Late thrombotic events after bioresorbable scaffold implantation: a systematic review and meta-analysis of randomized clinical trials

Review on Bioinspired Design of ECM-Mimicking Scaffolds by Computer-Aided Assembly of Cell-Free and Cell Laden Micro-Modules

Tissue engineering needs bioactive drug delivery scaffolds capable of guiding cell biosynthesis and tissue morphogenesis in three dimensions. Several strategies have been developed to design and fabricate ECM-mimicking scaffolds suitable for directing in vitro cell/scaffold interaction, and controlling tissue morphogenesis in vivo. Among these strategies, emerging computer aided design and manufacturing processes, such as modular tissue unit patterning, promise to provide unprecedented control over the generation of biologically and biomechanically competent tissue analogues. This review discusses recent studies and highlights the role of scaffold microstructural properties and their drug release capability in cell fate control and tissue morphogenesis. Furthermore, the work highlights recent advances in the bottom-up fabrication of porous scaffolds and hybrid constructs through the computer-aided assembly of cell-free and/or cell-laden micro-modules. The advantages, current limitations, and future challenges of these strategies are described and discussed.

Bioresorbable scaffolds vs. drug-eluting stents for patients with myocardial infarction: A systematic review and meta-analysis of randomized clinical trials

Objective

To compare the efficacy and safety of bioresorbable scaffolds (BRS) with drug-eluting stents (DES) in patients with myocardial infarction undergoing percutaneous coronary interventions (PCI).

Methods

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing BRS with DES on clinical outcomes with at least 12 months follow-up. Electronic databases of PubMed, CENTRAL, EMBASE, and Web of Science from inception to 1 March 2022 were systematically searched to identify relevant studies. The primary outcome of this study was the device-oriented composite endpoint (DOCE) consisting of cardiac death, target-vessel myocardial infarction, and target lesion revascularization. Secondary outcomes were a composite of major adverse cardiac events (MACE, all-cause death, target-vessel myocardial infarction, or target vessel revascularization) and the patient-oriented composite endpoint (POCE, defined as a composite of all-cause death, myocardial infarction, or revascularization). The safety outcomes were definite/probable device thrombosis and adverse events.

Results

Four randomized clinical trials including 803 participants with a mean age of 60.5 ± 10.8 years were included in this analysis. Patients treated with BRS had a higher risk of the DOCE (RR 1.62, 95% CI: 1.02–2.57, P = 0.04) and MACE (RR 1.77, 95% CI: 1.02–3.08, P = 0.04) compared with patients treated with DES. No significant difference on the POCE (RR 1.33, 95% CI: 0.89–1.98, P = 0.16) and the definite/probable device thrombosis (RR 1.31, 95% CI: 0.46–3.77, P = 0.61) were observed between BRS and DES. No treatment-related serious adverse events were reported.

Conclusion

BRS was associated with a higher risk of DOCE and MACE compared with DES in patients undergoing PCI for myocardial infarction. Although this seems less effective in preventing DOCE, BRS appears as safe as DES.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=321501], identifier [CRD 42022321501].

Safety and Efficacy of Bioresorbable Vascular Scaffolds in Coronary Bifurcation Lesions: A Systematic Review and Meta-Analysis

INTRODUCTION

Coronary bifurcation lesions (CBL) are one fifth of all coronary lesions and they do not have an optimal strategy for stenting yet. Bioresorbable scaffolds (BRS) are novel inventions proposed to be the optimal solution. The aim of this systematic review was to assess the role of BRS in treating CBL by comparing it to dedicated bifurcation stents (DBS).

METHODS

A systematic review was conducted following the PRISMA guidelines, searching databases such as ScienceDirect, EMBASE, MEDLINE, NIH, TRIP, PUBMED, and ClinicalTrials. gov. The risk of bias was assessed by MINORS and modified Cowley's criteria. Q statistic was used for heterogeneity testing and a meta-analysis was conducted using the "meta" package in the R software application.

RESULTS

Fourteen studies were included with an average follow-up period of twelve months. Almost 80% of the participants were male (p-value= 0.148) and around two-thirds were smokers. Meta-analysis was performed for myocardial infarction (MI), target lesion revascularisation (TLR), major adverse cardiac events (MACE), and stent thrombosis (ST). These showed statistically nonsignificant differences, with a slight trend favouring BRS except with stent thrombosis.

CONCLUSION

There is a lack of randomised trials on the topic, which may be an area for further research. But the results showed favourable yet statistically insignificant outcomes for BRS except for ST, an issue that can be addressed with technological advancement.

Improved Biocompatibility of Intra-Arterial Poly-L-Lactic Acid Stent by Tantalum Ion Implantation : 3-Month Results in a Swine Model

Objective

Biodegradable poly-L-lactic acid (PLLA) with a highly biocompatible surface via tantalum (Ta) ion implantation can be an innovative solution for the problems associated with current biodegradable stents. The purpose of this study is to develop a Ta-implanted PLLA stent for clinical use and to investigate its biological performance capabilities.

Methods

A series of in vitro and in vivo tests were used to assess the biological performance of bare and Ta-implanted PLLA stents. The re-endothelialization ability and thrombogenicity were examined through in vitro endothelial cell and platelet adhesion tests. An in vivo swine model was used to evaluate the effects of Ta ion implantation on subacute restenosis and thrombosis. Angiographic and histologic evaluations were conducted at one, two and three months post-treatment.

Results

The Ta-implanted PLLA stent was successfully fabricated, exhibiting a smooth surface morphology and modified layer integration. After Ta ion implantation, the surface properties were more favorable for rapid endothelialization and for less platelet attachment compared to the bare PLLA stent. In an in vivo animal test, follow-up angiography showed no evidence of in-stent stenosis in either group. In a microscopic histologic examination, luminal thrombus formation was significantly suppressed in the Ta-implanted PLLA stent group according to the 2-month follow-up assessment (21.2% vs. 63.9%, p=0.005). Cells positive for CD 68, a marker for the monocyte lineage, were less frequently identified around the Ta-implanted PLLA stent in the 1-month follow-up assessments.

Conclusion

The use of a Ta-implanted PLLA stent appears to promote re-endothelialization and anti-thrombogenicity.

The impact of plaque type on strut embedment/protrusion and shear stress distribution in bioresorbable scaffold

AIMS

Scaffold design and plaque characteristics influence implantation outcomes and local flow dynamics in treated coronary segments. Our aim is to assess the impact of strut embedment/protrusion of bioresorbable scaffold on local shear stress distribution in different atherosclerotic plaque types.

METHODS AND RESULTS

Fifteen Absorb everolimus-eluting Bioresorbable Vascular Scaffolds were implanted in human epicardial coronary arteries. Optical coherence tomography (OCT) was performed post-scaffold implantation and strut embedment/protrusion were analysed using a dedicated software. OCT data were fused with angiography to reconstruct 3D coronary anatomy. Blood flow simulation was performed and wall shear stress (WSS) was estimated in each scaffolded surface and the relationship between strut embedment/protrusion and WSS was evaluated. There were 9083 struts analysed. Ninety-seven percent of the struts (n = 8840) were well-apposed and 243 (3%) were malapposed. At cross-section level (n = 1289), strut embedment was significantly increased in fibroatheromatous plaques (76 ± 48 µm) and decreased in fibrocalcific plaques (35 ± 52 µm). Compatible with strut embedment, WSS was significantly higher in lipid-rich fibroatheromatous plaques (1.50 ± 0.81 Pa), whereas significantly decreased in fibrocalcified plaques (1.05 ± 0.91 Pa). After categorization of WSS as low (<1.0 Pa) and normal/high WSS (≥1.0 Pa), the percent of low WSS in the plaque subgroups were 30.1%, 31.1%, 25.4%, and 36.2% for non-diseased vessel wall, fibrous plaque, fibroatheromatous plaque, and fibrocalcific plaque, respectively (P-overall < 0.001).

CONCLUSION

The composition of the underlying plaque influences strut embedment which seems to have effect on WSS. The struts deeply embedded in lipid-rich fibroatheromas plaques resulted in higher WSS compared with the other plaque types.

Bioresorbable Scaffolds: Contemporary Status and Future Directions

Percutaneous coronary intervention, which is safe, effective, and timely, has become an important treatment for coronary artery diseases and has been widely used in clinical practice. However, there are still some problems that urgently need to be solved. Permanent vessel caging through metallic implants not only prevents the process of positive vessel remodeling and the restoration of vascular physiology but also makes the future revascularization of target vessels more difficult. Bioresorbable scaffolds (BRSs) have been developed as a potential solution to avoid the above adverse reactions caused by permanent metallic devices. BRSs provide temporary support to the vessel wall in the short term and then gradually degrade over time to restore the natural state of coronary arteries. Nonetheless, long-term follow-up of large-scale trials has drawn considerable attention to the safety of BRSs, and the significantly increased risk of late scaffold thrombosis (ScT) limits its clinical application. In this review, we summarize the current status and clinical experiences of BRSs to understand the application prospects and limitations of these devices. In addition, we focus on ScT after implantation, as it is currently the primary drawback of BRS. We also analyze the causes of ScT and discuss improvements required to overcome this serious drawback and to move the field forward.

Three-year outcomes of bioresorbable vascular scaffolds versus second-generation drug-eluting stents: Meta-analysis of randomized trials

BACKGROUND

Bioresorbable vascular scaffolds (BVS) completely resorb within 3 years after placement into the coronary artery. The safety and effectiveness of bioabsorbable scaffolds are of critical importance during this 3-year period.

OBJECTIVE

We performed a meta-analysis to compare the safety and efficacy of BVS and second-generation drug-eluting stents (DES) at 3 years after implantation.

METHODS

Published randomized trials comparing BVS to second-generation DES for the treatment of coronary artery disease were identified within PubMed, EMBASE, Cochrane Library, Web of Science, and relevant Web sites with publication dates through June 2019. The primary efficacy endpoint was target lesion failure. The primary safety endpoint was definite/probable stent/scaffold thrombosis. Secondary outcomes were cardiac death, target vessel myocardial infarction, ischemia-driven target lesion revascularization, and a patient-oriented composite end point.

RESULTS

Six randomized controlled trials, with a total of 5,412 patients (BVS n = 3,177; DES n = 2,235), were included. At 3 years, BVS was associated with higher rates of target lesion failure (OR = 1.33, 95%CI: 1.10-1.60, P = 0.003) and definite/probable stent/scaffold thrombosis (OR = 3.75, 95% CI: 2.22-6.35, P < .00001)compared with DES. The incidence of target vessel myocardial infarction (OR = 1.68, 95% CI: 1.30-2.17, P < .0001), ischemia-driven target lesion revascularization (OR = 1.46, 95% CI: 1.14-1.86, P = .003), and the patient-oriented composite end point(OR = 1.20, 95% CI: 1.04-1.39, P = .01) were higher for those treated with BVS compared with DES. However, there was no significant difference in risk of cardiac death (OR = 0.94, 95%CI: 0.61-1.45, P = .79) between treatment groups.

CONCLUSIONS

At the 3-year follow-up, BVS was inferior to second-generation DES in both safety and efficacy.

Effects of clazosentan, cilostazol, and statins on aneurysmal subarachnoid hemorrhage: A protocol for systematic review and meta-analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a disease caused by the infiltration of blood into the subarachnoid space due to the rupture of an intracranial aneurysm. It is a serious cerebrovascular disease, with a mortality rate of about 40% worldwide, which seriously threatens human life and health. Many drugs are used to treat aSAH and its complications, and some have been tested in systematic reviews and have shown good effects. But which drug has the best effect remains unclear. This network meta-analysis (NMA) aims to assess the effectiveness and feasibility of clazosentan, cilostazol, and statins in patients with aSAH.

METHODS

We will search for EMBASE.com, PubMed, the Cochrane Library, and Web of Science from inception to December 2019. Randomized controlled trials (RCTs) reporting efficacy and safety of clazosentan, cilostazol, and statins compared with the control, or compared with each other for the treatment of aSAH will be included. Two independent reviewers will assess the risk of bias of the included RCTs with the Cochrane "Risk of bias" tool. The pairwise meta-analysis will be performed with the random-effects model. The NMA will be performed in a Bayesian hierarchical framework using Markov Chain Monte Carlo method in WinBUGS 1.4.3. Egger test and funnel plot will be used to assess the publication bias. We will evaluate the quality of evidence for each outcome according to the GRADE approach.

RESULTS

The results of this NMA will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will summarize up-to-date evidence to compare the efficacy and safety of clazosentan, cilostazol, and statins on aSAH.PROSPERO registration number: CRD42019147523.

The Absorb bioresorbable vascular scaffold in real-world practice: long-term follow-up of the AMC Single Centre Real World PCI Registry

BACKGROUND

Bioresorbable scaffolds have been introduced to overcome the shortcomings of drug-eluting stents. Higher rates of device thrombosis, however, have been reported up to 3 years after implantation of the Absorb bioresorbable vascular scaffold (BVS). In the current article, we therefore report long-term clinical outcomes of the AMC Absorb Registry.

METHODS AND RESULTS

In the AMC Absorb Registry, all patients who underwent a percutaneous coronary intervention with Absorb BVS implantation between 30 August 2012 and 5 August 2013 at the Amsterdam University Medical Centre-Academic Medical Centre were included. The composite endpoint of this analysis was target-vessel failure (TVF). The median follow-up of the study cohort of the AMC Absorb Registry was 1534 days. At the time of the cross-sectional data sweep the clinical status at 4 years was known in 124 of 135 patients (91.9%). At long-term follow-up, the composite endpoint of TVF had occurred in 27 patients. The 4‑year Kaplan-Meier estimate of TVF was 19.8%. At 4 years cardiac death had occurred in 4 patients (3.2%) and target-vessel myocardial infarction in 9 (6.9%) patients. Definite scaffold thrombosis occurred in 5 (3.8%) patients. We found 1 case of very late scaffold thrombosis that occurred at 911 days after device implantation in a patient who was not on dual anti-platelet therapy.

CONCLUSION

In a patient population reflecting routine clinical practice, we found that cases of TVF continued to accrue beyond 2 years after Absorb BVS implantation.

Medium-Term Bioresorbable Scaffold Outcomes Utilising Data From an Australian Clinical Quality Registry

BACKGROUND

Bioresorbable scaffolds (BRS) are a novel technology in coronary intervention. However, recent trials demonstrate higher rates of device failure compared to contemporary drug-eluting stents. This study sought to utilise a clinical quality registry to assess the medium-term safety of the Abbott Absorb BRS (Abbott Vascular, Santa Clara, CA, USA), in an Australian context.

METHODS

A prospective, observational study of 192 BRS percutaneous coronary interventions (PCI) compared to 31,773 non-BRS PCIs entered in the Victorian Cardiac Outcomes Registry from 2013 to 2017. The main outcome measure was patient-oriented composite endpoint (POCE) events comprising all-cause mortality, any myocardial infarction (MI), and any revascularisation.

RESULTS

Bioresorbable scaffolds patients (mean age 61.6±10.5 years, 79% male) were younger, had less comorbidity, less prior PCI, fewer ST elevation myocardial infarction (STEMI) presentations, lower rates of multi-lesion disease and more adjuvant devices compared to non-BRS PCI (all p<0.01). All-cause mortality was 2.1%, myocardial infarction (MI) 2.1%, scaffold thrombosis 3.1% and any revascularisation 14.1% (mean follow-up 27.4±8.9 months). POCE events occurred in 11.5% at 1 year and 16.9% at 2 years, comparable to pooled-trial data. Multivariate predictors of POCE were >1 scaffold used (odds ratio [OR] 4.6, 95% confidence interval [CI] 1.9-11.4, p<0.01) and scaffold diameter ≤2.5 mm (OR 3.3, 95% CI 1.4-7.6, p=0.02). Over 95% guideline adherence was achieved in six of eight patient selection criteria and four of six device deployment criteria.

CONCLUSION

In an Australian setting, BRS were used in non-complex patients. Most guidelines for use were adhered to and outcomes were comparable to pooled trial data. Clinical quality registries are effective in assessing novel treatments and technologies when potential safety concerns develop.

Endothelial shear stress 5 years after implantation of a coronary bioresorbable scaffold

Aims

As a sine qua non for arterial wall physiology, local hemodynamic forces such as endothelial shear stress (ESS) may influence long-term vessel changes as bioabsorbable scaffolds dissolve. The aim of this study was to perform serial computational fluid dynamic (CFD) simulations to examine immediate and long-term haemodynamic and vascular changes following bioresorbable scaffold placement.

Methods and results

Coronary arterial models with long-term serial assessment (baseline and 5 years) were reconstructed through fusion of intravascular optical coherence tomography and angiography. Pulsatile non-Newtonian CFD simulations were performed to calculate the ESS and relative blood viscosity. Time-averaged, systolic, and diastolic results were compared between follow-ups. Seven patients (seven lesions) were included in this analysis. A marked heterogeneity in ESS and localised regions of high blood viscosity were observed post-implantation. Percent vessel area exposed to low averaged ESS (<1 Pa) significantly decreased over 5 years (15.92% vs. 4.99%, P < 0.0001) whereas moderate (1-7 Pa) and high ESS (>7 Pa) did not significantly change (moderate ESS: 76.93% vs. 80.7%, P = 0.546; high ESS: 7.15% vs. 14.31%, P = 0.281), leading to higher ESS at follow-up. A positive correlation was observed between baseline ESS and change in lumen area at 5 years (P < 0.0001). Maximum blood viscosity significantly decreased over 5 years (4.30 ± 1.54 vs. 3.21± 0.57, P = 0.028).

Conclusion

Immediately after scaffold implantation, coronary arteries demonstrate an alternans of extremely low and high ESS values and localized areas of high blood viscosity. These initial local haemodynamic disturbances may trigger fibrin deposition and thrombosis. Also, low ESS can promote neointimal hyperplasia, but may also contribute to appropriate scaffold healing with normalisation of ESS and reduction in peak blood viscosity by 5 years.

The 1‑year safety and efficacy outcomes of Absorb bioresorbable vascular scaffolds for coronary artery disease treatment in diabetes mellitus patients: the ABSORB DM Benelux study

BACKGROUND

Diabetes mellitus (DM) patients show higher rates of repeat revascularisation even in the era of modern drug-eluting stents (DES). The concept of bioresorbable scaffolds is becoming captivating, as it might allow for repeat interventions, prolonging the time span during which patients can be treated by percutaneous coronary intervention (PCI).

AIMS

We intend to evaluate the short- and long-term safety and efficacy of Absorb bioresorbable vascular scaffolds (Absorb BVS) in the treatment of coronary artery disease (CAD) in DM patients for any indication.

METHODS

The ABSORB DM Benelux is an international prospective study in DM patients who have undergone PCI with ≥1 Absorb BVS. Major adverse cardiac events (MACE) at 1 year was the primary endpoint, defined as a composite of all-cause death, any myocardial infarction (MI) and ischaemia-driven target vessel revascularisation (TVR). Secondary endpoints were target lesion failure (TLF) and definite or probable scaffold thrombosis (ScT).

RESULTS

Between April 2015 and March 2017, 150 DM patients and 188 non-complex lesions were treated. Device implantation was successful in 100%. MACE occurred in 14 (9.5%) patients, with all-cause death occurring in 4 (2.7%), any MI in 6 (4.1%) and ischaemia-driven TVR in 7 (4.8%) respectively. TLF was reported in 11 (7.5%). Definite and probable ScT was observed in 2 (1.4%).

CONCLUSION

Absorb BVS for treatment of anatomically low-risk patients with DM show acceptable safety and efficacy outcomes at 1 year. If these promising results are confirmed after a longer follow-up period, new-generation bioresorbable scaffolds combined with refinement of implantation techniques might open new horizons for CAD treatment in DM patients.

Coronary Shear Stress after Implantation of Bioresorbable Scaffolds – a Modern Interdisciplinary Concept at the Border between Interventional Cardiology and Cardiac Imaging

Bioresorbable scaffolds/stents offer new and exciting perspectives in the treatment of patients with acute coronary syndromes, especially after the recent development of invasive imaging techniques, such as optical coherence tomography, which allow complete assessment of vascu-lar segments. A particular advantage of bioresorbable scaffolds is that once the biosorption of the scaffold is complete, the vascular segment regains its normal physiological functions, thus eliminating the risk of late complications. New studies show the importance of shear stress in the progression of vascular atherosclerosis or in accelerating endothelial turnover. Based on the current knowledge in this field, a future standardized determination of shear stress may help in the long-term follow-up of patients that have suffered or are at risk of developing an acute coronary syndrome.

Very Late Scaffold Thrombosis after Everolimus-Eluting Bioresorbable Scaffold Implantation in Patients with Unremarkable Interim Surveillance Angiography

PURPOSE

Everolimus-eluting bioresorbable scaffolds (BRS) demonstrated an increased risk of very late scaffold thrombosis (VLScT) in comparison with conventional drug-eluting stents. However, characterization of VLScT cases remains scant and the role of interim angiographic surveillance in identifying patients at risk of VLScT is unclear. We therefore set out to identify angiographic predictors of VLScT in our present case series.

METHODS

We analyzed a series of consecutive patients with VLScT presenting to two centers in Munich, Germany. Of interest, all patients had undergone interim planned surveillance angiography. Angiographic films were collected and reviewed and quantitative coronary angiography analysis was done at a core laboratory. Optical coherence tomography (OCT) images at presentation with VLScT were analyzed in patients with available data.

RESULTS

Nine patients presented with 10 VLScT events. Mean age was 62.6 years. Surveillance angiography (between 159 and 476 days) were unremarkable in all cases. Time from index intervention to VLScT ranged from 393 to 1494 days. Nine of 10 events occurred after discontinuation of dual antiplatelet therapy. Four patients underwent OCT. The dominant finding at the time of VLScT was scaffold discontinuity.

CONCLUSIONS

In a series of patients with VLScT after treatment with BRS, routine interim surveillance angiography was available in all patients and failed to identify features predictive of subsequent adverse events.

Incidental Finding of Strut Malapposition Is a Predictor of Late and Very Late Thrombosis in Coronary Bioresorbable Scaffolds

Malapposition is a common finding in stent and scaffold thrombosis (ScT). Evidence from studies with prospective follow-up, however, is scarce. We hypothesized that incidental observations of strut malapposition might be predictive of late ScT during subsequent follow-up. One hundred ninety-seven patients were enrolled in a multicentre registry with prospective follow-up. Optical coherence tomography (OCT), performed in an elective setting, was available in all at 353 (0–376) days after bioresorbable scaffold (BRS) implantation. Forty-four patients showed evidence of malapposition that was deemed not worthy of intervention. Malapposition was not associated with any clinical or procedural parameter except for a higher implantation pressure (p = 0.0008). OCT revealed that malapposition was associated with larger vessel size, less eccentricity (all p < 0.01), and a tendency for more uncovered struts (p = 0.06). Late or very late ScT was recorded in seven of these patients 293 (38–579) days after OCT. OCT-diagnosed malapposition was a predictor of late and very late scaffold thrombosis (p < 0.001) that was independent of the timing of diagnosis. We provide evidence that an incidental finding of malapposition—regardless of the timing of diagnosis of the malapposition—during an elective exam is a predictor of late and very late ScT. Our data provide a rationale to consider prolonged dual antiplatelet therapy if strut malapposition is observed.

Everolimus-eluting bioresorbable scaffolds for treatment of coronary artery disease in patients with diabetes mellitus: the midterm follow-up of the prospective ABSORB DM Benelux study

Background

Percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) remains challenging even with modern drug-eluting stents (DES) due to high rates of repeat revascularization. Everolimus-eluting bioresorbable scaffolds (EE-BRS) might allow for repeat intervention prolonging the time interval of percutaneous treatment options.

Methods

The ABSORB DM Benelux Study is a dedicated prospective, international study to evaluate the midterm safety and efficacy of EE-BRS in DM patients. All DM patients that received ≥ 1 EE-BRS for any indication were enrolled and prospectively followed. Study endpoints were major adverse cardiac events (MACE): a composite of all-cause death, any myocardial infarction (MI) and ischemic-driven target vessel revascularization (TVR); target lesion failure (TLF): a composite of cardiac death (CD), target vessel MI, and ischemic-driven target lesion revascularization (TLR), as well as definite or probable scaffold thrombosis (ScT).

Results

Between April 2015 till March 2017, 150 DM patients and 188 lesions were treated and followed up to 3 years. Device implantation success was 100%. MACE occurred in 15.2% (event rate of 8.8 per 100 PY). TLF was reported in 11.7% (7.0 events per 100 PY). CD, target vessel MI, ischemic-driven TLR occurred in 3.4%, 3.6% and 5.5% respectively, while ScT was observed in 1.4%. There were no occurrences of late or very late ScT.

Conclusion

EE-BRS treatment in DM patients shows comparable midterm safety and efficacy outcomes when historically compared with modern DES. New-generation EE-BRS might offer an attractive alternative to metallic DES in treatment of fast progressing atherosclerosis population as in DM patients.

Trial registration NTR5447. Registered 05 October 2015, retrospectively registered

Early and long-term outcomes of bioresorbable vascular scaffolds in the treatment of patients with coronary artery disease in real-world clinical practice - insights from the ZABRZE-BVS registry

Introduction

Randomized trials have proven the feasibility and safety of the bioresorbable vascular scaffold (BVS) in selected populations of patients. Data concerning the results of BVS in “real-world” registries with an appropriate sample size are limited.

Aim

Assessment of early- and long-term outcomes of patients undergoing bioresorbable scaffold implantation in an all-comers population of the ZABRZE-BVS registry.

Material and methods

The ZABRZE-BVS registry is a prospective registry including consecutive patients treated in the period 2013–2016 with the intention to implant a BVS (ABSORB, Abbott Vascular, Santa Clara, California). The primary endpoint was occurrence of the 12- and 24-month device-oriented composite endpoint (DoCE) defined as cardiac death, target-vessel myocardial infarction (TV-MI) or target lesion revascularization (TLR). The secondary endpoint includes occurrence of patient-oriented composite endpoint (PoCE) at 12 and 24 months, device (lesion basis) and procedural success (patient basis).

Results

A total of 456 patients during 467 procedures received 588 scaffolds in 563 lesions. Of note, 25.4% of patients presented with diabetes mellitus and 62.3% had an acute coronary syndrome. In QCA analysis, 78.7% of patients had type B2/C lesions, minimal lumen diameter was 0.78 ±0.54 mm, whereas post-procedural acute lumen gain was 1.61 ±0.61 mm. Median follow-up was 781 days. The cumulative rate of DoCE was 6.7% at 12 months and 12.2% at 24 months. Rates of 12- and 24-month PoCE were 12.4% and 20.1%, respectively. The percentage of device success was 98.7%, while the procedural success rate was 96.9%.

Conclusions

The Absorb BVS was successfully and safely implanted in an unselected group of patients. Scaffold thrombosis developed predominantly in patients with acute coronary syndrome (ACS).

Undiscovered pathology of transient scaffolding t1remains a driver of failures in clinical trials

AIM

To statistically examine the released clinical trials and meta-analyses of polymeric bioresorbable scaffolds resuming the main accomplishments in the field with a translation to the routine clinical practice.

METHODS

The statistical power in clinical trials such as ABSORB Japan, ABSORB China, EVERBIO II, AIDA, and few meta-analyses by the post hoc odds ratio-based sample size calculation, and the patterns of artery remodeling published in papers from ABSORB A and B trials were evaluated.

RESULTS

The phenomenal admiration from the first ABSORB studies in 2006-2013 was replaced by the tremendous disappointment in 2014-2017 due to reported relatively higher rates of target lesion failure (a mean prevalence of 9.16%) and device thrombosis (2.38%) in randomized controlled trials. Otherwise, bioresorbable vascular scaffold (BVS) performs as well as the metallic drug-eluting stent (DES) with a trend toward some benefits for cardiac mortality [risk ratio (RR), 0.58-0.94, P > 0.05]. The underpowered design was confirmed for some studies such as ABSORB Japan, ABSORB China, EVERBIO II, AIDA trials, and meta-analyses of Polimeni, Collet, and Mahmoud with some unintentional bias (judged by the asymmetrical Funnel plot). Scaffold thrombosis rates with Absorb BRS were comparable with DES performed with a so-called strategy of the BVS implantation with optimized pre-dilation (P), sizing (S) and post-dilation (P) (PSP) implantation (RR, PSP vs no PSP 0.37) achieving 0.35 per 100 patient-years, which is comparable to the RR 0.49 with bare-metal stents and the RR 1.06 with everolimus DES. Both ABSORB II and ABSORB III trials were powered enough for a five-year follow-up, but the results were not entirely conclusive due to the mostly non-significant fashion of data. The powered meta-analyses were built mostly on statistically poor findings.

CONCLUSION

The misunderstanding of the pathology of transient scaffolding drives the failures of the clinical trials. More bench studies of the vascular response are required. Several next-generation BVS including multifunctional electronic scaffold grant cardiology with a huge promise to make BVS technology great again.

Implantation techniques (predilatation, sizing, and post-dilatation) and the incidence of scaffold thrombosis and revascularisation in lesions treated with an everolimus-eluting bioresorbable vascular scaffold: insights from the AIDA trial

AIMS

Specific implantation strategies have been proposed for the Absorb bioresorbable vascular scaffold (Absorb BVS) to optimise outcomes. We aimed to analyse whether the occurrence of definite scaffold thrombosis (ScT) and target lesion revascularisation (TLR) in Absorb-treated AIDA patients was influenced by scaffold implantation techniques.

METHODS AND RESULTS

Absorb BVS implantation in 1,074 lesions was graded according to definitions of optimal implantation based on predilatation, sizing, and post-dilatation (PSP). Lesion-oriented outcomes (definite ScT and TLR) that occurred during a median follow-up of 707 days were related to the presence or absence of PSP. Of 1,074 lesions, 158 (14.7%) lesions met PSP criteria. The most prevalent reason for not meeting PSP criteria was inadequate sizing: 863 (94.2%). Definite ScT occurred in four of 158 PSP-treated lesions compared with 27 of 916 non PSP-treated lesions, with two-year KM estimates of 3.0% vs. 4.1% and an HR of 1.14 (p=0.811). TLR occurred in eight of 158 PSP-treated lesions compared with 61 of 916 non PSP-treated lesions, with KM estimates of 5.6% vs. 7.1% and an HR of 1.29 (p=0.492).

CONCLUSIONS

In AIDA, lesions that underwent scaffold implantation according to an optimised Absorb BVS implantation technique did not have lower rates of ScT and TLR compared to scaffold-treated lesions that did not meet PSP criteria.

Transradial experience with bioresorbable vascular scaffolds: A case-matched study with metallic drug-eluting stents

BACKGROUND

Whether polymeric bioresorbable vascular scaffolds (BVS) implantation with transradial approach is feasible and safe is unknown. We compared the feasibility and safety of the transradial approach for BVS delivery with metallic drug-eluting stents (DES).

METHODS

We identified 118 consecutive patients who underwent BVS implantation and we compared 30-days and 1-year results with 118 matched patients with DES. Patients were matched for age, sex, risk factors and clinical indication.

RESULTS

Rates of transradial approach were 98% in the BVS group vs 95% in the DES group (P = 0.16) with 5Fr used in 38% and 32% (P = 0.34), respectively. The number of stents was similar in both groups, 2.6 ± 1.5 vs 2.4 ± 1.3 (P = 0.23). Although maximal pressure for stent deployment was identical in both groups (16 ± 3 atm), more lesions were pre-dilated (83% vs 52%, P < 0.001) and post-dilated (71% vs 33%, P < 0.001) in the BVS group. Contrast volume (217 ± 97 vs 175 ± 108 ml, P < 0.001), fluoroscopy time (16 [10-23] vs 13 [8-21] min, P = 0.04) and procedure duration (65 ± 31 vs 56 ± 47 min, P = 0.045) were significantly higher in the BVS group. Major adverse cardiac events, including death, myocardial infarction and target vessel revascularization remained similar in both groups, 1.7% vs 0.8% (P = 0.56) at 30 days and 10% vs 8.5% (P = 0.66) at 1 year. At 1 year, stent thrombosis occurred in 2 (1.7%) patients in the BVS group and 1 (0.8%) patient in the DES group (P = 0.56).

CONCLUSION

The use of transradial approach for BVS compared to DES implantation was feasible and safe in all-comers, although BVS implantation included more technical challenges. Outcomes up to 1-year remained comparable in both groups.

Acute and one-year clinical outcomes following implantation of bioresorbable vascular scaffolds: the ABSORB UK Registry

AIMS

The aim of this registry was to monitor practice patterns and outcomes in patients treated with Absorb bioresorbable vascular scaffolds (BVS) during the early phase of usage in the UK.

METHODS AND RESULTS

A total of 1,005 patients with de novo coronary lesions were treated using careful implantation techniques at 24 centres. Follow-up at one year was obtained in 99%. An independent clinical events committee and angiographic core lab adjudicated all events. Patient age was 52 years and 46% presented with acute coronary syndromes. Lesion complexity was B2/C in 47.4%, with an average of 1.4±0.6 BVS implanted and a BVS length of 28±14.3 mm. A single BVS was implanted in 71.3%. High pressure post-dilatation was performed in 94.9%, with 50% using intravascular imaging. Device success was achieved in 98.7% and procedure success in 97.3% of patients. At one year, the device-oriented endpoint target lesion failure was 3.2%, and the patient-oriented endpoint major adverse cardiac events was 3.4%. Definite ST occurred in 1.4%. By multivariable analysis, scaffold size of 2.5 mm predicted ST at one year (OR 3.27, 95% CI: 1.28-8.37; p=0.014).

CONCLUSIONS

With careful patient selection and technique, TLF rates following BVS implantation in real-world practice are comparable with contemporary drug-eluting stents. ST rates remain high, with small vessel size identified as a contributory factor.

Decision Analytic Markov Model Weighting Expected Benefits and Current Limitations of First-Generation Bioresorbable Vascular Scaffolds: Implications for Manufacturers and Next Device Iterations

BACKGROUND

Relative benefits of bioresorbable vascular scaffolds (BVS) compared with everolimus-eluting stents (EES) are expected to accrue after complete bioresorption.

METHODS AND RESULTS

We built a decision analytic Markov model comparing BVS and EES for a contemporary percutaneous coronary intervention population. Procedure-related morbidity and outcome data from the available literature were used to derive model probabilities. The net benefit of BVS and EES was estimated in terms of quality-adjusted life expectancy. Under the assumption of no risk for device thrombosis and target lesion revascularization with BVS beyond 3 years, the equipoise in quality-adjusted life expectancy (12.86) between BVS and EES was achieved 19 years after implantation. The maximum tolerable excess risk of 3-year BVS thrombosis equalizing the model-predicted quality-adjusted life expectancy of BVS and EES at 10 years was 1.40, corresponding to an absolute tolerable rate of 1.45%.

CONCLUSIONS

At the currently observed relative increase in device thrombosis and under the extreme hypothesis of no scaffold thrombosis and target lesion revascularization beyond 3 years, the incremental benefit of BVS over EES becomes apparent only after 19 years. This simulation suggests that there is a small degree of benefit that clinicians and decision-makers may expect from the first-generation BVS at the current risk of device thrombosis. Manufacturers should target scaffold thrombosis rates <1.45% at 3 years to make their technologies attractive during a 10-year horizon.

Three-Year Outcomes With the Absorb Bioresorbable Scaffold: Individual-Patient-Data Meta-Analysis From the ABSORB Randomized Trials

BACKGROUND

The Absorb bioresorbable vascular scaffold (BVS) completely resorbs within 3 years after coronary artery implantation. The safety and effectiveness of BVS through this critical 3-year period have not been characterized.

METHODS

We performed an individual-patient-data pooled meta-analysis of the 4 randomized ABSORB trials in which 3389 patients with coronary artery disease were randomly assigned to everolimus-eluting Absorb BVS (n=2164) or cobalt-chromium everolimus-eluting stents (n=1225). The primary efficacy outcome measure was target lesion failure (cardiac mortality, target vessel myocardial infarction, or ischemia-driven target lesion revascularization), and the primary safety outcome measure was device thrombosis.

RESULTS

BVS compared with cobalt-chromium everolimus-eluting stents resulted in higher 3-year rates of target lesion failure (11.7% versus 8.1%; risk ratio [RR], 1.38; 95% confidence interval [CI], 1.10-1.73; P=0.006), driven by greater target vessel myocardial infarction (7.8% versus 4.2%; RR, 1.72; 95% CI, 1.26-2.35; P=0.0006) and ischemia-driven target lesion revascularization (6.6% versus 4.4%; RR, 1.44; 95% CI, 1.05-1.98; P=0.02), with comparable cardiac mortality (1.1% versus 1.1%; RR, 0.93; 95% CI, 0.47-1.88; P=0.85). Device thrombosis rates through 3 years were also higher with BVS (2.4% versus 0.6%; RR, 3.71; 95% CI, 1.70-8.11; P=0.001). Between 1 and 3 years, target lesion failure rates (6.1% versus 3.9%; P=0.02) and device thrombosis rates (1.1% versus 0.0%; P<0.0001) were higher with BVS than cobalt-chromium everolimus-eluting stents.

CONCLUSIONS

In the present individual-patient-data pooled meta-analysis of the ABSORB trials, BVS was associated with increased rates of target lesion failure and device thrombosis between 1 and 3 years and cumulatively through 3 years of follow-up compared with everolimus-eluting stents.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifiers: NCT01751906, NCT01844284, NCT01923740, and NCT01425281.

BRS implantation in long lesions requiring device overlapping: myth or reality?

Dealing with bioresorbable vascular scaffolds (BVS) implantation in long lesions requiring device overlapping in this particular moment might seem a little provocative for several reasons. First, most studies testing BVS have focused on their safety and efficacy profile in simple patients with simple lesions. Second, ABSORB II did not meet its primary endpoint, while ABSORB III showed a higher rate of target vessel-myocardial infarction (TV-MI) at 2 years. Third, data on porcine model showed that overlapping zone has delayed but greater neointimal proliferation with consequent higher risk for scaffold thrombosis in the short-term and of in-scaffold restenosis in the long-term. Fourth, recently published data showed higher risk of TVF in patients treated with ≥60 mm BVS. Given all these premises, it may seem right to put aside this technology, while it may seem inappropriate to hypothesize the use of BVS in long lesions. The aim of the present review is precisely to critically review the available evidences regarding BVS with particular regard to overlapping BVS in order to understand whether this technology has a future per se and especially in long coronary lesions requiring overlap.