Three-Year Outcomes With the Absorb Bioresorbable Scaffold: Individual-Patient-Data Meta-Analysis From the ABSORB Randomized Trials

Accelerated degradation testing impacts the degradation processes in 3D printed amorphous PLLA

Additive manufacturing and electrospinning are widely used to create degradable biomedical components. This work presents important new data showing that the temperature used in accelerated tests has a significant impact on the degradation process in amorphous 3D printed poly-l-lactic acid (PLLA) fibres. Samples (c. 100 μ m diameter) were degraded in a fluid environment at37 ° C,50 ° C and80   ° C over a period of 6 months. Our findings suggest that across all three fluid temperatures, the fibres underwent bulk homogeneous degradation. A three-stage degradation process was identified by measuring changes in fluid pH, PLLA fibre mass, molecular weight and polydispersity index. At37   ° C, the fibres remained amorphous but, at elevated temperatures, the PLLA crystallised. A short-term hydration study revealed a reduction in glass transition (Tg), allowing the fibres to crystallise, even at temperatures below the dry Tg. The findings suggest that degradation testing of amorphous PLLA fibres at elevated temperatures changes the degradation pathway which, in turn, affects the sample crystallinity and microstructure. The implication is that, although higher temperatures might be suitable for testing bulk material, predictive testing of the degradation of amorphous PLLA fibres (such as those produced via 3D printing or electrospinning) should be conducted at37   ° C.

Drug-eluting stents for coronary artery disease in the perspective of bibliometric analysis

Drug-eluting stents (DES) play a crucial role in treating coronary artery disease (CAD) by preventing restenosis. These stents are coated with drug carriers that release antiproliferative drugs within the vessel. Over the past two decades, DES have been employed in clinical practice using various materials, polymers, and drug types. Despite optimizations in their design and materials to enhance biocompatibility and antithrombotic properties, evaluating their long-term efficacy and safety necessitates improved clinical follow-up and monitoring. To delineate future research directions, this study employs a bibliometric analysis approach. We comprehensively surveyed two decades' worth of literature on DES for CAD using the Web of Science Core Collection (WOSCC). Out of 5,778 articles, we meticulously screened them based on predefined inclusion and exclusion criteria. Subsequently, we conducted an in-depth analysis encompassing annual publication trends, authorship affiliations, journal affiliations, keywords, and more. Employing tools such as Excel 2021, CiteSpace 6.2R3, VOSviewer 1.6.19, and Pajek 5.17, we harnessed bibliometric methods to derive insights from this corpus. Analysis of annual publication data indicates a recent stabilisation or even a downward trend in research output in this area. The United States emerged as the leading contributor, with Columbia University and CRF at the forefront in both publication output and citation impact. The most cited document pertained to standardized definitions for clinical endpoints in coronary stent trials. Our author analysis identifies Patrick W. Serruys as the most prolific contributor, underscoring a dynamic exchange of knowledge within the field.Moreover, the dual chart overlay illustrates a close interrelation between journals in the "Medicine," "Medical," and "Clinical" domains and those in "Health," "Nursing," and "Medicine." Frequently recurring keywords in this research landscape include DES coronary artery disease, percutaneous coronary intervention, implantation, and restenosis. This study presents a comprehensive panorama encompassing countries, research institutions, journals, keyword distributions, and contributions within the realm of DES therapy for CAD. By highlighting keywords exhibiting recent surges in frequency, we elucidate current research hotspots and frontiers, thereby furnishing novel insights to guide future researchers in this evolving field.

Enabling Proregenerative Medical Devices via Citrate-Based Biomaterials: Transitioning from Inert to Regenerative Biomaterials

Regenerative medicine aims to restore tissue and organ function without the use of prosthetics and permanent implants. However, achieving this goal has been elusive, and the field remains mostly an academic discipline with few products widely used in clinical practice. From a materials science perspective, barriers include the lack of proregenerative biomaterials, a complex regulatory process to demonstrate safety and efficacy, and user adoption challenges. Although biomaterials, particularly biodegradable polymers, can play a major role in regenerative medicine, their suboptimal mechanical and degradation properties often limit their use, and they do not support inherent biological processes that facilitate tissue regeneration. As of 2020, nine synthetic biodegradable polymers used in medical devices are cleared or approved for use in the United States of America. Despite the limitations in the design, production, and marketing of these devices, this small number of biodegradable polymers has dominated the resorbable medical device market for the past 50 years. This perspective will review the history and applications of biodegradable polymers used in medical devices, highlight the need and requirements for regenerative biomaterials, and discuss the path behind the recent successful introduction of citrate-based biomaterials for manufacturing innovative medical products aimed at improving the outcome of musculoskeletal surgeries.

Synchrotron microtomography reveals insights into the degradation kinetics of bio-degradable coronary magnesium scaffolds

Bioresorbable magnesium scaffolds are a promising future treatment option for coronary artery stenosis, especially for young adults. Due to the degradation of these scaffolds (<1 year), long-term device-related clinical events could be reduced compared to treatments with conventional drug eluting stents. First clinical trials indicate a return of vasomotion after one year, which may be associated with improved long-term clinical outcomes. However, even after decades of development, the degradation process, ideal degradation time and biological response in vivo are still not fully understood. The present study investigates the in vivo degradation of magnesium scaffolds in the coronary arteries of pigs influenced by different strut thicknesses and the presence of antiproliferative drugs. Due to high 3D image contrast of synchrotron-based micro-CT with phase contrast (SR-μCT), a qualitative and quantitative evaluation of the degradation morphology of magnesium scaffolds was obtained. For the segmentation of the μCT images a convolutional network architecture (U-net) was exploited, demonstrating the huge potential of merging high resolution SR-μCT with deep learning (DL) supported data analysis. In total, 30 scaffolds, made of the rare earth alloy Resoloy®, with different strut designs were implanted into the coronary arteries of 10 domestic pigs for 28 days using drug-coated or uncoated angioplasty balloons for post-dilatation. The degradation morphology was analyzed using scanning electron microscopy, energy dispersive x-ray spectroscopy and SR-μCT. The data from these methods were then related to data from angiography, optical coherence tomography and histology. A thinner strut size (95 vs. 130 μm) and the presence of paclitaxel indicated a slower degradation rate at 28 d in vivo, which positively influences the late lumen loss (0.5 and 0.6 mm vs. 1.0 and 1.1 mm) and recoil values (0 and 1.7% vs. 6.1 and 22%).

Hybrid interpenetrating network of polyester coronary stent with tunable biodegradation and mechanical properties

Poly(l-lactide) (PLLA) is an important candidate raw material of the next-generation biodegradable stent for percutaneous coronary intervention, yet how to make a polyester stent with sufficient mechanical strength and relatively fast biodegradation gets to be a dilemma. Herein, we put forward a hybrid interpenetrating network (H-IPN) strategy to resolve this dilemma. As such, we synthesize a multi-functional biodegradable macromer of star-like poly(d,l-lactide-co-ɛ-caprolactone) with six acrylate end groups, and photoinitiate it, after mixing with linear PLLA homopolymer, to trigger the free radical polymerization. The resultant crosslinked polymer blend is different from the classic semi-interpenetrating network, and partial chemical crosslinking occurs between the linear polymer and the macromer network. Combined with the tube blow molding and the postprocessing laser cutting, we fabricate a semi-crosslinked-polyester biodegradable coronary stent composed of H-IPN, which includes a physical network of polyester spherulites and a chemical crosslinking network of copolyester macromers and a part of homopolymers. Compared with the currently main-stream PLLA stent in research, this H-IPN stent realizes a higher and more appropriate biodegradation rate while maintaining sufficient radial strength. A series of polymer chemistry, polymer physics, polymer processing, and in vitro and in vivo biological assessments of medical devices have been made to examine the H-IPN material. The interventional implanting of the H-IPN stent into aorta abdominalis of rabbits and the follow-ups to 12 months have confirmed the safety and effectiveness.

How to perform a successful drug-coated balloon angioplasty? Tips and tricks

Drug-coated balloons (DCB) offer an excellent alternative to stents as the antiproliferative drugs are delivered via balloons and hence there is no permanent implant of metal or polymer. This rationale applies perfectly in in-stent restenosis (ISR) as we want to avoid another layer of metal in a previously failed stent. However, their use has also been extended to de novo lesions especially in patients and lesion subsets where stents are not ideal. There is an increased desire toward expanding this further and studies are now being done which are testing DCB in large-caliber vessels. As the use of DCB is escalating, we felt the importance of writing this article whereby we aim to provide important tips and tricks when using DCB especially for the operators who are in the early phase or have the desire of embarking this technology. From our experience, the DCB-angioplasty substantially differs on several aspects from DES-angioplasty. We have provided several case bases examples including algorithm when using DCB in ISR and de novo lesions.

Mid-term safe and effective profile of the Magmaris scaffold in percutaneous coronary intervention: a prospective, single-center study

Introduction

Significant advances have been made in the diagnosis and treatment of coronary artery disease over the years. New generations of scaffolds containing novel material and eluting drug have produced one of the most significant advancements in coronary intervention. The newest generation would be Magmaris with a magnesium frame and a sirolimus cover.

Methods

From July 2018 to August 2020, 58 patients treated with Magmaris at the University Medical Center Ho Chi Minh City were enrolled in this study.

Results

A total of 60 lesions were stented, 60.3% of which were left anterior descending (LAD) lesions. There was no in-hospital event. Within 1 year after discharge, we noted one myocardial infarction event that required target-lesion revascularization, one stroke event, one non-target-lesion revascularization patient, two target-vessel revascularization patients, and one in-stent thrombosis. Among them, one myocardial infarction occurrence, one non-target-lesion revascularization, and one in-stent thrombosis event were recorded within the first 30 days after discharge.

Conclusion

In conclusion, the Magmaris scaffold is a safe and effective option for structural procedures performed with imaging device support, particularly intravascular ultrasound.

Restoring endothelial function: shedding light on cardiovascular stent development

Complete endothelialization is highly important for maintaining long-term patency and avoiding subsequent complications in implanting cardiovascular stents. It not only refers to endothelial cells (ECs) fully covering the inserted stents, but also includes the newly formed endothelium, which could exert physiological functions, such as anti-thrombosis and anti-stenosis. Clinical outcomes have indicated that endothelial dysfunction, especially the insufficiency of antithrombotic and barrier functions, is responsible for stent failure. Learning from vascular pathophysiology, endothelial dysfunction on stents is closely linked to the microenvironment of ECs. Evidence points to inflammatory responses, oxidative stress, altered hemodynamic shear stress, and impaired endothelial barrier affecting the normal growth of ECs, which are the four major causes of endothelial dysfunction. The related molecular mechanisms and efforts dedicated to improving the endothelial function are emphasized in this review. From the perspective of endothelial function, the design principles, advantages, and disadvantages behind current stents are introduced to enlighten the development of new-generation stents, aiming to offer new alternatives for restoring endothelial function.

Negative findings but positive contributions in cardiovascular research

Researchers have always concluded that results that do not support the hypothesis as unimportant, unworthy, or simply not good enough for publication. However, negative findings are essential for the progress of science and its self-correcting nature. We also believe in the importance and indispensability of negative results. Therefore, in this review, we discussed the factors contributing to the publication bias of negative results and the problems to assess the factuality and validity of negative results. Moreover, we emphasized the importance of reporting negative results in cardiovascular research, including treatments, and suggest that the negative results could clarify previously controversial topics in the treatment of cardiovascular diseases and prompt the translation of research on precision cardiovascular disease prevention and treatment.

The plasticity of biocompatibility

Biocompatibility concerns the phenomena that occur within the interactions between biomaterials and human patients, which ultimately control the performance of many facets of medical technology. It involves aspects of materials science, many different forms of engineering and nanotechnology, chemistry, biophysics, molecular and cellular biology, immunology, pathology and a myriad of clinical applications. It is not surprising that an overarching framework of mechanisms of biocompatibility has been difficult to elucidate and validate. This essay discusses one fundamental reason for this; we have tended to consider biocompatibility pathways as essentially linear sequences of events which follow well-understood processes of materials science and biology. The reality, however, is that the pathways may involve a great deal of plasticity, in which many additional idiosyncratic factors, including those of genetic, epigenetic and viral origin, exert influence, as do complex mechanical, physical and pharmacological variables. Plasticity is an inherent core feature of the performance of synthetic materials; here we follow the more recent biological applications of plasticity concepts into the sphere of biocompatibility pathways. A straightforward linear pathway may result in successful outcomes for many patients; we may describe this in terms of classic biocompatibility pathways. In other situations, which usually command much more attention because of their unsuccessful outcomes, these plasticity-driven processes follow alternative biocompatibility pathways; often, the variability in outcomes with identical technologies is due to biological plasticity rather than material or device deficiency.

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.

Challenges of the newer generation of resorbable magnesium scaffolds: Lessons from failure mechanisms of the past generation

Bioresorbable scaffolds (BRS) were developed to overcome the obstacles of metallic stents, mostly related to sustained presence of metallic foreign body in the coronary vessel. Following earlier success of single-arm BRS studies, randomized controlled trials of Absorb bioresorbable vascular scaffold (Abbott Vascular, Santa Clara, CA, USA) showed poor long-term clinical outcomes, particularly in terms of scaffold thrombosis. BRS made from magnesium alloy provide a promising alternative in terms of radial force, strut thickness and, potentially lower thrombogenicity. A recent clinical study demonstrated that magnesium-based BRS seems to be promising with regards to the risk of scaffold thrombosis. In this review, our aim is to describe the issues that prevented Absorb BVS from achieving favorable outcomes, provide current status of existing BRS technologies and the challenges that newer generation BRSs need to overcome, and the results of clinical studies for commercially available magnesium-based BRS, which remain the only BRS actively studied in clinical practice.

Biodegradable polymer everolimus-eluting stents versus contemporary drug-eluting stents: a systematic review and meta‑analysis

In spite of similar efficacy and safety in pilot studies, compared with the contemporary durable polymer drug-eluting stent (DP-DES), the bioabsorbable polymer drug-eluting stent (BP-DES) may be more superior in promoting blood vessel healing. We sought to compare the safety and efficacy of everolimus-eluting BP-DES (BP-EES) with contemporary DP-DES through a meta-analysis. We performed this meta-analysis to provide further evidence of the safety and efficacy of BP-EES. Medline, Embase and the Cochrane library databases were searched for randomized controlled trials comparing clinical efficacy and safety of BP-EES versus contemporary DP-DES. Fifteen RCTs with a total of 15,572 patients were selected. The rate of MACE was 9.4% in patients receiving BP-EES and 7.3% receiving DP-EES (RR 1.13, 95% CI 0.99-1.29, p = 0.05; I² = 46%). TLF and MI were also similar in both groups. Based on the available data, this review demonstrates that BP-EES displays a clinically comparable efficacy and safety profile to that of contemporary DP-DES at years of follow-up in patients undergoing PCI.

The standard versus prolonged dual antiplatelet therapy after the XINSORB bioresorbable scaffold implantation (SPARTA) trial: study protocol for a randomized controlled trial

BACKGROUND

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care after coronary stenting, including coronary stenting involving bioresorbable scaffolds (BRSs). Current clinical guidelines recommend at least 12 months of DAPT after BRS implantation. However, the correlation between prolonged DAPT and net clinical benefits remains unknown.

METHODS

The SPARTA trial is designed to be a prospective, randomized, parallel-group, clinical trial. It aims to compare the benefits and risks of DAPT applied for either 12 or 36 months after XINSORB BRS implantation. The primary endpoints are the incidence of the composite endpoint of major adverse cardiac events (MACEs), including all-cause death, any myocardial infarction (MI), and all revascularizations, as well as Bleeding Academic Research Consortium Definition (BARC) type 3 or 5 bleeding events. The secondary endpoints of the study include the device-oriented composite endpoint of target lesion failure (defined as cardiac death, target vessel-related MI, or ischemia-driven target lesion revascularization), target vessel failure (defined as cardiac death, MI, or ischemia-driven target vessel revascularization), scaffold thrombosis, and minor bleeding events. This trial will enroll 2106 subjects treated with the XINSORB BRS only. All subjects will receive DAPT after the index procedure for 12 (± 1) months. Subjects without MACEs or major bleeding will be randomized to receive either 24 additional months of DAPT or aspirin alone.

DISCUSSION

This trial is designed to investigate the impact of extending the duration of DAPT up to 3 years after XINSORB BRS implantation by investigating the balance of risks and benefits in a broad population of treated patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04501900 . Registered on 6 August 2020.

Everolimus-eluting bioresorbable scaffold versus everolimus-eluting metallic stent in primary percutaneous coronary intervention of ST-segment elevation myocardial infarction: a randomized controlled trial

BACKGROUND

Primary percutaneous coronary intervention with implantation of a metallic drug-eluting stent (DES) is the standard treatment for patients presenting with ST-elevation myocardial infarction (STEMI). Implantation of a bioresorbable scaffold (BRS) during STEMI represents a novel strategy without intravascular metal.

OBJECTIVE

The aim of the study was to investigate 12-month healing response in an STEMI population after implantation of either the Absorb BRS or Xience DES (Abbott Vascular, USA).

METHODS

The present trial was a prospective, randomized, controlled, nonblinded, noninferiority study with planned inclusion of 120 patients with STEMI. Patients were randomly assigned 1:1 to treatment with Absorb BRS or Xience DES. Implantation result and healing response were evaluated by angiography and optical coherence tomography (OCT) at baseline and 12-month follow-up. The primary endpoint was minimum flow area (MFA) assessed at 12 months. Coronary stent healing index (CSHI) was calculated from OCT images.

RESULTS

Out of 66 included patients, 58 had follow-up OCT after 12 months, and 49 entered matched analysis. One death occurred in each group; none were stent-related. MFA was 5.13 ± 1.70 mm2 (95% CI, 4.44-5.82) in the BRS group compared with 6.30 ± 2.49 mm2 (95% CI, 5.22-7.37) (P = 0.06) in the DES group. Noninferiority could not be evaluated. CSHI for both groups had a median score of 3.

CONCLUSION

The DES group performed numerically better in primary and secondary endpoints, but the CSHI showed good stent healing in both groups.

Comparison of a Bioresorbable, Magnesium-Based Sirolimus-Eluting Stent with a Permanent, Everolimus-Eluting Metallic Stent for Treating Patients with Acute Coronary Syndrome: the PRAGUE-22 Study

BACKGROUND

Magnesium-based bioresorbable Magmaris stents are rapidly resorbed. Few randomized studies have evaluated the efficacy of such stents in patients with acute coronary syndrome.

AIM

To investigate late lumen loss as assessed via quantitative coronary angiography (QCA) and optical coherence tomography (OCT) in patients with acute coronary syndrome treated with Magmaris stents or permanent, everolimus-eluting metallic Xience stents.

METHODS AND RESULTS

This PRAGUE-22 study was a two-centre, investigator-initiated, randomized study. Fifty patients were randomized based on the inclusion criteria for acute coronary syndrome and the anatomical suitability to receive Magmaris or Xience stents. The patient characteristics did not differ between the Magmaris group (n = 25) and Xience group (n = 25). The mean ages were 57.0 ± 10.5 vs. 55.5 ± 9.2 years (p = 0.541) and the total implanted stent length was 24.6 ± 10.7 mm vs. 27.6 ± 11.1 mm (p = 0.368), respectively. Four clinical events occurred in the Magmaris group and one in the Xience group during 12 months of follow-up. The extent of late lumen loss (assessed via QCA) at 12 months was greater in the Magmaris group than in the Xience group (0.54 ± 0.70 vs. 0.11 ± 0.37 mm; p = 0.029). The late lumen loss diameter (measured via OCT) in the Magmaris group was also significantly larger than that in the Xience group (0.59 ± 0.37 vs. 0.22 ± 0.20 mm; p = 0.01).

CONCLUSION

Implantation of a magnesium-based bioresorbable stent in patients with acute coronary syndrome is associated with a greater extent of late lumen loss at the 12-month follow-up compared with implantation of a permanent, everolimus-eluting metallic stent.

TRIAL REGISTRATION

ISRCTN89434356.

A Biodegradable Metal-Polymer Composite Stent Safe and Effective on Physiological and Serum-Containing Biomimetic Conditions

The new-generation coronary stents are expected to be biodegradable, and then the biocompatibility along with biodegradation becomes more challenging. It is a critical issue to choose appropriate biomimetic conditions to evaluate biocompatibility. Compared with other candidates for biodegradable stents, iron-based materials are of high mechanical strength, yet have raised more concerns about biodegradability and biocompatibility. Herein, a metal-polymer composite strategy is applied to accelerate the degradation of iron-based stents in vitro and in a porcine model. Furthermore, it is found that serum, the main environment of vascular stents, ensured the safety of iron corrosion through its antioxidants. This work highlights the importance of serum, particularly albumin, for an in vitro condition mimicking blood-related physiological condition, when reactive oxygen species, inflammatory response, and neointimal hyperplasia are concerned. The resultant metal-polymer composite stent is implanted into a patient in clinical research via interventional treatment, and the follow-up confirms its safety, efficacy, and appropriate biodegradability.

Stent Thrombosis After Percutaneous Coronary Intervention: From Bare-Metal to the Last Generation of Drug-Eluting Stents

Since their introduction in clinical practice in 1986, different types of coronary stents have been developed and become available for the treatment of coronary artery disease. Stent thrombosis (ST) is an uncommon but harmful complication after percutaneous coronary implantation, with a high occurrence of acute myocardial infarction and risk of mortality. Among several procedural and clinical predictors, the type of coronary stent is a strong determinant of ST. This article reviews the available evidence on the most used coronary stent types in the modern era and the related risk of ST.

Bioresorbable scaffolds vs. drug-eluting stents on short- and mid-term target lesion outcomes in patients after PCI: A systematic review and meta-analysis

Background

While current concerns about bioresorbable scaffolds (BRS) are centered on late or very late scaffold thrombosis, less attention had been paid to short- and mid-term clinical outcomes. This review aimed to compare the short- and mid-term outcomes between BRS and drug-eluting stents (DES).

Methods

A systematic review of randomized controlled trials (RCTs) that compared BRS vs. DES was conducted by searching PubMed, Cochrane Library, Web of Science, CNKI, WanFang, and VIP databases from inception until 19 April 2022 (language limited to English or Chinese). The primary outcome was target lesion failure (TLF) within 12 months, defined as a composite of target lesion revascularization (TLR), target vessel myocardial infarction (TVMI), and cardiac death. The secondary outcomes were in-stent diameter stenosis (DS%) provided by intraluminal imaging.

Results

A total of 13 studies were eligible and were included in this review (N = 9,702 patients). The follow-up duration ranged from 6 months to 1 year. A significantly higher rate of TLF [RR, 1.22, 95% CI (1.03, 1.44)] driven by the higher rate of TVMI [RR, 1.39, 95% CI (1.09, 1.76)] was observed in the BRS group than in the DES group. The risk of TLR and cardiac death was similar between the groups. Also, compared with the DES group, the BRS group had a significantly higher in-stent DS% within 1 year [MD = 5.23, 95%CI (3.43, 7.04); I² = 97%; p < 0.00001].

Conclusion

Bioresorbable scaffolds were associated with an increased risk of target lesion failure within 1 year as compared with DES, driven by the increased rates of target vessel myocardial infarction. Also, the in-stent DS% seemed to be higher with BRS. Therefore, BRS was inferior to DES in terms of target lesion outcomes at short- or mid-term follow-up.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=327966, PROSPERO (CRD42022327966).

Evolution of drug-eluting coronary stents: a back-and-forth journey from the bench-to-bedside

Coronary stents have revolutionized the treatment of coronary artery disease. Compared with balloon angioplasty, bare-metal stents effectively prevented abrupt vessel closure but were limited by in-stent restenosis due to smooth muscle cell proliferation and neointimal hyperplasia. The first-generation drug-eluting stent (DES), with its antiproliferative drug coating, offered substantial advantages over bare-metal stents as it mitigated the risk of in-stent restenosis. Nonetheless, they had several design limitations that increased the risk of late stent thrombosis. Significant advances in stent design, including thinner struts, enhanced polymers' formulation, and more potent antiproliferative agents, have led to the introduction of new-generation DES with a superior safety profile. Cardiologists have over 20 different DES types to choose from, each with its unique features and characteristics. This review highlights the evolution of stent design and summarizes the clinical data on the different stent types. We conclude by discussing the clinical implications of stent design in high-risk subsets of patients.

A First-in-Human Study of the Bioheart Sirolimus-Eluting Bioresorbable Vascular Scaffold in Patients with Coronary Artery Disease: Two-Year Clinical and Imaging Outcomes

INTRODUCTION

Newer generation bioresorbable scaffolds (BRSs) with thinner struts and improved deliverability are expected to enhance safety and efficacy profiles. Bioheart (Bio-Heart, Shanghai, China) BRS is constructed from a PLLA (poly-l-lactic acid) backbone coated with a PDLLA (poly D-l-lactic acid) layer eluting sirolimus. We report 2-year serial intracoronary imaging findings.

METHODS

In this first-in-human study, 46 patients with single de novo lesions in native coronary vessels (vessel size 3.0-3.75 mm, lesion length ≤ 25 mm) were enrolled at a single institution. Baseline intravascular ultrasound (IVUS) and post-implantation IVUS and optical coherence tomography (OCT) examinations were mandatory. After successful implantations of BRS, the 46 patients were randomized to two different follow-up cohorts in a 2:1 ratio. Thirty patients in cohort 1 had to undergo angiography, IVUS, and OCT follow-ups at 6 and 24 months, respectively. The 16 patients in cohort 2 underwent the same types of imaging follow-ups at 12 and 36 months, respectively. Clinical follow-ups were scheduled uniformly in both cohorts at 1, 6, and 12 months and annually up to 5 years for all patients.

RESULTS

Between August and November 2016, a total of 54 patients were assessed. However, 8 patients could not meet all the inclusion criteria; thus, the remaining 46 patients (age 57.5 ± 8.7 years, 34.8% female, 50.0% with unstable angina, 26.1% diabetics) with 46 target lesions were enrolled in this study. All patients in both cohorts were required to complete clinical follow-up uniformly and regularly. In cohort 1, one patient had definite scaffold thrombosis within 6 months of follow-up; thus, after 6 months, cohort 1 had 96.7% patients . Imaging follow-up was available in 24 patients, and in-scaffold late loss was 0.44 ± 0.47 mm; intracoronary imaging confirmed the late loss was mainly due to to neointimal hyperplasia, but not scaffold recoil.

CONCLUSIONS

Serial 2-year clinical and imaging follow-up results confirmed the preliminary safety and efficacy of Bioheart BRS for treatment of simple coronary lesions.

Optical Coherence Tomography: An Eye Into the Coronary Artery

Optical coherence tomography (OCT) is slowly but surely gaining a foothold in the hands of interventional cardiologists. Intraluminal and transmural contents of the coronary arteries are no longer elusive to the cardiologist's probing eye. Although the graduation of an interventionalist in imaging techniques right from naked eye angiographies to ultrasound-based coronary sonographies to the modern light-based OCT has been slow, with the increasing regularity of complex coronary cases in practice, such a transition is inevitable. Although intravascular ultrasound (IVUS) due to its robust clinical data has been the preferred imaging modality in recent years, OCT provides a distinct upgrade over it in many imaging and procedural aspects. Better image resolution, accurate estimation of the calcified lesion, and better evaluation of acute and chronic stent failure are the distinct advantages of OCT over IVUS. Despite the obvious imaging advantages of OCT, its clinical impact remains subdued. However, upcoming newer trials and data have been encouraging for expanding the use of OCT to wider indications in clinical utility. During percutaneous coronary intervention (PCI), OCT provides the detailed information (dissection, tissue prolapse, thrombi, and incomplete stent apposition) required for optimal stent deployment, which is the key to successfully reducing the major adverse cardiovascular event (MACE) and stent-related morbidities. The increasing use of OCT in complex bifurcation stenting involving the left main (LM) is being studied. Also, the traditional pitfalls of OCT, such as additional contrast load for image acquisition and stenting involving the ostial and proximal LM, have also been overcome recently. In this review, we discuss the interpretation of OCT images and its clinical impact on the outcome of procedures along with current barriers to its use and newer paradigms in which OCT is starting to become a promising tool for the interventionalist and what can be expected for the immediate future in the imaging world.

Long-Term Outcomes After Implantation of Magnesium-Based Bioresorbable Scaffolds—Insights From an All-Comer Registry

Background

The magnesium-based sirolimus-eluting bioresorbable scaffold (Mg-BRS) Magmaris™ showed promising clinical outcomes, including low rates of both the target lesion failure (TLF) and scaffold thrombosis (ScT), in selected study patients. However, insights regarding long-term outcomes (&gt;2 years) in all-comer populations remain scarce.

Methods

We analyzed data from a single-center registry, including patients with acute coronary syndrome (ACS) and chronic coronary syndrome (CCS), who had undergone percutaneous coronary intervention (PCI) using the Mg-BRS. The primary outcome comprised the device-oriented composite endpoint (DoCE) representing a hierarchical composite of cardiac death, ScT, target vessel myocardial infarction (TV-MI), and clinically driven target lesion revascularization (TLR) up to 5 years.

Results

In total, 84 patients [mean age 62 ± 11 years and 63 (75%) men] were treated with the Mg-BRS devices between June 2016 and March 2017. Overall, 101 lesions had successfully been treated with the Mg-BRS devices using 1.2 ± 0.4 devices per lesion. Pre- and postdilatation using dedicated devices had been performed in 101 (100%) and 98 (97%) of all the cases, respectively. After a median follow-up time of 62 (61–64) months, 14 (18%) patients had experienced DoCEs, whereas ScT was encountered in 4 (4.9%) patients [early ScTs (&lt;30 days) in three cases and two fatal cases]. In 4 (29%) of DoCE cases, optical coherence tomography confirmed the Mg-BRS collapse and uncontrolled dismantling.

Conclusion

In contradiction to earlier studies, we encountered a relatively high rate of DoCEs in an all-comer cohort treated with the Mg-BRS. We even observed scaffold collapse and uncontrolled dismantling. This implicates that this metal-based BRS requires further investigation and may only be used in highly selected cases.

Long-term clinical outcomes of everolimus-eluting bioresorbable scaffolds versus everolimus-eluting stents: final five-year results of the AIDA randomised clinical trial

BACKGROUND

Absorb bioresorbable vascular scaffold (BVS)-related events have been reported between 1 and 3 years - the period of active scaffold bioresorption. Data on the performance of the Absorb BVS in daily clinical practice beyond this time point are scarce.

AIMS

This report aimed to provide the final five-year clinical follow-up of the Absorb BVS in comparison with the XIENCE everolimus-eluting stent (EES). In addition, we evaluated the effect of prolonged dual antiplatelet therapy (DAPT) administration on events in the scaffold group.

METHODS

AIDA was a multicentre, investigator-initiated, non-inferiority trial, in which 1,845 unselected patients with coronary artery disease were randomly assigned to either the Absorb BVS (n=924) or the XIENCE EES (n=921). Target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction or target vessel revascularisation, was the primary endpoint. Scaffold thrombosis cases were matched with controls and tested for the effect of prolonged DAPT.

RESULTS

Up to five-year follow-up, there was no difference in TVF between the Absorb BVS (17.7%) and the XIENCE EES (16.1%) (hazard ratio [HR] 1.31, 95% confidence interval [CI]: 0.90-1.41; p=0.302). Definite or probable device thrombosis (DT) occurred in 43 patients (4.8%) in the scaffold group compared to 13 patients (1.5%) in the stent group (HR 3.32, 95% CI: 1.78-6.17; p<0.001). DT between 3 and 4 years occurred six times in the Absorb arm versus three times in the XIENCE arm. Between 4 and 5 years, the incidence was three versus two, respectively. Of those three DT in the scaffold group, two occurred in XIENCE EES-treated lesions. The odds ratio of scaffold thrombosis in patients on DAPT compared to off DAPT throughout five-year follow-up was 0.36 (95% CI: 0.15-0.86).

CONCLUSIONS

The excess risk of the Absorb BVS on late adverse events, in particular device thrombosis, in routine PCI continues up to 4 years and seems to plateau afterwards. Clinical Trial Registration ClinicalTrials.gov: NCT01858077.

Treatment of in-stent restenosis with sirolimus-eluting magnesium bioresorbable scaffolds: optical coherence tomography insights

OBJECTIVES

To assess the value of sirolimus-eluting magnesium bioresorbable scaffolds (MgS) in the treatment of patients with in-stent restenosis (ISR). The better option for the treatment of patients with ISR remains unsettled. Bioresorbable vascular scaffolds represent an interesting strategy in this setting to avoid another permanent metal layer. The novel MgS is an attractive option to treat these challenging patients.

METHODS

We present the results of the first prospective series of consecutive patients with ISR treated with MgS under optical coherence tomography (OCT) guidance.

RESULTS

A total of 14 patients (15 lesions) were prospectively included. The mean age was 67 ± 9 years and six patients (40%) presented with an acute coronary syndrome. In 10 patients (67%), underlying neoatherosclerosis was disclosed by OCT. An excellent MgS expansion was obtained in all but two patients who showed persistent suboptimal expansion in heavily calcified vessels. Minor residual malapposition (n = 5) and angiographically silent minor edge dissections (n = 8) were readily recognized by OCT. After a median clinical follow-up of 30 (range, 20-54) months, no patient required repeated revascularization, suffered a myocardial infarction or device thrombosis.

CONCLUSIONS

These preliminary results suggest a potential role for the MgS in selected patients presenting with ISR.

Long-term results of long segment coronary artery lesions overlapped with novolimus-eluting DESolve scaffold: Disappointment or futuristic?

OBJECTIVE

The data on using novolimus-eluting DESolve bioresorbable scaffolds (BVS) for long-segment coronary artery lesions remains insufficient. In this study, our main objective was to assess the long-term effects of the overlapping applications of both DESolve-DESolve and the drug-eluting stent (DES)-DESolve.

METHODS

A single-centered study of 103 patients scheduled for DESolve placement for long-segment lesions (>28 mm) was conducted (October 2013 to November 2016). A DESolve-DESolve overlap was used on 43 patients and a DES-DESolve overlap on 60 patients. Acute procedural success and major adverse cardiac events (MACE) (stent thrombosis, targeted vessel revascularization, targeted lesion revascularization, and cardiac death) were evaluated. The patients were followed up for 48 months.

RESULTS

Revascularization was performed on 4 (6.7%) patients in the DES-DESolve group and 5 (11.6%) patients in the DESolve-DESolve group for target lesion revascularization. Among the study population, 10 (9.7%) patients had MACE, including 5 (8.3%) patients in the DES-DESolve group and 5 (11.6%) patients in the DESolve-DESolve group.

CONCLUSION

The positive results of our study concerning the use of DESolve for the treatment of long coronary lesions demonstrate that BVS will emerge with new platforms and become non-inferior to the DES.

Nanoparticles-reinforced poly-l-lactic acid composite materials as bioresorbable scaffold candidates for coronary stents: Insights from mechanical and finite element analysis

Current generation of bioresorbable coronary scaffolds (BRS) posed thrombogenicity and deployment issues owing to its thick struts and overall profile. To this end, we hypothesize that the use of nanocomposite materials is able to provide improved material properties and sufficient radial strength for the intended application even at reduced strut thickness. The nanocomposite formulations of tantalum dioxide (Ta₂O₅), L-lactide functionalized (LA)-Ta₂O₅, hydroxyapatite (HA) and LA-HA with poly-l-lactic acid (PLLA) were evaluated in this study. Results showed that tensile modulus and strength were enhanced with non-functionalized nanofillers up until 15 wt% loading, whereas ductility was compromised. On the other hand, functionalized nanofillers/PLLA exhibited improved nanofiller dispersion which resulted higher tensile modulus, strength, and ductility. Selected nanocomposite formulations were evaluated using finite element analysis (FEA) of a stent with varying strut thickness (80, 100 and 150 μm). FEA data has shown that nanocomposite BRS with thinner struts (80-100 μm) made with 15 wt% LA-Ta₂O₅/PLLA and 10 wt% LA-HA/PLLA have increased radial strength, stiffness and reduced recoil compared to PLLA BRS at 150 μm. The reduced strut thickness can potentially mitigate issues such as scaffold thrombosis and promote re-endothelialisation of the vessel.

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.

Poor past and look forward

.

First-in-Man trial of a drug-free bioresorbable stent designed to minimize the duration of coronary artery scaffolding

For the last two decades, various degradable stents have been proposed to treat coronary artery diseases and replace metallic stents to avoid residual foreign material after healing. To date, the right balance between suitable scaffolding and loss of radial strength soon after endothelium restoration is still an unmet need. The present article reports on the First-in-Man trial of a drug-free bioresorbable stent based on a lactic acid stereocopolymer composed of 98% l-lactyl units selected to release stress shielding earlier than in the case of homopoly(l-lactic acid). Thirty patients with single de novo coronary lesions were included in the trial. The fate of scaffolds was monitored by clinical and imaging follow-ups to assess rate of adverse events, acute recoil, late luminal loss, and late lumen recovery. There was no death, no myocardial infarction, and no stent thrombosis observed over the 36 months trial. Dismantling occurred about 3 months after implantation. Bioresorption was almost completed at 2 years. The late lumen loss observed at the end of the first year was partly compensated one year later by enlarging remodeling. At one year, a neointimal hyperplasia slightly greater than for drug-eluting metallic and bioresorbable stents was shown using optical coherence tomography. The excess of hyperplasia was discussed relative to struts thickness, absence of anti-proliferative drug, and release of degradation by-products.

Meta-analysis of Duration of Continuous Dual Antiplatelet Therapy and Late Stent Thrombosis After Second-Generation Drug Stent Implantation

INTRODUCTION

The aim of the present study was to perform a systematic comparison of the incidence of late and extremely late stent thrombosis (ST) with short-term and long-term dual antiplatelet therapy (DAPT) after a second-generation drug-eluting stent (DES) implantation.

METHODS

Randomized controlled trials using short-term and long-term DAPT and reporting late ST (30 days-1 year) and extremely late ST (longer than 1 year) after a percutaneous coronary intervention (PCI) with DES were searched and compared in the Life Sciences and Biomedical Information Bibliographic Database (MEDLINE), EMBASE, Cochrane Central, and ClinicalTrials.com. ST was used as the primary endpoint of the therapeutic outcome, and the fixed-effects model (I² < 50%) or random-effects model (I² ≥ 50%) was adopted for the combined analysis. The odds ratio (OR) and 95% confidence interval (CIs) were used to represent the results. P < 0.05 in the combined result indicated that the difference was statistically significant.

RESULTS

A total of five randomized controlled trials consisting of 7142 patients were included, with 3556 cases of short-term DAPT (at most 6 months), and 3586 cases of long-term DAPT (at least 12 months). There was no significant difference between late ST and administration duration of DAPT (OR 0.98, 95% CI 0.30-3.18; P = 0.97, I² = 0%). There was also no significant difference between the incidence of extremely late ST and the duration of DAPT application (OR 0.30, 95% CI 0.03-2.95; P = 0.31).

CONCLUSION

The duration of continuous DAPT application had no effect on the occurrence of late and extremely late ST.

Bioresorbable Scaffolds in Percutaneous Coronary Intervention: Facing Old Problems, Raising New Hopes

PURPOSE OF REVIEW

In this review, we discuss about the reasons behind the failure of the Absorb bioresorbable vascular scaffold (BVS) device and about the challenges the future holds for the next generation of the bioresorbable scaffold (BRS) technology.

RECENT FINDINGS

Absorb BVS was burdened by intrinsic structural limitations which resulted in augmented rates of device thrombosis and clinical adverse events compared to current-generation metallic stent. Nevertheless, new generation devices with novel design and materials are in development. Second generation BRS have enhanced mechanical strength, smaller footprints, less thrombogenicity and modified bioresorption. These features, paired with proper patient and lesion selection and optimal "user-friendly" implant techniques, could possibly overcome the previous BRS generation limitations, rekindling physicians, and industry interest on this promising technology.

Inflammation as a determinant of healing response after coronary stent implantation

Cardiovascular disease remains the leading cause of death and morbidity worldwide. Inflammation plays an important role in the development of atherosclerosis and is associated with adverse clinical outcomes in patients after percutaneous coronary interventions. Data on stent elements that lead to excessive inflammatory response, proper identification of high-risk patients, prevention and treatment targeting residual inflammatory risk are limited. This review aims to present the role of inflammation in the context of evolving stent technologies and appraise the potential imaging modalities in detection of inflammatory response and anti-inflammatory therapies.

Recent Least Burdensome Approach for the Approval of Innovative Medical Devices in Japan -Regulatory Approval Review of an Everolimus-eluting Bioresorbable Scaffold

Although a domestic trial in Japan revealed that Absorb bioresorbable vascular scaffold (BVS) has no inferiority to everolimus-eluting stent (EES) cohort in the primary endpoint of the target lesion failure at 12 months, the scaffold/stent thrombosis (ST) rates with the BVS at 24 months were higher than those with the EES (Absorb BVS 3.1% vs. EES 1.5%), the ST rate of 3.1% with Absorb BVS is not an acceptable level in Japan. A cause-of-ST analysis revealed that cases in which diagnostic imaging and ensuing post-dilatation had been performed appropriately had lower ST rates than those without such management (within 1 year: 1.37% vs. 7.69%, from 1 to 2 years: 0.00% vs. 8.33%). Therefore, a further evaluation was needed to confirm that the ST rate with the Absorb BVS would be reduced by a proper implementation procedure. Regulatory approval was given conditionally to initiate rigorous post-marketing data collection in order to ensure the proper use of this device in limited facilities. The One-year Use-Result Survey in Japan for the Absorb BVS revealed no instances of ST. This approach to reducing the premarket regulatory burden of clinical trials and enhancing the post-marketing commitments of medical device regulation is useful for expediting patient access to innovative medical devices.

In vivo evaluation of a pro-healing polydopamine coated stent through an in-stent restenosis rat model

Drug-eluting stents have demonstrated efficiency in in-stent restenosis (ISR) but induced a risk of late acute thrombosis by delaying strut re-endothelialization. Polydopamine (PDA), a biocompatible polymer inspired from adhesive proteins of mussels, has been reported to promote endothelial cell (EC) proliferation while limiting SMC proliferation in vitro, thus suggesting the pro-healing potential. This study aimed at evaluating in vivo the impact of the pro-healing PDA-coated stent on ISR and on the quality of the strut re-endothelialization in a rat model. PDA-coated stents demonstrated a significant reduction in ISR in vivo compared to bare metal stents (ratio neointima/media = 0.48 (±0.26) versus 0.83 (±0.42), p < 0.001). Western blot analyses identified a trend towards an increased activation of p38 MAPK phosphorylation and its anti-proliferative effects on vascular SMC that could explain the results observed in morphological analyses. This bioinspired and biocompatible polydopamine layer could intrinsically limit ISR. In addition, according to its latent reactivity, PDA offers the possibility to immobilize some relevant drugs on the PDA-functionalized stent to provide potential synergistic effects.

Five-year follow-up of patients who underwent everolimus-eluting bioresorbable scaffold implantation

OBJECTIVES

The aim of this study was to evaluate very long-term results after unrestricted everolimus-eluting bioresorbable scaffolds (BRS) implantation.

BACKGROUND

Previous randomized studies mainly included selected patients differing from those seen during daily routine and long-term data from all-comers registries are sparse.

METHODS

Consecutive patients undergoing BRS implantation were included in this observational, single center study. Clinical follow-up was conducted up to 5 years. Endpoint of interest was the composite of target lesion failure (TLF), including target-vessel myocardial infarction and target lesion revascularization and cardiac death. Furthermore, ARC-defined scaffold thrombosis (ScT) were assessed.

RESULTS

A total of 176 patients with a median age of 64 (55 - 72) years were analyzed, of which 59.6% presented an acute coronary syndrome. A total of 183 mainly complex lesions (55.8%) were treated. At 5 years, the rate for TLF was 21.6%. Definite or probable ScT rate was 4.1%. The rate of ScT within the first year was 2.8% and afterwards 1.2%. Notably, no ScT was seen later than 2 years.

CONCLUSIONS

Although this real-world registry displays high rates of clinical events during long-term follow-up, no ScT was seen after 2 years.

PERK Inhibition Promotes Post-angioplasty Re-endothelialization via Modulating SMC Phenotype Changes

BACKGROUND

Drug-eluting stents impair post-angioplasty re-endothelialization thus compromising restenosis prevention while heightening thrombotic risks. We recently found that inhibition of protein kinase RNA-like endoplasmic reticulum kinase (PERK) effectively mitigated both restenosis and thrombosis in rodent models. This motivated us to determine how PERK inhibition impacts re-endothelialization.

METHODS

Re-endothelialization was evaluated in endothelial-denuded rat carotid arteries after balloon angioplasty and periadventitial administration of PERK inhibitor in a hydrogel. To study whether PERK in smooth muscle cells (SMCs) regulates re-endothelialization by paracrinally influencing endothelial cells (ECs), denuded arteries exposing SMCs were lentiviral-infected to silence PERK; in vitro, the extracellular vesicles isolated from the medium of PDGF-activated, PERK-upregulating human primary SMCs were transferred to human primary ECs.

RESULTS

Treatment with PERK inhibitor versus vehicle control accelerated re-endothelialization in denuded arteries. PERK-specific silencing in the denuded arterial wall (mainly SMCs) also enhanced re-endothelialization compared to scrambled shRNA control. In vitro, while medium transfer from PDGF-activated SMCs impaired EC viability and increased the mRNA levels of dysfunctional EC markers, either PERK inhibition or silencing in donor SMCs mitigated these EC changes. Furthermore, CXCL10, a paracrine cytokine detrimental to ECs, was increased by PDGF activation and decreased after PERK inhibition or silencing in SMCs.

CONCLUSIONS

Attenuating PERK activity pharmacologically or genetically provides an approach to accelerating post-angioplasty re-endothelialization in rats. The mechanism may involve paracrine factors regulated by PERK in SMCs that impact neighboring ECs. This study rationalizes future development of PERK-targeted endothelium-friendly vascular interventions.

Three-year clinical outcomes of a sirolimus-eluting bioresorbable scaffold (XINSORB) and a metallic stent to treat coronary artery stenosis

Background

Recent studies have shown increased risks of late target lesion failure (TLF) and thrombosis using a bioresorbable scaffold (BRS). However, the results of the ABSORB China study offered a different means of understanding the long-term performance of BRSs. We tested the 3-year clinical outcome of the XINSORB BRS in a multicenter, randomized controlled clinical trial (ChiCTR1800014966).

Methods

Eligible patients with one or two de novo coronary lesions were randomly assigned 1:1 to be treated with XINSORB scaffolds and metallic sirolimus-eluting stents (SESs). The clinical endpoints include TLF [cardiac death, target vessel-related myocardial infarction (TV-MI), or ischemia-driven target lesion revascularization (ID-TLR)], its components, and devised thrombosis.

Results

Three hundred ninety-five patients were enrolled and randomized to the XINSORB (N=200) and SES (N=195) arms. The clinical 3-year follow-up included 95.5% of the XINSORB-treated patients and 92.8% of the SES-treated patients. Dual antiplatelet therapy was at 59.0% of the XINSORB-treated and 52.8% of the SES-treated patients (P=0.34). There were no significant differences in the clinical outcomes between the XINSORB and SES arms, including in TLF (4.0% vs. 6.2%, P=0.29), cardiac death (1.0% vs. 0%, P=NA), TV-MI (1.0% vs. 0%, P=NA), and ID-TLR (3.5% vs. 6.2%, P=0.19). The rate of confirmed/probable device thrombosis in the XINSORB-treated patients was only 1.0% (2/200).

Conclusions

In this XINSORB randomized clinical trial, the XINSORB scaffolds and SESs showed similar efficacy and safety up to the 3-year follow-up. The rates of TLF and device thrombosis were low and comparable between the two arms.

Long-term comparison of everolimus- vs. novolimus-eluting bioresorbable vascular scaffolds in real world patients

INTRODUCTION

Elevated risk of adverse events in comparison to metallic stents resulted in withdrawal of everolimus-eluting bioresorbable scaffolds (eBVS), known as the most intensively studied BVS. There is a paucity of data comparing the two different BVS.

AIM

To evaluate the long-term clinical outcomes of the novolimus-eluting bioresorbable vascular scaffold (nBVS) compared with eBVS.

MATERIAL AND METHODS

Consecutive patients treated with nBVS or eBVS in our center were screened. The primary outcome was the 3-year rate of major adverse cardiovascular events (MACE), defined as the composite of cardiac death, target vessel myocardial infarction (TV-MI), and target-lesion revascularization (TLR).

RESULTS

After matching, 98 patients treated with 135 eBVS were compared with 98 patients treated with 136 nBVS. Baseline characteristics, clinical presentation, and lesion characteristics were comparable in both groups. The 3-year MACE rate was higher in the eBVS group (17.3% vs. 6.1%; p log-rank = 0.02). The occurrence of TLR (16.3% vs. 5.1%; p log-rank = 0.02) and TV-MI (8.2% vs. 0 %; p log-rank = 0.004) was also higher in the eBVS group except for cardiac deaths (1% vs. 2%; p log-rank = 0.98, eBVS vs. nBVS, respectively). Of note, definite device thrombosis rate was markedly increased in the eBVS group (5.1% vs. 0%; p log-rank = 0.03).

CONCLUSIONS

The present study revealed that the 3-year event risk was lower for nBVS compared to eBVS. More evidence is needed to evaluate long-term performance of novolimus-eluting biovascular platforms.

Bioresorbable Scaffolds: Contemporary Status and Future Directions

Percutaneous coronary intervention, which is safe, effective, and timely, has become an important treatment for coronary artery diseases and has been widely used in clinical practice. However, there are still some problems that urgently need to be solved. Permanent vessel caging through metallic implants not only prevents the process of positive vessel remodeling and the restoration of vascular physiology but also makes the future revascularization of target vessels more difficult. Bioresorbable scaffolds (BRSs) have been developed as a potential solution to avoid the above adverse reactions caused by permanent metallic devices. BRSs provide temporary support to the vessel wall in the short term and then gradually degrade over time to restore the natural state of coronary arteries. Nonetheless, long-term follow-up of large-scale trials has drawn considerable attention to the safety of BRSs, and the significantly increased risk of late scaffold thrombosis (ScT) limits its clinical application. In this review, we summarize the current status and clinical experiences of BRSs to understand the application prospects and limitations of these devices. In addition, we focus on ScT after implantation, as it is currently the primary drawback of BRS. We also analyze the causes of ScT and discuss improvements required to overcome this serious drawback and to move the field forward.

Three-year clinical outcomes with the ABSORB bioresorbable vascular scaffold in real life: Insights from the France ABSORB registry

OBJECTIVES

The aim of this study was to determine the 3-year outcomes of patients treated with Absorb bioresorbable vascular scaffold (BVS) implantation.

BACKGROUND

Randomized trials and observational registries performed in patients undergoing percutaneous coronary intervention have demonstrated higher 1-year and midterm rates of device thrombosis and adverse events with BVS compared to contemporary drug eluting stent. Data on long-term follow-up of patients treated with BVS are scarce.

METHODS

All patients treated with BVS were included in a large nationwide prospective multicenter registry (FRANCE ABSORB). The primary endpoint was a composite of cardiovascular death, myocardial infarction, and target lesion revascularization at 3 years. Secondary endpoints were 3-year scaffold thrombosis and target vessel revascularization (TVR).

RESULTS

Between September 2014 and April 2016, 2070 patients were included (mean age 55 ± 11 years; 80% men). The indication was acute coronary syndrome (ACS) in 49% of patients. At 3 years, the primary endpoint occurred in 184 patients (8.9%) and 3-year mortality in 43 patients (2.1%). Scaffold thrombosis and TVR rates through 3 years were, respectively, 3 and 7.6%. In a multivariable analysis, independent predictors of primary endpoint occurrence were diabetes, oral anticoagulation, active smoking, absence of initial angiographic success and the association of a total BVS length ≥30 mm with the use of 2.5 mm diameter BVS.

CONCLUSIONS

Although 3-year mortality was low in this ACS population, device-related events were significant beyond 1 year. Total BVS length and 2.5 mm BVS were associated with higher rates of MACE at long-term follow-up.