New-Generation Coronary Stents: Current Data and Future Directions

Necessity sequential intermediate kissing balloon dilation for crush stenting: Further insights from metal/polymer vessel scaffolds bench testing

Sequential intermediate kissing balloon dilation (sIKBD) is crucial for crush stenting, but it require appropriate procedure remains unclear for crush stenting. This study aims to investigate whether sIKBD is necessary and how it can be properly performed during crush stenting. Mini-crush stenting (mini-CS) and sIKBD for mini-crush stenting (sIKBD-mini-CS) using metal drug-eluting stents/polymer bioresorbable vessel scaffolds (mDES/pBVS) were emulated in bifurcation models considering the branch diameter difference, and sIKBD was added to mini-CS for pretreating side-branch (SB) stent before main-branch (MB) stenting (second figure), respectively. Micro-computed tomography was used to assess the morphological parameters of bifurcated stents including length of overlapping stent segment, residual ostial stenosis of the SB, and neocarina length using quantitative methods. Further, optical coherence tomography was to analyze the incidence of stent malapposition. Quantitative analysis demonstrated that in mDES/pBVS phantom, the neocarina length (mDES: 0.45 ± 0.10 mm vs 0.30 ± 0.09 mm, P = .005; pBVS: 0.47 ± 0.11 mm vs 0.29 ± 0.09 mm, P = .001), residual ostial stenosis at the SB (mDES: 19.37 ± 8.21% vs 12.47 ± 2.05%, P = .001; pBVS: 21.89 ± 8.54% vs 9.98 ± 3.35%, P = .035), and stent malapposition in the overlapping segment (mDES: 10.29 ± 3.31% vs 3.83 ± 0.97%, P = .001; pBVS: 12.05 ± 3.87% vs 6.40 ± 1.59%, P = .003) were lower in the sIKBD-mini-CS group than those in the mini-CS group (P < .05 for all). The results of factorial analysis showed that mDES platform tended to have better morphological indicators than the pBVS platform. Adding the sIKBD to mini-CS showed better morphologic characteristics of mDES/pBVS phantoms when compared with mini-CS. Therefore, it should be considered as a critical and proper technique for crush stenting.

Nanotechnology in development of next generation of stent and related medical devices: Current and future aspects

Coronary stents have saved millions of lives in the last three decades by treating atherosclerosis especially, by preventing plaque protrusion and subsequent aneurysms. They attenuate the vascular SMC proliferation and promote reconstruction of the endothelial bed to ensure superior revascularization. With the evolution of modern stent types, nanotechnology has become an integral part of stent technology. Nanocoating and nanosurface fabrication on metallic and polymeric stents have improved their drug loading capacity as well as other mechanical, physico-chemical, and biological properties. Nanofeatures can mimic the natural nanofeatures of vascular tissue and control drug-delivery. This review will highlight the role of nanotechnology in addressing the challenges of coronary stents and the recent advancements in the field of related medical devices. Different generations of stents carrying nanoparticle-based formulations like liposomes, lipid-polymer hybrid NPs, polymeric micelles, and dendrimers are discussed highlighting their roles in local drug delivery and anti-restenotic properties. Drug nanoparticles like Paclitaxel embedded in metal stents are discussed as a feature of first-generation drug-eluting stents. Customized precision stents ensure safe delivery of nanoparticle-mediated genes or concerted transfer of gene, drug, and/or bioactive molecules like antibodies, gene mimics via nanofabricated stents. Nanotechnology can aid such therapies for drug delivery successfully due to its easy scale-up possibilities. However, limitations of this technology such as their potential cytotoxic effects associated with nanoparticle delivery that can trigger hypersensitivity reactions have also been discussed in this review. This article is categorized under: Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Fine-Tuning the Nanostructured Titanium Oxide Surface for Selective Biological Response

Cardiovascular diseases are a pre-eminent global cause of mortality in the modern world. Typically, surgical intervention with implantable medical devices such as cardiovascular stents is deployed to reinstate unobstructed blood flow. Unfortunately, existing stent materials frequently induce restenosis and thrombosis, necessitating the development of superior biomaterials. These biomaterials should inhibit platelet adhesion (mitigating stent-induced thrombosis) and smooth muscle cell proliferation (minimizing restenosis) while enhancing endothelial cell proliferation at the same time. To optimize the surface properties of Ti6Al4V medical implants, we investigated two surface treatment procedures: gaseous plasma treatment and hydrothermal treatment. We analyzed these modified surfaces through scanning electron microscopy (SEM), water contact angle analysis (WCA), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. Additionally, we assessed in vitro biological responses, including platelet adhesion and activation, as well as endothelial and smooth muscle cell proliferation. Herein, we report the influence of pre/post oxygen plasma treatment on titanium oxide layer formation via a hydrothermal technique. Our results indicate that alterations in the titanium oxide layer and surface nanotopography significantly influence cell interactions. This work offers promising insights into designing multifunctional biomaterial surfaces that selectively promote specific cell types' proliferation─which is a crucial advancement in next-generation vascular implants.

Drug-Coated Balloon-Only Strategy for De Novo Coronary Artery Disease: A Meta-analysis of Randomized Clinical Trials

Backgrounds

Many clinical trials have demonstrated the value of drug-coated balloons (DCB) for in-stent restenosis. However, their role in de novo lesions is not well documented. The aim of this study is to evaluate the safety and efficacy of the DCB-only strategy compared to other percutaneous coronary intervention strategies for de novo coronary lesions.

Methods

The PubMed, Embase, Web of Science, and Cochrane Library Central Register of Controlled Trials (CENTRAL) electronic databases were searched for randomized controlled trials published up to May 6, 2023. The primary outcomes were major adverse cardiac events and late lumen loss.

Results

A total of eighteen trials with 3336 participants were included. Compared with drug-eluting stents, the DCB-only strategy was associated with a similar risk of major adverse cardiac events (risk ratio (RR) = 0.90; 95% confidence interval (CI): 0.59 to 1.37, P = 0.631) and a significant decrease in late lumen loss (standardized mean difference (SMD) = -0.29, 95% CI: -0.53 to -0.04, P = 0.021). This effect was consistent in subgroup analysis regardless of indication, follow-up time, drug-eluting stent type, and dual antiplatelet therapy duration. However, DCBs were inferior to DESs for minimum lumen diameter and percentage diameter stenosis. The DCB-only strategy showed significantly better outcomes for most endpoints compared to plain-old balloon angioplasty or bare metal stents.

Conclusions

Interventions with a DCB-only strategy are comparable to those of drug-eluting stents and superior to plain-old balloon angioplasty or bare metal stents for the treatment of selected de novo coronary lesions. Additional evidence is still warranted to confirm the value of DCB before widespread clinical utilization can be recommended.

Drug loaded implantable devices to treat cardiovascular disease

INTRODUCTION

It is widely acknowledged that cardiovascular diseases (CVDs) continue to be the leading cause of death globally. Furthermore, CVDs are the leading cause of diminished quality of life for patients, frequently as a result of their progressive deterioration. Medical implants that release drugs into the body are active implants that do more than just provide mechanical support; they also have a therapeutic role. Primarily, this is achieved through the controlled release of active pharmaceutical ingredients (API) at the implementation site.

AREAS COVERED

In this review, the authors discuss drug-eluting stents, drug-eluting vascular grafts, and drug-eluting cardiac patches with the aim of providing a broad overview of the three most common types of cardiac implant.

EXPERT OPINION

Drug eluting implants are an ideal alternative to traditional drug delivery because they allow for accurate drug release, local drug delivery to the target tissue, and minimise the adverse side effects associated with systemic administration. Despite the fact that there are still challenges that need to be addressed, the ever-evolving new technologies are making the fabrication of drug eluting implants a rewarding therapeutic endeavour with the possibility for even greater advances.

Histone Acetyltransferases p300 and CBP Coordinate Distinct Chromatin Remodeling Programs in Vascular Smooth Muscle Plasticity

BACKGROUND

Vascular smooth muscle cell (VSMC) phenotypic switching contributes to cardiovascular diseases. Epigenetic regulation is emerging as a key regulatory mechanism, with the methylcytosine dioxygenase TET2 acting as a master regulator of smooth muscle cell phenotype. The histone acetyl-transferases p300 and CREB-binding protein (CBP) are highly homologous and often considered to be interchangeable, and their roles in smooth muscle cell phenotypic regulation are not known.

METHODS

We assessed the roles of p300 and CBP in human VSMC with knockdown, in inducible smooth muscle-specific knockout mice (inducible knockout [iKO]; p300^iKO or CBP^iKO), and in samples of human intimal hyperplasia.

RESULTS

P300, CBP, and histone acetylation were differently regulated in VSMCs undergoing phenotypic switching and in vessel remodeling after vascular injury. Medial p300 expression and activity were repressed by injury, but CBP and histone acetylation were induced in neointima. Knockdown experiments revealed opposing effects of p300 and CBP in the VSMC phenotype: p300 promoted contractile protein expression and inhibited migration, but CBP inhibited contractile genes and enhanced migration. p300^iKO mice exhibited severe intimal hyperplasia after arterial injury compared with controls, whereas CBP^iKO mice were entirely protected. In normal aorta, p300^iKO reduced, but CBP^iKO enhanced, contractile protein expression and contractility compared with controls. Mechanistically, we found that these histone acetyl-transferases oppositely regulate histone acetylation, DNA hydroxymethylation, and PolII (RNA polymerase II) binding to promoters of differentiation-specific contractile genes. Our data indicate that p300 and TET2 function together, because p300 was required for TET2-dependent hydroxymethylation of contractile promoters, and TET2 was required for p300-dependent acetylation of these loci. TET2 coimmunoprecipitated with p300, and this interaction was enhanced by rapamycin but repressed by platelet-derived growth factor (PDGF) treatment, with p300 promoting TET2 protein stability. CBP did not associate with TET2, but instead facilitated recruitment of histone deacetylases (HDAC2, HDAC5) to contractile protein promoters. Furthermore, CBP inhibited TET2 mRNA levels. Immunostaining of cardiac allograft vasculopathy samples revealed that p300 expression is repressed but CBP is induced in human intimal hyperplasia.

CONCLUSIONS

This work reveals that p300 and CBP serve nonredundant and opposing functions in VSMC phenotypic switching and coordinately regulate chromatin modifications through distinct functional interactions with TET2 or HDACs. Targeting specific histone acetyl-transferases may hold therapeutic promise for cardiovascular diseases.

Bio-Performance of Hydrothermally and Plasma-Treated Titanium: The New Generation of Vascular Stents

The research presented herein follows an urgent global need for the development of novel surface engineering techniques that would allow the fabrication of next-generation cardiovascular stents, which would drastically reduce cardiovascular diseases (CVD). The combination of hydrothermal treatment (HT) and treatment with highly reactive oxygen plasma (P) allowed for the formation of an oxygen-rich nanostructured surface. The morphology, surface roughness, chemical composition and wettability of the newly prepared oxide layer on the Ti substrate were characterized by scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) analysis. The alteration of surface characteristics influenced the material’s bio-performance; platelet aggregation and activation was reduced on surfaces treated by hydrothermal treatment, as well as after plasma treatment. Moreover, it was shown that surfaces treated by both treatment procedures (HT and P) promoted the adhesion and proliferation of vascular endothelial cells, while at the same time inhibiting the adhesion and proliferation of vascular smooth muscle cells. The combination of both techniques presents a novel approach for the fabrication of vascular implants, with superior characteristics.

Clinical outcomes of ultrathin biodegradable polymer-coated sirolimus-eluting stents in an all-comer population: One-year results from the T-FLEX registry including high-risk subgroups

OBJECTIVE

T-Flex registry was designed to investigate the safety and clinical performance of the ultrathin (60 µm) strut biodegradable polymer-coated sirolimus-eluting stent (SES) with a unique long dual Z (LDZ) link design on a cobalt-chromium stent platform (Sahajanand Medical Technologies Pvt. Ltd., Surat, India) in a real-world all-comer population including high-risk subgroups.

METHODS

This was an observational, multicenter, single-arm, and investigator-initiated retrospective registry. A total of 1,203 patients treated with an ultrathin biodegradable polymer-coated SES, irrespective of lesion complexity, comorbidities, and acute presentation were analyzed from May 2016 to January 2017. The primary endpoint was the one-year incidence of target lesion failure (TLF), a composite of cardiac death, target-vessel myocardial infarction (TV-MI), and clinically-indicated target lesion revascularization (CI-TLR). Stent thrombosis was assessed as an additional safety endpoint.

RESULTS

At the one-year follow-up, TLF was observed in 3.8% [95% confidence interval (CI) 2.9-5.1] patients, composed of 0.6% (95% CI: 0.3-1.3) cardiac death, 1.3% (95% CI: 0.8-2.2) TV-MI, and 1.9% (95% CI: 1.3-2.9) CI-TLR. In the high-risk subgroups, TLF at one-year was 6.8% (95% CI: 4.6-9.8) in patients with diabetes, 5.2% (95% CI: 3.4-8) in patients with small-vessel disease, 6.1% (95% CI: 3.9-9.6) in patients with ST-elevation myocardial infarction, and 4.5% (95% CI: 2.4-8.3) in patients with total occlusion. During follow-up, stent thrombosis was reported in 0.8% (95% CI: 0.4-1.5) patients in the overall population.

CONCLUSION

Low event rates of TLF and stent thrombosis at one-year follow-up indicate that this ultrathin biodegradable polymer-coated SES has encouraging safety and clinical performance in real-world all-comer populations as well as in high-risk subgroups.

Targeting smooth muscle cell phenotypic switching in vascular disease

Objective

The phenotypic plasticity of vascular smooth muscle cells (VSMCs) is central to vessel growth and remodeling, but also contributes to cardiovascular pathologies. New technologies including fate mapping, single cell transcriptomics, and genetic and pharmacologic inhibitors have provided fundamental new insights into the biology of VSMC. The goal of this review is to summarize the mechanisms underlying VSMC phenotypic modulation and how these might be targeted for therapeutic benefit.

Methods

We summarize findings from extensive literature searches to highlight recent discoveries in the mechanisms underlying VSMC phenotypic switching with particular relevance to intimal hyperplasia. PubMed was searched for publications between January 2001 and December 2020. Search terms included VSMCs, restenosis, intimal hyperplasia, phenotypic switching or modulation, and drug-eluting stents. We sought to highlight druggable pathways as well as recent landmark studies in phenotypic modulation.

Results

Lineage tracing methods have determined that a small number of mature VSMCs dedifferentiate to give rise to oligoclonal lesions in intimal hyperplasia and atherosclerosis. In atherosclerosis and aneurysm, single cell transcriptomics reveal a striking diversity of phenotypes that can arise from these VSMCs. Mechanistic studies continue to identify new pathways that influence VSMC phenotypic plasticity. We review the mechanisms by which the current drug-eluting stent agents prevent restenosis and note remaining challenges in peripheral and diabetic revascularization for which new approaches would be beneficial. We summarize findings on new epigenetic (DNA methylation/TET methylcytosine dioxygenase 2, histone deacetylation, bromodomain proteins), transcriptional (Hippo/Yes-associated protein, peroxisome proliferator-activity receptor-gamma, Notch), and β3-integrin-mediated mechanisms that influence VSMC phenotypic modulation. Pharmacologic and genetic targeting of these pathways with agents including ascorbic acid, histone deacetylase or bromodomain inhibitors, thiazolidinediones, and integrin inhibitors suggests potential therapeutic value in the setting of intimal hyperplasia.

Conclusions

Understanding the molecular mechanisms that underlie the remarkable plasticity of VSMCs may lead to novel approaches to treat and prevent cardiovascular disease and restenosis.

Development of In Vitro Endothelialised Stents - Review

Endovascular treatment is prevalent as a primary treatment for coronary and peripheral arterial diseases. Although the introduction of drug-eluting stents (DES) dramatically reduced the risk of in-stent restenosis, stent thrombosis persists as an issue. Notwithstanding improvements in newer generation DES, they are yet to address the urgent clinical need to abolish the late stent complications that result from in-stent restenosis and are associated with late thrombus formation. These often lead to acute coronary syndromes with high mortality in coronary artery disease and acute limb ischemia with a high risk of limb amputation in peripheral arterial disease. Recently, a significant amount of research has focused on alternative solutions to improve stent biocompatibility by using tissue engineering. There are two types of tissue engineering endothelialisation methods: in vitro and in vivo. To date, commercially available in vivo endothelialised stents have failed to demonstrate antithrombotic or anti-stenosis efficacy in clinical trials. In contrast, the in vitro endothelialisation methods exhibit the advantage of monitoring cell type and growth prior to implantation, enabling better quality control. The present review discusses tissue-engineered candidate stents constructed by distinct in vitro endothelialisation approaches, with a particular focus on fabrication processes, including cell source selection, stent material composition, stent surface modifications, efficacy and safety evidence from in vitro and in vivo studies, and future directions.

Long-acting implants to treat and prevent HIV infection

PURPOSE OF REVIEW

Subcutaneous implants are a promising technology to enable long-acting parenteral delivery of antiretroviral drugs (ARV) because they may be able to provide protective drugs concentrations for a year or longer following a single implant. The present review covers the current status of preclinical and clinical development of antiretroviral implants.

RECENT FINDINGS

Over the past three decades, subcutaneous implants have been widely used for long-acting hormonal contraception and the treatment of hormonally-driven malignancies. They are economical and scalable to manufacture, but require special procedures for insertion and removal. They are generally well tolerated, and can remain in place for up to five years. As long-acting delivery of ARV would confer significant advantages, a few investigational implants are under development for the delivery of ARV; most remain at preclinical stages of development. Islatravir, a potent nucleoside analog reverse transcriptase translocation inhibitor that shows particular promise, has entered clinical testing in implant form. Investigational implants containing tenofovir alafenamide and nevirapine, and entecavir (for hepatitis B virus) have been developed and tested in animal models, with varying degrees of success. There is also burgeoning interest in bioerodable implant formulations of established ARVs.

SUMMARY

LARV implants are a promising new technology, but are in early stages of clinical development. Their potential advantages include more consistent and predictable drug release than that provided by intramuscular injections, the possibility of combining several partner drugs into one implant, and the fact that implants can be removed in the case of a desire to stop treatment or the development of adverse events.

Amphiphilic Core Cross-Linked Star Polymers for the Delivery of Hydrophilic Drugs from Hydrophobic Matrices

The delivery of hydrophilic drugs from hydrophobic polymers is a long-standing challenge in the biomaterials field due to the limited solubility of the therapeutic agent within the polymer matrix. In this work, we develop a drug delivery mechanism that enables the impregnation and subsequent elution of hydrophilic drugs from a hydrophobic polymer material. This was achieved by synthesizing core cross-linked star polymer amphiphiles with hydrophilic cores and hydrophobic coronas. While significant work has been done to create nanocarriers for hydrophilic drugs, this work is distinct from previous work in that it designs amphiphilic and core cross-linked particles for controlled release from hydrophobic matrices. Ultraviolet-mediated atom transfer radical polymerization was used to synthesize the poly(ethylene glycol) (PEG)-based hydrophilic cores of the star polymers, and hydrophobic coronas of poly(caprolactone) (PCL) were then built onto the stars using ring-opening polymerization. We illustrated the cytocompatibility of PCL loaded with these star polymers through human endothelial cell adhesion and proliferation for up to 7 days, with star loadings of up to 40 wt %. We demonstrated successful loading of the hydrophilic drug heparin into the star polymer core, achieving a loading efficiency and content of 50 and 5%, respectively. Finally, the heparin-loaded star polymers were incorporated into a PCL matrix and sustained release of heparin was illustrated for over 40 days. These results support the use of core cross-linked star polymer amphiphiles for the delivery of hydrophilic drugs from hydrophobic polymer matrices. These materials were developed for application as drug-eluting and biodegradable coronary artery stents, but this flexible drug delivery platform could have impact in a broad range of medical applications.

Cardiovascular Stents: A Review of Past, Current, and Emerging Devices

One of the leading causes of morbidity and mortality worldwide is coronary artery disease, a condition characterized by the narrowing of the artery due to plaque deposits. The standard of care for treating this disease is the introduction of a stent at the lesion site. This life-saving tubular device ensures vessel support, keeping the blood-flow path open so that the cardiac muscle receives its vital nutrients and oxygen supply. Several generations of stents have been iteratively developed towards improving patient outcomes and diminishing adverse side effects following the implanting procedure. Moving from bare-metal stents to drug-eluting stents, and recently reaching bioresorbable stents, this research field is under continuous development. To keep up with how stent technology has advanced in the past few decades, this paper reviews the evolution of these devices, focusing on how they can be further optimized towards creating an ideal vascular scaffold.

Clinical outcomes with unselected use of an ultrathin-strut sirolimus-eluting stent: a report from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

AIMS

The aim of this study was to assess the real-world clinical performance of a sirolimus-eluting ultrathin-strut drug-eluting stent (DES) (Orsiro) in a large nationwide cohort of patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

From the Swedish Coronary Angiography and Angioplasty Registry, the two-year outcomes of 4,561 patients implanted with Orsiro (Orsiro group) and 69,570 receiving other newer-generation DES (n-DES group) were analysed. The rate of definite stent thrombosis was low in both groups (0.67% and 0.83% for Orsiro and n-DES, respectively; adjusted hazard ratio [HR] 0.90, 95% confidence interval [CI]: 0.55-1.46, p-value 0.66). Restenosis was also infrequent (1.5% vs 2.0% with Orsiro and n-DES, adjusted HR 0.81, 95% CI: 0.63-1.03, p-value=0.09). The risk of target lesion revascularisation by PCI was lower in the Orsiro group (1.6% vs 2.3%, adjusted HR 0.75, 95% CI: 0.60-0.94, p-value=0.013). All-cause mortality and myocardial infarction did not show a statistically significant difference between the two groups (mortality of 7.5% in both groups, adjusted HR 0.99, 95% CI: 0.72-1.35, p-value=0.94; 6.0% vs 5.2% for myocardial infarction, adjusted HR 1.19, 95% CI: 1.00-1.43, p-value=0.06).

CONCLUSIONS

In a nationwide scenario, the use of a sirolimus-eluting ultrathin-strut DES portended favourable clinical outcomes.

Impact of optimal preparation before drug-coated balloon dilatation for de novo lesion in patients with coronary artery disease

BACKGROUND

Drug eluting stent (DES) remain several problems, including stent thrombosis, stent fracture and neoatherosclerosis. Stent-less Percutaneous coronary intervention (PCI) using a drug coated balloon (DCB) is a stent-less strategy, and several trials have supported the efficacy of DCB. However, the optimal preparation before using DCB was uncertain. The aim of this study was to investigate the optimal preparation for plaque oppression/debulking before DCB dilatation for de novo coronary artery lesion.

METHODS

A total 936 patients were treated using DCB from 2014 to 2017 at our institution. Among them, we analyzed 247 patients who underwent PCI using DCB alone for de novo lesion. The primary end point of this study was target lesion failure (TLF).

RESULTS

The area under the receiver operating characteristic (ROC) curve (AUC) was used to determine the optimal cutoff value of % plaque area to predict TLF. ROC curve analysis revealed plaque area ≥ 58.5% (AUC, 0.81) were associated with TLF. Eligible 188 patients were divided into 2 groups (plaque area ≥ 58.5% [n = 38] and <58.5% [n = 150]) according to IVUS data before using DCB. TLF was significantly higher in plaque area ≥ 58.5% group than in <58.5% group (P < 0.01). Multivariable analysis selected plaque area ≥ 58.5% as an independent predictor of TLF (hazard ratio 7.59, P < 0.01).

CONCLUSIONS

Lesion preparation achieving plaque area < 58.5% was important in stent-less PCI using DCB.

Personalized, Mechanically Strong, and Biodegradable Coronary Artery Stents via Melt Electrowriting

Biodegradable coronary artery stents are sought-after alternatives to permanent stents. These devices are designed to degrade after the blood vessel heals, leaving behind a regenerated artery. The original generation of clinically available biodegradable stents required significantly thicker struts (∼150 μm) than nondegradable ones to ensure sufficient mechanical strength. However, these thicker struts proved to be a key contributor to the clinical failure of the stents. A current challenge lies in the fabrication of stents that possess both thin struts and adequate mechanical strength. In this contribution, we describe a method for the bottom-up, additive manufacturing of biodegradable composite stents with ultrathin fibers and superior mechanical properties compared to the base polymer. Specifically, we illustrate that melt electrowriting (MEW) can be used to 3D print composite structures with thin struts (60-80 μm) and a high degree of geometric complexity required for stenting applications. Additionally, this technology allows additive manufacture of personalized stents that are customized to a patient's unique anatomy and disease state. Furthermore, we illustrate that polycaprolactone-reduced graphene oxide nanocomposites have superior mechanical properties compared to original polycaprolactone without detriment to the material's cytocompatibility and that customizable stent-like structures can be fabricated from these materials with struts as thin as 60 μm, well below the target value for clinical use of 80 μm.

Dual Antiplatelet Therapy for Long-term Secondary Prevention of Atherosclerotic Cardiovascular Events

PURPOSE

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ inhibitor is currently recommended to prevent further ischemic events after percutaneous coronary intervention and acute coronary syndrome (ACS). Guidelines currently recommend a minimum of 6 months after elective drug-eluting stent placement and at least 12 months of DAPT after ACS; however, the benefits of prolonged treatment are unclear. The purpose of this review was to conduct a detailed examination of the data refuting or supporting the use of DAPT beyond 1 year in patients with ACS and in patients receiving percutaneous coronary intervention with stenting.

METHODS

A search of PubMed was performed to identify articles published in the last 20 years that addressed the role of DAPT beyond 12 months' duration.

FINDINGS

A number of studies have shown ischemic benefits associated with prolonging DAPT beyond 12 months, but this finding is dependent on the patient population studied and the quality of the study design. Many studies also show that longer duration therapy has been associated with increased bleeding risk. In patients with previous myocardial infarction completing at least 1 year of DAPT, continuing DAPT with a reduced dose of ticagrelor 60 mg BID is a regimen to be considered for these patients; in general ACS patients, a reduced dose of 60 mg BID of ticagrelor after the first year of DAPT should be considered; and in the post-percutaneous coronary intervention patients, DAPT beyond 1 year should be considered after careful evaluation of the patient's thrombotic and bleeding risks.

IMPLICATIONS

The duration of DAPT, and the choice of P2Y₁₂ inhibitor, should be tailored to the individual patient. To optimize patient outcomes, the benefits and risks associated with prolonging DAPT need to be evaluated, considering comorbidities and the presence of bleeding and ischemic risk factors. Despite some limitations, risk scores, such as the DAPT score, are available to help guide decisions for the best approach for each patient.

Design of Self-Expanding Auxetic Stents Using Topology Optimization

Implanting stents is the most efficient and minimally invasive technique for treating coronary artery diseases, but the risks of stent thrombosis (ST) and in-stent restenosis (IRS) hamper the healing process. There have been a variety of stents in market but dominated by ad hoc design motifs. A systematic design method that can enhance deliverability, safety and efficacy is still in demand. Most existing designs are focused on patient and biological factors, while the mechanical failures related to stenting architectures, e.g., inadequate stent expansion, stent fracture, stent malapposition and foreshortening, are often underestimated. With regard to these issues, the self-expanding (SE) stents may perform better than balloon-expandable (BE) stents, but the SE stents are not popular in clinic practice due to poor deliverability, placement accuracy, and precise match of the stent size and shape to the vessel. This paper addresses the importance between stent structures and clinic outcomes in the treatment of coronary artery disease. First, a concurrent topological optimization method will be developed to systematically find the best material distribution within the design domain. An extended parametric level set method with shell elements is proposed in the topology optimization to ensure the accuracy and efficiency of computations. Second, the auxetic metamaterial with negative Poisson’s ratio is introduced into the self-expanding stents. Auxetics can enhance mechanical properties of structures, e.g., fracture toughness, indentation and shear resistance and vibration energy absorption, which will help resolve the drawbacks due to the mechanical failures. Final, the optimized SE stent is numerically validated with the commercial software ANSYS and then prototyped using additive manufacturing techniques. Topological optimization gives a rare opportunity to exploiting the unique advantages of additive manufacturing. Hence, the topologically optimized auxetic architectures will provide a new solution for developing novel stenting structures, especially conductive to self-expanding SE stents. The new design will overcome the limitations of conventional SE stents associated with mechanical structures while maintain their valuable features, to help reduce the occurrence of ST and ISR and benefit the clinic practice in treating coronary heart disease.

Coronary Artery Bypass Grafting vs Percutaneous Coronary Intervention in Patients With Diabetes

As percutaneous coronary intervention (PCI) continues to evolve, comparative outcomes for PCI vs coronary artery bypass grafting (CABG) remain relevant in diabetic patients. All revascularization procedures in patients with coronary artery disease and diabetes mellitus from 2010 to 2018 were included. Propensity matching was used to identify equivalent cohorts to compare revascularization strategies. Primary outcomes included 30-day, 1-year, and 5-year mortality. Multivariable analysis was used to define factors associated with major adverse cardiovascular and cerebrovascular events (MACCE). A total of 2869 patients with diabetes were divided into PCI (n = 653) and CABG (n = 2216) cohorts. Propensity matching yielded a 1:1 match consisting of 552 patients in each cohort (CABG vs PCI). Total median follow-up was 3.28 years (range: 1.83-5.00). Following propensity matching in patients with no prior PCI (1:1; n = 279), mortality remained significantly higher in the PCI cohort at 1 year (13.98% vs 7.53%; P = 0.014) and 5 years (26.88% vs 16.85%; P < 0.004). Hospital readmissions were higher for PCI patients at 1 year (16.49% vs 9.32%; P < 0.0122) and 5 years (19.71% vs 11.83%; P = 0.011). MACCE occurred more frequently in the PCI cohort (32.97% vs 21.51%; P = 0.002). Need for subsequent revascularization (6.45% vs 2.51%; P = 0.024) were significantly higher in the PCI cohort, and time interval to revascularization was significantly longer in the CABG cohort (3.48 [2.11-5.17] vs 2.62 [1.33-4.25] years; P < 0.001). The current study reports improved survival, fewer long-term hospital readmissions, and reduced MACCE and need for repeat revascularization in the CABG cohort. Given these data, patients with diabetes mellitus and coronary artery disease may fare better with surgical revascularization, compared to PCI.

Effect of P2Y12 inhibitor monotherapy versus dual antiplatelet therapy on cardiovascular events in patients undergoing percutaneous coronary intervention: systematic review and meta-analysis

INTRODUCTION

Clinical data on short mandatory dual antiplatelet therapy (DAPT) followed by P2Y12 inhibitor monotherapy, compared with prolonged DAPT in patients undergoing percutaneous coronary intervention (PCI) are insufficient. We aim to evaluate the effectiveness and safety of P2Y12 inhibitor monotherapy and prolonged DAPT after short mandatory DAPT on cardiovascular events in patients undergoing PCI.

EVIDENCE ACQUISITION

A systematic literature search was performed in seven medical databases from building the database until July 2019. Three studies with randomized controlled trial (RCTs), totaling 21,970 patients, were included in this meta-analysis. The included studies were assessed by the Cochrane risk of bias and analyzed by Review Manager v. 5.3 software.

EVIDENCE SYNTHESIS

Our result of pooled analysis showed that there was noninferior rates of in major adverse cardiac and cerebrovascular events (MACCE), stroke, myocardial infarction and cardiac death between short mandatory DAPT followed by P2Y12 inhibitor monotherapy and prolonged DAPT in patients undergoing PCI. Pooled analysis showed that short mandatory DAPT followed by P2Y12 inhibitor monotherapy could significantly reduce the risk of bleeding BARC type 2-5 (OR=0.47, 95% CI: 0.31-0.70, P=0.002), compared with prolonged DAPT in patients undergoing PCI. However, Pooled analysis showed that short mandatory DAPT followed by P2Y12 inhibitor monotherapy was not associated with BARC type 3-5, compared with prolonged DAPT.

CONCLUSIONS

This meta-analysis demonstrated that short mandatory DAPT followed by P2Y12 inhibitor monotherapy compared with prolonged DAPT resulted in noninferior rates of MACCE, all-cause mortality, cardiac death, stroke, myocardial infarction and stent thrombosis. Furthermore, short mandatory DAPT followed by P2Y12 inhibitor monotherapy could significantly reduce the risk of bleeding BARC type 2-5.

Deep Learning in Personalization of Cardiovascular Stents

Deep learning (DL) application has demonstrated its enormous potential in accomplishing biomedical tasks, such as vessel segmentation, brain visualization, and speech recognition. This review article has mainly covered recent advances in the principles of DL algorithms, existing DL software, and designing strategies of DL models. Latest progresses in cardiovascular devices, especially DL-based cardiovascular stent used for angioplasty, differential and advanced diagnostic means, and the treatment outcomes involved with coronary artery disease (CAD), are discussed. Also presented is DL-based discovery of new materials and future medical technologies that will facilitate the development of tailored and personalized treatment strategies by identifying and forecasting individual impending risks of cardiovascular diseases.

Design of a Biocompatible Drug-Eluting Tracheal Stent in Mice with Laryngotracheal Stenosis

Laryngotracheal stenosis (LTS) is a pathologic narrowing of the subglottis and trachea leading to extrathoracic obstruction and significant shortness of breath. LTS results from mucosal injury from a foreign body in the trachea, leading to tissue damage and a local inflammatory response that goes awry, leading to the deposition of pathologic scar tissue. Treatment for LTS is surgical due to the lack of effective medical therapies. The purpose of this method is to construct a biocompatible stent that can be miniaturized to place into mice with LTS. We demonstrated that a PLLA-PCL (70% poly-L-lactide and 30% polycaprolactone) construct had optimal biomechanical strength, was biocompatible, practicable for an in vivo placement stent, and capable of eluting drug. This method provides a drug delivery system for testing various immunomodulatory agents to locally inhibit inflammation and reduce airway fibrosis. Manufacturing the stents takes 28-30 h and can be reproduced easily, allowing for experiments with large cohorts. Here we incorporated the drug rapamycin within the stent to test its effectiveness in reducing fibrosis and collagen deposition. Results revealed that PLLA-PCL tents showed reliable rapamycin release, were mechanically stable in physiological conditions, and were biocompatible, inducing little inflammatory response in the trachea. Further, the rapamycin-eluting PLLA-PCL stents reduced scar formation in the trachea in vivo.

Drug-Eluting Stents Compared With Bare Metal Stents for Stenting the Ductus Arteriosus in Infants With Ductal-Dependent Pulmonary Blood Flow

There have been no clinical studies evaluating the use of drug-eluting stents (DES) versus bare metal stents (BMS) for infants who underwent ductus arteriosus (DA) stent placement for ductal-dependent pulmonary blood flow (PBF). We aimed to compare the use of second-generation (fluoropolymer-coated everolimus) DES to BMS in infants who underwent DA stenting for ductal-dependent PBF. A retrospective study of infants who underwent DA stenting for ductal-dependent PBF from January 2004 to March 2018 at a single tertiary care pediatric hospital was performed. Of 94 infants identified, 71 (46 BMS and 25 DES) met inclusion criteria. Baseline characteristics of the DES and BMS cohorts were comparable. The patent lumen to stent diameter on subsequent angiographic evaluation was 81% in DES as compared with 50% in BMS group; p = 0.01. There were 2 deaths early in our experience, both in the BMS group. Unplanned reinterventions were less in the DES group (3, 12% patients) compared with the BMS group (13, 28%), p = 0.03. Pulmonary artery size as assessed using Nakata and pulmonary artery symmetry index was comparable in both the groups. There was no difference in infection rates between the groups. On multivariate analysis, prematurity, BMS, and lower oxygen saturations at discharge were associated with subsequent unplanned reintervention (p = 0.01, 0.03 and 0.03, respectively). In conclusion, our clinical experience suggests that in infants who underwent DA stenting for ductal-dependent PBF, (fluoropolymer-coated everolimus eluting) DES results in less luminal loss and lower unplanned reintervention for cyanosis as compared with BMS implantation.

Engineering an immunomodulatory drug-eluting stent to treat laryngotracheal stenosis

OBJECTIVE

Develop a drug-eluting stent construct with a reliable drug-release profile and adequate mechanically stability for a trial in a small animal model of laryngotracheal stenosis (LTS), a debilitating pathologic narrowing of the airway leading to significant shortness of breath.

METHODS

Biodegradable, biocompatible stents containing 1.0% rapamycin made of PLLA-PCL (70% Poly-l-Lactide and 30% Polycaprolactone blend) and 50 : 50 PDLGA (Poly(dl-lactide-co-glycolide)) were compared. Mechanical strength testing and drug elution rates using high performance liquid chromatography analysis (HPLC) was assessed. Next, efficacy of stent elution on LTS derived scar fibroblasts. Finally, stents were placed in situ in an LTS mouse model.

RESULTS

The PLLA-PCL stent construct exhibited greater mechanical strength compared to the PDLGA stent over a 4-week period (Young's Modulus (PLLA-PCL) = 13.82; Young's Modulus (PDLGA) = 4.015). Moreover, the PLLA-PCL stent showed a reliable rapamycin release profile for 6 weeks (30% elution for PLLA-PCL stents compared to <1% elution for PDLGA). Collagen 1 (p < 0.05) and fibroblast cell proliferation were decreased in vitro when treated with the rapamycin stent. In vivo, the rapamycin stent reduced lamina propria thickness (p < 0.05) and collagen 1(p < 0.05), collagen 3, TGF-B (p < 0.05) and a-SMA (p < 0.05).

CONCLUSIONS

The PLLA-PCL construct demonstrated superior mechanical strength and greater drug elution compared to PDLGA stents. We demonstrated the feasibility of testing this drug-eluting stent in vivo, showing that the rapamycin-eluting stent treats fibrosis. To our knowledge this is the first study to deploy a drug-eluting stent to treat tracheal pathology in an animal model. Optimization of a rapamycin-eluting PLLA-PCL stent for translational investigation will lead to improved treatment strategies of LTS.

Antiretroviral implants for treatment and prevention of HIV infection

PURPOSE OF REVIEW

Poor adherence to oral antiretroviral formulations remains the major barrier to the success of long-term treatment and prevention strategies. Although a number of approaches have been developed for long-acting parenteral delivery of antiretroviral drugs, subcutaneous implants are a particularly promising technology as they may be able to provide protective drugs concentrations for a year or longer following a single implant. This review addresses the current status of preclinical and clinical development of antiretroviral implants.

RECENT FINDINGS

Subcutaneous implants have been widely used for hormonal contraception and the treatment of hormonally driven malignancies for more than 3 decades. These implants are economical to manufacture and deliver, but require special procedures for insertion and removal. They are generally well tolerated and can remain in place for as long as 5 years. A small number of investigational implants are under development for the delivery of antiretroviral drugs. The most advanced of these, containing the investigational antiretroviral MK-8591 (4'-ethynyl-2-fluoro-2'-deoxyadenosine), a potent nucleoside analog reverse transcriptase translocation inhibitor that demonstrates particular promise for subcutaneous implantation, is closest to testing in human subjects. Investigational implants containing tenofovir alafenamide and nevirapine have also been developed and tested in animal models.

SUMMARY

Long-acting antiretroviral implants are a promising new technology, but are in very early stages of development. Potential advantages of these systems include more consistent and predictable drug release than intramuscular injections, and the fact that implants can be removed in the case of adverse events or the desire to stop treatment.

Most Promising Therapies in Interventional Cardiology

PURPOSE OF REVIEW

The last 40 years of clinical research in interventional cardiology were extraordinarily innovative. This article will review the most promising up and coming interventional cardiovascular therapies, with a primary focus on the treatment of coronary artery disease.

RECENT FINDINGS

From the first stent, to the first transcatheter aortic valve implantation (TAVI), and the left appendage closure technique, percutaneous interventions revolutionized the treatment of multiple diseases and dramatically improved the prognosis of many patients. While these advances have decreased the risk of mortality in some patients (such as ST-elevation myocardial infarction), 15% of acute coronary syndrome (ACS) patients still experience recurrent ischemic events within the first year, challenging us to develop new pharmaceutical targets and new devices. The continued emergence of data supporting inflammation as a risk factor and pharmacologic target as well as data supporting the importance of cholesterol efflux have identified novel therapeutic targets that may play a major role in the improvement of prognosis of patients with coronary artery disease. In addition, novel medical devices are being developed to allow even earlier detection of acute cardiac events and to support high-risk percutaneous coronary interventions. Advances in computing and the ability to analyze large datasets will allow us to use artificial intelligence to augment the clinician patient experience, both in and out of the catheterization laboratory, with live procedural guidance as well as pre- and post-operative prognostication tools.

Engineering Approaches to Prevent Blood Clotting from Medical Implants

Injectable and/or Implantable medical devices are widely used in the treatment of diseases. Among them, vascular stents provide the medical solution to treat blood clotting. However, traditional metallic stents, even with current improvements in anticoagulation properties, have potential drawbacks in local inflammation when first implanted into the body and undesirable protein adsorption and cell adhesion after a prolonged period of time in the body. In this perspective, we discuss several engineering approaches, including drug-eluting materials, polymeric and non-polymeric coatings, and surface modifications to coating materials that can be applied to the surface of medical implants to significantly improve the hemocompatibility. These coatings are expected to have a slow degradation rate with the ability to either load drugs or attach biomacromolecules to form an architecture that mimics the surrounding cells. In general, our perspective provides a current view on the achievements of hemo-compatible coatings and future trends in coating materials that will extend the life of the medical implants.

A rapamycin derivative, biolimus, preferentially activates autophagy in vascular smooth muscle cells

Although rapamycin is a well-known conformational inhibitor of mTORC1, it is now widely used for treating arterial restenosis. Various rapamycin analogues (rapalogue) have been made for applying to drug-eluting stents. Here we show that two major rapalogues, everolimus and biolimus, exert a differential effect on the mTORC1-mediated signaling pathways in vascular smooth muscle cells. In balloon-injured carotid arteries, both rapalogues strongly inhibit neointimal hyperplasia. Signaling pathway analyses reveal that everolimus exert cytotoxicity by increasing cellular reactive oxygen species and consequently reduce energy metabolism. By contrast, biolimus confers a preferential induction of autophagy by more strongly activating major autophagy regulator, ULK1, in vascular smooth muscle cells than everolimus does. As a consequence, the implantation of biolimus-eluting stent reduces endothelial loss, which in turn reduces inflammation, in porcine coronary arteries. Thus, this study reveals that a chemical derivatization can cause a change among mTORC1-dependent signaling pathways in vascular smooth muscle cells, thereby enabling to elicit a differential efficacy on arterial restenosis.

Drug-Coated Balloon-Only Percutaneous Coronary Intervention for the Treatment of De Novo Coronary Artery Disease: A Systematic Review

Percutaneous coronary intervention (PCI) with a drug coated balloon (DCB) is a novel treatment which seeks to acutely dilate a coronary stenosis and deliver an anti-proliferative drug to the vessel wall (reducing the risk of re-stenosis), without implanting a drug eluting stent (DES). In this study, we performed a systematic review of stentless DCB-only angioplasty in de novo coronary artery disease. We identified 41 studies examining the effects of DCB-only PCI in a variety of clinical scenarios including small vessels, bifurcations, calcified lesions, and primary PCI. DCB-only PCI appears to be associated with comparable clinical outcomes to DESs and superior angiographic outcomes to plain-old balloon angioplasty. Although current data are promising, there is still a need for further long-term randomized control trial data comparing a DCB-only approach specifically against a second- or third-generation DES. A 4-week period of dual antiplatelet therapy provides a real advantage for the DCB-only PCI approach, which is not possible with most DESs. Since rates of adverse clinical outcomes are very low for all PCI procedures attention should be turned to the development of robust endpoints with which to compare DCB-only PCI approaches to the standard treatment with a DES.

Long-Acting HIV Drugs for Treatment and Prevention

Antiretroviral drugs have revolutionized the treatment and prevention of HIV infection; however, adherence is critical for sustained efficacy. Current HIV treatment consists of three-drug regimens, and current HIV pre-exposure prophylaxis (PrEP) consists of a two-drug regimen; both generally require adherence to once-daily dosing. Long-acting formulations are useful in the treatment and prevention of other conditions (e.g., contraceptives, antipsychotics) and help promote adherence. Newer long-acting formulations of approved and investigational antiretroviral drugs in existing and newer mechanistic classes are under study for HIV treatment and prevention, including some phase III trials. Although long-acting antiretroviral drugs hold promise, some clinical challenges exist, including managing side effects, drug-drug interactions, pregnancy, and long-lasting drug concentrations that could lead to the development of drug resistance. This review aims to summarize currently available information on long-acting antiretroviral drugs for HIV treatment and prevention.

Comparison of drug eluting stents (DESs) and bare metal stents (BMSs) with STEMI: who received BMS in the era of 2nd generation DES?

BACKGROUND

The aim of this study was to analyze the indications for using bare metal stents (BMSs) in hospitalizations with ST segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI).

METHODS

The study cohorts were identified from the National Inpatient Sample database from 2010-2014 using appropriate, International Classification of Diseases, 9^th Revision, Clinical Modification, diagnostic and procedural codes.

RESULTS

A total of 123,487 hospitalizations were identified for this study. Drug eluting stent (DES) use demonstrated lower in-hospital mortality (5.8% vs. 3.3%, P = < 0.01) and other in-hospital outcomes, thus resulting in lower hospitalization stay. Higher age, black race, greater comorbidity burden, inferior wall myocardial infarction, and the use of mechanical circulatory devices were all associated with BMS use.

CONCLUSION

DES was the preferred standard of care in the era of 2nd generation DES; however, BMSs were used in hospitalizations with high-risk procedures and multiple risk factors.

Drug discovery targeting the mTOR pathway

Mechanistic target of rapamycin (mTOR) is the kinase subunit of two structurally and functionally distinct large multiprotein complexes, referred to as mTOR complex 1 (mTORC1) and mTORC2. mTORC1 and mTORC2 play key physiological roles as they control anabolic and catabolic processes in response to external cues in a variety of tissues and organs. However, mTORC1 and mTORC2 activities are deregulated in widespread human diseases, including cancer. Cancer cells take advantage of mTOR oncogenic signaling to drive their proliferation, survival, metabolic transformation, and metastatic potential. Therefore, mTOR lends itself very well as a therapeutic target for innovative cancer treatment. mTOR was initially identified as the target of the antibiotic rapamycin that displayed remarkable antitumor activity in vitro Promising preclinical studies using rapamycin and its derivatives (rapalogs) demonstrated efficacy in many human cancer types, hence supporting the launch of numerous clinical trials aimed to evaluate the real effectiveness of mTOR-targeted therapies. However, rapamycin and rapalogs have shown very limited activity in most clinical contexts, also when combined with other drugs. Thus, novel classes of mTOR inhibitors with a stronger antineoplastic potency have been developed. Nevertheless, emerging clinical data suggest that also these novel mTOR-targeting drugs may have a weak antitumor activity. Here, we summarize the current status of available mTOR inhibitors and highlight the most relevant results from both preclinical and clinical studies that have provided valuable insights into both their efficacy and failure.

The Newest Generation of Drug-eluting Stents and Beyond

There has been a great evolution in the development of coronary stents in order to avoid both restenosis and thrombosis. Improvements have led to improvements in the design and conformation of metallic or resorbable structures, with an adequate balance between trackability and radial force, the development of antiproliferative drugs and the polymers to control release and allow adequate endothelialisation and an optimal duration of the antiplatelet regimen. Some suggestions are provided about the ideal characteristics of future coronary stents.

Phenotypic switching prevention and proliferation/migration inhibition of vascular smooth muscle cells by the ruthenium nitrosyl complex trans-[Ru(NO)Cl(cyclam](PF6 )2

OBJECTIVES

Vascular smooth muscle cell (VSMC) migration and proliferation at sites of vascular injury are both critical steps in the development of intimal hyperplasia (IH). Local delivery of nitric oxide (NO) largely prevents these events. Among the NO donors, tetraazamacrocyclic nitrosyl complexes, such as trans-[Ru(NO)Cl(cyclam)](PF₆ )₂ (cyclamNO), gained attention for their features, which include the possibility of being embedded in solid matrices, and ability to participate in a nitrite/NO catalytic conversion cycle.

METHODS

Methods used to evaluate cyclamNO activity: safety margin by NR and MTT; cell proliferation by 3H-thymidine incorporation and proliferating cell nuclear antigen (PCNA) expression; antimigratory properties by transwell and wound healing; prevention of cell phenotypic switching under platelet-derived growth factor type BB (PDGF-BB) stimuli by analysis of alpha smooth muscle actin (α-SMA) expression.

KEY FINDINGS

Cell proliferation and migration induced by PDGF-BB were significantly inhibited by cyclamNO. The ~60% reduction on expression of contractile protein α-SMA induced by PDGF-BB revealed VSMC phenotypic switching which is significantly prevented by cyclamNO. Compared to the NO donor sodium nitroprusside, cyclamNO showed to be significantly less cytotoxic.

CONCLUSIONS

With great potential to maintain VSMC functionality and prevent IH-associated events, cyclamNO might be a promissory drug for several applications in cardiovascular medicine, as in stents.