5-Year Outcomes After Bioresorbable Coronary Scaffolds Implanted With Improved Technique

Rationale and design of INFINITY-SWEDEHEART: A registry-based randomized clinical trial comparing clinical outcomes of the sirolimus-eluting DynamX bioadaptor to the zotarolimus-eluting Resolute Onyx stent

BACKGROUND

Modern drug-eluting stents have seen significant improvements, yet still create a rigid cage within the coronary artery. There is a 2% to 4% annual incidence of target lesion failure (TLF) beyond 1 year, and half of the patients experience angina after 5 years. The DynamX bioadaptor is a sirolimus-eluting, thin (71 µm) cobalt-chromium platform with helical strands that unlock and separate after in vivo degradation of the bioresorbable polymer coating. This allows the vessel to return to normal physiological function and motion, along with compensatory adaptive remodeling, which may reduce the need for reintervention and alleviate angina following percutaneous coronary intervention (PCI).

METHODS

The INFINITY-SWEDEHEART trial is a single-blind, registry-based randomized clinical trial (R-RCT) to evaluate the safety and effectiveness of the DynamX bioadaptor compared to the Resolute Onyx stent in the treatment of patients with ischemic heart disease with de novo native coronary artery lesions. The R-RCT framework allows for recruitment, randomization, and pragmatic data collection of baseline demographics, medications, and clinical outcomes using existing national clinical registries integrated with the trial database. The primary objective is to demonstrate noninferiority in terms of freedom from TLF (cardiovascular death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization) at 1 year. Powered secondary endpoints will be tested sequentially for superiority from 6 months to the end of follow-up (5 years) for the following: 1) TLF in all subjects, 2) target vessel failure in all subjects, and 3) TLF in subjects with acute coronary syndrome (ACS). Subsequent superiority testing will be performed at a time determined depending on the number of events, ensuring sufficient statistical power. Change in angina-related symptoms, function and quality of life will be assessed using the Seattle Angina Questionnaire-short version. Predefined sub-groups will be analyzed. In total, 2400 patients have been randomized at 20 sites in Sweden. Available baseline characteristic reveal relatively old age (68 years) and a large proportion of ACS patients including 25% STEMI and 37% NSTEMI patients.

SUMMARY

The INFINITY-SWEDEHEART study is designed to evaluate the long-term safety and efficacy of the DynamX bioadaptor compared to the Resolute Onyx stent in a general PCI patient population.

Illusion of revascularization: does anyone achieve optimal revascularization during percutaneous coronary intervention?

This Perspective article is a form of 'pastiche', inspired by the 1993 review by Lincoff and Topol entitled 'Illusion of reperfusion', and explores how their concept continues to apply to percutaneous revascularization in patients with coronary artery disease and ischaemia. Just as Lincoff and Topol argued that reperfusion of acute myocardial infarction was facing unresolved obstacles that hampered clinical success in 1993, we propose that challenging issues are similarly jeopardizing the potential benefits of stent-based angioplasty today. By analysing the appropriateness and efficacy of percutaneous coronary intervention (PCI), we emphasize the limitations of relying solely on visual angiographic guidance, which frequently leads to inappropriate stenting and overtreatment in up to one-third of patients and the associated increased risk of periprocedural myocardial infarction. The lack of optimal revascularization observed in half of patients undergoing PCI confers risks such as suboptimal physiology after PCI, residual angina and long-term stent-related events, leaving an estimated 76% of patients with an 'illusion of revascularization'. These outcomes highlight the need to refine our diagnostic tools by integrating physiological assessments with targeted intracoronary imaging and emerging strategies, such as co-registration systems and angiography-based computational methods enhanced by artificial intelligence, to achieve optimal revascularization outcomes.

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 Results of Bioresorbable Vascular Scaffolds in Patients With In-Stent Restenosis: The RIBS VI Study

BACKGROUND

In patients with in-stent restenosis (ISR) bioresorbable vascular scaffolds (BVS) provide similar results to drug-coated balloons (DCBs) but are inferior to drug-eluting stents (DES) at 1 year. However, the long-term efficacy of BVS in these patients remains unknown.

OBJECTIVES

This study sought to assess the long-term safety and efficacy of BVS in patients with ISR.

METHODS

RIBS VI (Restenosis Intrastent: Bioresorbable Vascular Scaffolds Treatment; NCT02672878) and RIBS VI Scoring (Restenosis Intrastent: Bioresorbable Vascular Scaffolds Treatment With Scoring Balloon; NTC03069066) are prospective multicenter studies designed to evaluate the results of BVS in patients with ISR (N = 220). The inclusion and exclusion criteria were identical to those used in the RIBS IV (ISR of DES) (Restenosis Intra-stent of Drug-eluting Stents: Drug-eluting Balloon vs Everolimus-eluting Stent; NCT01239940) and RIBS V (ISR of bare-metal stents) (Restenosis Intra-stent of Bare Metal Stents: Paclitaxel-eluting Balloon vs Everolimus-eluting Stent; NCT01239953) randomized trials (including 249 ISR patients treated with DCBs and 249 ISR patients treated with DES). A prespecified comparison of the long-term results obtained with these treatment modalities (ie, DES, DCBs, and BVS) was performed.

RESULTS

Clinical follow-up at 3 years was obtained in all (100%) 718 patients. The 3-year target lesion revascularization rate after BVS was 14.1% (vs 12.9% after DCBs [not significant], and 5.2% after DES [HR: 2.80; 95% CI: 1.47-5.36; P = 0.001]). In a landmark analysis (>1 year), the target lesion revascularization rate after BVS was higher than after DES (adjusted HR: 3.41; 95% CI: 1.15-10.08) and DCBs (adjusted HR: 3.33; 95% CI: 1.14-9.70). Very late vessel thrombosis was also more frequent with BVS (BVS: 1.8%, DCBs: 0.4%, DES: 0%; P = 0.03).

CONCLUSIONS

In patients with ISR, late clinical results of DES are superior to those obtained with DCBs and BVS. Beyond the first year, DCBs are safer and more effective than BVS.

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.

Bioresorbable Scaffold Use in Coronary Chronic Total Occlusions: A Long-Term, Single-Center Follow-Up Study

Background and Objectives: Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is often associated with longer total stent length. Our aim was to evaluate the long-term safety and effectiveness of bioresorbable scaffold (BRS) implantation in CTO to avoid using a full metal jacket. Materials and Methods: We conducted a single-center prospective longitudinal case study including 34 patients who underwent PCI of CTO with at least one BRS and drug-eluting stent (DES) implantation (n = 27) or BRS-only at the Latvian Centre of Cardiology between 2016 and 2018. Quantitative coronary angiography (QCA) and intravascular ultrasound were performed during the index procedure and long-term follow-up. Results: Of 34 patients with a mean age of 60.6 ± 9.5 years, 76.5% were male. The most common CTO artery was the right coronary artery (73.5%, n = 25). The median length of occlusion was 23.0 mm (interquartile range (IQR) = 13.9-32.7), with a total mean BRS/DES length of 49.6 ± 20.4 mm. During the median follow-up of 5.6 years (IQR = 5.0-5.9), the primary endpoint of target vessel re-occlusion occurred in 5.9% (n = 2) of patients. Target lesion revascularization (TLR) was performed in 35.3% (n = 12) of patients, with a mean time to TLR of 62.5 (95% confidence interval (CI), 53.9-71.2) months. Through QCA, there was a statistically significant increase in median residual diameter stenosis (20.1-31.4%, p < 0.01) and residual length of stenosis (5.2-7.1%, p = 0.04) compared with the index procedure. Conclusions: Our study demonstrates that BRS is a safe and feasible option for PCI of CTO, allowing for the avoidance of long segment stenting and ensuring long-term patency of the coronary artery.

Safety and efficacy of everolimus-eluting bioresorbable vascular scaffold for cardiac allograft vasculopathy (CART)

BACKGROUND

Cardiac allograft vasculopathy (CAV) is still the main drawback of heart transplantation (HTx) and percutaneous coronary intervention (PCI) is a palliative measure because of the high incidence of failure.

OBJECTIVE

This study aimed to investigate the safety and efficacy of bioresorbable scaffolds (BRSs) as potential novel therapeutic tool for the treatment of coronary stenoses in CAV.

METHODS

This is a multicenter, single-arm, prospective, open-label study (CART, NCT02377648), that included patients affected by advanced CAV treated with PCI and second-generation ABSORB BRS (Abbott Vascular). The primary endpoint was the incidence of 12-month angiographic in-segment scaffold restenosis (ISSR). Secondary endpoints were the incidence of major adverse cardiac events (MACEs) at 12- and 36-month follow-up and the incidence of ISSR at 36 months. A paired intracoronary imaging analysis at baseline and follow-up was also performed.

RESULTS

Between 2015 and 2017 35 HTx patients were enrolled and treated for 44 coronary lesions with 51 BRSs. The primary endpoint occurred in 13.5% of the lesions (5/37), with a cumulative ISSR rate up to 3 years of 16.2% (6/37). Angiographic lumen loss was 0.40 ± 0.62 mm at 12 months and 0.53 ± 0.57 mm at 36 months. Overall survival rate was 91.4% and 74.3%, and MACEs incidence 14.2% and 31.4% at 12 and 36 months, respectively. At the paired intracoronary imaging analysis, a significant increase of the vessel external elastic membrane area in the treated segment and some progression of CAV proximally to the BRS were detected.

CONCLUSIONS

BRS-based PCI for the treatment of CAV is feasible and safe, with an ISSR incidence similar to what reported in retrospective studies with drug-eluting stents.

The Absorb GT1 Bioresorbable Vascular Scaffold System - 5-Year Post-Market Surveillance Study in Japan

BACKGROUND

The 1-year clinical outcomes of the Absorb GT1 Japan post-market surveillance (PMS) suggested that an appropriate intracoronary imaging-guided bioresorbable vascular scaffold (BVS) implantation technique may reduce the risk of target lesion failure (TLF) and scaffold thrombosis (ST) associated with the Absorb GT1 BVS. The long-term outcomes through 5 years are now available.

METHODS AND RESULTS

This study enrolled 135 consecutive patients (n=139 lesions) with ischemic heart disease in whom percutaneous coronary intervention (PCI) with the Absorb GT1 BVS was attempted. Adequate lesion preparation, imaging-guided appropriate sizing, and high-pressure post-dilatation using a non-compliant balloon were strongly encouraged. All patients had at least 1 Absorb GT1 successfully implanted at the index procedure. Intracoronary imaging was performed in all patients (optical coherence tomography: 127/139 [91.4%] lesions) and adherence to the implantation technique recommendations was excellent: predilatation, 100% (139/139) lesions; post-dilatation, 98.6% (137/139) lesions; mean (±SD) post-dilatation pressure, 18.8±3.5 atm. At 5 years, the follow-up rate was 87.4% (118/135). No definite/probable ST was reported through 5 years. The cumulative TLF rate was 5.1% (6/118), including 2 cardiac deaths, 1 target vessel-attributable myocardial infarction, and 3 ischemia-driven target lesion revascularizations.

CONCLUSIONS

Appropriate intracoronary imaging-guided BVS implantation, including the proactive use of pre- and post-balloon dilatation during implantation may be beneficial, reducing the risk of TLF and ST through 5 years.

Is it time for a retinoic acid-eluting stent or retinoic acid-coated balloon? Insights from experimental studies of systemic and local delivery of retinoids

Although the incidence of restenosis and stent thrombosis has substantially declined during the last decades, they still constitute the two major causes of stent failure. These complications are partially attributed to the currently used cytostatic drugs, which can cause local inflammation, delay or prevent re-endothelialization and essentially cause arterial cell toxicity. Retinoic acid (RA), a vitamin A (retinol) derivative, is a naturally occurring substance used for the treatment of cell proliferation disorders. The agent has pleiotropic effects on vascular smooth muscle cells and macrophages: it influences the proliferation, migration, and transition of smooth muscle cells to other cell types and modulates macrophage activation. These observations are supported by accumulated evidence from in vitro and in vivo experiments. In addition, systemic and topical administration of RA can decrease the development of atherosclerotic plaques and reduce or inhibit restenosis after vascular injury (caused by embolectomy, balloon catheters, or ligation of arteries) in various experimental models. Recently, an RA-drug eluting stent (DES) has been tested in an animal model. In this review, we explore the effects of RA in atherosclerosis and the potential of the local delivery of RA through an RA-DES or RA-coated balloon for targeted therapeutic percutaneous vascular interventions. Despite promising published results, further experimental study is warranted to examine the safety and efficacy of RA-eluting devices in vascular artery disease.

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.