First Report of Edge Vascular Response at 12 Months of Magmaris, A Second-Generation Drug-Eluting Resorbable Magnesium Scaffold, Assessed by Grayscale Intravascular Ultrasound, Virtual Histology, and Optical Coherence Tomography. A Biosolve-II Trial Sub-Study

Applying Principles of Regenerative Medicine to Vascular Stent Development

Stents are a widely-used device to treat a variety of cardiovascular diseases. The purpose of this review is to explore the application of regenerative medicine principles into current and future stent designs. This review will cover regeneration-relevant approaches emerging in the current research landscape of stent technology. Regenerative stent technologies include surface engineering of stents with cell secretomes, cell-capture coatings, mimics of endothelial products, surface topography, endothelial growth factors or cell-adhesive peptides, as well as design of bioresorable materials for temporary stent support. These technologies are comparatively analyzed in terms of their regenerative effects, therapeutic effects and challenges faced; their benefits and risks are weighed up for suggestions about future stent developments. This review highlights two unique regenerative features of stent technologies: selective regeneration, which is to selectively grow endothelial cells on a stent but inhibit the proliferation and migration of smooth muscle cells, and stent-assisted regeneration of ischemic tissue injury.

Ultrasound Methods in the Evaluation of Atherosclerosis: From Pathophysiology to Clinic

Atherosclerosis is a key pathological process that causes a plethora of pathologies, including coronary artery disease, peripheral artery disease, and ischemic stroke. The silent progression of the atherosclerotic disease prompts for new surveillance tools that can visualize, characterize, and provide a risk evaluation of the atherosclerotic plaque. Conventional ultrasound methods-bright (B)-mode US plus Doppler mode-provide a rapid, cost-efficient way to visualize an established plaque and give a rapid risk stratification of the patient through the Gray-Weale standardization-echolucent plaques with ≥50% stenosis have a significantly greater risk of ipsilateral stroke. Although rather disputed, the measurement of carotid intima-media thickness (C-IMT) may prove useful in identifying subclinical atherosclerosis. In addition, contrast-enhanced ultrasonography (CEUS) allows for a better image resolution and the visualization and quantification of plaque neovascularization, which has been correlated with future cardiovascular events. Newly emerging elastography techniques such as strain elastography and shear-wave elastography add a new dimension to this evaluation-the biomechanics of the arterial wall, which is altered in atherosclerosis. The invasive counterpart, intravascular ultrasound (IVUS), enables an individualized assessment of the anti-atherosclerotic therapies, as well as a direct risk assessment of these lesions through virtual histology IVUS.

New Approaches for Hydrogen Therapy of Various Diseases

Hydrogen therapy has recently received increasing attention as an emerging and promising therapeutic technology due to its selective antioxidant property and cell energy regulatory capability in vivo. To solve the low solubility issue of hydrogen, a variety of nanomaterials and devices for hydrogen supply have recently been developed, aiming to increase the concentration of hydrogen in the specific disease site and realize controlled hydrogen release and combined treatment. In this review, we mainly focus on the latest advances in using hydrogen-generating devices and nanomaterials for hydrogen therapy. These developments include sustained release of H2, controlled release of H2, versatile modalities of synergistic therapy, etc. Also, bio-safety issues and challenges are discussed to further promote the clinical applications of hydrogen therapy and the development of hydrogen medicine.

Successful bailout stenting strategy against rare spontaneous retrograde dissection of partially absorbed magnesium-based resorbable scaffold: A case report

BACKGROUND

In the development of coronary stent technology, bioresorbable scaffolds are promising milestones in improving the clinical treatment of coronary artery disease. The “leave nothing behind” motto is the premise of the fourth revolution in percutaneous coronary intervention (PCI). Studies proving the safety and efficacy of the magnesium-based resorbable scaffolds (MgBRSs) include the BIOSOLVE-I and BIOSOLVE-II trials and the latest BIOSOLVE-IV registry. However, spontaneous retrograde dissection of a partially absorbed MgBRS may still occur, albeit rarely.

CASE SUMMARY

We describe an unusual case of coronary artery disease in a patient who had undergone a successful PCI 8 mo earlier, where an MgBRS was implanted into the left anterior descending artery (LAD) and left circumflex artery with drug-coated balloons for a ramus intermedius branch stenosis to achieve the “leave nothing behind” therapeutic intention and was currently presenting with a gradual worsening of chest tightness. The distal edge vascular response, during subsequent attempts with balloon angioplasty was performed smoothly. However, spontaneous retrograde dissection of a partially absorbed MgBRS in the LAD ensued. Successful bailout stenting was performed with revascularization of the entry and exit sites created by spontaneous dissection and complete sealing of the intramural hematoma. The patient recovered well and was discharged after 2 d of intervention. When followed up in August 2020 (7 mo later), the patient showed uneventful recovery.

CONCLUSION

Spontaneous retrograde dissection of a partially absorbed MgBRS was successfully treated using bailout sirolimus-eluting coronary stent strategy.

Modern Stents: Where Are We Going?

Coronary artery stenting is the treatment of choice for patients requiring coronary angioplasty. We describe the major advancements with this technology. There have been significant developments in the design of stents and adjunctive medical therapies. Newer-generation drug-eluting stents (DES) have almost negligible restenosis rates and, when combined with proper anti-platelet treatment and optimal deployment, a low risk of stent thrombosis. The introduction of newer-generation DES with thinner stent struts, novel durable or biodegradable polymer coatings, and new antiproliferative agents has further improved the safety profile of early-generation DES. In parallel the effectiveness has been kept, with a significant reduction in the risk of target lesion revascularization compared with the early-generation DES. However, to date, the development of completely bioresorbable vascular scaffolds has failed to achieve further clinical benefits and has been associated with increased thrombosis. Newer-generation DES-including both durable polymer as well as biodegradable polymer-have become the standard of care in all patient and lesion subsets, with excellent long-term results.

Sustained Safety and Performance of the Second-Generation Sirolimus-Eluting Absorbable Metal Scaffold: Pooled Outcomes of the BIOSOLVE-II and -III Trials at 3 Years

BACKGROUND/PURPOSE

To avoid long-term effects associated with permanent implants, bioresorbable vascular scaffolds were developed, as they provide transient vessel support and disappear thereafter. The aim of the BIOSOLVE-II and -III studies was to assess the safety and performance of a magnesium-based sirolimus-eluting scaffold; we report the clinical outcomes at 3 years, 2 years after scaffold resorption.

METHODS/MATERIALS

BIOSOLVE-II and BIOSOLVE-III are international, prospective multi-center studies, including 184 patients with 189 de novo lesions and stable or unstable angina, or documented silent ischemia. Acute myocardial infarction, 3-vessel coronary artery disease, and heavily calcified lesions were excluded. Antiplatelet therapy was recommended for 6 months.

RESULTS

Patients were 65.5 ± 10.8 years old, and lesions were 12.1 ± 4.5 mm long and located in vessels with a diameter of 2.7 ± 0.4 mm. More than half of the lesions (56.5%) were type B2/C lesions. At 2 years, 92.5% (160/173) of patients were symptom-free and 91.5% (151/165) at 3 years; all the other patients had stable angina. At 3 years, target lesion failure occurred in 11 patients (6.3%), consisting of 4 cardiac deaths (2.3%), one target-vessel myocardial infarction (0.6%), and 6 clinically driven target lesion revascularizations (3.4%). There was no definite or probable scaffold thrombosis.

CONCLUSION

In a low-risk patient population, treatment with a sirolimus-eluting magnesium bioresorbable scaffold can be considered safe, in particular with no definite or probable scaffold thrombosis.

ANNOTATED TABLE OF CONTENTS

BIOSOLVE-II and -III are prospective, international, multi-center studies including 184 patients with de novo lesions. At 3 years, target lesion failure was 6.3%, consisting of 4 cardiac deaths (2.3%), one target-vessel myocardial infarction (0.6%), and 6 clinically driven target lesion revascularizations (3.4%). There was no definite or probable scaffold thrombosis.

Acute treatment of critical vascular stenoses with a bioabsorbable magnesium scaffold in infants with CHDs

BACKGROUND

Post-operative severe vascular stenosis and proliferating endothelial tissue lead to severe circulatory disorders and impair organ perfusion. Bioabsorbable magnesium scaffolds may help to overcome these obstructions without leaving obstructing stent material. We analyse their role in the treatment of vascular stenosis in infants.

METHODS

Since 2016, 15 magnesium scaffolds with a diameter of 3.5 mm were implanted in 9 patients aged 15 days to 7.6 years. Eight scaffolds were implanted in pulmonary venous restenoses, five in pulmonary arterial stenosis including one in-stent stenosis, one into a stenotic brachiocephalic artery, and one in a recurrent innominate vein thrombosis.

RESULTS

All patients clinically improved after the implantation of a scaffold. The magnesium scaffolds lost integrity after 30-48 days (mean 42 days). The innominate vein thrombosed early, while all other vessels remained open. Two patients died after 1.3 and 14 weeks not related to the scaffolds. Five patients needed further balloon dilations or stent implantations after the scaffold had fractured. At first recatheterisation after in mean 2.5 months, the mean minimum/maximum diameter in relation to the scaffold's original diameter was 89%/99% in the arterial implantations (n = 6) and 66%/77% in the pulmonary venous implantations.

CONCLUSIONS

The magnesium scaffolds can be used as a bridging solution to treat severe vascular stenosis in different locations. Restenosis can occur after degradation and make further interventions necessary, but neither vessel growth nor further interventions are hindered by stent material. Larger diameters may improve therapeutic options.

The Development of Magnesium-Based Resorbable and Iron-Based Biocorrodible Metal Scaffold Technology and Biomedical Applications in Coronary Artery Disease Patients

In the treatment of atherosclerotic disease patients, the adoption of second-generation drug-eluting stents (DES) in percutaneous coronary intervention reduced the occurrence of in-stent restenosis (ISR) and acute stent thrombosis (ST) when compared to bare metal stents and 1st generation DES. However, the permanent encaging of the vessel wall by any of the metallic stents perpetuates the inflammation process and prevents vasomotion in the treated segment. Aiming to overcome this issue, the bioresorbable scaffold (BRS) concept was developed by providing transient vascular radial support to the target segment during the necessary time to heal and disappearing after a period of time. Close to 20 years since BRS technology was first reported, the interventional cardiology field saw the rise and fall of several BRS devices. Although iron-based BRS is an emerging technology, currently, magnesium-alloy resorbable scaffolds devices are supported with the most robust data. This manuscript aims to review the concept of magnesium-based BRS devices, as well as their bioresorption mechanisms and the status of this technology, and the clinical outcomes of patients treated with magnesium BRS and to review the available evidence on iron-based BRS technology.