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

Current situation and overview of resorbable magnesium scaffolds: a perspective for overcoming the remaining issues of polymeric bioresorbable scaffold

Bioresorbable scaffolds (BRS) were developed as an innovative solution to overcome the limitations of metallic stents. While polymeric BRS initially demonstrated comparable clinical outcomes to drug-eluting stent (DES) in clinical trials, subsequent large-scale studies revealed that patients implanted with polymeric BRS experienced higher rates of scaffold thrombosis (ScT) and target lesion failure compared to those with metallic stents. Resorbable magnesium scaffolds (RMS) have emerged as a promising alternative owing to magnesium's natural degradability and favorable mechanical properties. Learning from the mechanism of polymeric BRS failure and through continuous improvements, recent clinical trials have shown promising clinical performance for RMS technology. However, comparative studies between RMS and DES have continued to highlight the remaining challenges with RMS, particularly in regard to late lumen loss. Recent advancements in third-generation RMS show improvements in strut thickness and homogeneous degradation, which enhances sustained structural integrity throughout the degradation process. Based on encouraging results from a first-in-human trial of the latest version of RMS, a randomized controlled trial has been initiated to compare the outcomes between metallic stents and the latest RMS, with patient enrollment already underway. This review aims to explore the limitations of polymeric BRS and provide an overview of the current developments and future potential of magnesium-based BRS.

Biodegradable Stents in the Treatment of Arterial Stenosis

Arterial diseases (ADs) are a significant health problem, with high mortality and morbidity rates. Endovascular interventions, such as balloon angioplasty (BA), bare-metal stents (BMSs), drug-eluting stents (DESs) and drug-coated balloons (DCBs), have made significant progress in their treatments. However, the issue has not been fully resolved, with restenosis remaining a major concern. In this context, bioresorbable vascular stents (BVSs) have emerged as a promising area of investigation. This manuscript includes articles that assess the use of BVSs. Studies have identified ongoing challenges, such as negative vascular remodeling and elastic recoil post-angioplasty, stent-related injury, and in-stent restenosis following BMS placement. While DESs have mitigated these issues to a considerable extent, their durable structures are unable to prevent late stent thrombosis and delay arterial recovery. BVSs, with their lower support strength and tendency towards thicker scaffolds, increase the risk of scaffold thrombosis. Despite inconsistent study results, the superiority of BVSs over DESs has not been demonstrated in randomized trials, and DES devices continue to be the preferred choice for most cases of arterial disease. Esprit BTK (Abbott Vascular) received approval from the US FDA for below-knee lesions in 2024, offering hope for the use of BVSs in other vascular conditions. Enhancing the design and thickness of BVS scaffolds may open up new possibilities. Large-scale and longer-term comparative studies are still required. This article aims to provide an overview of the use of biodegradable stents in the endovascular treatment of vascular stenosis.

Early and Late Outcomes With the Absorb Bioresorbable Vascular Scaffold: Final Report From the ABSORB Clinical Trial Program

BACKGROUND

The risk-benefit ratio of the Absorb bioresorbable vascular scaffold (BVS) may vary before and after 3 years, the time point of complete bioresorption of the poly-L-lactic acid scaffold.

OBJECTIVES

The aim of this study was to determine the time-varying outcomes of the Absorb BVS compared with cobalt-chromium everolimus-eluting stents (EES) from a large individual-patient-data pooled analysis of randomized trials.

METHODS

The individual patient data from 5 trials that randomized 5,988 patients undergoing percutaneous coronary intervention to the Absorb BVS vs EES with 5-year follow-up were pooled. The primary effectiveness and safety endpoints were target lesion failure (TLF) (cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization) and device thrombosis (DT).

RESULTS

Between 0 and 5 years, TLF occurred in 15.9% BVS patients vs 13.1% EES patients (HR: 1.25; 95% CI: 1.08-1.43; P = 0.002), and DT occurred in 2.2% vs 1.0%, respectively (HR: 2.38; 95% CI: 1.49-3.79; P = 0.0002). Between 0 and 3 years, TLF occurred in 12.4% BVS patients vs 9.3% EES patients (HR: 1.35; 95% CI: 1.15-1.59; P = 0.0002), and DT occurred in 2.0% vs 0.6%, respectively (HR: 3.58; 95% CI: 2.01-6.36; P < 0.0001). Between 3 and 5 years, TLF occurred in 4.5% BVS patients vs 4.7% EES patients (HR: 0.99; 95% CI: 0.76-1.27; P = 0.91), and DT occurred in 0.2% vs 0.4%, respectively (HR: 0.49; 95% CI: 0.18-1.38; P = 0.17). By spline analysis, the TLF hazard by 5 years was lower with BVS than EES.

CONCLUSIONS

Compared with EES treatment, BVS increased TLF and DT rates through 5-year follow-up. However, the period of excess risk for the first-generation Absorb BVS ended at 3 years, when poly-L-lactic acid bioresorption is complete. Thereafter event rates were comparable or lower with BVS. (ABSORB II Randomized Controlled Trial, NCT01425281; A Clinical Evaluation of Absorb™ Bioresorbable Vascular Scaffold [Absorb™ BVS] System in Chinese Population - ABSORB CHINA Randomized Controlled Trial [ABSORB CHINA], NCT01923740; AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 [Absorb™ BVS] in Japanese Population [ABSORB JAPAN], NCT01844284; ABSORB III Randomized Controlled Trial [ABSORB III], NCT01751906; Absorb IV Randomized Controlled Trial, NCT02173379).

A Randomized Comparison of Bioheart Sirolimus-Eluting Bioresorbable Scaffold and Everolimus-Eluting Stents: The BIOHEART-II Trial

BACKGROUND

First-generation bioresorbable scaffolds (BRS) increased risks of stent thrombosis and adverse events. The Bioheart scaffold is a new poly-L-lactic acid-based BRS.

OBJECTIVES

This study sought to evaluate the efficacy and safety of the BRS in patients with coronary artery disease.

METHODS

This was a prospective, multicenter, randomized, noninferiority trial comparing the Bioheart BRS with a cobalt-chromium everolimus-eluting stent (CoCr-EES) in patients with coronary artery disease. Angiography was planned at 12 months in all patients. The primary endpoint was 12-month in-segment late loss. The key secondary endpoint was the 12-month proportion of covered struts assessed on optical coherence tomography. Three-year clinical follow-up was completed.

RESULTS

A total of 434 patients from 22 Chinese sites were included (Bioheart BRS, n =218; CoCr-EES, n = 216). One-year in-segment late loss was 0.17 ± 0.38 mm with the Bioheart BRS vs 0.14 ± 0.24 mm with CoCr-EES; the 1-sided 97.5% upper confidence limit of the difference was 0.10 mm (P for noninferiority < 0.0001). The proportion of covered struts was 97.9% in the Bioheart BRS and 98.5% in the CoCr-EES (difference 0.02%; 95% CI: -0.3% to 0.26%; P for noninferiority < 0.0001; P for superiority = 0.91). Clinical outcomes at 3 years were similar in the 2 groups, as were the rates of target lesion failure (5.6% vs 5.2%; P = 0.84).

CONCLUSIONS

In this multicenter randomized trial, the Bioheart BRS was noninferior to the CoCr-EES for 1-year in-segment late loss, and resulted in a comparable 3-year clinical outcome. (Bioheart Rapamycin Drug-Eluting Bioresorbable Coronary Stent System Clinical Study; NCT03284255).

Prognostic Value of Postpercutaneous Coronary Intervention Murray-Law-Based Quantitative Flow Ratio: Post Hoc Analysis From FLAVOUR Trial

Background

Coronary physiology measured by fractional flow reserve (FFR) is superior to angiography for assessing the efficacy of percutaneous coronary intervention (PCI). Yet, the clinical adoption of post-PCI FFR is limited. Murray law-based quantitative flow ratio (μQFR) may represent a promising alternative, as it can quickly compute FFR from a single angiographic view.

Objectives

The authors aimed to investigate the potential role of post-PCI μQFR in predicting clinical outcomes.

Methods

This was a post hoc blinded analysis of the FLAVOUR trial. Patients with angiographically intermediate lesions randomized 1:1 to receive FFR or intravascular ultrasound-guided PCI were included. Post-PCI μQFR was assessed in successfully stented vessels, blinded to clinical outcomes. Suboptimal physiological outcome post-PCI was defined a priori as post-PCI μQFR <0.90. The primary endpoint was 2-year target vessel failure, including cardiac death, target vessel myocardial infarction, and target vessel revascularization. Secondary endpoints included the diagnostic concordance of pre-PCI μQFR with FFR in the FFR-guidance arm.

Results

Post-PCI μQFR was successfully analyzed in 806 vessels from 777 participants (feasibility 97.0% [806 of 831]). Suboptimal physiological outcome post-PCI was identified in 24.7% (199 of 806) of vessels and post-PCI μQFR <0.90 was associated with higher risk of 2-year target vessel failure (6.1% [12 of 199] vs 2.7% [16 of 607]; HR: 2.45 [95% CI: 1.14-5.26]; P = 0.022). Pre-PCI μQFR was obtained in 877 of 919 vessels (feasibility 95.4%), showing 90% accuracy, 82% sensitivity, and 94% specificity for identifying physiologically significant stenosis defined by pre-PCI FFR ≤0.80.

Conclusions

In patients with intermediate lesions who underwent PCI with contemporary imaging or physiology guidance, lower post-PCI μQFR values predict subsequent adverse events. (Fractional FLow Reserve And IVUS for Clinical OUtcomes in Patients With InteRmediate Stenosis [FLAVOUR]; NCT02673424).

Five-year clinical outcomes of STEMI patients treated with a pre-specified bioresorbable vascular scaffold implantation technique: Final results of the BVS STEMI STRATEGY-IT

BACKGROUND

Data on Absorb bioresorbable vascular scaffold (BVS) use in patients presenting with ST-segment elevation myocardial infarction (STEMI) are limited. Furthermore, Absorb studies including STEMI patients lacked a prespecified implantation technique to optimize BVS deployment. This study examines the 5-year outcomes of BVS in STEMI patients using an optimized implantation strategy and the impact of prolonged dual antiplatelet therapy (DAPT).

METHODS

The BVS STEMI STRATEGY-IT study is a prospective, non-randomized, single-arm multicenter trial (NCT02601781). It involved 505 STEMI patients undergoing primary percutaneous coronary intervention with a predefined BVS implantation protocol. Key endpoints were a 5-year device-oriented composite endpoint (DOCE) of cardiac death, target-vessel myocardial infarction (TV-MI), and ischemia-driven target lesion revascularization (ID-TLR). The study also compared outcomes based on DAPT duration (36 months vs. shorter).

RESULTS

502 (99.4 %) patients completed the 5-year follow-up. DOCE rate was 2.4 %. ID-TLR, TV-MI, and cardiac death rates were 1.6 %, 0.8 %, and 0.6 %, respectively. No DOCE occurred between three and five years. Scaffold thrombosis (ScT) was 1 %, all occurring within 24 months. Longer-term DAPT significantly reduced DOCE (1.3 % vs. 4.3 %; HR: 0.29; 95 % CI: 0.1-0.9; p = 0.03) driven by a lower rate of TV-MI (0 % vs. 2.2 %; p = 0.018) compared to shorter-term DAPT, as well as ScT (0 % vs 2.7 %, p = 0.007).

CONCLUSIONS

This study shows favorable 5-year outcomes for BVS in selected STEMI patients with an optimized implantation strategy. Prolonged DAPT further improved outcomes, emphasizing its role in reducing adverse events during scaffold resorption. Further research is needed to assess newer-generation bioresorbable devices.

Bioadaptor implant versus contemporary drug-eluting stent in percutaneous coronary interventions in Sweden (INFINITY-SWEDEHEART): a single-blind, non-inferiority, registry-based, randomised controlled trial

BACKGROUND

Persistent non-plateauing adverse event rates in patients who underwent percutaneous coronary intervention (PCI) remain a challenge. A bioadaptor is a novel implant that addresses this issue by restoring the haemodynamic modulation of the artery, allowing cyclic pulsatility, vasomotion, and adaptative remodelling, by unlocking and providing dynamic support to the artery. We aimed to assess outcomes with the device versus a contemporary drug-eluting stent (DES) in a representative PCI population.

METHODS

INFINITY-SWEDEHEART is a single-blind, non-inferiority, registry-based, randomised controlled study conducted in 20 hospitals in Sweden. Patients aged 18-85 years, with chronic or acute coronary syndrome ischaemic heart disease, with an indication for PCI, with up to three de novo lesions suitable for implantation with one single device per lesion, and successful pre-dilatation were identified via the Swedish Coronary Angiography and Angioplasty Registry and eligible for enrolment. Participants were randomly assigned (1:1), using block randomisation with random variation in block size and stratified by site, to either the DynamX bioadaptor (Elixir Medical, Milpitas, CA, USA) or a zotarolimus-eluting DES (Resolute Onyx and Onyx Trustar, Medtronic, Minneapolis, MN, USA). The primary endpoint was the device-oriented clinical endpoint of target lesion failure at 12 months (a composite of cardiovascular death, target vessel myocardial infarction, and ischaemia-driven target lesion revascularisation), assessed in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment, regardless of treatment received) who had either experienced an event up to 12 months or completed the trial up to 12 months. Non-inferiority was established if the upper limit of the two-sided 95% CI for the absolute risk difference was less than 4·2%. Powered secondary endpoints were landmark analyses from 6 months onwards for target lesion failure, target vessel failure (composite of cardiovascular death, target vessel myocardial infarction, and ischaemia-driven target vessel revascularisation), and target lesion failure for patients with acute coronary syndrome assessed in the ITT population). This study is registered with ClinicalTrials.gov, NCT04562805, and follow-up to 5 years is ongoing.

FINDINGS

Between Sept 30, 2020, and July 11, 2023, 2399 patients were randomly assigned to receive the bioadaptor (n=1201) or DES (n=1198; ITT population). Median age was 69·5 years (IQR 61·2-75·6), 575 (24·0%) of 2399 patients were female, and 1824 (76·0%) were male (data on race and ethnicity were not collected), and 1838 (76·6%) patients presented with acute coronary syndrome. The primary endpoint of 12-month target lesion failure occurred in 28 (2·4%) of 1189 assessable patients in the bioadaptor group versus 33 (2·8%) of 1192 assessable patients in the DES group, with a risk difference of -0·41% (95% CI -1·94 to 1·11; pnon-inferiority<0·0001). In the prespecified landmark analysis from 6 months to 12 months, the Kaplan-Meier estimates of target lesion failure were 0·3% (with events in three of 1170 patients) in the bioadaptor group versus 1·7% (with events in 16 of 1176 patients) in the DES group (hazard ratio 0·19 [95% CI 0·06 to 0·65]; p=0·0079), of target vessel failure were 0·8% (events in eight of 1167) versus 2·5% (events in 23 of 1174; 0·35 [0·16 to 0·79]; p=0·011), and of target lesion failure in patients with acute coronary syndrome were 0·3% (events in two of 906) versus 1·8% (events in 12 of 895; 0·17 [0·04 to 0·74]; p=0·018). The rate of definite or probable device thrombosis, which was recorded as a safety outcome, was low and did not differ between groups (eight [0·7%] of 1201 in the bioadaptor group vs six [0·5%] of 1198 in the DES group; difference in event rates of 0·16% [95% CI -0·50 to 0·83]).

INTERPRETATION

Among patients with coronary artery disease, including those with acute coronary syndrome, treatment with the bioadaptor was non-inferior to contemporary DES, showing potential to mitigate non-plateauing device-related events and improving outcomes in patients undergoing PCI. The additional planned follow-up will help to reinforce the clinical significance of the 1-year findings.

FUNDING

Elixir Medical.

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.

Advances in Technology and Technique in Percutaneous Coronary Intervention: A Clinical Review

Percutaneous coronary intervention (PCI) has become the standard procedure for patients with angina and acute coronary syndrome. From the perspective of technology and technique, PCI has advanced over the last four decades, resulting in considerably improved clinical outcomes in patients with coronary artery disease in the current era. In this review article, we summarize recent advances, promising technologies, and areas for research in the field of PCI.

Ten-year clinical outcomes of everolimus- and biolimus-eluting coronary stents vs. everolimus-eluting bioresorbable vascular scaffolds-insights from the EVERBIO-2 trial

Background

Bioresorbable vascular scaffolds (BVSs) have been developed as a potential solution to mitigate late complications associated with drug-eluting metallic stents (DESs) in percutaneous coronary intervention for coronary artery disease. While numerous studies have compared BVSs to DESs, none have assessed clinical outcomes beyond 5 years.

Objectives

This study aimed to compare the 10-year clinical outcomes of patients treated with BVSs vs. DESs.

Methods

The EverBio-2 trial (Comparison of Everolimus- and Biolimus-Eluting Coronary Stents with Everolimus-Eluting Bioresorbable Vascular Scaffold) is a single-center, assessor-blinded, randomized controlled trial that enrolled 240 patients allocated in a 1:1:1 ratio to receive BVSs, everolimus-eluting stents, or biolimus-eluting stents (BESs). Clinical follow-up was scheduled for 10 years.

Results

Clinical follow-up was completed in 222 patients (93%) at the 10-year mark. The rate of device-oriented composite events (DOCE) was 28% in the DES group and 29% in the BVS group (p = 0.72) at 10 years. Similarly, the rate of patient-oriented composite events (POCE) was 55% in the DES group and 49% in the BVS group (p = 0.43) at 10 years. Notably, the rate of myocardial infarction (MI) within the target vessel was 5% in the BVS group and 0% in the BES group (p = 0.04), while the rate of any MI was 10% in the BVS group and 2% in the BES group (p = 0.04). In addition, the rate of Academic Research Consortium (ARC) possible stent thrombosis was 3% in the BVS group and 0% in the DES group (p = 0.04).

Conclusions

Over 10 years, the rates of clinical DOCE and POCE were similar between the BVS and DES groups but individual outcomes of stent thrombosis were higher (3%) in the BVS group compared to the DES group.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT01711931).

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.