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.

Exploring new insights in coronary lesion assessment and treatment in patients with diabetes mellitus: the impact of optical coherence tomography.

In this review, we summarise new insights into diagnostic approaches and treatment strategies for coronary artery disease (CAD) in patients with diabetes mellitus (DM). Despite the improvements in therapy, the clinical management of DM patients remains challenging as they develop more extensive CAD at a younger age and consistently have worse clinical outcomes than non-DM patients. Current diagnostic modalities as well as revascularisation treatments mainly focus on ischemic lesions. However, the impact of plaque morphology and composition are emerging as strong predictors of adverse cardiac events even in the absence of identified ischemia. In particular, the presence of vulnerable plaques such as thin-cap fibroatheroma (TCFA) lesions has been identified as a very strong predictor of future adverse events. This emphasises the need for an approach combining both functional and morphological methods in the assessment of lesions. In particular, optical coherence tomography (OCT) has proven to be a valuable asset by truly identifying TCFAs. New treatment strategies should consist of individualised and advanced medical regimens and may evolve towards plaque sealing through percutaneous treatment.

A word of caution: Early failure of Magmaris® bioresorbable stent after pulmonary artery stenting.

Bioresorbable scaffolds (BRS) have been advocated as the fourth revolution in interventional cardiology medical devices with promising technology to improve the treatment of coronary artery disease with an event-free future. We describe the first reported use and early collapse of the Magmaris® Resorbable Magnesium Scaffold (RMS) stent (BIOTRONIK AG, Switzerland) to relieve left pulmonary artery severe stenosis in a newborn after the Norwood procedure. The stent collapse was detected 2 weeks after implantation and urgently treated with a balloon-expandable stent. This complication raises the alarm about the need to keep implanted RMS under scrutiny. The possibility of faster scaffold resorption in small babies or lack of sufficient radial force of RMS to resist acute vessel recoil has led to ineffective relief of branch pulmonary artery stenosis and failure to enable a safe short-term bridge to Stage II palliation.

Plaque burden estimated from optical coherence tomography with deep learning: In vivo validation using co-registered intravascular ultrasound.

OBJECTIVES: The objective of the present study was to compare plaque burden (PB) calculated from optical coherence tomography (OCT) using deep learning (DL) with PB derived from co-registered intravascular ultrasound (IVUS). BACKGROUND: A DL algorithm was developed for automated plaque characterization and PB quantification from OCT images. However, the performance of this algorithm for PB quantification has not been validated. METHODS: Five-year follow-up OCT and IVUS images from 15 patients implanted with bioresorbable vascular scaffold (BVS) at baseline were analyzed. Precise co-registration for 72 anatomical slices was achieved utilizing unique BVS radiopaque markers. PB derived from OCT DL and IVUS were compared. OCT cross-sections were divided into four subgroups with different media visibility level. The impact of media visibility on the numerical difference between OCT-derived and IVUS-derived PB was investigated. The stent sizes selected by OCT DL and IVUS were compared. RESULTS: Sixty-four paired OCT and IVUS cross-sections were compared. OCT DL showed good concordance with IVUS for PB assessment (ICC = 0.81, difference = -3.53 ± 6.17%, p < 0.001). The numerical difference between OCT DL-derived PB and IVUS-derived PB was not substantially impacted by missing segments of media visualization (p = 0.21). OCT DL showed a diagnostic accuracy of 92% in identifying PB > 65%. The stent sizes selected by OCT DL were smaller compared to the ones selected by IVUS (difference = 0.30 ± 0.34 mm, p < 0.001). CONCLUSIONS: The DL algorithm provides a feasible and reliable method for automated PB estimation from OCT, irrespective of media visibility. OCT DL showed good diagnostic accuracy in identifying PB > 65%, revealing its potential to complement conventional OCT imaging.

Bioresorbable magnesium scaffold in the treatment of simple coronary bifurcation lesions: The BIFSORB pilot II study.

OBJECTIVES: To evaluate the feasibility, safety, and healing response of a magnesium-based bioresorbable scaffold (BRS) in the treatment of simple bifurcation lesions using the single stent provisional technique. BACKGROUND: BRS may hold potential advantages in the treatment of coronary bifurcation lesions, however low radial strength and expansion capacity has been an issue with polymer-based scaffolds. The magnesium BRS may prove suitable for bifurcation treatment as its mechanical properties are closer to those of permanent metallic drug-eluting stents. METHODS: The study was a proof-of-concept study with planned inclusion of 20 patients with stable angina pectoris and a bifurcation lesion involving a large side branch (SB) > 2.5 mm with less than 50% diameter stenosis. Procedure and healing response were evaluated by optical coherence tomography (OCT). The main endpoints were a composite clinical safety endpoint and an OCT healing index at 1 month (range: 0-98). RESULTS: Eleven patients were included in the study. The study was prematurely terminated due to scaffold fractures and embolization of scaffold fragments in three cases requiring bailout stenting with drug-eluting stents. One patient underwent bypass surgery at 3 months due to stenosis proximal to the study segment. All SB were patent for 1 month. One-month OCT evaluation showed strut coverage of 96.9% and no malapposition. Scaffold fractures and uncovered jailing struts resulted in a less favorable mean OCT healing index score of 10.4 ± 9.0. CONCLUSIONS: Implanting a magnesium scaffold by the provisional technique in nontrue bifurcation lesions was associated with scaffold fracture, embolization of scaffold fragments, and a high need for bailout stenting.

Usability of Fantom Encore® scaffold in non-complex bifurcations-Analysis in bench models.

OBJECTIVE: Present bench study aimed to evaluate whether technical characteristics of Fantom Encore® bioresorbable scaffold (BRS) allow to perform proximal optimization/side branch dilation/proximal optimization (POT-SB-POT) technique, as an adequate solution for bifurcation percutaneous coronary intervention. METHODS: Two Fantom Encore® BRS platforms (small with 3.0 mm nominal diameter, n = 7; and large with 3.5 mm nominal diameter, n = 7) were evaluated in bench models, which were designed according to Finet-law and fitted to nominal scaffold diameter in the distal main branch (MB) and fitted to indicated maximal expansion capacity in the proximal main branch (MB). Results were evaluated by (a) fluoroscopy, (b) optical coherence tomography (OCT) and (c) micro-computed tomography (µCT). RESULTS: All procedures were performed according to the protocol. Careful review of the fluoroscopic loops by an independent operator did not reveal any strut fracture or major deformation. By OCT the overall rate of perfectly apposed struts in the bifurcation area was 15 ± 6% after SB opening, that increased significantly but remained low with 22 ± 9% after final POT (p = .001). Compared to SB ballooning alone, significant benefit of final POT was found in rate of perfect apposition in the proximal MB (15 ± 12% vs. 26 ± 15%, respectively; p = .017) and at the abostial side of polygon of confluence (7 ± 9% vs. 16 ± 13%, respectively; p = .005). µCT analysis revealed a single strut fracture in one case with the small platform, while four cases showed single or multiple strut fractures with the large platform. CONCLUSION: The mechanical characteristics of the device are not suitable for use of Conventional techniques for bifurcation PCI such as POT-SB-POT. The use of Fantom Encore® BRS for bifurcation PCI with relevant SB should not be encouraged.

Very late vasomotor responses and gene expression with bioresorbable scaffolds and metallic drug-eluting stents.

OBJECTIVES: To investigate the long-term vasomotor response and inflammatory changes in Absorb bioresorbable vascular scaffold (BVS) and metallic drug-eluting stent (DES) implanted artery. BACKGROUND: Clinical evidence has demonstrated that compared to DES, BVS is associated with higher rates of target lesion failure. However, it is not known whether the higher event rates observed with BVS are related to endothelial dysfunction or inflammation associated with polymer degradation. METHODS: Ten Absorb BVS and six Xience V DES were randomly implanted in the main coronaries of six nonatherosclerotic swine. At 4-years, vasomotor response was evaluated in vivo by quantitative coronary angiography response to intracoronary infusion of Ach and ex vivo by the biomechanical response to prostaglandin F2-α (PGF2-α), substance P and bradykinin and gene expression analysis. RESULTS: Absorb BVS implanted arteries showed significantly restored vasoconstrictive responses after Ach compared to in-stent Xience V. The contractility of Absorb BVS treated segments induced by PGF2-α was significantly greater compared to Xience V treated segments and endothelial-dependent vasorelaxation was greater with Absorb BVS compared to Xience V. Gene expression analyses indicated the pro-inflammatory lymphotoxin-beta receptor (LTßR) signaling pathway was significantly upregulated in arteries treated with a metallic stent compared to Absorb BVS treated arterial segments. CONCLUSIONS: At 4 years, arteries treated with Absorb BVS compared with Xience V, demonstrate significantly greater restoration of vasomotor responses. Genetic analysis suggests mechanobiologic reparation of Absorb BVS treated arteries at 4 years as opposed to Xience V treated vessels.

Everolimus eluting bioresorbable vascular scaffolds in patients with acute coronary syndromes: Two-year results from the German-Austrian ABSORB registry.

OBJECTIVES: To identify potential differences in 2-year outcome between patients who underwent coronary revascularization using bioresorbable vascular scafffolds (BVS) in stable coronary artery disease (CAD) and acute coronary syndromes (ACS). BACKGROUND: Data from randomized trials suggest a significantly higher event rate following coronary revascularization using everolimus-eluting BVS as compared to new generation drug eluting stents. Whether particular patient subgroups are at increased risk for scaffold thrombosis and target lesion failure (TLF) has not clearly been demonstrated. METHODS: German-Austrian ABSORB RegIstRy is a prospective all-comer multi-center observational study of consecutive patients who were considered for coronary revascularization with BVS. We compared 1499 patients with stable CAD to 1594 patients with ACS. Endpoints were major adverse cardiac events (MACE), TLF, and scaffold thrombosis. RESULTS: While single vessel disease was more prevalent in ACS (46% vs. 37%, p < 0.0001), lesion complexity (B2/C stenosis 37% vs. 36%, bifurcation 2.4% vs. 3.4%, p < 0.05), number of implanted scaffolds/patient (1.34 vs. 1.43), scaffold length (18 vs. 18 mm) or the rate of high pressure postdilatation (68% vs. 70%) did not differ between ACS and stable CAD. Two-year MACE rates were 11.6% in ACS and 11.4% in stable CAD, TLF occurred in 7.0% versus 7.4% and target vessel revascularization in 8.8 versus 10.2% (n.s. for all). Definite scaffold thrombosis rates were not significantly different (ACS 1.9% vs. stable CAD 2.1%). CONCLUSION: Real-world 2-year event rates after coronary revascularization with BVS are not significantly different between individuals with ACS as compared to stable CAD.

BIOSOLVE-IV-registry: Safety and performance of the Magmaris scaffold: 12-month outcomes of the first cohort of 1,075 patients.

OBJECTIVES: We aimed to assess the safety and performance of the Magmaris sirolimus-eluting bioresorbable magnesium scaffold in a large patient population. BACKGROUND: Magmaris has shown good outcomes in small-sized controlled trials, but further data are needed to confirm its usability, safety, and performance. METHODS: BIOSOLVE-IV is an international, single arm, multicenter registry including patients with a maximum of two single de novo lesions. Follow-up is scheduled up to 5 years; the primary outcome is target lesion failure (TLF) at 12 months. RESULTS: A total of 1,075 patients with 1,121 lesions were enrolled. Mean patient age was 61.3 ± 10.5 years and 19.2% (n = 206) presented with non-ST-elevation myocardial infarction (NSTEMI). Lesions were 3.2 ± 0.3 mm in diameter and 14.9 ± 4.2 mm long; 5.1% (n = 57) were bifurcation lesions. Device success was 97.3% (n = 1,129) and procedure success 98.9% (n = 1,063). The Kaplan-Meier estimate of TLF at 12 months was 4.3% [95% confidence interval, CI: 3.2, 5.7] consisting of 3.9% target lesion revascularizations, 0.2% cardiac death, and 1.1% target-vessel myocardial infarction. Definite/probable scaffold thrombosis occurred in five patients (0.5% [95% CI: 0.2, 1.1]), thereof four after early discontinuation of antiplatelet/anticoagulation therapy. CONCLUSION: BIOSOLVE-IV confirms the safety and performance of the Magmaris scaffold in a large population with excellent device and procedure success and a very good safety profile up to 12 months in a low-risk population.

Three-year clinical outcomes of the absorb bioresorbable vascular scaffold compared to Xience everolimus-eluting stent in routine PCI in patients with diabetes mellitus-AIDA sub-study.

BACKGROUND: In this prespecified AIDA-trial sub-study we investigate the clinical performance of absorb bioresorbable vascular scaffold (BVS) compared to Xience everolimus-eluting stent (EES) in routine percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) at complete 3-year follow-up. METHODS AND RESULTS: All 1,845 randomized patients were subdivided by medical history with DM or without DM. Of the 924 Absorb BVS patients, 171 (18.5%) patients had DM, of which 65 (38.0%) were treated with insulin (iTDM). Of the 921 Xience EES patients, 153 (16.6%) patients had DM, of which 45 (29.4%) were insulin-treated diabetes mellitus (iTDM). Target vessel failure (TVF), composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization, occurred in 18.7% of diabetic patients treated with Absorb patients versus in 18.0% patients treated with Xience EES (p = .840). In nondiabetics the rates of TVF were 12.3% in Absorb BVS versus 11.0% in Xience EES (p = .391). Definite/probable device thrombosis occurred more frequently in Absorb BVS compared to Xience EES in both diabetic and nondiabetic patients (4.8% versus 0.7%; p = .028 and 3.2% vs. 0.5%; p < .001, respectively). CONCLUSIONS: In routine PCI practice, both Absorb BVS and Xience EES have worse clinical outcomes in diabetic patients as compared to nondiabetic patients. Throughout all clinical presentations, Absorb BVS was associated with higher rates of device thrombosis at 3-year follow-up.

Strain-induced accelerated asymmetric spatial degradation of polymeric vascular scaffolds.

Polymer-based bioresorbable scaffolds (BRS) seek to eliminate long-term complications of metal stents. However, current BRS designs bear substantially higher incidence of clinical failures, especially thrombosis, compared with metal stents. Research strategies inherited from metal stents fail to consider polymer microstructures and dynamics--issues critical to BRS. Using Raman spectroscopy, we demonstrate microstructural heterogeneities within polymeric scaffolds arising from integrated strain during fabrication and implantation. Stress generated from crimping and inflation causes loss of structural integrity even before chemical degradation, and the induced differences in crystallinity and polymer alignment across scaffolds lead to faster degradation in scaffold cores than on the surface, which further enlarge localized deformation. We postulate that these structural irregularities and asymmetric material degradation present a response to strain and thereby clinical performance different from metal stents. Unlike metal stents which stay patent and intact until catastrophic fracture, BRS exhibit loss of structural integrity almost immediately upon crimping and expansion. Irregularities in microstructure amplify these effects and can have profound clinical implications. Therefore, polymer microstructure should be considered in earliest design stages of resorbable devices, and fabrication processes must be well-designed with microscopic perspective.

Comparison of Long-Term Safety and Efficacy of Bioresorbable Scaffolds between Patients with and without Diabetes Mellitus.

INTRODUCTION: Diabetes mellitus (DM) is a major risk of cardiovascular events. Bioresorbable stent frame materials capable of providing mechanical support and drug-delivery functions have been developed in an attempt to improve long-term outcomes. However, publications about the long-term outcomes of bioresorbable scaffolds (BRS) in DM patients are still limited. The aim of this study was to investigate the long-term safety and efficacy of BRS between patients with and without diabetes. METHODS: Data regarding BRS placement in consecutive patients receiving percutaneous coronary interventions were collected from the cardiovascular center of a single tertiary medical center from 2014 to 2017. RESULTS: A total of 138 cases were included and followed up for 4 years. The mortality rate was 1.1% in the non-diabetic group and 4.1% in the diabetic group (p = 0.2542). No cardiac mortality was observed. One patient had an acute myocardial infarction (0.7%) in the non-diabetic group. The rate of target lesion revascularization was 3.4% in the non-diabetic group and 4.08% in the diabetic group. The ratio of target vessel revascularization was 6.74% in the non-diabetic group and 4.1% in the diabetic group. CONCLUSIONS: This study demonstrated no significant difference in long-term outcomes after BRS implantation between patients with and without diabetes in a single tertiary medical center.

Everolimus-eluting bioresorbable scaffolds and metallic stents in diabetic patients: a patient-level pooled analysis of the prospective ABSORB DM Benelux Study, TWENTE and DUTCH PEERS.

BACKGROUND: Several studies compared everolimus-eluting bioresorbable scaffolds (EE-BRS) with everolimus-eluting stents (EES), but only few assessed these devices in patients with diabetes mellitus. AIM: To evaluate the safety and efficacy outcomes of all-comer patients with diabetes mellitus up to 2 years after treatment with EE-BRS or EES. METHODS: We performed a post hoc pooled analysis of patient-level data in diabetic patients who were treated with EE-BRS or EES in 3 prospective clinical trials: The ABSORB DM Benelux Study (NTR5447), TWENTE (NTR1256/NCT01066650) and DUTCH PEERS (NTR2413/NCT01331707). Primary endpoint of the analysis was target lesion failure (TLF): a composite of cardiac death, target vessel myocardial infarction or clinically driven target lesion revascularization. Secondary endpoints included major adverse cardiac events (MACE): a composite of all-cause death, any myocardial infarction or clinically driven target vessel revascularization, as well as definite or probable device thrombosis (ST). RESULTS: A total of 499 diabetic patients were assessed, of whom 150 received EE-BRS and 249 received EES. Total available follow-up was 222.6 patient years (PY) in the EE-BRS and 464.9 PY in the EES group. The adverse events rates were similar in both treatment groups for TLF (7.2 vs. 5.2 events per 100 PY, p = 0.39; adjusted hazard ratio (HR) = 1.48 (95% confidence interval (CI): 0.77-2.87), p = 0.24), MACE (9.1 vs. 8.3 per 100 PY, p = 0.83; adjusted HR = 1.23 (95% CI: 0.70-2.17), p = 0.47), and ST (0.9 vs. 0.6 per 100 PY, p > 0.99). CONCLUSION: In this patient-level pooled analysis of patients with diabetes mellitus from 3 clinical trials, EE-BRS showed clinical outcomes that were quite similar to EES.

Magmaris very late in-scaffold restenosis: Has the "black boxes" nightmare come back?

Magnesium Bioresorbable Scaffold (Magmaris, Biotronik) is a device with promising outcomes at 24 months of follow up. Previous studies with first generation, everolimus-eluting Bioresorbable Vascular Scaffold (Absorb, Abbott) showed that very late restenosis seems to be attributed to pure intrascaffold tissue growth but very late. Magmaris very late restenosis has not been previously published, probably because of the 95% of resorption at 12 months. We present in-scaffold very late restenosis within Magmaris, with Optical Coherence Tomography, highlighting mechanism of degradation and in scaffold "neo-tissue" growth.

Mechanical properties of the drug-eluting bioresorbable magnesium scaffold compared with polymeric scaffolds and a permanent metallic drug-eluting stent.

OBJECTIVES: To compare on the bench the physical and mechanical properties of Magmaris, a magnesium bioresorbable scaffold (BRS), with Absorb and DESolve polymeric BRS and a permanent metallic stent. BACKGROUND: Understanding the mechanical and physical properties of BRS is crucial for appropriate implantation and postdilatation. METHODS: Testing was performed in fluid at 37°C and in silicone bifurcation phantoms with a 30° angle between main branch (MB) and side branch. RESULTS: The 3.0-mm Magmaris BRS did not fracture after MB postdilatation up to 4.4 mm in contrast to the Absorb where the safe postdilatation diameter was 3.7 mm. For dilatation through stent cells, there were no Magmaris fractures with 3.0-mm noncompliant (NC) balloons inflated to nominal pressure. Mini-kissing balloon postdilatation with two 3.0-mm NC balloons up to 17 atm was without fracture except for an outlier. Longitudinal and radial strengths were similar for Magmaris and Absorb BRS. The crossing profile for the Magmaris was larger than other devices. Recoil 120 min after deployment was the greatest for Magmaris but 120 min after 3.5 mm postdilatation all devices had similar diameters. CONCLUSIONS: The Magmaris BRS was more resistant to strut fracture than Absorb. It had a larger crossing profile than other devices and similar radial and longitudinal strengths to Absorb. While recoil after deployment was greater with Magmaris, 120 min after 3.5 mm postdilatation all devices had similar diameters.

Serial invasive imaging follow-up of the first clinical experience with the Magmaris magnesium bioresorbable scaffold.

OBJECTIVES: To assess the performance of the commercially available Magmaris sirolimus-eluting bioresorbable scaffold (BRS) with invasive imaging at different time points. BACKGROUND: Coronary BRS with a magnesium backbone have been recently studied as an alternative to polymeric scaffolds, providing enhanced vessel support and a faster resorption rate. We aimed to assess the performance of the commercially available Magmaris sirolimus-eluting BRS at different time points. METHODS: A prospective, single-center, nonrandomized study was performed at the Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands. Six patients with stable de novo coronary artery lesions underwent single-vessel revascularization with the Magmaris sirolimus-eluting BRS. Invasive follow-up including intravascular imaging using optical coherence tomography (OCT) was performed at different time points. RESULTS: At a median of 8 months (range 4-12 months) target lesion failure occurred in one patient. Angiography revealed a late lumen loss of 0.59 ± 0.39 mm, a percentage diameter stenosis of 39.65 ± 15.81%, and a binary restenosis rate of 33.3%. OCT showed a significant reduction in both minimal lumen area (MLA) and scaffold area at the site of the MLA by 43.44 ± 28.62 and 38.20 ± 25.74%, respectively. A fast and heterogeneous scaffold degradation process was found with a significant reduction of patent struts at 4-5 months. CONCLUSIONS: Our findings show that the latest iteration of magnesium BRS suffers from premature dismantling, resulting in a higher than expected decrease in MLA.

Long-Term Outcomes of Absorb Bioresorbable Vascular Scaffold vs. Everolimus-Eluting Metallic Stent　- A Randomized Comparison Through 5 Years in Japan.

BACKGROUND: Bioresorbable vascular scaffolds (BVS) are promising alternatives to metallic drug-eluting stents (DES) in percutaneous coronary interventions. Absorb BVS was comparable to XIENCE (DES) for patient- and device-oriented composite endpoints through 1 year post-procedure. Mid-term results showed increased rates of device-oriented events with Absorb. The objective of this study was to evaluate the long-term safety and effectiveness of Absorb BVS compared with XIENCE metallic DES when implanted in patients in Japan with de novo coronary artery lesions.Methods and Results:ABSORB Japan randomized 400 patients into either Absorb (n=266) or XIENCE (n=134) treatment arm. Through 5-year follow-up, the composite endpoints of DMR (death, myocardial infarction [MI], and all revascularization), target vessel failure (TVF), major adverse cardiac events (MACE), target lesion failure (TLF), and cardiac death/all MI were evaluated. Individual endpoints included death, MI, coronary revascularization, and scaffold/stent thrombosis. There were no significant differences in the composite or individual endpoint outcomes between the Absorb and XIENCE arms through 5 years or between 3 and 5 years. Numerically lower TVF, MACE, and all MI rates were observed for the Absorb vs. XIENCE arm after 3 years. No scaffold/stent thrombosis was reported beyond 3 years. Post-procedure imaging subgroups showed comparable event rates. CONCLUSIONS: Following resorption of the scaffold, between 3 and 5 years post-procedure, the Absorb BVS performed comparably to XIENCE in all patient- and device-oriented endpoints (ClinicalTrials.gov, #NCT01844284).

Bioresorbable Polymeric Scaffold in Cardiovascular Applications.

Advances in material science and innovative medical technologies have allowed the development of less invasive interventional procedures for deploying implant devices, including scaffolds for cardiac tissue engineering. Biodegradable materials (e.g., resorbable polymers) are employed in devices that are only needed for a transient period. In the case of coronary stents, the device is only required for 6-8 months before positive remodelling takes place. Hence, biodegradable polymeric stents have been considered to promote this positive remodelling and eliminate the issue of permanent caging of the vessel. In tissue engineering, the role of the scaffold is to support favourable cell-scaffold interaction to stimulate formation of functional tissue. The ideal outcome is for the cells to produce their own extracellular matrix over time and eventually replace the implanted scaffold or tissue engineered construct. Synthetic biodegradable polymers are the favoured candidates as scaffolds, because their degradation rates can be manipulated over a broad time scale, and they may be functionalised easily. This review presents an overview of coronary heart disease, the limitations of current interventions and how biomaterials can be used to potentially circumvent these shortcomings in bioresorbable stents, vascular grafts and cardiac patches. The material specifications, type of polymers used, current progress and future challenges for each application will be discussed in this manuscript.

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.

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 4­year 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.