The Orsiro Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stent: A Review of Current Evidence

Interpreting clinical outcomes using different strut thickness in coronary artery disease: insights from vascular imaging analysis

Background

Coronary artery disease is a global health concern that necessitates treatments, such as percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Recent advancements in biodegradable polymer-coated DES have improved long-term outcomes by reducing neointimal hyperplasia. Superior long-term outcomes in patients with ultrathin-strut sirolimus-eluting Orsiro stent (BP-SES) compared with those with thick-strut biolimus-eluting BioMatrix stent (BP-BES) have been shown. This study aimed to explore the mechanisms underlying these differences by using quantitative coronary angiography (QCA) and optical coherence tomography (OCT).

Methods

This sub-analysis of the BIODEGRADE trial, a prospective, randomized, multi-center study, compared BP-SES and BP-BES in patients who underwent PCI between July 2014 and September 2017. Patients with positive stress test results, ischemic symptoms, or those who consented to routine follow-up angiography were included. QCA and OCT were used to evaluate the lumen diameter, cross-sectional areas and stent apposition or coverage. OCT images were analyzed at 1 mm intervals within 5 mm proximal and distal to the stented segment.

Results

Of the 2,341 patients, 689 underwent follow-up angiography between 18- and 36-months post-PCI, and 929 stents were analyzed via QCA. OCT images of 61 participants were available. The BP-SES group exhibited a significantly larger minimal lumen diameter and reduced late lumen loss compared to the BP-BES group (0.34 ± 0.45 mm vs. 0.42 ± 0.44 mm, P = 0.005). OCT analysis showed significantly less neointimal hyperplasia in the BP-SES group (0.04 ± 0.4 mm2 vs. 0.64 ± 0.54 mm2, P < 0.001), with no significant differences in stent strut coverage or inflammation markers, than in the BP-BES group.

Conclusions

QCA and OCT analyses revealed less neointimal growth with BP-SES than with BP-BES, without delayed healing or increased inflammation. These findings underscore the importance of stent design characteristics and suggest that thinner struts may enhance clinical success by reducing restenosis and improving long-term vessel patency.

Clinical Trial Registration

https://clinicaltrials.gov/study/NCT02299011 (NCT02299011).

A novel stent flow chamber system demonstrates reduced thrombogenicity of bioresorbable magnesium scaffolds

Coronary artery disease (CAD) is characterized by narrowing and subsequent blockade of coronary arteries, and imposes a significant health and economic burden. Stent and scaffold devices are introduced in advanced CAD to improve vascular stability and restore blood flow. Although in vitro flow systems like the Chandler loop have been developed to enhance the understanding of interactions between device materials, their coatings, and vascular cells, imaging-based in vitro analysis of device performance is limited. In this study, we established a novel stent flow chamber system designed to assess the thrombogenicity of bioresorbable magnesium scaffold (RMS) and stent materials in vitro. Additionally, we compared the thrombogenicity - an important clinical parameter in stent performance - of the Magmaris-316 L stainless steel stent with its predecessors, Magmaris RMS and a prototype of the third-generation RMS (DREAMS 3G). Analysis of platelet adhesion and coverage of the different devices under flow conditions demonstrated that the Magmaris RMS exhibits reduced thrombogenicity compared to the Magmaris-316 L stainless steel stent. Moreover, thrombogenicity of the DREAMS 3G prototype, composed of BIOmag material, is further decreased compared to its predecessors. The observed reduction in thrombogenicity of the DREAMS 3G prototype in vitro suggests additional improvements in clinical safety and efficacy, highlighting its promise for treating CAD. Future research on this prototype may thus open avenues for analyzing other blood components and patient-derived endothelial cells. In line with the 3R principles, this approach may also help reduce the need for animal testing.

Two-year real world clinical outcomes after intravascular imaging device guided percutaneous coronary intervention with ultrathin-strut biodegradable-polymer sirolimus-eluting stent

BACKGROUND

There are little clinical data on imaging-guided percutaneous coronary intervention (PCI) 1 year after the biodegradable-polymer sirolimus-eluting stents (BP-SES) implantation, when the polymer disappears.

METHODS

We retrospectively analyzed 2455 patients who underwent successful PCI with BP-SES or durable-polymer everolimus-eluting stents (DP-EES) between September 2011 and March 2021, and compared 2-year clinical outcomes of BP-SES (n = 459) with DP-EES (n = 1996). The outcome measures were target lesion revascularization (TLR) and major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, target vessel revascularization, and stent thrombosis. Multivariate analysis using the Cox proportional hazard model and inverse probability weighting (IPW) analysis based on the propensity score were used to evaluate the clinical outcomes.

RESULTS

The 2-year cumulative incidences of TLR (BP-SES: 4.9% vs. DP-SES: 6.1%, p = 0.304) and MACE (10.3% vs. 12.5%, p = 0.159) were similar between the two groups. Multivariable and IPW analysis revealed the risks of TLR (p = 0.388 and p = 0.500) and MACE (p = 0.139 and p = 0.083) also had no significant difference. There was a significant interaction between none/mild and moderate/severe calcification with respect to MACE and TLR (adjusted p for interaction = 0.036 and 0.047, respectively). The risk of MACE was significantly lower in BP-SES than in DP-EES in lesions with none/mild calcification (adjusted hazard ratio [aHR]: 0.53; 95% confidence interval [CI]: 0.30-0.91), while it was similar in those with moderate/severe calcification (aHR: 0.95; 95% CI: 0.58-1.55).

CONCLUSIONS

Compared with DP-EES, BP-SES demonstrated durable 2-year clinical outcomes. However, BP-SES showed better clinical performance than DP-EES for lesions with none/mild calcification.

Drug loaded implantable devices to treat cardiovascular disease

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

BioMatrix Versus Orsiro Stents for Coronary Artery Disease: A Multicenter, Randomized, Open-Label Study

BACKGROUND

Comparative studies of ultrathin-strut biodegradable polymer sirolimus-eluting stent (BP-SES) have reported promising results and validated its excellent outcomes in terms of safety and efficacy. However, there are limited studies comparing BP drug-eluting stents with struts of different thicknesses. We compared the long-term clinical outcomes of patients treated with an ultrathin-strut BP-SES or a thick-strut biodegradable polymer biolimus-eluting stent (BP-BES).

METHODS

The BIODEGRADE trial (Biomatrix and Orsiro Drug-Eluting Stents in Angiographic Result in Patients With Coronary Artery Disease) is a multicenter prospective randomized study comparing coronary revascularization in patients with ultrathin-strut BP-SES and thick-strut BP-BES with the primary end point of target lesion failure at 18 months posttreatment. We performed the prespecified analysis of 3-year clinical outcomes.

RESULTS

In total, 2341 patients were randomized to receive treatment with ultrathin-strut BP-SES (N=1175) or thick-strut BP-BES (N=1166). The 3-year incidence rate of target lesion failure was 3.2% for BP-SES and 5.1% for BP-BES (P=0.023). The difference was primarily due to differences in ischemia-driven target lesion revascularization (BP-SES, 1.5%; BP-BES, 2.8%; P=0.035) between groups. A landmark analysis of the late follow-up period showed significant differences in target lesion failure, with outcomes being better in BP-SES. Cardiac death and target lesion revascularization were significantly lower in the BP-SES group.

CONCLUSIONS

In a large, randomized trial, the long-term clinical outcome of target lesion failure at 3 years was significantly better among patients treated with the ultrathin-strut BP-SES. The results indicate the superiority of the ultrathin-strut BP-SES compared with the thick-strut BP-BES.

REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT02299011.

Clinical outcomes of an ultrathin-strut sirolimus-eluting stent in all-comers population: Thailand Orsiro registry

Background

Despite numerous studies supporting the outperformance of ultrathin-strut bioresorbable polymer sirolimus-eluting stent (Orsiro SES, Biotronik AG), the generalizability of the study results remains unclear in the Asian population. We sought to evaluate the clinical outcomes of the Orsiro SES in unselected Thai population.

Methods

The Thailand Orsiro registry was a prospective, open-label clinical study evaluating all patients with obstructive coronary artery disease implanted with Orsiro SES. The primary endpoint was target lesion failure (TLF) at 12 months. TLF is defined as a composite of cardiac death, target vessel myocardial infarction (TVMI), emergent coronary artery bypass graft (CABG), and clinically driven target lesion revascularization (CD-TLR). Patients with diabetes, small vessels (≤ 2.75 mm), chronic total occlusions (CTOs), and acute myocardial infarction (AMI) were pre-specified subgroups for statistical analysis.

Result

A total of 150 patients with 235 lesions were included in the analysis. Half of the patients (53.3%) presented with AMI, and 24% had diabetes. Among 235 lesions, 93(39.4%) were small vessels, and 24(10.2%) were chronic total occlusions. The primary endpoint, TLF at 12 months, occurred in eight patients (5.3%), predominately caused by cardiac death. By contrast, the incidences of TVMI and CD-TLR were null. The outcomes in pre-specified subgroup were not different from the overall population (all p > 0.05). One definite late stent thrombosis(0.7%) was incidentally observed during primary percutaneous coronary intervention to the non-target vessel.

Conclusion

The safety and efficacy of the ultrathin strut sirolimus-eluting stent in unselected cases are confirmed in the Thailand Orsiro registry. Despite the high proportion of pre-specified high-risk subgroups, the excellent stent performance was consistent with the overall population.

Trial Registration TCTR20190325001.

Ultrathin biodegradable polymer sirolimus-eluting stent versus contemporary durable polymer everolimus-eluting stent for percutaneous coronary intervention: a meta-analysis of randomized trials

INTRODUCTION

Improvements in coronary drug-eluting stent technology has focused on reducing the long-term complications associated with the effects of the residual footprint on the vessel wall. Although many of the newer stents have exhibited noninferiority to the durable polymer everolimus-eluting stent (DP-EES), they have yet to exhibit clear superiority. We compared the performance of the latest ultrathin strut biodegradable polymer sirolimus-eluting stents (BP-SES) to DP-EES.

METHODS

We searched the electronic databases for randomized controlled trials comparing BP-SES to DP-EES. A random effect meta-analysis was performed using the Poisson regression model. The primary end point was target lesion failure (TLF), a composite of target vessel myocardial infarction (TVMI), cardiac death and target lesion revascularization (TLR).

RESULTS

There was no difference between the stents in stent thrombosis [incidence rate ratio (IRR) = 0.79, 95% confidence interval (CI) 0.58-1.06), TLR (IRR = 0.88, 95% CI 0.57-1.38), TVMI (IRR = 0.79, 95% CI 0.61-1.01), cardiac death (IRR = 0.99, 95% CI 0.76-1.29) and target vessel failure (IRR = 0.82, 95% CI 0.64-1.06). In addition, there was no difference in TLF (IRR = 0.82, 95% CI 0.64-1.06). There was evidence of reduced TLF in small vessels with BP-SES based on definition used (defined as ≤2.75 mm; IRR 0.64, 95% CI 0.46-0.91 versus ≤3 mm; IRR 1.11, 95% CI 0.90-1.36).

CONCLUSION

In our study, the performance of the latest generation BP-SES was comparable to DP-EES but failed to show superiority. The possible benefit in patients with small vessels should be explored future trials.

Biodegradable Iron-Based Materials-What Was Done and What More Can Be Done?

Iron, while attracting less attention than magnesium and zinc, is still one of the best candidates for biodegradable metal stents thanks its biocompatibility, great elastic moduli and high strength. Due to the low corrosion rate, and thus slow biodegradation, iron stents have still not been put into use. While these problems have still not been fully resolved, many studies have been published that propose different approaches to the issues. This brief overview report summarises the latest developments in the field of biodegradable iron-based stents and presents some techniques that can accelerate their biocorrosion rate. Basic data related to iron metabolism and its biocompatibility, the mechanism of the corrosion process, as well as a critical look at the rate of degradation of iron-based systems obtained by several different methods are included. All this illustrates as the title says, what was done within the topic of biodegradable iron-based materials and what more can be done.

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.

•

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

•

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

•

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