Magnesium-based resorbable scaffold vs permanent metallic sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction: 3-year results of the MAGSTEMI randomised controlled trial

Sirolimus-eluting iron bioresorbable scaffold versus cobalt-chromium everolimus-eluting stents in patients with coronary artery disease: Rationale and design of the IRONMAN-II trial

BACKGROUND

The previous first-in-human study established the preliminary safety and effectiveness of the novel thin-strut iron bioresorbable scaffold (IBS). The current study aims to directly compare the imaging and physiological efficacy, and clinical outcomes of IBS with contemporary metallic drug-eluting stents (DES).

METHODS

A total of 518 patients were randomly allocated to treatment with IBS (257 patients) or metallic DES (261 patients) from 36 centers in China. The study is powered to test noninferiority of the IBS compared with the metallic everolimus-eluting stent in terms of the primary endpoint of in-segment late lumen loss at 2 years, and major secondary endpoints including 2-year quantitative flow ratio and cross-sectional mean flow area measured by optical coherence tomography (OCT) (limited to the OCT subgroup, 25 patients in each group).

CONCLUSION

This will be the first powered randomized trial investigating the safety and efficacy of the novel thin-strut IBS compared to a contemporary metallic DES. The findings will provide valuable evidence for future research of this kind and the application of metallic bioresorbable scaffolds.

Challenges and Advances in Interventional Cardiology for Coronary Artery Disease Management

The development of percutaneous coronary intervention (PCI) has been one of the greatest advances in cardiology and has changed clinical practice for patients with coronary artery disease (CAD). Despite continuous improvements in operators' experience, techniques, and the development of new-generation devices, significant challenges remain in improving the efficacy of PCI, including calcification, bifurcation, multivascular disease, stent restenosis, and stent thrombosis, among others. The present review aims to provide an overview of the current status of knowledge of endovascular revascularization in CAD, including relevant trials, therapeutic strategies, and new technologies addressing particular scenarios that can impact the prognosis of this vulnerable population.

Long-term outcomes following bioresorbable vascular scaffolds

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Optimal lesion preparation before implantation of a Magmaris bioresorbable scaffold in patients with coronary artery stenosis: Rationale, design and methodology of the OPTIMIS study

Introduction

Percutaneous coronary intervention with implantation of a bioresorbable scaffold (BRS) provide the vessel support for a limited period allowing the vessel to restore normal vasomotion after degradation of the BRS, opposed to treatment with drug-eluting stents where the metal persist in the vessel wall. Late lumen loss and reduction in lumen area after implantation have been reported. The purpose of this study was to investigate whether intense pre-dilatation before BRS implantation resulted in less reduction of minimal lumen area at 6- and 12-month follow-up after implantation of a Magmaris BRS (MgBRS). Coronary imaging with optical coherence tomography (OCT) and intravascular ultrasound (IVUS) was assessed to track changes in lumen and vessel dimensions.

Methods

The prospective Optimal lesion PreparaTion before Implantation of the Magmaris bioresorbable scaffold In patients with coronary artery Stenosis (OPTIMIS) study randomly assigned eighty-two patients with chronic coronary syndrome to two pre-dilatation treatment strategies. Patients were randomized in a 1:1 ratio to pre-dilatation with either a non-compliant scoring balloon or a standard non-compliant balloon prior to implantation of a MgBRS. The treated segment was evaluated with OCT and IVUS at baseline, after 6 and 12 months to assess changes in lumen and vessel dimensions. The hypothesis was that more intense pre-dilatation with a non-compliant scoring balloon before MgBRS implantation can reduce the risk of late lumen reduction compared to standard pre-dilatation. The power calculation used expected MLA after 6 months (6.22 mm2 for the scoring balloon and 5.01 mm2 for the standard non-compliant balloon), power of 80 %, significance level of 0.05 and expected drop-out rate of 15 %, requiring 82 patients to be enrolled.

Results

Eighty-two patients were included in the study. Enrollment was from December 2020 to September 2023.

Conclusion

The hypothesis was that more intense pre-dilatation with a non-compliant scoring balloon before MgBRS implantation can reduce the risk of late lumen reduction compared to standard pre-dilatation.

Long-term outcomes of patients treated with sirolimus-eluting resorbable magnesium scaffolds: Insights from the SHERPA-MAGIC study

BACKGROUND

The resorbable magnesium scaffold (RMS) is a second-generation bioresorbable scaffold (BRS) that has shown conflicting results in previous studies. These findings suggest that patient selection and implantation technique may have an impact on clinical outcomes. This study aimed to investigate the safety and long-term effectiveness of RMS in a narrowly selected population.

METHODS

SHERPA-MAGIC is an investigator-driven, multicenter, prospective, single-arm study that enrolled patients undergoing BRS coronary implantation in 18 Italian centers. The present analysis considered the first 543 enrolled patients treated with RMS, with a minimum follow-up of 1 year. The study protocol included strict criteria for patient selection and standardization of RMS implantation. The primary outcome was the occurrence of the vessel-oriented composite endpoints (VOCE), including cardiac death, target vessel myocardial infarction, and ischemia-driven target vessel revascularization.

RESULTS

Overall, 635 vessels were treated. The 1-year cumulative occurrence of VOCE was 22 (3.5%, 95% CI 2.2%-5.2%), which was significantly lower than the prespecified estimation (from 5.5% to 8.5%). At the median follow-up of 3.5 [2.6-4.3] years, there were 3 (0.5%) cardiac deaths, 12 (1.9%) target vessel myocardial infarctions, and 33 (5.2%) ischemia-driven target vessel revascularizations. A total of 37 (5.8%, 95%CI 4.1%-7.9%) VOCEs were detected. Scaffold thrombosis occurred in 4 (0.6%, 95%CI 0.1%-1.6%) cases. Patient-level analysis confirmed the findings of the vessel-level analysis.

CONCLUSIONS

These results confirm the safety and performance of RMS technology. If confirmed in randomized controlled trials, they may rekindle interest in the use of scaffolds in daily practice.

Coronary Computed Tomography Angiography for the Assessment of Sirolimus-Eluting Resorbable Magnesium Scaffold

Background: Little evidence to date has described the feasibility and diagnostic accuracy of coronary computed tomography angiography (CCTA) with noninvasive fractional flow reserve (CT-FFR) in coronary vessels with resorbable magnesium scaffold (RMS). Methods: The SHERPA-MAGIC is a prospective study enrolling patients receiving RMS. The present analysis considered patients undergoing CCTA 18 months after the index procedure. CCTA images were employed to investigate reabsorption status, luminal measurements, and noninvasive FFR. Three-year follow-up was available for all patients. Results: Overall, 26 patients with a total of 29 coronary arteries treated with 35 RMS were considered. The most frequently involved vessel was left anterior descendent (LAD). Median stent length was 25 (20–25) mm, with a median diameter of 3 (3–3.5) mm. At 18-month CCTA, all scaffolded segments were patent. Complete RMS reabsorption was observed in 27 (93%, 95% CI 77–99%) cases. Median minimal lumen diameter (MLD) and area (MLA) of the scaffolded segments were 2.5 [2.1–2.8] mm and 6.4 [4.4–8.4] mm², respectively. Median CT-FFR was 0.88 [0.81–0.91]. Only one (3.5%) vessel showed a flow-limiting CT-FFR value ≤0.80. During the 3-year follow-up, only one (4%) adverse event was observed. Conclusions: In patients undergoing RMS implantation, CCTA including noninvasive CT-FFR evaluation is feasible and allows investigation of long-term RMS performance.

The bioresorbable magnesium scaffold (Magmaris)-State of the art: From basic concept to clinical application

Since its introduction to clinical practice, coronary artery stent implantation has become a crucial part of the therapy of coronary artery disease (CAD). Despite the undeniable evolution of percutaneous coronary revascularization procedures, drug-eluting stent (DES) technology shows some limitations. To overcome these limitations bioresorbable vascular scaffolds (BRS) were designed as a vessel-supporting technology allowing for anatomical and functional restoration of the vessel after the scaffold intended resorption. Various materials have been proposed as the basis of the scaffold backbone. In this narrative review, we present second-generation magnesium-alloy bioresorbable scaffold devices (Magmaris; Biotronik). Additionally, we discuss available preclinical and clinical data regarding this new magnesium BRS.

Five-year clinical outcomes using the bioresorbable vascular scaffold: Insights from the FRANCE ABSORB registry

BACKGROUND

Randomized trials comparing the first-generation absorb bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, CA, USA) with a drug-eluting stent showed a moderate but significant increase in the rate of 3-year major adverse cardiac events and scaffold thrombosis, followed by a decrease in adverse events after 3 years.

AIM

The objective of this study was to assess the 5-year outcomes of patients treated with at least one absorb BVS and included in the FRANCE ABSORB registry.

METHODS

All patients treated in France with an absorb BVS were prospectively included in a large nationwide multicentre registry. The primary efficacy outcome was the occurrence of 5-year major adverse cardiac events. Secondary efficacy outcomes were the rates of 5-year target vessel revascularization and definite/probable scaffold thrombosis.

RESULTS

Between September 2014 and April 2016, 2,070 patients were included in 86 centres (mean age 55±11 years; 80% men; 49% with acute coronary syndrome). The rates of 1-, 3- and 5-year major adverse cardiac events were 3.9%, 9.4% and 12.1%, respectively (including cardiac death in 2.5% and target vessel revascularization in 10.4%). By multivariable analysis, diabetes, oral anticoagulation, the use of multiple Absorb BVSs and the use of a 2.5mm diameter absorb BVS were associated with 5-year major adverse cardiac events. The rates of 1-, 3- and 5-year definite/probable scaffold thrombosis were 1.5%, 3.1% and 3.6%, respectively. By multivariable analysis, older age, diabetes, anticoagulation at discharge and the use of a 2.5mm diameter absorb BVS were associated with 5-year scaffold thrombosis.

CONCLUSIONS

Absorb BVS implantation was associated with low rates of 1-year major adverse cardiac events, which increased significantly at 3-year follow-up. There was a clear decrease in the rates of scaffold thrombosis and major adverse cardiac events after 3 years.