ostial lesion were associated with early restenosis, while severe calcification, smaller vessel, and involving popliteal arterial lesions were associated with late restenosis.Early restenosis indicates "balloon failure" and would potentially result from recoil, which primary stent implantation might be required. On the other hand, late restenosis after 6 months would be attributed to "DCB failure", with inadequate drug uptake into the arterial wall, which might be minimized by the use of atherectomy devices.

Mast cell activation and degranulation in acute artery injury: A target for post-operative therapy

The increasing incidence of cardiovascular disease (CVD) has led to a significant ongoing need to address this surgically through coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI). From this, there continues to be a substantial burden of mortality and morbidity due to complications arising from endothelial damage, resulting in restenosis. Whilst mast cells (MC) have been shown to have a causative role in atherosclerosis and other vascular diseases, including restenosis due to vein engraftment; here, we demonstrate their rapid response to arterial wire injury, recapitulating the endothelial damage seen in PCI procedures. Using wild-type mice, we demonstrate accumulation of MC in the femoral artery post-acute wire injury, with rapid activation and degranulation, resulting in neointimal hyperplasia, which was not observed in MC-deficient Kit^W-sh/W-sh mice. Furthermore, neutrophils, macrophages, and T cells were abundant in the wild-type mice area of injury but reduced in the Kit^W-sh/W-sh mice. Following bone-marrow-derived MC (BMMC) transplantation into Kit^W-sh/W-sh mice, not only was the neointimal hyperplasia induced, but the neutrophil, macrophage, and T-cell populations were also present in these transplanted mice. To demonstrate the utility of MC as a target for therapy, we administered the MC stabilizing drug, disodium cromoglycate (DSCG) immediately following arterial injury and were able to show a reduction in neointimal hyperplasia in wild-type mice. These studies suggest a critical role for MC in inducing the conditions and coordinating the detrimental inflammatory response seen post-endothelial injury in arteries undergoing revascularization procedures, and by targeting the rapid MC degranulation immediately post-surgery with DSCG, this restenosis may become a preventable clinical complication.

Safe and effective profile of the VSTENT bioresorbable polymer sirolimus-eluting stent in the treatment of patients with de novo coronary artery lesions: a prospective, cohort, multicenter study

Background

The drug-eluting stent was a significant stride forward in the development of enhanced therapeutic therapy for coronary intervention, with three generations of increased advancement. VSTENT is a newly developed stent manufactured in Vietnam that aims to provide coronary artery patients with a safe, effective, and cost-efficient option. The purpose of this trial was to determine the efficacy and safety of a new bioresorbable polymer sirolimus-eluting stent called VSTENT.

Methods

This is a prospective, cohort, multicenter research in 5 centers of Vietnam. A prespecified subgroup received intravascular ultrasound (IVUS) or optical coherence tomography (OCT) imaging. We determined procedure success and complications during index hospitalization. We monitored all participants for a year. Six-month and 12-month rates of major cardiovascular events were reported. All patients had coronary angiography after 6 months to detect late lumen loss (LLL). Prespecified patients also had IVUS or OCT performed.

Results

The rate of device success was 100% (95% CI: 98.3-100%; P<0.001). Major cardiovascular events were 4.7% (95% CI: 1.9-9.4%; P<0.001). The LLL over quantitative coronary angiography (QCA) was 0.08±0.19 mm (95% CI: 0.05-0.10; P<0.001) in the in-stent segment and 0.07±0.31 mm (95% CI: 0.03-0.11; P=0.002) in 5 mm within the two ends of the stent segment. The LLL recorded by IVUS and OCT at 6 months was 0.12±0.35 mm (95% CI: 0.01-0.22; P=0.028) and 0.15±0.24 mm (95% CI: 0.02-0.28; P=0.024), respectively.

Conclusions

This study's device success rates were perfect. IVUS and OCT findings on LLL were favorable at 6-month follow-up. One-year follow-up showed low in-stent restenosis (ISR) and target lesion revascularization (TLR) rates, reflecting few significant cardiovascular events. VSTENT's safety and efficacy make it a promising percutaneous intervention option in developing nations.

Adaptation of Vascular Smooth Muscle Cell to Degradable Metal Stent Implantation

Iron-, magnesium-, or zinc-based metal vessel stents support vessel expansion at the period early after implantation and degrade away after vascular reconstruction, eliminating the side effects due to the long stay of stent implants in the body and the risks of restenosis and neoatherosclerosis. However, emerging evidence has indicated that their degradation alters the vascular microenvironment and induces adaptive responses of surrounding vessel cells, especially vascular smooth muscle cells (VSMCs). VSMCs are highly flexible cells that actively alter their phenotype in response to the stenting, similarly to what they do during all stages of atherosclerosis pathology, which significantly influences stent performance. This Review discusses how biodegradable metal stents modify vascular conditions and how VSMCs respond to various chemical, biological, and physical signals attributable to stent implantation. The focus is placed on the phenotypic adaptation of VSMCs and the clinical complications, which highlight the importance of VSMC transformation in future stent design.

Polymer-coated paclitaxel-eluting stents for the treatment of stenosed native arteriovenous fistulas: Long-term results from the ELUDIA study

BACKGROUND

Percutaneous transluminal angioplasty is the preferred treatment of stenosed failing arteriovenous fistulas (AVF) but is hampered by increasing rates of vascular restenosis because of development of myointimal hyperplasia.

METHODS

This multicenter observational study of polymer-coated low-dose paclitaxel-eluting stents (ELUvia stents by Boston Scientific) in stenosed AVF undergoing hemoDIAlysis (ELUDIA) was jointly conducted in three tertiary hospitals from Greece and Singapore. Failure of AVF was defined according to K-DOQI criteria and significant fistula stenosis (>50%DS by visual estimate) was determined with subtraction angiography. Patients were considered for ELUVIA stent insertion based on significant elastic recoil following balloon angioplasty for the treatment of a single vascular stenosis within a native AVF. The primary outcome measure was sustained long-term patency of the treated lesion/fistula circuit defined as successful stent placement with resumption of uninterrupted hemodialysis and without significant vascular restenosis (50%DS threshold) or other secondary interventions during follow-up.

RESULTS

Some 23 patients received the ELUVIA paclitaxel-eluting stent (eight radiocephalic, 12 brachiocephalic, and three transposed brachiobasilic native AVFs). Mean AVF age at the time of failure was 33.9 ± 20.4 months. Treated lesions included 12 stenoses at the juxta-anastomotic segment, nine at the outflow veins, and two cephalic arch lesions with a mean diameter stenosis of 86 ± 8%. Median stent diameter and length used were 7 mm and 40 mm, respectively. After a median follow-up period of 20 months, some 18 stents out of 23 cases remained patent (cumulative rate 78.3%) without any clinical or imaging evidence of recurrent stenosis. Estimated primary patency of the ELUVIA stents was 80.6% and of the corresponding fistula circuit 65.1% at 2 years by Kaplan-Meier methods.

CONCLUSIONS

This observational study has shown promising long-term results of polymer-coated paclitaxel-eluting stents for the treatment of failing arteriovenous fistulas. Large-scale controlled studies are necessary.

Mulberry extract upregulates cholesterol efflux and inhibits p38 MAPK-NLRP3-mediated inflammation in foam cells

The accumulation of foam cells in arterial intima and the accompanied chronic inflammation are considered major causes of neoatherosclerosis and restenosis. However, both the underlying mechanism and effective treatment for the disease are yet to be uncovered. In this study, we combined transcriptome profiling of restenosis artery tissue and bioinformatic analysis to reveal that NLRP3 inflammasome is markedly upregulated in restenosis and that several restenosis-related DEGs are also targets of mulberry extract, a natural dietary supplement used in traditional Chinese medicine. We demonstrated that mulberry extract suppresses the formation of ox-LDL-induced foam cells, possibly by upregulating the cholesterol efflux genes ABCA1 and ABCG1 to inhibit intracellular lipid accumulation. In addition, mulberry extract dampens NLRP3 inflammasome activation by stressing the MAPK signaling pathway. These findings unveil the therapeutic value of mulberry extract in neoatherosclerosis and restenosis treatment by regulating lipid metabolism and inflammatory response of foam cells.

In-stent restenosis is associated with proliferative skin healing and specific immune and endothelial cell profiles: results from the RACHEL trial

Introduction

In-stent restenosis (ISR) is a major challenge in interventional cardiology. Both ISR and excessive skin healing are aberrant hyperplasic responses, which may be functionally related. However, the cellular component underlying ISR remains unclear, especially regarding vascular homeostasis. Recent evidence suggest that novel immune cell populations may be involved in vascular repair and damage, but their role in ISR has not been explored. The aims of this study is to analyze (i) the association between ISR and skin healing outcomes, and (ii) the alterations in vascular homeostasis mediators in ISR in univariate and integrative analyses.

Methods

30 patients with ≥1 previous stent implantation with restenosis and 30 patients with ≥1 stent without restenosis both confirmed in a second angiogram were recruited. Cellular mediators were quantified in peripheral blood by flow cytometry. Skin healing outcomes were analyzed after two consecutive biopsies.

Results

Hypertrophic skin healing was more frequent in ISR patients (36.7%) compared to those ISR-free (16.7%). Patients with ISR were more likely to develop hypertrophic skin healing patterns (OR 4.334 [95% CI 1.044-18.073], p=0.033), even after correcting for confounders. ISR was associated with decreased circulating angiogenic T-cells (p=0.005) and endothelial progenitor cells (p<0.001), whereas CD4+CD28null and detached endothelial cells counts were higher (p<0.0001 and p=0.006, respectively) compared to their ISR-free counterparts. No differences in the frequency of monocyte subsets were found, although Angiotensin-Converting Enzyme expression was increased (non-classical: p<0.001; and intermediate: p<0.0001) in ISR. Despite no differences were noted in Low-Density Granulocytes, a relative increase in the CD16- compartment was observed in ISR (p=0.004). An unsupervised cluster analysis revealed the presence of three profiles with different clinical severity, unrelated to stent types or traditional risk factors.

Conclusion

ISR is linked to excessive skin healing and profound alterations in cellular populations related to vascular repair and endothelial damage. Distinct cellular profiles can be distinguished within ISR, suggesting that different alterations may uncover different ISR clinical phenotypes.

Markers of Restenosis after Percutaneous Transluminal Balloon Angioplasty in Patients with Critical Limb Ischemia

Among cardiovascular diseases, chronic obliterating lesions of the arteries of lower extremities, which are one of the important problems of modern healthcare, are distinguished. In most cases, the cause of damage to the arteries of lower extremities is atherosclerosis. The most severe form is chronic ischemia, characterized by pain at rest and ischemic ulcers, ultimately increasing the risk of limb loss and cardiovascular mortality. Therefore, patients with critical limb ischemia need limb revascularization. Percutaneous transluminal balloon angioplasty is one of the least invasive and safe approaches, with advantages for patients with comorbidities. However, after this procedure, restenosis is still possible. Early detection of changes in the composition of some molecules as markers of restenosis will help screen patients at the risk of restenosis, as well as find ways to apply efforts for further directions of inhibition of this process. The purpose of this review is to provide the most important and up-to-date information on the mechanisms of restenosis development, as well as possible predictors of their occurrence. The information collected in this publication may be useful in predicting outcomes after surgical treatment and will also find new ways for the target implication to the mechanisms of development of restenosis and atherosclerosis.

Selective NLRP3 Inflammasome Inhibitor MCC950 Suppresses Inflammation and Facilitates Healing in Vascular Materials

Minimally invasive interventions using drug-eluting stents or balloons are a first-line treatment for certain occlusive cardiovascular diseases, but the major long-term cause of failure is neointimal hyperplasia (NIH). The drugs eluted from these devices are non-specific anti-proliferative drugs, such as paclitaxel (PTX) or sirolimus (SMS), which do not address the underlying inflammation. MCC950 is a selective inhibitor of the NLRP3-inflammasome, which drives sterile inflammation commonly observed in NIH. Additionally, in contrast to broad-spectrum anti-inflammatory drugs, MCC950 does not compromise global immune function due this selective activity. In this study, MCC950 is found to not impact the viability, integrity, or function of human coronary endothelial cells, in contrast to the non-specific anti-proliferative effects of PTX and SMS. Using an in vitro model of NLRP3-mediated inflammation in murine macrophages, MCC950 reduced IL-1β expression, which is a key driver of NIH. In an in vivo mouse model of NIH in vascular grafts, MCC950 significantly enhanced re-endothelialization and reduced NIH compared to PTX or SMS. These findings show the effectiveness of a targeted anti-inflammatory drug-elution strategy with significant implications for cardiovascular device intervention.

Machine Learning Identifies New Predictors on Restenosis Risk after Coronary Artery Stenting in 10,004 Patients with Surveillance Angiography

OBJECTIVE

Machine learning (ML) approaches have the potential to uncover regular patterns in multi-layered data. Here we applied self-organizing maps (SOMs) to detect such patterns with the aim to better predict in-stent restenosis (ISR) at surveillance angiography 6 to 8 months after percutaneous coronary intervention with stenting.

METHODS

In prospectively collected data from 10,004 patients receiving percutaneous coronary intervention (PCI) for 15,004 lesions, we applied SOMs to predict ISR angiographically 6-8 months after index procedure. SOM findings were compared with results of conventional uni- and multivariate analyses. The predictive value of both approaches was assessed after random splitting of patients into training and test sets (50:50).

RESULTS

Conventional multivariate analyses revealed 10, mostly known, predictors for restenosis after coronary stenting: balloon-to-vessel ratio, complex lesion morphology, diabetes mellitus, left main stenting, stent type (bare metal vs. first vs. second generation drug eluting stent), stent length, stenosis severity, vessel size reduction, and prior bypass surgery. The SOM approach identified all these and nine further predictors, including chronic vessel occlusion, lesion length, and prior PCI. Moreover, the SOM-based model performed well in predicting ISR (AUC under ROC: 0.728); however, there was no meaningful advantage in predicting ISR at surveillance angiography in comparison with the conventional multivariable model (0.726, p = 0.3).

CONCLUSIONS

The agnostic SOM-based approach identified-without clinical knowledge-even more contributors to restenosis risk. In fact, SOMs applied to a large prospectively sampled cohort identified several novel predictors of restenosis after PCI. However, as compared with established covariates, ML technologies did not improve identification of patients at high risk for restenosis after PCI in a clinically relevant fashion.

Predicting and Analyzing Restenosis Risk after Endovascular Treatment in Lower Extremity Arterial Disease: Development and Assessment of a Predictive Nomogram

PURPOSE

This study aimed to develop and internally validate nomograms for predicting restenosis after endovascular treatment of lower extremity arterial diseases.

MATERIALS AND METHODS

A total of 181 hospitalized patients with lower extremity arterial disease diagnosed for the first time between 2018 and 2019 were retrospectively collected. Patients were randomly divided into a primary cohort (n=127) and a validation cohort (n=54) at a ratio of 7:3. The least absolute shrinkage and selection operator (LASSO) regression was used to optimize the feature selection of the prediction model. Combined with the best characteristics of LASSO regression, the prediction model was established by multivariate Cox regression analysis. The predictive models' identification, calibration, and clinical practicability were evaluated by the C index, calibration curve, and decision curve. The prognosis of patients with different grades was compared by survival analysis. Internal validation of the model used data from the validation cohort.

RESULTS

The predictive factors included in the nomogram were lesion site, use of antiplatelet drugs, application of drug coating technology, calibration, coronary heart disease, and international normalized ratio (INR). The prediction model demonstrated good calibration ability, and the C index was 0.762 (95% confidence interval: 0.691-0.823). The C index of the validation cohort was 0.864 (95% confidence interval: 0.801-0.927), which also showed good calibration ability. The decision curve shows that when the threshold probability of the prediction model is more significant than 2.5%, the patients benefit significantly from our prediction model, and the maximum net benefit rate is 30.9%. Patients were graded according to the nomogram. Survival analysis found that there was a significant difference in the postoperative primary patency rate between patients of different classifications (log-rank p<0.001) in both the primary cohort and the validation cohort.

CONCLUSION

We developed a nomogram to predict the risk of target vessel restenosis after endovascular treatment by considering information on lesion site, postoperative antiplatelet drugs, calcification, coronary heart disease, drug coating technology, and INR.

CLINICAL IMPACT

Clinicians can grade patients after endovascular procedure according to the scores of the nomograms and apply intervention measures of different intensities for people at different risk levels. During the follow-up process, an individualized follow-up plan can be further formulated according to the risk classification. Identifying and analyzing risk factors is essential for making appropriate clinical decisions to prevent restenosis.

BMPER Improves Vascular Remodeling and the Contractile Vascular SMC Phenotype

Dedifferentiated vascular smooth muscle cells (vSMCs) play an essential role in neointima formation, and we now aim to investigate the role of the bone morphogenetic protein (BMP) modulator BMPER (BMP endothelial cell precursor-derived regulator) in neointima formation. To assess BMPER expression in arterial restenosis, we used a mouse carotid ligation model with perivascular cuff placement. Overall BMPER expression after vessel injury was increased; however, expression in the tunica media was decreased compared to untreated control. Consistently, BMPER expression was decreased in proliferative, dedifferentiated vSMC in vitro. C57BL/6_Bmper+/- mice displayed increased neointima formation 21 days after carotid ligation and enhanced expression of Col3A1, MMP2, and MMP9. Silencing of BMPER increased the proliferation and migration capacity of primary vSMCs, as well as reduced contractibility and expression of contractile markers, whereas stimulation with recombinant BMPER protein had the opposite effect. Mechanistically, we showed that BMPER binds insulin-like growth factor-binding protein 4 (IGFBP4), resulting in the modulation of IGF signaling. Furthermore, perivascular application of recombinant BMPER protein prevented neointima formation and ECM deposition in C57BL/6N mice after carotid ligation. Our data demonstrate that BMPER stimulation causes a contractile vSMC phenotype and suggest that BMPER has the potential for a future therapeutic agent in occlusive cardiovascular diseases.

Independent Clinical and Echocardiographic Predictors of Restenosis After Percutaneous Mitral Balloon Commissurotomy in a Large, Consecutive Cohort Followed for 24 Years

OBJECTIVE

To enlighten preprocedural risk factors of mitral valve restenosis in a large, single-center cohort of patients submitted to percutaneous mitral balloon commissurotomy (PMBC) for the treatment of mitral stenosis (MS) secondary to rheumatic heart disease.

METHODS

This is a database analysis of a single-center, high-volume tertiary institution involving all consecutive PMBC procedures performed in the mitral valve (MV). Restenosis was diagnosed when MV area was <1.5 cm² and/or loss of 50% or more of the immediate procedural result aligned with the return/worsened symptoms of heart failure. The primary endpoint was to determine the preprocedural independent predictors of restenosis after PMBC.

RESULTS

Among a total of 1921 PMBC procedures, 1794 consecutive patients without previous intervention were treated between 1987 and 2010. Throughout 24 years of follow-up, MV restenosis was observed in 483 cases (26%). Mean age was 36 years and most (87%) were female. Median follow-up duration was 9.03 years (interquartile range, 0.33-23.38). Restenosis population, however, presented a significantly lower age at the procedure time as well as a higher Wilkins-Block score. At multivariate analysis, independent preprocedure predictors of restenosis were left atrium diameter (hazard risk [HR], 1.03; 95% confidence interval [CI], 1.02-1.05; P<.04), preprocedure maximum gradient (HR, 1.02; 95% CI, 1.00-1.03; P=.04), and higher Wilkins-Block score (>8) (HR, 1.38; 95% CI, 1.14-1.67; P<.01).

CONCLUSIONS

At long-term follow-up, MV restenosis was observed in a quarter of the population undergoing PMBC. Preprocedure echocardiographic findings, including left atrial diameter, maximum MV gradient, and Wilkins-Block score were found to be the only independent predictors.

Relationship Between Neutrophil-Lymphocyte Ratio and Drug-Coated Balloon Restenosis in Patients With Femoropopliteal Arterial Disease

We investigated the relationship between neutrophil-lymphocyte ratio (NLR) and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty. Patients (n = 120) were divided into 3 groups according to the development of restenosis and the time of restenosis occurrence. The postoperative NLR was higher in the late-restenosis group than that in the no-restenosis group (3.53 vs 2.70; p = .011). In multivariate logistic analysis, postoperative NLR was an independent predictor of late restenosis (odds ratio: 1.404, 95% confidence interval: 1.073-1.839; p = .014). The postoperative NLR cutoff value for predicting late restenosis was 2.78 with a sensitivity of 80.8% and a specificity of 53.2% (area under the ROC curve was .666 (95% CI: .541-.791, p = .010). The incidence of late restenosis in the NLR ≥2.78 group was higher than that in the NLR <2.78 group (32.3 vs 9.1%; p = .002). Postoperative NLR is independently associated with late restenosis in patients treated with DCB for femoropopliteal arterial disease.

Genetic Variants in PHACTR1 & LPL Mediate Restenosis Risk in Coronary Artery Patients

Background and Objective

Coronary artery disease (CAD) is a major cause of death worldwide. Revascularization via stent placement or coronary artery bypass grafting (CABG) are standard treatments for CAD. Despite a high success rate, these approaches are associated with long-term failure due to restenosis. Risk factors associated with restenosis were investigated using a case-control association study design.

Methods

Five thousand two hundred and forty-two patients were enrolled in this study and were assigned as follows: Stenosis Group: 3570 patients with CAD >50% without a prior stent or CABG (1394 genotyped), and Restenosis Group: 1672 patients with CAD >50% and prior stent deployment or CABG (705 genotyped). Binomial regression models were applied to investigate the association of restenosis with diabetes, hypertension, and dyslipidemia. The genetic association with restenosis was conducted using PLINK 1.9.

Results

Dyslipidemia is a major risk factor (Odds Ratio (OR) = 2.14, P-value <0.0001) for restenosis particularly among men (OR = 2.32, P < 0.0001), while type 2 diabetes (T2D) was associated with an increased risk of restenosis in women (OR = 1.36, P = 0.01). The rs9349379 (PHACTR1) and rs264 (LPL) were associated with an increased risk of restenosis in our patients. PHACTR1 variant was associated with increased risk of restenosis mainly in women and in diabetic patients, while the LPL variant was associated with increased risk of restenosis in men.

Conclusion

The rs9349379 in PHACTR1 gene is significantly associated with restenosis, this association is more pronounced in women and in diabetic patients. The rs264 in LPL gene was associated with increased risk of restenosis in male patients.

A novel polymer-free everolimus-eluting stent with a nitrogen-doped titanium dioxide film inhibits restenosis and thrombosis in a swine coronary model

BACKGROUND

Short-term outcomes regarding the safety and efficacy of a polymer-free everolimus-eluting stent (EES) with a nitrogen-doped titanium dioxide (N-TiO₂) film in a swine coronary model have been reported. However, the long-term results of the use of this type of stent have not yet been evaluated or compared to those of other polymer-free coronary stents. Therefore, this study aimed to determine the mid- to long-term safety and efficacy of a polymer-free EES with an N-TiO₂ film in a swine coronary model.

METHODS

Polymer-free EES with N-TiO₂ films (n = 30) and polymer-free sirolimus-eluting stents (SES; n = 30) were implanted in 30 pigs. Quantitative coronary analysis and optical coherence tomography were conducted immediately and at 1 (quantitative coronary analysis only), 3, and 6 months after stenting. Histopathologic examinations were performed at 1, 3, and 6 months after stenting.

RESULTS

The polymer-free EES group had a lower percentage of neointimal growth than the polymer-free SES group at 3 months (22.5% ± 11.4% vs. 32.1% ± 12.3%; p < 0.001). The polymer-free EES group had a lower fibrin score than the polymer-free SES group at 1 month (1.9 ± 0.45 vs. 2.5 ± 0.54; p = 0.001). The re-endothelialization rates were similar between groups. The polymer-free EES group had a lower percentage of the area of stenosis than the polymer-free SES group throughout the follow-up period.

CONCLUSIONS

The novel polymer-free EES with an N-TiO₂ film has superior safety and efficacy than the polymer-free SES at the 6-month follow-up in a swine model.

MiR-30a-5p Promotes Vein Graft Restenosis by Inhibiting Cell Autophagy through Targeting ATG5

OBJECTIVE

The aim of the study was to investigate the role of miR-30a-5p in restenosis of rats following vein grafting and the underlying mechanism.

METHODS

Vein graft rat models were established and perfused with miR-30a-5p antagomir and si-ATG5 to probe the regulation of miR-30a-5p/ATG5 on intimal hyperplasia. Human saphenous vein smooth muscle cells (HSVSMCs) were obtained from the great saphenous veins of patients undergoing coronary artery bypass grafting and subjected to assays for autophagy, proliferation, and migration after gain and loss of function of miR-30a-5p and/or ATG5. The binding of miR-30a-5p and ATG5 was confirmed by RIP and dual-luciferase reporter assays.

RESULTS

MiR-30a-5p expression gradually increased, ATG5 expression gradually decreased, and the intima was increasingly thickened during restenosis of grafted veins. Knockdown of miR-30a-5p in rats repressed the restenosis of vein grafts, while a deficiency of ATG5 reversed the effect of miR-30a-5p inhibition. Upregulation of miR-30a-5p enhanced the proliferation and migration of HSVSMCs and inhibited the autophagy, while downregulation of miR-30a-5p or overexpression of ATG5 showed opposite effects. ATG5 is a target gene of miR-30a-5p.

CONCLUSION

MiR-30a-5p exacerbates vein graft restenosis by repressing ATG5 expression and inhibiting autophagy.

Stent Thrombosis and Restenosis with Contemporary Drug-Eluting Stents: Predictors and Current Evidence

Iterations in stent technologies, advances in pharmacotherapy, and awareness of the implications of implantation techniques have markedly reduced the risk of stent failure, both in the form of stent thrombosis (ST) and in-stent restenosis (ISR). However, given the number of percutaneous coronary interventions (PCI) performed worldwide every year, ST and ISR, albeit occurring at a fairly low rate, represent a public health problem even with contemporary DES platforms. The understanding of mechanisms and risk factors for these two PCI complications has been of fundamental importance for the parallel evolution of stent technologies. Risk factors associated with ST and ISR are usually divided into patient-, lesion-, device- and procedure-related. A number of studies have shown how certain risk factors are related to early (1 month) versus late/very late ST (between 1 month and 1 year and >1 year, respectively). However, more research is required to conclusively show the role of time-dependence of risk factors also in the incidence of ISR (early [1 year] or late [>1 year]). A thorough risk assessment is required due to the complex etiology of ST and ISR. The most effective strategy to treat ST and ISR is still to prevent them; hence, it is crucial to identify patient-, lesion-, device- and procedure-related predictors.

The Autotaxin-LPA Axis Emerges as a Novel Regulator of Smooth Muscle Cell Phenotypic Modulation during Intimal Hyperplasia

Neointimal hyperplasia is characterized by a loss of the contractile phenotype of vascular smooth muscle cells (VSMCs). Our group has recently shown that VSMC proliferation and migration are mediated by lysophosphatidic acid (LPA) during restenosis, but the role of autotaxin (ATX; lysophospholipase D), which produces LPA, remains unclear. Endothelial denudation of the mouse carotid artery was performed to induce neointimal hyperplasia, and the extent of damage caused by the ATX-LPA axis was assessed in VSMCs. We observed the upregulation of ATX activity (p < 0.0002) in the injured carotid artery using an AR2 probe fluorescence assay. Further, the tissue carotid LPA levels were elevated 2.7-fold in carotid vessels, augmenting neointimal hyperplasia. We used an electrical cell-substrate impedance sensor (ECIS) to measure VSMC proliferation and migration. Treatment with an ATX inhibitor (PF8380) or LPA receptor inhibitor (Ki16425) attenuated VSMC proliferation (extracellular signal-regulated kinases) activity and migration in response to recombinant ATX. Indeed, PF8380 treatment rescued the aggravated post-wire injury neointima formation of carotid arteries. The upregulation of ATX following vessel injury leads to LPA production in VSMCs, favoring restenosis. Our observations suggest that inhibition of the ATX-LPA axis could be therapeutically targeted in restenosis to minimize VSMC phenotypic modulation and inflammation after vascular injury.

Biomarkers Associated with Immune Checkpoint, N6-Methyladenosine, and Ferroptosis in Patients with Restenosis

Purpose

This study aimed to identify potential diagnostic markers of restenosis after stent implantation and to determine their association with immune checkpoint, ferroptosis, and N6-methyladenosine (m6A).

Patients and methods

Microarray data were downloaded from the National Center for Biotechnology Information (NCBI: GSE46560 and GSE48060 datasets) to identify differentially expressed genes (DEGs) between in-stent restenosis and no-restenosis samples. We then conducted systematic functional enrichment analyses of the DEGs based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and further predicted the interactions of different proteins using the Search Tool for the Retrieval of Interacting Genes (STRING). We used the MCC and MCODE algorithms in the cytoHubba plug-in to screen three key genes in the network, and employed receiver operating characteristic (ROC) curves to determine their diagnostic significance using a multiscale curvature classification algorithm. Next, we investigated the relationships between these target genes, immune checkpoint, ferroptosis, and m6A. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the above results.

Results

We identified 62 upregulated genes and 243 downregulated genes. Based on GO, KEGG, and screening results, EEF1D, RPL36, and RPSA are promising genes for predicting restenosis. In addition, the methylation of YTHDF2, the ferroptosis-related gene GLS2, and the immune checkpoint-related gene CTLA4 were observed to be associated with restenosis. The qRT-PCR test confirmed that RPSA and RPL36 are useful diagnostic markers of the restenosis that can provide new insights for future studies on its occurrence and molecular mechanisms.

Conclusion

We found that RPSA and RPL36, as useful diagnostic markers of restenosis, can provide new insights for future studies on its occurrence and molecular mechanisms.

Vascular smooth muscle cells in intimal hyperplasia, an update

Arterial occlusive disease is the leading cause of death in Western countries. Core contemporary therapies for this disease include angioplasties, stents, endarterectomies and bypass surgery. However, these treatments suffer from high failure rates due to re-occlusive vascular wall adaptations and restenosis. Restenosis following vascular surgery is largely due to intimal hyperplasia. Intimal hyperplasia develops in response to vessel injury, leading to inflammation, vascular smooth muscle cells dedifferentiation, migration, proliferation and secretion of extra-cellular matrix into the vessel's innermost layer or intima. In this review, we describe the current state of knowledge on the origin and mechanisms underlying the dysregulated proliferation of vascular smooth muscle cells in intimal hyperplasia, and we present the new avenues of research targeting VSMC phenotype and proliferation.