Safety and efficacy of the novel sirolimus‐eluting bioresorbable scaffold for the treatment of de novo coronary artery disease: One‐year results from a prospective patient‐level pooled analysis of NeoVas trials

Long-term outcomes following bioresorbable vascular scaffolds

INTRODUCTION

The higher scaffold thrombosis rates observed with the first-generation bioresorbable scaffolds (BRSs) compared to conventional drug-eluting stents were likely due in part to bioresorbable polymers having insufficient radial strength, necessitating larger strut profiles. Meta-analysis of the long-term outcomes from the first-generation Absorb bioresorbable vascular scaffold (BVS) showed that this period of excess risk ended at 3 years. Therefore, current attention has been focused on improving early outcomes by increasing the scaffold's tensile strength and reducing strut thickness.

AREAS COVERED

This review summaries the lessons learned from the first-generation BRS. It updates the long-term clinical outcomes of trials evaluating the ABSORB BVS and metallic alloy-based BRS. In addition, it reviews the next-generation BRSs manufactured in Asia.

EXPERT OPINION

Critical areas to improve the performance and safety of biodegradable scaffolds include further development in material science, surface modification, delivery systems, and long-term follow-up studies.

Dynamic changes in inflammatory responses and 3-year clinical outcomes of XINSORB scaffolds in coronary stenting

BACKGROUND

Inflammation is known to play a crucial role in the development of coronary atherosclerosis and vascular healing after stenting. This study aimed to investigate the dynamic changes in inflammatory responses between XINSORB and TIVOLI scaffolds and their correlation with 3-year clinical outcomes.

METHOD

A total of 140 patients in the XINSORB group and 42 patients in the TIVOLI group were included in this prospective, single-center study, conducted in Shanghai tenth People's Hospital. Blood samples were collected at baseline, 24 h, 6 months, and 12 months after stent implantation to measure high sensitivity C-reactive protein (hsCRP), fibrinogen (FBG), white blood cell count (WBC), tumor necrosis factor (TNF), and interleukin-6 (IL-6). Receiver-operating characteristic curves and proportional hazards models were generated to evaluate the relationship between 24-h postoperative inflammatory indicators and 3-year patient-oriented composite endpoints (POCE).

RESULT

The levels of hsCRP, FBG, WBC, TNF, and IL-6 reached their peak levels 24 h after stenting and then gradually decreased to levels comparable to baseline at 6 and 12 months. During the 3-year follow-up, 11.4 % of the XINSORB cohort and 9.5 % of the TIVOLI cohort experienced POCE (P = 0.948). High levels of hsCRP and IL-6 24 h after the procedure were associated with clinical endpoints, and the combination of these two biomarkers improved the predictive ability of prognosis.

CONCLUSIONS

There were no significant differences between the changes in the concentration of inflammatory biomarkers after XINSORB stents or drug-eluting stent implantation. Reduction in postoperative inflammatory levels may decrease the occurrence of clinical outcomes. This study provides insights into the dynamic changes of inflammatory responses and their correlation with clinical outcomes, which could have implications for the management of patients undergoing coronary stenting.

TRIAL REGISTRATION

The study has been registered on the official website of the China Clinical Trial Registry (ChiCTR1800014966).

Three-year clinical outcomes of the novel sirolimus-eluting bioresorbable scaffold for the treatment of de novo coronary artery disease: A prospective patient-level pooled analysis of NeoVas trials

OBJECTIVES

We aimed to evaluate the long-term outcomes of the novel NeoVas sirolimus-eluting bioresorbable scaffold (BRS) for the treatment of de novo coronary artery disease.

BACKGROUND

The long-term safety and efficacy of the novel NeoVas BRS are still needed to be elucidated.

METHODS

A total of 1103 patients with de novo native coronary lesions for coronary stenting were enrolled. The primary endpoint of target lesion failure (TLF) was defined as a composite of cardiac death (CD), target vessel myocardial infarction (TV-MI), or ischemia-driven-target lesion revascularization (ID-TLR).

RESULTS

A three-year clinical follow-up period was available for 1,091 (98.9%) patients. The cumulative TLF rate was 7.2% with 0.8% for CD, 2.6% for TV-MI, and 5.1% for ID-TLR. Additionally, 128 (11.8%) patient-oriented composite endpoint and 11 definite/probable stent thromboses (1.0%) were recorded.

CONCLUSIONS

The extended outcomes of the NeoVas objective performance criterion trial demonstrated a promising 3-year efficacy and safety of the NeoVas BRS in low-risk patients with low complexity in terms of lesions and comorbidities.

A Novel PLLA/MgF2 Coating on Mg Alloy by Ultrasonic Atomization Spraying for Controlling Degradation and Improving Biocompatibility

Problems of rapid degradation and poor biocompatibility (endothelialization and hemocompatibility) limit magnesium (Mg) alloy's further applications in vascular stents. To solve these problems, a novel composite coating was designed on Mg alloy via a two-step method. First, a Mg alloy sample was immersed in hydrofluoric acid. Then, a poly-l-lactic acid (PLLA) coating was made by ultrasonic atomization spraying with 5 and 10 layers (referred to as PLLA(5)-HF-Mg and PLLA(10)-HF-Mg). Characterizations were analyzed from the microstructure, element distribution, and wettability. The degradation behavior was tested with an electrochemical test and immersion test. Endothelialization was investigated using human umbilical vein endothelial cells (HUVECs). Hemocompatibility was examined with a platelet adhesion test. The results showed that the PLLA coating could not only cover the surface, but also could permeate through and cover the holes on the MgF₂ layer, mechanically locked with the substrate. Thus, the composite coating had higher corrosion resistance. The PLLA/MgF₂ coating, especially on PLLA(10)-HF-Mg, enhanced HUVECs' viability and growth. While incubated with platelets, the PLLA/MgF₂ coating, especially on PLLA(10)-HF-Mg, had the lowest platelet adhesion number and activity. Taken together, the novel PLLA/MgF₂ coating controls Mg alloy's degradation by spraying different layers of PLLA, resulting in better endothelialization and hemocompatibility, providing a promising candidate for cardiovascular stents.

Development of Innovative Biomaterials and Devices for the Treatment of Cardiovascular Diseases

Cardiovascular diseases have become the leading cause of death worldwide. The increasing burden of cardiovascular diseases has become a major public health problem and how to carry out efficient and reliable treatment of cardiovascular diseases has become an urgent global problem to be solved. Recently, implantable biomaterials and devices, especially minimally invasive interventional ones, such as vascular stents, artificial heart valves, bioprosthetic cardiac occluders, artificial graft cardiac patches, atrial shunts, and injectable hydrogels against heart failure, have become the most effective means in the treatment of cardiovascular diseases. Herein, an overview of the challenges and research frontier of innovative biomaterials and devices for the treatment of cardiovascular diseases is provided, and their future development directions are discussed.

The Development of Design and Manufacture Techniques for Bioresorbable Coronary Artery Stents

Coronary artery disease (CAD) is the leading killer of humans worldwide. Bioresorbable polymeric stents have attracted a great deal of interest because they can treat CAD without producing long-term complications. Bioresorbable polymeric stents (BMSs) have undergone a sustainable revolution in terms of material processing, mechanical performance, biodegradability and manufacture techniques. Biodegradable polymers and copolymers have been widely studied as potential material candidates for bioresorbable stents. It is a great challenge to find a reasonable balance between the mechanical properties and degradation behavior of bioresorbable polymeric stents. Surface modification and drug-coating methods are generally used to improve biocompatibility and drug loading performance, which are decisive factors for the safety and efficacy of bioresorbable stents. Traditional stent manufacture techniques include etching, micro-electro discharge machining, electroforming, die-casting and laser cutting. The rapid development of 3D printing has brought continuous innovation and the wide application of biodegradable materials, which provides a novel technique for the additive manufacture of bioresorbable stents. This review aims to describe the problems regarding and the achievements of biodegradable stents from their birth to the present and discuss potential difficulties and challenges in the future.

Current perspectives on bioresorbable scaffolds in coronary intervention and other fields

Introduction: The first-generation bioresorbable scaffolds (BRSs) had a large strut profile to compensate for the insufficient radial strength of bioresorbable polymer materials, resulting in higher scaffold thrombosis rates than conventional drug-eluting stents. To improve the clinical safety and efficacy, the new generation BRSs have been improved by optimal structure design, post-processing of bioresorbable polymer materials, or altering bioresorbable metallic alloys.Areas covered: This review summarizes the lessons learned from the first-generation BRS, updates the clinical outcomes of trials evaluating ABSORB bioresorbable vascular scaffold at long-term and bioresorbable metallic alloy-based devices, and examines recent outcomes of BRS treated in STEMI patients. This review also provides an overview of the current clinical data of seven BRSs manufactured in Asia, and of the BRSs extended application in other clinical arenas.Expert opinion: Drawbacks of the first-generation BRSs need to be addressed by the next generation of these stents with novel materials and technologies. Clinical research, including randomized controlled trials, are required to further evaluate BRSs application in coronary artery disease. The encouraging results of BRSs innovation applied in the peripheral arteries and gastrointestinal tracts support other potential clinical applications of BRS technology.

In vivo degradation and endothelialization of an iron bioresorbable scaffold

Detection of in vivo biodegradation is critical for development of next-generation medical devices such as bioresorbable stents or scaffolds (BRSs). In particular, it is urgent to establish a nondestructive approach to examine in vivo degradation of a new-generation coronary stent for interventional treatment based on mammal experiments; otherwise it is not available to semi-quantitatively monitor biodegradation in any clinical trial. Herein, we put forward a semi-quantitative approach to measure degradation of a sirolimus-eluting iron bioresorbable scaffold (IBS) based on optical coherence tomography (OCT) images; this approach was confirmed to be consistent with the present weight-loss measurements, which is, however, a destructive approach. The IBS was fabricated by a metal-polymer composite technique with a polylactide coating on an iron stent. The efficacy as a coronary stent of this new bioresorbable scaffold was compared with that of a permanent metal stent with the name of trade mark Xience, which has been widely used in clinic. The endothelial coverage on IBS was found to be greater than on Xience after implantation in a rabbit model; and our well-designed ultrathin stent exhibited less individual variation. We further examined degradation of the IBSs in both minipig coronary artery and rabbit abdominal aorta models. The present result indicated much faster iron degradation of IBS in the rabbit model than in the porcine model. The semi-quantitative approach to detect biodegradation of IBS and the finding of the species difference might be stimulating for fundamental investigation of biodegradable implants and clinical translation of the next-generation coronary stents.

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A semi-quantitative OCT method was suggested to evaluate in vivo biodegradation of an iron based coronary stent IBS in a nondestructive manner.

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The in vivo biodegradation of IBS exhibited dependence on animal species.

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The endothelial coverage on the biodegradable stent IBS was better than on the commercialized nonbiodegradable stent Xience in rabbits.