Beyond the early stages: insights from the ASSURE registry on bioresorbable vascular scaffolds

Bioresorbable Vascular Scaffolds-Dead End or Still a Rough Diamond?

Percutaneous coronary interventions with stent-based restorations of vessel patency have become the gold standard in the treatment of acute coronary states. Bioresorbable vascular scaffolds (BVS) have been designed to combine the efficiency of drug-eluting stents (DES) at the time of implantation and the advantages of a lack of foreign body afterwards. Complete resolution of the scaffold was intended to enable the restoration of vasomotor function and reduce the risk of device thrombosis. While early reports demonstrated superiority of BVS over DES, larger-scale application and longer observation exposed major concerns about their use, including lower radial strength and higher risk of thrombosis resulting in higher rate of major adverse cardiac events. Further focus on procedural details and research on the second generation of BVS with novel properties did not allow to unequivocally challenge position of DES. Nevertheless, BVS still have a chance to present superiority in distinctive indications. This review presents an outlook on the available first and second generation BVS and a summary of results of clinical trials on their use. It discusses explanations for unfavorable outcomes, proposed enhancement techniques and a potential niche for the use of BVS.

Long-term clinical results of biodegradable vascular scaffold ABSORB BVS™ using the PSP-technique in patients with acute coronary syndrome

BACKGROUND

The PSP (predilatation, sizing, post-dilatation)-technique was developed to improve the prognosis of patients after bioresorbable vascular scaffold (BVS) implantation. In acute coronary syndrome (ACS) the use of BVS is particularly demanding and carries some potential risk regarding aggressive lesion preparation, proper vessel sizing due to spasm and thrombus inside the artery. The aim herein, was to determine the long-term results of BVS stenting in ACS patients depending on the scaffold implantation technique.

METHODS

The present study is a prospective, two-center study, which consisted of 182 patients who underwent percutaneous coronary intervention (PCI) with BVS (Absorb, Abbott Vascular, Santa Clara, California, USA) implantation for the ACS. All patients were divided into two groups. The first consisted of 52 patients treated with the PSP-technique (PSP group). The second group enrolled 130 patients treated with a non-PSP procedure (non-PSP group).

RESULTS

The procedure was successful in all patients. The mean observation time was 28.8 ± 16.5 months (median 28.3 months, interquartile range 24.0 [17.0-41.0] months). It was found that target vessel failure (TVF) was consistently reduced in patients using the PSP-technique as compared with the non-PSP group (5.8% vs. 17.7%, p = 0.03). Moreover, PSP-technique was superior to non-PSP-technique concerning major adverse cardiac events (MACE) (3.7% vs. 22.3%, p = 0.02). Logistic regression analysis revealed that the use of PSP technique significantly decreased the risk of target vessel revascularization (odds ratio [OR] 0.11, p = 0.01), TVF (OR 0.28, p = 0.03) and MACE (OR 0.29, p = 0.02).

CONCLUSIONS

The PSP-technique for BVS implantation improves long-term results and should also be recommended for newer generations of the bioresorbable scaffold.

Bioresorbable Coronary Scaffolds: Deployment Tips and Tricks and the Future of the Technology

Bioresorbable scaffolds (BRS) were developed as an alternative to drug-eluting stents (DES) to facilitate vessel restoration and reduce the risk of future adverse events. However, recent meta-analyses and "real-world" registries have raised some concern about the safety of this novel technology, especially due to an increased risk of thrombosis within the first weeks of scaffold implantation. These devices appear to be less forgiving to poor implantation strategies when compared to contemporary DES. Moreover, problems with the first generation of these devices-bulky struts and high crossing prolife, prolonged resorption time, lack of x-ray visibility, and limited tolerance to postdilation-have restricted their clinical application and negatively impacted their short- to mid-term safety performance. However, the potential for long-term improvements has encouraged further research into strategies to overcome these limitations, and potentially safer next-generation devices are already undergoing in-human clinical evaluations. Based on the current literature and our center's experience with these devices, this review discusses various approaches to optimize BRS implantation, drawbacks related to current-generation BRS, and potentially advantageous features of three next-generation scaffold systems.

Coronary Bioresorbable Vascular Scaffold Use in the Treatment of Coronary Artery Disease

Bioresorbable vascular scaffolds (BVS) represent a promising novel approach for the treatment of coronary artery disease. BVS promise to address some of the well-known limitations of current drug-eluting stents, while providing a transient scaffolding of the vessel to prevent acute vessel closure/recoil. Drug elution by BVS prevents neointimal proliferation in a similar fashion to drug-eluting stents, and complete bioresorption is associated with late vessel lumen enlargement, plaque regression, and restoration of vasomotion. Based on the pathophysiological reasons and on the results derived from clinical studies, BVS are increasingly being used in clinical practice. The aim of this review is to provide an overview of the current evidence supporting the use of BVS in clinical practice. In particular, we will discuss the randomized controlled trials and registries evaluating the clinical outcome of these devices, with a special focus on their application in patients with acute coronary syndrome and in specific lesion subsets (bifurcations, chronic total occlusions, and in-stent restenosis).

Possible mechanical causes of scaffold thrombosis: insights from case reports with intracoronary imaging

The advent of intracoronary stents has greatly increased the safety and applicability of percutaneous coronary interventions. One of the drawbacks of drug-eluting stents (DES) is the increased risk of late and very late stent thrombosis (ST). It was anticipated that the risks of ST after DES implantation would be solved with the advent of fully biodegradable scaffolds, which offer the possibility of transient scaffolding of the vessel to prevent acute vessel closure and recoil while also transiently eluting an antiproliferative drug to counteract constrictive remodelling and excessive neointimal hyperplasia. In spite of the enthusiasm for the concept of bioresorbable scaffolds, current clinical data on the Absorb bioresorbable vascular scaffold (BVS) have generated concerns about scaffold thrombosis (ScT) in both the early and late phases. However, the causes of ScT in both the early and late phases have yet to be fully elucidated. This article seeks to provide insights into the possible mechanical causes of ScT in the early and late phases with data stemming from intracoronary imaging (intravascular ultrasound and optical coherence tomography) of the currently published ScT cases following the implantation of BVS and reviews the practical recommendations for implantation of the BVS made by a group of experts.

Bioresorbable Vascular Scaffold Korean Expert Panel Report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Applicability and procedural success rate of bioresorbable -vascular scaffolds for percutaneous coronary intervention in an all-comer cohort of 383 consecutive patients

Objectives The purpose of this study was to determine applicability and procedural success of bioresorbable vascular scaffolds (BVS) for percutaneous coronary intervention (PCI) in an all-comer cohort. Background BVS use in bifurcations and severely calcified lesions is not recommended, and a relatively large crossing profile may cause limitations. It is has never been studied how widely BVS can be applied in all-comer cohorts. Methods In 383 consecutive patients (acute coronary syndrome: 124, stable coronary disease 259), a BVS (Absorb) was used as first-line device unless any of the following contraindications were present: bifurcation with side branch >2.0 mm, reference diameter <2.5 mm or >4.0 mm, required device length <12 mm, in-stent stenosis, or contraindications to 6 months of DAPT. Patients and lesions were evaluated regarding suitability for BVS treatment, procedural success (successful BVS placement and residual stenosis <30%), and outcome. Results Of 588 lesions, 303 (52%) were unsuitable for BVS placement due to presence of a bifurcation (30% of unsuitable lesions), reference -diameter >4.0 mm (13%) or <2.5 mm (12%), contraindication to 6 months DAPT (13%), in-stent stenosis (14%), and desired device length <12 mm (4%). If BVS use was attempted, procedural success with a scaffold was 95% (271/285). Crossing failure occurred in 14 cases (5%), affected lesions were significantly more calcified. After a mean follow-up period of 259 days, definite/probable scaffold thrombosis occurred in 1.1% of patients. Conclusions Approximately one-half of lesions in an all-comer population can successfully be treated with BVS. Crossing failure is rare.

Are acute coronary syndromes an ideal scenario for bioresorbable vascular scaffold implantation?

Bioresorbable vascular scaffolds (BRS) represent the latest innovation in the field of interventional cardiology. BRS have recently been introduced in routine clinical practice and their use has progressively extended in everyday clinical practice. The BRS use appears theoretically attractive in patients presenting with acute coronary syndromes (ACS) as they are generally young with long life expectancy, thus possibly benefiting more of the so-called vascular reparative therapy. Furthermore, "culprit" lesions are usually softer and more easily expandable by current BRS compared to stable chronic lesions. However an increased risk of BRS thrombosis has been reported in clinical trials excluding ACS patients. Therefore, concerns have been raised on the safety of BRS implantation in the ACS setting in which the risk of thrombotic recurrences is definitely higher (compared to stable lesions) independently by the device implanted. Aim of this review is to provide an overview of the available data on the BRS performance in ACS patients.

Everolimus-Eluting Bioresorbable Vascular Scaffold in Real World Practice - A Single Center Experience

BACKGROUND

Drug-eluting stents are widely used in coronary artery intervention. However, vessel caging and very late thrombotic events are of persistent and substantial concern. Bioresorbable vascular scaffolds (BVS) were developed to deliver vascular reparative therapy, by eliminating permanent mechanical restraint. However, data regarding its clinical performance is lacking.

METHODS

After the BVS implantation procedure received national approval in May 2014, patients receiving BVS implantation until November 2014 in National Taiwan University Hospital (NTUH) were enrolled. Clinical variables, angiographic data, procedural details, and follow-up information were collected and compared with those receiving BVS at NTUH as part of the global ABSORB EXTEND trial.

RESULTS

A total of 35 patients (38 target vessels) with 48 BVS implanted after approval were enrolled, as the "real-world practice" group. Data of the 34 patients (34 target vessels) with 37 BVS implanted in the ABSORB EXTEND trial were also obtained. Differences in lesion complexity (0% type B2/C lesion in ABSORB EXTEND, versus 23.7% in real-world, p = 0.007) and lesion length (20.9 ± 6.1 mm in ABSORB EXTEND, versus 29.5 ± 15.9 mm in real-world, p = 0.008) were noted. The ischemia-driven target vessel revascularization after an average of 732 days follow-up was 11.8% in the ABSORB EXTEND trial. However, there was no ischemia-driven target lesion revascularization (TLR), no scaffold thrombosis, no myocardial infarction (MI), and no patients passed during the follow-up period. In real-world patients, there is 5.3% of MI, 2.6% ischemia-driven TLR, and 2.6% of non-fatal probable scaffold thrombosis.

CONCLUSIONS

The use of BVS in real-world practice is feasible, with clinical outcomes comparable to those in the ABSORB EXTEND trial.

Mid- to long-term outcome of patients treated with everolimus-eluting bioresorbable vascular scaffolds: Data of the BVS registry Göttingen predominantly from ACS patients

BACKGROUND

Bioresorbable vascular scaffolds (BVS) are widely used in routine clinical practice. While previous studies reported acceptable short- to midterm outcome after BVS implantation, data on longer-term outcome are rare.

METHODS

Patients treated with at least one Absorb®-BVS were consecutively enrolled. Follow-up data were assessed after 834.0 [769.0-1026.0] days. The primary device-oriented composite endpoint (DOCE) was defined as cardiovascular death, myocardial infarction (MI) and/or target lesion revascularization (TLR).

RESULTS

Between 2012 and 2014, 195 patients were included into study analysis. Overall, 244 BVS were implanted. Mean patient age was 64.0[54.3-74.0] years. Three-quarter of patients had an ACS; of those 42.9% had ST-elevation-MI and 40.8% had non-ST-elevation-MI. DOCE occurred in 3.1%, 6.7%, 11.8% and 15.4% of patients during hospital stay, within 6-months, 18-months or during the complete follow-up period, respectively. In those patients, median time until DOCE was 211.5[43.25-567.25] days. In 11 (36.7%) patients DOCE occurred after >12months. Using univariable analysis, bifurcation stenting was associated with a hazard ratio (HR) of 11.8[2.38-58.57] for TLR (p=0.002) and 2.1[1.02-4.49] for DOCE (p=0.045). Similarly, in ACS patients, bifurcation stenting was associated with an increased risk for TLR (HR=10.4[2.01-53.56]; p=0.005) and for DOCE (HR=2.4[1.09-5.32]; p=0.029) and in multivariable analysis, it remained an independent predictor of DOCE (HR=3.0; p=0.018).

CONCLUSIONS

Although, the rates of (potentially) device-related complications following BVS implantation are acceptable, they are nonetheless not negligible. Interestingly, they did not decline over time. Bifurcation stenting could be found as relevant procedure-related predictor of DOCE, especially in ACS patients. Randomized trials are warranted to confirm these findings.

Expanded clinical use of everolimus eluting bioresorbable vascular scaffolds for treatment of coronary artery disease

BACKGROUND

Limited data are currently available on the performance of everolimus eluting bioresorbable vascular scaffold (BVS) for treatment of complex coronary lesions representative of daily practice.

METHODS

This is a prospective, mono-center, single-arm study, reporting data after BVS implantation in patients presenting with stable, unstable angina, or non-ST segment elevation myocardial infarction caused by de novo stenotic lesions in native coronary arteries. No restrictions were applied to lesion complexity. Procedural results and 12-month clinical outcomes were reported.

RESULTS

A total of 180 patients have been evaluated in the present study, with 249 treated coronary lesions. Device Success per lesion was 99.2%. A total of 119 calcified lesions were treated. Comparable results were observed among severe, moderate and noncalcified lesions in term of %diameter stenosis (%DS) (20.3 ± 10.5%, 17.8 ± 7.7%, 16.8 ± 8.6%; P = 0.112) and acute gain (1.36 ± 0.41 mm, 1.48 ± 0.44 mm, 1.56 ± 0.54 mm; P = 0.109). In bifurcations (54 lesions), side-branch ballooning after main vessel treatment was often performed (33.3%) with low rate of side-branch impairment (9.3%). A total of 29 cases with coronary total occlusions were treated. After BVS implantation %DS was not different from other lesion types (17.2 ± 9.4%, vs. 17.7 ± 8.6%; P = 0.780). At one year, all-cause mortality was reported in three cases. The rate of target lesion revascularization and target vessel revascularization was 3.3%. The rate of definite scaffold thrombosis was 2.6%.

CONCLUSIONS

The implantation of the everolimus eluting bioresorbable vascular scaffold in an expanded range of coronary lesion types and clinical presentations was observed to be feasible with promising angiographic results and mid-term clinical outcomes. © 2016 Wiley Periodicals, Inc.

Bioresorbable vascular scaffold thrombosis in a consecutive cohort of 550 patients

OBJECTIVE

To determine the rate of bioresorbable vascular scaffold (BVS) thrombosis in a large, real-world population.

BACKGROUND

There is some concern about device thrombosis after percutaneous coronary intervention (PCI) using BVS. No data have been published for PCI using both BVS and metal stents.

METHODS

A cohort of 550 consecutive patients who underwent PCI for stable chest pain or acute coronary syndromes with implantation of at least one BVS (Absorb, Abbott Vascular) was systematically followed up by telephone interview and review of medical charts. Data on device thrombosis were retrospectively analyzed in relationship to clinical and angiographic characteristics.

RESULTS

Follow-up was achieved in 533 patients (97%, median follow-up 233 days). A total of 964 BVS were implanted in 645 vessels. In addition, 234 metal stents were implanted in 149 patients, including "hybrid intervention" with the combined use of BVS and stents in the same artery in 122 patients. Documented were 15 definite, 1 probable, and 8 possible cases of device thrombosis (rate of definite/probable device thrombosis: 3.0%). Of these, 6 definite and 6 possible thromboses could be unambiguously attributed to BVS (1.1%), whereas a total of 11 definite, 1 probable, and 8 possible thromboses were potentially attributable to BVS (2.3%). Definite device thrombosis occurred in 7/122 patients with "hybrid intervention" (5.7%).

CONCLUSIONS

In a large real-world cohort treated with BVS, the rate of scaffold thrombosis was higher than published for randomized trials. A high rate of thrombosis was observed after combined implantation of BVS and stents within one vessel. © 2016 Wiley Periodicals, Inc.

Update on clinical evidence (Part II): A summary of the main post market studies

Bioresorbable vascular scaffolds (BVS, Absorb, Abbott Vascular, Santa Clara, CA) received the CE mark in October 2011, and were approved by the Food and Drug Administration in July 2016. After their introduction in clinical practice a broad amount of post-marketing clinical experience with BVS has been generated so far in Europe and outside the United States. The available BVS registries differ in many aspects, including their being single-center or multicenter, single-arm or controlled, sponsored or investigator-initiated, published or presented at a large-scale international meeting. This article provides an overview of clinical results of the main post-marketing studies of BVS available. © 2016 Wiley Periodicals, Inc.

Current practices of Asia-Pacific cardiologists in the utilization of bioresorbable scaffolds

BACKGROUND & AIMS

Although Absorb Bioresorbable Vascular Scaffolds (A-BVS) are routinely used in the Asia-Pacific, there is little information on patient selection or deployment technique here. This document investigates the experiences of leading interventional cardiologists from the Asia-Pacific region with a focus on patient characteristics, deployment techniques and management.

METHODS AND RESULTS

A detailed questionnaire was distributed to 28 highly-experienced interventional cardiologists ('Authors') from 13 Asia-Pacific countries. The results were discussed at a meeting on patient selection, technical consideration, deployment practices and patient management. Potential patient benefits of Absorb compared to metallic DES, the learning curve for patient selection and preparation, device deployment, and subsequent patient management approaches are presented.

CONCLUSIONS

Current practices are derived from guidelines optimized for European patients. Differences in approach exist in the Asia-Pacific context, including limited access to imaging and frequency of occurrence of complex lesions. Nevertheless, the use of the Absorb BVS ('Absorb') in certain Asia-Pacific countries has flourished and practices here are continuing to mature.

Scaffold Thrombosis After Percutaneous Coronary Intervention With ABSORB Bioresorbable Vascular Scaffold: A Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this study was to determine the risk of scaffold thrombosis (ST) after percutaneous coronary intervention (PCI) with placement of an ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) by conducting a systematic review and meta-analysis.

BACKGROUND

PCI with BVS placement holds great potential, but concern has recently been raised regarding the risk of ST.

METHODS

MEDLINE/PubMed, Cochrane CENTRAL, and meeting abstracts were searched for all studies that included outcomes data for patients after PCI with BVS placement. For studies comparing BVSs with drug-eluting stents (DES), pooled estimates of outcomes, presented as odds ratios (ORs) with 95% confidence intervals (CIs), were generated with random-effects models.

RESULTS

Our analysis included 10,510 patients (8,351 with a BVS and 2,159 with DES) with a follow-up of 6.4 ± 5.1 months and 60 ± 11 years of age; 78% were male, 36% had stable angina, and 59% had acute coronary syndrome (ACS). Among patients with a BVS, cardiovascular death occurred in 0.6%, myocardial infarction (MI) in 2.1%, target lesion revascularization in 2.0%, and definite/probable ST in 1.2% of patients. Of BVS patients, 0.27% had acute ST and 0.57% had subacute ST. Meta-analysis demonstrated that patients who received a BVS were at a higher risk of MI (OR: 2.06, 95% CI: 1.31 to 3.22, p = 0.002) and definite/probable ST (OR: 2.06, 95% CI: 1.07 to 3.98, p = 0.03) compared with patients who received DES, whereas there was a trend toward decreased all-cause mortality with a BVS (OR: 0.40, 95% CI: 0.15 to 1.06, p = 0.06).

CONCLUSIONS

Patients undergoing PCI with a BVS had increased definite/probable ST and MI during follow-up compared with DES. Further studies with long-term follow-up are needed to assess the risk of ST with a BVS.

Bioresorbable vascular scaffolds - basic concepts and clinical outcome

The introduction of percutaneous treatment of coronary artery stenosis with balloon angioplasty was the first revolution in interventional cardiology; the advent of metallic coronary stents (bare and drug-eluting) marked the second and third revolutions. However, the latest generation of drug-eluting stents is limited by several factors. Permanent vessel caging impairs arterial physiology, and the incidence of very late stent thrombosis - although lower with the second generation than with the first generation of drug-eluting stents - remains a major concern. This complication is mainly related to the presence of permanent metallic implants, chronic degeneration triggered by an inflammatory response to the coating polymer, and/or adverse effects of antiproliferative drugs on endothelial regeneration. In 2011, self-degrading coronary stents - the bioresorbable vascular scaffolds (BVS) - were introduced into clinical practice, showing good short-term results owing to their adequate strength. The advantage of these devices is the transient nature of vascular scaffolding, which avoids permanent vessel caging. In this Review, we summarize the latest research on BVS, with a particular emphasis on the implantation technique (which is different from that used with metallic stents) to outline the concept that BVS deployment methods have a major effect on procedural success and prognosis of patients with coronary artery stenosis. Furthermore, the clinical outcome of BVS in randomized clinical trials and in phase IV studies are discussed in different pathophysiological settings, such as stable or acute coronary disease. Finally, all the available data on the safety profile of BVS regarding scaffold thrombosis are discussed.

Bioresorbable vascular scaffolds for the treatment of coronary artery disease: what have we learned from randomized-controlled clinical trials?

Although current everolimus-eluting coronary stents have shown improved event-free survival within the first year following implantation compared with bare-metal stents or earlier generation drug-eluting stents, they remain associated with an ongoing risk for adverse outcomes (thrombosis, myocardial infarction, and restenosis) beyond 1 year at rates similar to those observed following bare-metal stent deployment. This ongoing very late hazard has been attributed to the permanent presence of the metal frame and/or polymer in these stents. The Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) has been developed to provide mechanical support and drug-delivery functions similar to metallic drug-eluting stents, followed by complete resorption with recovery of more normal vascular structure and function, thus avoiding the limitations associated with permanent metallic endovascular prostheses. Absorb BVS has shown safety and efficacy in the dedicated clinical trial development program of Abbott Vascular and in an array of investigator-sponsored studies involving a broad spectrum of clinical (patient) as well as coronary anatomic complexity. Longer-term evidence, largely limited to single-arm studies, appears to reflect durable safety and efficacy and suggests Absorb BVS to be an attractive therapeutic option. Interim evidence from a series of randomized-clinical trials (RCTs) comparing Absorb BVS with the Xience cobalt-chromium metallic everolimus-eluting stent has shown noninferiority of Absorb BVS with respect to target lesion failure (composite occurrence of cardiac death, target vessel-related myocardial infarction, and ischemia-driven target lesion revascularization) beyond the first year, with no statistically significant differences in other safety/efficacy measures. However, concerns do exist in terms of increased rates of scaffold thrombosis, the risk for which may be mitigated by improved patient and lesion selection, procedural technique, and device iteration. We provide an overview of the evolution of percutaneous coronary intervention, in-vivo characterization of Absorb BVS resorption, and a summary with a critical evaluation of available evidence from RCTs, pooled analyses, and meta-analyses of RCTs for the safety and efficacy of Absorb BVS obtained primarily following the treatment of noncomplex coronary lesions in patients with stable ischemic heart disease and/or stabilized acute coronary syndromes.

Bioresorbable scaffolds in daily clinical routine: a practical review of all-comers results

PURPOSE OF REVIEW

Bioresorbable scaffolds (BRS) are a major advancement in interventional cardiology, but experience with BRS use in daily routine is currently limited. Here, we review technical features of commercially available BRS and place them in context with current clinical scientific evidence.

RECENT FINDINGS

Everolimus and novolimus-eluting poly-L-lactic acid (PLLA)-based BRS are commercially available in Europe. The everolimus-eluting BRS is the most widely investigated BRS and several all-comers investigations with this device are ongoing. Of the patients in these studies, 37-100% underwent catheterization due to acute coronary syndrome and up to 25% were diabetic. Up to 64.7% of all lesions treated were considered to be complex. Follow-up varied between 30 days and 1 year. The target lesion revascularization rate was up to 10% and scaffold thrombosis was 0-3%.

SUMMARY

Accumulating data on BRS application are now available. Several studies have demonstrated that BRS implantation is technically feasible in a variety of different patient subsets and clinical presentations, and follow-up results support BRS use. Patients with acute coronary syndrome represent the most investigated subpopulation, and results suggest that BRS use for this indication is reasonable.

Two-year clinical outcomes of Absorb bioresorbable vascular scaffold implantation in complex coronary artery disease patients stratified by SYNTAX score and ABSORB II study enrolment criteria

AIMS

This study presents the two-year clinical outcomes of the Amsterdam ABSORB registry stratified by lesion and patient characteristics complexity (SYNTAX score and ABSORB II study enrolment criteria).

METHODS AND RESULTS

Patients treated with BVS were included in this prospective registry and stratified according to the ABSORB II trial inclusion and exclusion criteria and the SYNTAX score. The registry comprises 135 patients (59±11 years, 73% male, 18% diabetic) with 159 lesions. Median follow-up duration was 774 days (742-829). Median SYNTAX score was 11.5 (Q1-Q3: 6-17.5). Two-year event rates were cardiac death 0.7%, MI 5.3%, TVR 13.6%, TLR 11.4%, definite ST 3.0% and TVF 14.4%, respectively. Stratified analyses showed a significantly higher revascularisation rate in patients not meeting ABSORB II criteria (TVR: 2.3% vs. 19.2%, p=0.010, and TLR: 2.3% vs. 15.8%, p=0.025) and patients with SYNTAX score ≥11.5 (TVR: 4.8% vs. 21.8%, p=0.006, and TLR: 3.2% vs. 17.4%, p=0.007).

CONCLUSIONS

The use of Absorb BVS in patients meeting the ABSORB II trial inclusion criteria or those with low SYNTAX scores is associated with acceptable clinical outcomes at two-year follow-up. Patients with more complex characteristics have significantly higher revascularisation rates.

Mid- to Long-Term Clinical Outcomes of Patients Treated With the Everolimus-Eluting Bioresorbable Vascular Scaffold: The BVS Expand Registry

OBJECTIVES

This study sought to report on clinical outcomes beyond 1 year of the BVS Expand registry.

BACKGROUND

Multiple studies have proven feasibility and safety of the Absorb bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California). However, data on medium- to long-term outcomes are limited and available only for simpler lesions.

METHODS

This is an investigator-initiated, prospective, single-center, single-arm study evaluating performance of the BVS in a lesion subset representative of daily clinical practice, including calcified lesions, total occlusions, long lesions, and small vessels. Inclusion criteria were patients presenting with non-ST-segment elevation myocardial infarction, stable/unstable angina, or silent ischemia caused by a de novo stenotic lesion in a native previously untreated coronary artery. Procedural and medium- to long-term clinical outcomes were assessed. Primary endpoint was major adverse cardiac events, defined as a composite of cardiac death, myocardial infarction, and target lesion revascularization.

RESULTS

From September 2012 to January 2015, 249 patients with 335 lesions were enrolled. Mean number of scaffolds per patient was 1.79 ± 1.15. Invasive imaging was used in 39%. In 38.1% there were American College of Cardiology/American Heart Association classification type B2/C lesions. Mean lesion length was 22.16 ± 13.79 mm. Post-procedural acute lumen gain was 1.39 ± 0.59 mm. Median follow-up period was 622 (interquartile range: 376 to 734) days. Using Kaplan-Meier methods, the MACE rate at 18 months was 6.8%. Rates of cardiac mortality, myocardial infarction, and target lesion revascularization at 18 months were 1.8%, 5.2%, and 4.0%, respectively. Definite scaffold thrombosis rate was 1.9%.

CONCLUSIONS

In our study, BVS implantation in a complex patient and lesion subset was associated with an acceptable rate of adverse events in the longer term, whereas no cases of early thrombosis were observed.

Bioresorbable vascular scaffolds technology: current use and future developments

Coronary bioresorbable vascular scaffolds are a new appealing therapeutic option in interventional cardiology. The most used and studied is currently the Absorb BVS™. Its backbone is made of poly-L-lactide and coated by a thin layer of poly-D,L-lactide, it releases everolimus and is fully degraded to H2O and CO2 in 2-3 years. Absorb BVS™ seems to offer several theoretical advantages over metallic stent, as it gives temporary mechanical support to vessel wall without permanently caging it. Therefore, long-term endothelial function and structure are not affected. A possible future surgical revascularization is not compromised. Natural vasomotion in response to external stimuli is also recovered. Several observational and randomized trials have been published about BVS clinical outcomes. The main aim of this review is to carry out a systematic analysis about Absorb BVS™ studies, evaluating also the technical improvements of the Absorb GT1 BVS™.

The ABSORB bioresorbable vascular scaffold: A novel, fully resorbable drug-eluting stent: Current concepts and overview of clinical evidence

The advent of fully bioresorbable stent technology and specifically the ABSORB™, a bioresorbable vascular scaffold (BVS) stent, is heralded as breakthrough technology in the current era of percutaneous coronary interventions. This article reviews the current understanding of this technology along with the clinical evidence from trials and registries of ABSORB BVS that included patients with both simple as well as more complex "real-world" coronary lesions. In addition, considering the current limitations of this device-mostly associated with the mechanical properties of the polymeric scaffold structure-a review of guidelines on successful implantation of the ABSORB BVS is presented. Although expert feedback suggests extensive use of this device in routine clinical practice outside the United States despite a paucity of data on long-term safety in this setting, attention to procedural details and implantation technique is obligatory to achieve optimal clinical outcomes.

Clinical results of single and multiple bioresorbable drug-eluting scaffolds for treatment of de-novo coronary artery disease

OBJECTIVES

Data on multiple bioresorbable vascular scaffolds (BVS) for the treatment of coronary lesions are limited. We compared clinical results after implantation of single or multiple BVS for the treatment of de-novo coronary artery disease.

METHODS

We enrolled 236 patients with 311 lesions treated with Absorb BVS. Quantitative coronary angiography before and after scaffold implantation was performed. All lesions were predilated. Absorb was implanted with slow inflation and 81% were postdilated with a high-pressure balloon. Patients received dual antiplatelet therapy for 6 months for stable angina pectoris and for 12 months for acute coronary syndrome. Patients were clinically followed for 12 months. Acute gain was 1.39±0.47 mm. Multiple scaffolds per lesion were implanted in 23.8% (N=74/311 lesions). The mean scaffold length was 21 mm for single and 48 mm (range 28-112 mm) for multiple BVS. Periprocedural myocardial infarction (13.5 vs. 4.6%, P<0.013) and target lesion revascularization (6.8 vs. 0.8%; P=0.003) were significantly higher in the multiple-scaffold group compared with the single-scaffold group. There was no definite scaffold thrombosis. (http://www.clinicaltrials.gov, NCT02162056).

CONCLUSION

Target lesion revascularization within 12 months and periprocedural myocardial infarction were higher for lesions treated with multiple scaffolds compared with lesions treated with single BVS.

Absorb bioresorbable stents for the treatment of coronary artery disease

Bioresorbable stents are considered to be the 'fourth revolution' in percutaneous coronary intervention. The first clinically available Absorb(®) bioresorbable device is made of poly-l-lactic acid polymer and elutes everolimus. The process of bioresorption is completed in 3 years. The introduction of this device into clinical practice went through several logical phases: first-in-man studies, randomized Absorb II study with moderately complex patients and lesions, registries of real life patient population and reports of challenging cases. The procedural results are excellent; many insights have been gained by intracoronary imaging. Intermediate-term outcomes are very encouraging both from imaging and from clinical perspectives. The issue of increased stent thrombosis rate was raised in one study, but other studies have been reassuring. Excellent lesion preparation, sizing and complete expansion of the Absorb device are crucial for optimal procedural and clinical results. Results of ongoing large randomized studies will determine the future role of this technology.

Twelve months clinical outcome after bioresorbable vascular scaffold implantation in patients with stable angina and acute coronary syndrome. Data from the Polish National Registry

Introduction

There are limited data describing bioresorbable vascular scaffold (BVS) implantation in complex lesions. Only short-term clinical outcomes are available for patients with acute coronary syndrome (ACS).

Aim

To evaluate 12-month clinical outcome, safety and effectiveness of BVS implantation in complex lesions and in stable angina (SA) or ACS.

Material and methods

Five hundred ninety-one patients with SA/ACS were enrolled between October 2012 and November 2013 in 30 invasive cardiology centres in Poland. At least one BVS implantation during percutaneous coronary intervention (PCI) was the only inclusion criteria. The clinical endpoint was the occurrence of a major adverse cardiovascular event (MACE) (all-cause death, myocardial infarction (MI), clinically driven target lesion revascularisation (TLR) with urgent PCI or target vessel revascularisation (TVR) with urgent coronary artery bypass grafting (CABG)) and device-oriented composite endpoint (DOCE) (cardiac death, urgent target vessel revascularisation with PCI/CABG, target vessel MI) during 12-month follow-up.

Results

After 12 months TLR with urgent PCI was significantly more often reported in patients with diagnosed UA (4.59%; p < 0.02) in comparison with other PCI indications. No significant differences were found in terms of composite MACE endpoint, cumulative MACE (p = 0.09), stent thrombosis (p = 0.2) or restenosis (p = 0.2). There were no significant differences in cumulative MACE and composite MACE endpoint between patients with no/mild versus moderate/severe tortuosity and no/mild versus moderate/severe calcification of the target vessel. No significant difference was found between groups of patients with or without bifurcation of the target vessel. Device-oriented composite endpoint was significantly more often reported in the ACS group (3.2% vs. 0.47%; p < 0.03), most frequently in patients with diagnosed UA (5.5%).

Conclusions

Bioresorbable vascular scaffold can be successfully and safely used for ACS treatment and in lesions of higher complexity.

Bioresorbable scaffold - A magic bullet for the treatment of coronary artery disease?

Today, drug-eluting metal stents are considered the gold standard for interventional treatment of coronary artery disease. While providing inhibition of neointimal hyperplasia, drug-eluting metal stents have many limitations such as the risk of late and very late stent thrombosis, restriction of vascular vasomotion and chronic local inflammatory reaction due to permanent implantation of a 'metallic cage', recognized as a foreign body. Bioresorbable scaffold stents (BRS) are a new solution, which is trying to overcome the limitation of the 'metallic cage'. This structure provides short-term scaffolding of the vessel and then disappears, leaving nothing behind. The purpose of this review is to present the theoretical rationale for the use of BRS and to outline the clinical outcomes associated with their use in terms of data obtained from RCTs, clinical trials, registries and real life use. We have also tried to answer all questions on this intervention based on available data, with a focus on ABSORB BVS (Abbott Vascular, Santa Clara, USA). We consider that this new technology can be the "magic bullet" to treat coronary artery disease.

[Complex coronary intervention with overlapping of bioresorbable scaffolds. Case report and new insights review in the use of bioresorbable vascular scaffolds guided by optical coherence tomography]

In recent years, the history of percutaneous coronary intervention has had a remarkable evolution. Currently, in México are available the bioresorbable vascular scaffolds which have a very precise indications, and offer a new option in coronary intervention. We present the case and review of the published evidence, a new option for intervention with these devices, a complex case with 3 overlapping bioresorbable vascular scaffolds guided by optical coherence tomography.

Clinical Outcomes of Bioresorbable Scaffold in Coronary Artery Disease: A Systematic Literature Review

OBJECTIVES

We aim to perform a systematic literature review on all studies reporting the clinical outcomes of the use of bioresorbable scaffolds (BRS) in different settings of coronary artery disease (CAD).

BACKGROUND

BRS are designed to provide early support of the vessel wall postangioplasty, deliver antiproliferative agents to prevent excessive hyperplastic healing responses and finally "disappear" when no longer required. Emerging data have provided evidence of their use in specific clinical scenarios.

METHODS

A comprehensive literature search was performed by 2 independent reviewers utilizing MEDLINE, EMBASE, and Cochrane Library databases. The only 2 CE marked BRS: everolimus-eluting Bioresorbable vascular scaffold ABSORB BVS and the myolimus-eluting DESolve Bioresorbable Coronary Scaffold (BCS) System were included.

RESULTS

The studies were categorized into: ST elevation myocardial infarction (STEMI), stable CAD, and "all-comers" group. Thirty-one studies were included; 8 in STEMI patients (all ABSORB), 15 in stable CAD patients. In the STEMI group (n = 606), acute procedural success ranged from 96% to 100%, cardiac mortality 0-9.1%, recurrent MI and stent thrombosis rates were 0-4.3%. In the stable CAD group, the 13 ABSORB studies (n = 3259) demonstrated cardiac mortality rate of 0-0.6%, recurrent MI rate 0-4.5%, and stent thrombosis rate 0-4.3%

CONCLUSIONS

Current clinical data suggest the BRS, especially the ABSORB BVS, may represent a reasonable alternative to DES in uncomplicated coronary anatomy.

Safety and performance of the second-generation drug-eluting absorbable metal scaffold in patients with de-novo coronary artery lesions (BIOSOLVE-II): 6 month results of a prospective, multicentre, non-randomised, first-in-man trial

BACKGROUND

Absorbable scaffolds were designed to overcome the limitations of conventional, non-absorbable metal-based drug-eluting stents. So far, only polymeric absorbable scaffolds are commercially available. We aimed to assess the safety and performance of a novel second-generation drug-eluting absorbable metal scaffold (DREAMS 2G) in patients with de-novo coronary artery lesions.

METHODS

We did this prospective, multicentre, non-randomised, first-in-man trial at 13 percutaneous coronary intervention centres in Belgium, Brazil, Denmark, Germany, Singapore, Spain, Switzerland, and the Netherlands. Eligible patients had stable or unstable angina or documented silent ischaemia, and a maximum of two de-novo lesions with a reference vessel diameter between 2·2 mm and 3·7 mm. Clinical follow-up was scheduled at months 1, 6, 12, 24, and 36. Patients were scheduled for angiographic follow-up at 6 months, and a subgroup of patients was scheduled for intravascular ultrasound, optical coherence tomography, and vasomotion assessment. All patients were recommended to take dual antiplatelet treatment for at least 6 months. The primary endpoint was in-segment late lumen loss at 6 months. We did analysis by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01960504.

FINDINGS

Between Oct 8, 2013, and May 22, 2015, we enrolled 123 patients with 123 coronary target lesions. At 6 months, mean in-segment late lumen loss was 0·27 mm (SD 0·37), and angiographically discernable vasomotion was documented in 20 (80%) of 25 patients. Intravascular ultrasound assessments showed a preservation of the scaffold area (mean 6·24 mm(2) [SD 1·15] post-procedure vs 6·21 mm(2) [1·22] at 6 months) with a low mean neointimal area (0·08 mm(2) [0·09]), and optical coherence tomography did not detect any intraluminal mass. Target lesion failure occurred in four (3%) patients: one (<1%) patient died from cardiac death, one (<1%) patient had periprocedural myocardial infarction, and two (2%) patients needed clinically driven target lesion revascularisation. No definite or probable scaffold thrombosis was observed.

INTERPRETATION

Our findings show that implantation of the DREAMS 2G device in de-novo coronary lesions is feasible, with favourable safety and performance outcomes at 6 months. This novel absorbable metal scaffold could be an alternative to absorbable polymeric scaffolds for treatment of obstructive coronary disease.

FUNDING

Biotronik AG.

Angiographic and clinical outcomes of patients treated with everolimus-eluting bioresorbable stents in routine clinical practice: Results of the ISAR-ABSORB registry

OBJECTIVES

We aimed to analyze angiographic and clinical results of patients undergoing BRS implantation in a real-world setting.

BACKGROUND

Angiographic and clinical outcome data from patients undergoing implantation of drug-eluting bioresorbable stents (BRS) in routine clinical practice is scant.

METHODS

Consecutive patients undergoing implantation of everolimus-eluting BRS at two high-volume centers in Munich, Germany were enrolled. Data were collected prospectively. All patients were scheduled for angiographic surveillance 6-8 months after stent implantation. Quantitative coronary angiographic analysis was performed in a core laboratory. Clinical follow-up was performed to 12 months and events were adjudicated by independent assessors.

RESULTS

A total of 419 patients were studied. Mean age was 66.6 ± 10.9 years, 31.5% had diabetes mellitus, 76.1% had multivessel disease, and 39.0% presented with acute coronary syndrome; 49.0% of lesions were AHA/ACC type B2/C, 13.1% had treatment of bifurcation lesions. Mean reference vessel diameter was 2.89 ± 0.46 mm. At angiographic follow-up in-stent late loss was 0.26 ± 0.51 mm, in-segment diameter stenosis was 27.5 ± 16.1, and binary angiographic restenosis was 7.5%. At 12 months, the rate of death, myocardial infarction, or target lesion revascularization was 13.1%. Definite stent thrombosis occurred in 2.6%.

CONCLUSIONS

The use of everolimus-eluting BRS in routine clinical practice is associated with high antirestenotic efficacy in patients undergoing angiographic surveillance. Overall clinical outcomes at 12 months are satisfactory though stent thrombosis rates are not insignificant. Further study with longer term follow-up and larger numbers of treated patients is required before we can be sure of the role of these devices in clinical practice.

Bioresorbable vascular scaffold implantation in acute coronary syndromes: clinical evidence, tips and tricks

Percutaneous coronary intervention (PCI) with a drug-eluting stent (DES) is routine treatment for patients with acute coronary syndromes (ACS). However, permanent metallic caging of the vessel has several shortcomings, such as side branch jailing and impossibility of late lumen enlargement. Moreover, DES PCI is affected by vasomotion impairment. In ACS a high thrombus burden and vasospasm lead to a higher risk of acute and late acquired stent malapposition than in stable patients. This increases the risk of acute, late and very late stent thrombosis. In this challenging clinical setting, the implantation of bioresorbable vascular scaffolds (BVS) could represent an appealing therapeutic option. Temporary vessel scaffolding has proved to have several advantages over metallic stent delivery, such as framework reabsorption, late lumen enlargement, side branch patency, and recovery of physiological reactivity to vasoactive stimuli. In the thrombotic environment of ACS, BVS implantation has the benefit of capping the thrombus and the vulnerable plaque. Bioresorbable vascular scaffolds also seems to reduce the incidence of angina during follow-up. Acute coronary syndromes patients may therefore benefit more from temporary polymeric caging than from permanent stent platform implantation. The aim of this review is to update the available knowledge concerning the use of BVS in ACS patients, by analyzing the potential pitfalls in this challenging clinical setting and presenting tricks to overcome these limitations.

Absorb bioresorbable vascular scaffold: What have we learned after 5 years of clinical experience?

Bioresorbable scaffolds have the potential to introduce a paradigm shift in interventional cardiology, a true anatomical and functional "vascular restoration" instead of an artificial stiff tube encased by persistent metallic foreign body. Early clinical studies using the first commercially available drug-eluting bioresorbable vascular scaffold (BVS) reported very promising safety and efficacy outcomes, comparable to best-in-class second-generation drug-eluting metal stent. To date, more than 60,000 Absorb BVSs have been implanted with only the interim analysis of one randomized trial (ABSORB II RCT) available. Recent registries have challenged the initial claim that BVS is immune from Scaffold Thrombosis (ST). However, suboptimal device expansion and insufficient intracoronary imaging guidance can explain higher than expected ST, especially in complex lesions. The aim of this review article is to critically evaluate the results of the available Absorb BVS studies and discuss the lessons learned to optimize lesion selection and implantation technique of such devices.

Everolimus-eluting stent platforms in percutaneous coronary intervention: comparative effectiveness and outcomes

Despite the remarkable benefits obtained following the introduction of the first-generation drug-eluting stent (DES), concerns were raised over its long-term safety, particularly with regard to very late (beyond 1 year) stent thrombosis. Newer-generation DESs have been developed to overcome this limitation using novel stent platforms, new drugs, more biocompatible durable polymers, and bioabsorbable polymers or backbones. To date, new-generation DESs have virtually replaced the use of first-generation DESs worldwide. In this review article, we discuss in detail the design, pharmacology, and mechanism of action of the newer-generation permanent and bioresorbable everolimus-eluting platforms. Furthermore, we present and evaluate the current evidence on the performance and safety of these devices compared to those of other available stent platforms.

Current status of clinically available bioresorbable scaffolds in percutaneous coronary interventions

Drug-eluting stents (DES) are widely used as first choice devices in percutaneous coronary interventions. However, certain concerns are associated with the use of DES, i.e. delayed arterial healing with a subsequent risk of neo-atherosclerosis, late stent thrombosis and hypersensitivity reactions to the DES polymer. Bioresorbable vascular scaffolds are the next step in percutaneous coronary interventions introducing the concept of supporting the natural healing process following initial intervention without leaving any foreign body materials resulting in late adverse events. The first-generation devices have shown encouraging results in multiple studies of selected patients up to the point of full bioresorption, supporting the introduction in regular patient care. During its introduction in daily clinical practice outside the previously selected patient groups, a careful approach should be followed in which outcome is continuously monitored.