Six-month outcomes of the XINSORB bioresorbable sirolimus-eluting scaffold in treating singlede novolesions in human coronary artery

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.

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.

Designing Better Cardiovascular Stent Materials - A Learning Curve

Cardiovascular stents are life-saving devices and one of the top 10 medical breakthroughs of the 21st century. Decades of research and clinical trials have taught us about the effects of material (metal or polymer), design (geometry, strut thickness, and the number of connectors), and drug-elution on vasculature mechanics, hemocompatibility, biocompatibility, and patient health. Recently developed novel bioresorbable stents are intended to overcome common issues of chronic inflammation, in-stent restenosis, and stent thrombosis associated with permanent stents, but there is still much to learn. Increased knowledge and advanced methods in material processing have led to new stent formulations aimed at improving the performance of their predecessors but often comes with potential tradeoffs. This review aims to discuss the advantages and disadvantages of stent material interactions with the host within five areas of contrasting characteristics, such as 1) metal or polymer, 2) bioresorbable or permanent, 3) drug elution or no drug elution, 4) bare or surface-modified, and 5) self-expanding or balloon-expanding perspectives, as they relate to pre-clinical and clinical outcomes and concludes with directions for future studies.

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.

Final report of the 5-year clinical outcomes of the XINSORB bioresorbable sirolimus-eluting scaffold in the treatment of single de novo coronary lesions in a first-in-human study

Background

We aimed to report the 5-year outcomes of XINSORB bioresorbable sirolimus-eluting scaffolds in the treatment of single de novo coronary lesions in a first-in-human (FIM) study. This is the final report of the long-term clinical outcomes of the study. Recent studies have shown that bioresorbable scaffolds (BRSs) increase the risks of late target lesion failure (TLF) and thrombosis.

Methods

In this prospective, single-arm study, eligible patients with single de novo coronary lesions were enrolled and treated with XINSORB scaffolds. The scaffolds measured 3.0 mm in diameter and 12, 15, and 18 mm in length. The clinical endpoints included TLF [cardiac death, target vessel-related myocardial infarction (TV-MI), or ischaemia-driven target lesion revascularization (ID-TLR)], its components, major adverse cardiac events (MACE), and scaffold thrombosis.

Results

From September 2013 to January 2014, 30 patients were enrolled and treated with XINSORB scaffolds. The procedure had a 100% success rate. None of the patients died during the 5 years of follow-up. The primary endpoint of TLF occurred in 4 patients (13.3%). Six patients were recanalized by intervention, including 4 by ID-TLR. The rate of MACE was 16.7% (5/30). One very late case of scaffold thrombosis was recorded, which led to TV-MI. No more cases of thrombosis were recorded beyond 2 years of follow-up. The rates of clinical endpoints remained steady with no changes after 3 years of follow-up.

Conclusions

Considering that this FIM study was launched at an early stage of the BRS era and without optimal implantation techniques, the clinical outcomes of TLF during the 5-year follow-up were acceptable. The rate of thrombosis was relatively low.

Fully bioresorbable vascular scaffolds: lessons learned and future directions

Fully bioresorbable scaffolds (BRS) were designed to overcome the limitations of metallic drug-eluting stents, which permanently cage the vessel wall, thereby preventing normal coronary vasomotion, preclude bypass grafting and can provoke long-term foreign-body responses. Although multiple scaffolds have been or are in development, the Absorb Bioresorbable Vascular Scaffold (BVS; Abbott Vascular) was the first FDA-approved device and was widely expected to fulfil the dream of interventional cardiologists of a transient scaffold that would disappear 'when the job was done' and would not hamper further treatment options. Although early, small studies and even large, randomized trials showed beneficial outcomes up to 1 year of follow-up, longer-term results have been disappointing, with increased rates of device thrombosis and target-lesion revascularization. The Absorb BVS device was withdrawn from the market because of low demand. In this Review, we summarize the preclinical and clinical data available for BRS to understand how the vascular biological reactions to these devices differ from biological reactions to metallic drug-eluting stents and how these responses translate into clinical outcomes. We also discuss next-generation BRS and outline modifications that are needed to improve the long-term outcomes with these devices so that they eventually become a viable option for patients with symptomatic obstructive coronary artery disease.

Twelve-month angiographic and clinical outcomes of the XINSORB bioresorbable sirolimus-eluting scaffold and a metallic stent in patients with coronary artery disease

BACKGROUND

Recent studies showed bioresorbable scaffold (BRS) increased risks of late target lesion failure (TLF) and thrombosis. XINSORB scaffold is a poly-L-lactic acid based BRS.

METHODS

The study included randomization and registry parts. Eligible patients with one or two de novo lesions were randomly 1:1 assigned to XINSORB scaffold and sirolimus-eluting stent (SES) in randomization part. These patients were clinically and angiographically assessed. In registry part, patients were treated with XINSORB scaffold only and were clinically assessed. The primary endpoint was in-segment late luminal loss (LLL) at 12-month in randomization part. The secondary endpoint was 12-month TLF in all XINSORB-treated patients.

RESULTS

Total 395 and 798 patients were enrolled in randomization and registry part, respectively. Device success was 98.0% (1069/1091) in all XINSORB-treated and 100% (221/221) in SES-treated lesions. The primary endpoint of in-segment LLL at 12-month was 0.19 ± 0.32 mm in XINSORB and 0.31 ± 0.41 mm in SES (P = 0.003), which met the noninferior margin of 0.195 mm (95% CI: -0.20, -0.04, P ≪ 0.0001). No difference was found in TLF between two devices. In all XINSORB-treated patients, 12-month TLF was 0.8% (8/998), which also met the noninferior margin of 9.0% (95% CI: 0.3%, 1.4%, P ≪ 0.0001). Only one device thrombosis was recorded in all XINSORB-treated patients while none in SES.

CONCLUSIONS

In the multicenter clinical trial, XINSORB BRS was noninferior to sirolimus-eluting stent for the primary endpoint of in-segment LLL at 12-month in patients with simple and moderate complex de novo coronary lesions. TLF at 12-month was low and comparable.

Biodegradable coronary scaffolds: their future and clinical and technological challenges

Angioplasty and stenting are standard treatment options for both stabile occlusive coronary artery disease and acute myocardial infarctions. Over the last years, several biodegradable stent systems have entered pre-clinical and clinical evaluation and into clinical practice. A strong supporting scaffold is necessary after angioplasty to prevent elastic recoil of the vessel but in the long term a permanent metallic stent will only impair normal physiology of the artery wall. Thus, the main advantage of a resorbable system is the potential for better vessel recovery and function in the long term. The new stent systems differ from traditional stents in size and biological responses and questions have risen regarding their mechanical strength and increased risk of stent thrombosis. Here, we present current treatment options with biodegradable scaffolds, discuss further key areas for improvements and review novel technological advances in the context of all up-to-date clinical trial information. New material choices are also covered as well as special considerations for pre-clinical testing.

Healing score of the Xinsorb scaffold in the treatment of de novo lesions: 6-month imaging outcomes

The objectives of this study are to assess the healing score (HS) and neointimal thickness of the Xinsorb scaffold, and explore the relationships between the implanted patterns, neointimal thickness, and HS. The Xinsorb bioresorbable sirolimus-eluting scaffold is the first domestically designed and fabricated bioresorbable scaffold in China. The 6-month follow-up found it to be safe and effective in the treatment of single de novo coronary lesions. The Xinsorb scaffolds were implanted in 30 patients with symptomatic ischemic coronary disease. A 6-month follow-up was performed in a subset of 19 patients; the HS and neointimal thickness were evaluated by optical coherence tomography. Struts were classified as ApposedCovered, ApposedUncovered, MalapposedCovered, MalapposedUncovered, jailing and presence of intraluminal masses. The implanted pressure, implanted duration, and post-expansion pressure were recorded during the operation. We evaluated the relationship between the HS or neointimal thickness and the implanted pressure, holding time, and post-expansion pressure. The device and procedure success rates were both 100%. No major adverse cardiac or scaffold-thrombus related events occurred. At 6 months, 12,295 struts were analyzed to determine the HS (6.23) and neointimal thickness (0.1021 ± 0.05718 mm) in the Xinsorb scaffolds. There was a strong negative relationship between the HS and the implantation duration (Pearson r = - 0.518, p = 0.023). A significant negative relationship also existed between the HS and post-dilatation (Pearson r = - 0.631, p = 0.004). The Xinsorb scaffold HS appears negative correlated with the implanted duration and post-dilatation. We will further evaluate the HS of randomized controlled trial of the Xissorb scaffold.

Bioresorbable Scaffolds in Coronary Intervention: Unmet Needs and Evolution

Bioresorbable scaffolds (BRS) represent a novel paradigm in the 40-year history of interventional cardiology. Restoration of cyclic pulsatility and physiologic vasomotion, adaptive vascular remodeling, plaque regression, and removal of the trigger for late adverse events are expected BRS benefits over current metallic drug-eluting stents. However, first-generation BRS devices have significant manufacturing limitations and rely on optimal implantation technique to avoid experiencing an excess of clinical events. There are currently at least 22 BRS devices in different stages of development, including many trials of device iterations with thinner (<150 µm) struts than first-generation BRS. This article reviews the outcomes of commercially available and potentially upcoming BRS, focusing on the most recent stages of clinical development and future directions for each scaffold type.