Percutaneous coronary intervention with everolimus-eluting bioresorbable vascular scaffolds in routine clinical practice: early and midterm outcomes from the European multicentre GHOST-EU registry

Everolimus-eluting bioresorbable vascular scaffolds versus second generation drug-eluting stents for percutaneous treatment of chronic total coronary occlusions: Technical and procedural outcomes from the GHOST-CTO registry

OBJECTIVES

We aimed at comparing the acute performance of bioresorbable scaffolds (BRS) and second-generation drug-eluting stents (DES) for the treatment of chronic total occlusions (CTO).

BACKGROUND

There is a lack of knowledge regarding the use of BRS in CTO.

METHODS

Key outcomes of interest were technical and procedural success. Technical success was defined as successful stent delivery and implantation, postprocedural residual diameter stenosis <30% within the treated segment, and restoration of thrombolysis in myocardial infarction (TIMI) grade 3 flow. Procedural success was defined as technical success with no in-hospital major adverse cardiac events (MACE).

RESULTS

Between May 2013 and May 2014, 32 patients underwent CTO percutaneous coronary intervention (PCI) with the Absorb BRS (Abbott Vascular, Santa Clara, CA) and were compared with a historical control group of 54 patients who had undergone CTO PCI with second-generation DES. Baseline characteristics were similar between the BRS and DES groups, with the exception of a larger mean reference vessel diameter in the BRS group (2.92 ± 0.34 vs 2.50 ± 0.68; P < 0.001). Technical success was less likely to be achieved in the BRS group compared with the DES group (78.1% vs 96.3%, P = 0.012). Procedural success rates were 78.1% and 94.4% in the BRS and DES group, respectively (P = 0.035).

CONCLUSIONS

Compared with second-generation DES for PCI of CTO lesions, BRS were associated with lower rates of technical and procedural success. © 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.

Role of invasive imaging in acute and long-term assessment of bioresorbable scaffold technology

Fully bioresorbable scaffolds (BRS) represent a novel approach for the percutaneous treatment of coronary artery stenosis, providing temporary vessel scaffolding with drug-eluting capability during the restenosis-prone phase of the vascular healing. Beyond this initial critical period, when mechanical scaffolding support is no longer necessary, the device is bioresorbed, restoring the normal vascular physiology with the aim to eliminate the long-term safety concerns related to permanent metallic implants. Nonetheless, current BRS technology suffers from limited mechanical properties as compared to available metallic platforms, requiring careful attention to lesion preparation, accurate vessel sizing, and implantation technique. Intravascular imaging has played an important role in providing knowledge on the acute effects after BRS deployment, and it helped refine the current technique of BRS implantation. In addition, extensive work with multiple intravascular imaging modalities have also contributed to the understanding of the unique dynamic vascular changes that are experienced in the treated segment from post-implantation up to complete device bioresorption. In this manuscript, we review the role of invasive imaging modalities-from angiography to sound- and light-based techniques-to guide BRS implantation procedures, to assess its acute results postimplantation, and the changes experienced in the long-term until complete bioresorption has ensued. © 2016 Wiley Periodicals, Inc.

A prospective evaluation of a standardized strategy for the use of a polymeric everolimus-eluting bioresorbable scaffold in ST-segment elevation myocardial infarction: Rationale and design of the BVS STEMI STRATEGY-IT study

OBJECTIVES

To assess the feasibility and the clinical results following a prespecified bioresorbable vascular scaffold (Absorb BVS) implantation strategy in ST-elevation myocardial infarction (STEMI) patients.

BACKGROUNDS

Concerns raised about the BVS safety in STEMI setting because a not negligible thrombosis rate was reported within 30 days and 12 months after implantation. Technical procedural issues related to the structural BVS features were advocated as probable causes for the thrombotic events.

METHODS

This is an investigators-owned and -directed, prospective, nonrandomized, single-arm multicenter registry intended to obtain data from 500 consecutive STEMI patients undergoing primary PCI with BVS (1.1 or GT1) following a prespecified implantation protocol. The study is recorded in ClinicalTrials.gov with the identifier: NCT02601781.

RESULTS

The primary endpoint is a device-oriented composite end-point (DOCE) of cardiac death, any myocardial infarction clearly attributable to the intervention culprit vessel and ischemic-driven target lesion revascularization within 30 days after the index procedure. The DOCE will be assessed even at 6-month, 1-, 3-, and 5-year follow-up.

CONCLUSIONS

This will be the first study investigating the feasibility and the early- and long-term clinical impact of a prespecified BVS implantation protocol in thrombotic lesions causing STEMI. Here, we describe the rationale and the design of the study. © 2016 Wiley Periodicals, Inc.

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.

Prevalence of parameters of suboptimal scaffold deployment following angiographic guided bioresorbable vascular scaffold implantation in real world practice - an optical coherence tomography analysis

AIM

To assess the prevalence of suboptimal bioresorbable vascular scaffold (BVS, Abbott Vascular, Santa Clara, California) deployment in real world practice with intracoronary optical coherence tomography (OCT) imaging.

METHODS

Consecutive patients who underwent percutaneous coronary intervention using BVS and the final optimization assessed with OCT imaging in two tertiary care centers between December 2012 and February 2015 were evaluated for parameters of suboptimal scaffold deployment by OCT.

RESULTS

Overall, 36 scaffolds were implanted in 27 patients during this period. Mean age of the population was 54.7±8.2years and 19 (70.4%) were type B2/C lesions. The prevalence of parameters of suboptimal scaffold deployment were: underexpansion-22(61.1%), geographic miss-3(8.3%), tissue prolapse-7(25.9%), scaffold pattern irregularity-1(2.8%), longitudinal elongation-7(38.8%). Of the 7 overlaps imaged: excessive overlap was observed in 3 and scaffold gap in one. The median duration of follow up was 679days (range 193-963days). There were four events during this period. None were associated with suboptimal scaffold deployment.

CONCLUSION

OCT based parameters of suboptimal scaffold deployment are common in real world scenario and were not associated with adverse outcomes on long term follow up. These findings need to be confirmed in larger studies.

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-what does the future bring?

Bioresorbable vascular scaffolds (BVS) have emerged as an interesting alternative since the presence of the prosthesis in the coronary artery is transient. This technology enables to restore the normal vasomotor tone and allows positive remodeling, simultaneously reducing the trigger for persistent inflammation and facilitating further interventions by percutaneous or surgical means. Absorb BVS(®) is the first generation everolimus-eluting poly-L-lactide (PLLA) bioresorbable scaffold. In recent meta-analyses Absorb BVS(®) was definitely proved to be safe and effective device in the treatment of symptomatic coronary artery disease. This was recently confirmed by FDA advisory panel of experts who recommended approval of the device based on an analysis of its risks and rewards. Nevertheless, still there are some concerns regarding stent thrombosis, and the real vessel functionality restoration at long-term observation. Worth mentioning is the fact that apart from stable coronary disease Absorb BVS(®) is used successfully in a series of off-label clinical settings such as acute coronary syndromes including STEMI, in-stent restenosis, coronary bifurcations, left main stenting or chronic total occlusions. Moreover, new bioresorbable scaffolds are under development with DEsolve(®) and DREAM 2G(®), which are the most advanced.

The Absorb bioresorbable vascular scaffold for the treatment of coronary artery disease

INTRODUCTION

Every decade the field of interventional cardiology is revolutionized by new technology. The fully bioresorbable everolimus-eluting scaffold (ABSORB BVS) technology would preserve the benefits of metallic stents by sealing balloon-induced dissections, avoiding elastic recoil and vessel occlusion. The polymeric scaffold would be resorbed to restore the natural integrity of the vessel, superseding the consequence of the permanent presence of a foreign body in the coronary artery.

AREAS COVERED

This technology evaluation focuses on the clinical evidence for the use of bioresorbable everolimus-eluting scaffold for the treatment of coronary artery disease.

EXPERT OPINION

The current generation of the bioresorbable scaffold has structural and mechanical limitations that might preclude the widespread use in clinical practice. The strut thickness (150 µm) limits deliverability and creates laminar flow disruptions that might be the nidus of an increased rate of scaffold thrombosis. In the next generation of bioresorbable scaffolds, the resorption process should be faster and in particular, strut thickness must be reduced. This will probably represent a significant step forward in an attempt to increase the efficacy and safety profile of the device and achieve a similar performance with the current generation drug-eluting stent even in complex scenarios.

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.

Use of bioresorbable vascular scaffold: a meta-analysis of patients with coronary artery disease

BACKGROUND

Differences in outcomes between bioresorbable vascular scaffold (BVS) systems and drug-eluting metal stents (DES) have not been fully evaluated. We aimed to compare clinical and angiographic outcomes in randomised studies of patients with coronary artery disease (CAD), with a secondary analysis performed among registry studies.

METHODS

A meta-analysis comparing outcomes between BVS and DES in patients with CAD. Overall estimates of treatment effect were calculated with random-effects model and fixed-effects model.

RESULTS

In 6 randomised trials (3818 patients), BVS increased the risk of subacute stent thrombosis (ST) over and above DES (OR 2.14; CI 1.01 to 4.53; p=0.05), with a trend towards an increase in the risk of myocardial infarction (MI) (125 events in those assigned to BVS and 50 to DES; OR 1.36; CI 0.97 to 1.91; p=0.07). The risk of in-device late lumen loss (LLL) was higher with BVS than DES (mean difference 0.08 mm; CI 0.03 to 0.13; p=0.004). There was no difference in the risk of death or target vessel revascularisation (TVR) between the two devices. In 6 registry studies (1845 patients), there was no difference in the risk of death, MI, TVR or subacute ST between the two stents. Final BVS dilation pressures were higher in registry than in randomised studies (18.7±4.6 vs 15.2±3.3 atm; p<0.001).

CONCLUSIONS

Patients treated with BVS had an increased risk of subacute ST and slightly higher LLL compared with those with DES, but this might be related to inadequate implantation techniques, in particular device underexpansion.

Late and Very Late Stent Thrombosis in the Era of Second-Generation Drug-Eluding Stents

Stent thrombosis is a life-threatening complication of percutaneous coronary intervention that often results in ST-segment myocardial infarction or sudden cardiac death. First-generation drug-eluting stents (DESs) are associated with an increased risk of late and very late stent thrombosis compared with bare- metal stents due to delayed endothelialisation of the stent struts. The second-generation DES design includes a number of improved features (thinner stent struts, fluorinated copolymers, and different anti-proliferative agents) to decrease the risk of late stent thrombosis. Currently, the cobalt-chromium everolimus-eluting stent, a second-generation stent, has the lowest risk of stent thrombosis when compared with the available alternatives. Given the improved design of second-generation stents, a shorter duration of dual antiplatelet therapy of 6 months may be enough to reduce the rate of bleeding complications without increasing the risk of adverse cardiovascular events. Future large-scale randomised trials are required to evaluate the safety and efficacy of third-generation DESs which feature bioresorbable polymers and scaffolds.

Impact of overlapping on 1-year clinical outcomes in patients undergoing everolimus-eluting bioresorbable scaffolds implantation in routine clinical practice: Insights from the European multicenter GHOST-EU registry

BACKGROUND

Overlapping implantation of bioresorbable scaffolds (BRSs) are frequent in long coronary lesions. Its impact on clinical outcomes is unknown.

OBJECTIVE

To compare the clinical outcomes of patients treated with overlapping BRS with those patients treated with no-overlap BRS.

METHODS

We analyzed the 1-year clinical outcomes of 1,477 patients treated with BRS in the GHOST-EU registry, according to the implantation of overlapping BRS. Primary endpoint was patient oriented composite endpoint (PoCE) of: all-cause death, any myocardial infarction (MI) and any repeated revascularization. Scaffold thrombosis, according to Academic Research Consortium definition, was also analyzed.

RESULTS

A total of 320 (21.7%) patients were treated with overlapping BRS (overlap group), whereas the remaining 1,157 (78.3%) received no-overlap BRS (no-overlap group). The overlap group had significantly higher frequency of male sex, diabetes mellitus, stable angina, B2/C lesion type, SYNTAX score ≥22, lesion length >34 mm, use of intracoronary imaging guidance, pre- and postdilatation. At 1-year, there were no differences in PoCE between the overlap versus no-overlap group (18.4% vs. 18.2%; HR 1.07, [0.80-1.44]; P = 0.636), even after adjustment (HR 1.05, [0.48-2.20]; P = 0.904). Scaffold thrombosis rate did not differ either at one-month (1.3% vs. 1.5%, P = 0.769) or at 1-year (1.9% vs. 2.1%, P = 0.823).

CONCLUSIONS

In "Real-world" clinical practice, overlapping BRS does not appear to have an impact on clinical outcomes as compared to no-overlapping BRS. These preliminary data should be confirmed. © 2016 Wiley Periodicals, Inc.

MicroRNAs for Restenosis and Thrombosis After Vascular Injury

Percutaneous revascularization revolutionized the therapy of patients with coronary artery disease. Despite continuous technical advances that substantially improved patients' outcome after percutaneous revascularization, some issues are still open. In particular, restenosis still represents a challenge, even though it was dramatically reduced with the advent of drug-eluting stents. At the same time, drug-eluting stent thrombosis emerged as a major concern because of incomplete or delayed re-endothelialization after vascular injury. The discovery of microRNAs revealed a previously unknown layer of regulation for several biological processes, increasing our knowledge on the biological mechanisms underlying restenosis and stent thrombosis, revealing novel promising targets for more efficient and selective therapies. The present review summarizes recent experimental and clinical evidence on the role of microRNAs after arterial injury, focusing on practical aspects of their potential therapeutic application for selective inhibition of smooth muscle cell proliferation, enhancement of endothelial regeneration, and inhibition of platelet activation after coronary interventions. Application of circulating microRNAs as potential biomarkers is also discussed.

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.

Early and midterm outcomes of bioresorbable vascular scaffolds for ostial coronary lesions: insights from the GHOST-EU registry

AIMS

We aimed to investigate the outcomes of bioresorbable vascular scaffolds (BVS) in coronary ostial lesions. Ostial lesions represent a challenging angiographic subset, with higher event rates compared with non-ostial lesions. BVS might be associated with advantages over the long term, but their safety in this setting remains to be explored.

METHODS AND RESULTS

Procedural and 12-month follow-up data from consecutive patients treated with BVS for lesions located at the ostium of the right (RCA), left anterior (LAD) or circumflex (LCX) coronary in 11 European centres were collected. The primary device-oriented endpoint was defined as a combination of cardiovascular death, target vessel myocardial infarction or target lesion revascularisation. The database included a total of 1,549 lesions in 1,304 patients with a mean age of 62±11years. There were 90 ostial lesions (5.8%) in 84 patients (6.4%) located at the ostial RCA (14; 16%), LCX (29; 32%), or LAD (47; 52%). Patients presenting with ostial lesions did not differ from the remaining cohort except for a higher incidence of prior revascularisation. Predilation was performed in 97% of the lesions (vs. 96% in non-ostial, p=0.618), post-dilation in 43% (versus 58% in the non-ostial group, p=0.008). At quantitative coronary angiography, treatment of ostial lesions was associated with higher residual stenosis (30% [23-41] vs. 26% [20-37], p=0.035), but no difference in minimum lumen diameter existed (p=0.447). Follow-up data were available at 385 [362-465] days. The 12-month Kaplan-Meier estimated rates of scaffold thrombosis were 4.9% and 2.0% (ostial and non-ostial lesion groups, respectively, log-rank p=0.005). The device-oriented composite endpoint occurred, respectively, in 12.6% and 4.6% at 12 months (log-rank p=0.001). Treatment of ostial lesions was an independent predictor of this endpoint (p=0.0025, HR 2.65 [1.41-4.97]).

CONCLUSIONS

In combination with a suboptimal implantation technique, treatment of coronary ostial lesions was an independent predictor of clinical events in a cohort of patients treated with BVS.

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 Coronary Scaffold Thrombosis: Multicenter Comprehensive Analysis of Clinical Presentation, Mechanisms, and Predictors

BACKGROUND

Recent reports suggest an elevated incidence of bioresorbable vascular scaffold (BVS) thrombosis (scaffold thrombosis [ScT]).

OBJECTIVES

This study investigated occurrence rates, clinical and angiographic characteristics, and possible mechanisms of ScT in all-comer patients undergoing BVS implantation at 2 German and 2 Swiss hospitals.

METHODS

A total of 1,305 consecutive patients (mean age 64 years, 78% male) who received 1,870 BVS (mean 1.4 ± 0.8 BVS/patient) were enrolled. Clinical/procedural characteristics, mortality, and ScT data at 485 days (range 312 to 652 days) were examined.

RESULTS

ScT occurred in 42 patients. The incidence of probable and definite ScT was 1.8% at 30 days and 3.0% at 12 months, without differences among centers (p = 0.60). A total of 22 (52%) ScTs presented as ST-segment elevation myocardial infarction and 6 (17%) as sudden cardiac death. In multivariable analysis, ostial lesions (p = 0.049) and impaired left ventricular ejection fraction (p = 0.019) were independently associated with ScT. Nine (21%) of the ScTs occurred in patients who had suspended dual antiplatelet therapy, in 6 cases prematurely. Lower post-procedural minimum lumen and reference vessel diameters were hallmarks of ScT (all p < 0.0001). The risk of ScT appeared to rapidly increase for post-procedural minimum lumen diameters below 2.4 mm (for the 2.5- to 3.0-mm BVS) and 2.8 mm (for the 3.5-mm BVS). When a BVS-specific implantation strategy was implemented, 12-month ScT rates fell from 3.3% to 1.0%, an effect that remained significant when adjusted for multivariable propensity score (p = 0.012; hazard ratio: 0.19; 95% confidence interval: 0.05 to 0.70).

CONCLUSIONS

The 12-month incidence of ScT reached 3% and could be significantly reduced when an optimized implantation strategy was employed. (retrospective multicentric registry and Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178).

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™.

Sequential Proximal Optimizing Technique in Provisional Bifurcation Stenting With Everolimus-Eluting Bioresorbable Vascular Scaffold: Fractal Coronary Bifurcation Bench for Comparative Test Between Absorb and XIENCE Xpedition

OBJECTIVES

The aim of this fractal bifurcation bench study was to compare provisional bifurcation stenting with a "re-POT" sequence, comprising a proximal optimizing technique (POT), side branch inflation, and final POT, between a bioresorbable vascular scaffold (BVS) and a metallic stent.

BACKGROUND

Re-POT proved significantly better than kissing balloon inflation in maintaining circular geometry without overstretch in metal stents, while significantly reducing side branch ostium strut obstruction and global strut malapposition. This should be useful for BVSs, which are more easily breakable.

METHODS

Twenty left main-like and 20 left anterior descending-like fractal coronary bifurcation bench models used 10 each 2.5 × 24 mm and 3.5 × 24 mm Absorb (Ab) BVSs and 10 each 2.5 × 24 mm and 3.5 × 24 mm XIENCE Xpedition (XX) metal stents, implanted by re-POT, with optical coherence tomographic analysis at each step and micro-computed tomographic analysis of Ab devices to detect strut fracture.

RESULTS

With Ab devices, re-POT reduced percentage strut malapposition close to XX rates (0.8 ± 0.7% vs. 0.0 ± 0.0%, p < 0.05; 3.5 ± 1.7% vs. 0.3 ± 0.6%, p < 0.05), conserving proximal circularity (elliptical ratio, 1.04 vs. 1.03 and 1.04 vs. 1.04; p = NS). Mean post-re-POT proximal expansion was 0.6 ± 0.1 mm (+21.6 ± 2.1%) for 2.5-mm and 1.0 ± 0.1 mm (+23.6 ± 2.2%) for 3.5-mm Ab devices, with only 1 strut fracture (left anterior descending-like bench). Side branch ostium strut obstruction was greater with Ab scaffolds than XX stents: 41.1 ± 9.4% versus 16.4 ± 8.1% (p < 0.05) and 31.8 ± 3.2% versus 10.0 ± 5.3% (p < 0.05), respectively, for 2.5- and 3.5-mm scaffolds and stents. Ab scaffolds showed 2 ± 1% moderate but significant late recoil as of 1 h, reaching 4 ± 2% by 24 h (p < 0.05).

CONCLUSIONS

Re-POT optimized most Ab provisional bifurcation treatments, without fracture, respecting fractal geometry, and without exceeding 1.0-mm proximal differential diameter.

Optical coherence tomography guidance for percutaneous coronary intervention with bioresorbable scaffolds

BACKGROUND

The effect of optical coherence tomography (OCT) guidance on the implantation strategy during all phases of percutaneous coronary intervention (PCI) with bioresorbable vascular scaffolds (BVSs) in a real-world scenario has been poorly investigated.

METHODS

Consecutive patients undergoing BVS implantation at our institution were included in this registry. Frequency-domain OCT pullbacks were performed at the operator's discretion during all phases of BVS implantation procedures to optimize preparation of lesions, confirm BVS size, and optimize expansion and apposition of scaffolds.

RESULTS

Between September 2012 and July 2015, 203 BVSs were implanted in 101 consecutive patients at our institution (2.01 BVSs/patient). In 66 patients, the procedure was performed under OCT guidance. In the OCT subgroup, 66 (77.6%) of the 85 treated lesions were complex (B2/C AHA/ACC type). Overall, 147 OCT pullbacks were performed and 72/147 (49.0%) pullbacks indicated the need for changing strategy. After angiography-only-guided optimisation of BVS in 27 (31.8%) lesions, an OCT examination prompted performance of a second post-expansion. This resulted in an increase in the minimal scaffold area (5.5 to 6.3mm(2), p=0.004) and a decrease in the incomplete scaffold apposition area (1.1 to 0.6mm(2), p=0.082), with no new stent fractures. When the population was divided according to the time of BVS implantation, an initial learning adaptation became evident, with the number of OCT-guided changes in strategy significantly decreasing between the initial and final time periods (p=0.017).

CONCLUSIONS

OCT guidance for BVS implantation significantly affects the procedural strategy, with favourable effects on acute results and the learning curve.

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.

Everolimus-eluting bioresorbable vascular scaffolds implanted in coronary bifurcation lesions: Impact of polymeric wide struts on side-branch impairment

BACKGROUND

Limited data are available on bioresorbable vascular scaffolds (BVS) performance in bifurcations lesions and on the impact of BVS wider struts on side-branch impairment.

METHODS

Patients with at least one coronary bifurcation lesion involving a side-branch ≥2mm in diameter and treated with at least one BVS were examined. Procedural and angiographic data were collected and a dedicated methodology for off-line quantitative coronary angiography (QCA) in bifurcation was applied (eleven-segment model), to assess side-branch impairment occurring any time during the procedure. Two- and three-dimensional QCA were used. Optical coherence tomography (OCT) analysis was performed in a subgroup of patients and long-term clinical outcomes reported.

RESULTS

A total of 102 patients with 107 lesions, were evaluated. Device- and procedural-successes were 99.1% and 94.3%, respectively. Side-branch impairment occurring any time during the procedure was reported in 13 bifurcations (12.1%) and at the end of the procedure in 6.5%. Side-branch minimal lumen diameter (Pre: 1.45±0.41mm vs Final: 1.48±0.42mm, p=0.587) %diameter-stenosis (Pre: 26.93±16.89% vs Final: 27.80±15.57%, p=0.904) and minimal lumen area (Pre: 1.97±0.89mm(2) vs Final: 2.17±1.09mm(2), p=0.334), were not significantly affected by BVS implantation. Mean malapposed struts at the bifurcation polygon-of-confluence were 0.63±1.11.

CONCLUSIONS

The results of the present investigation suggest feasibility and relative safety of BVS implantation in coronary bifurcations. BVS wide struts have a low impact on side-branch impairment when considering bifurcations with side-branch diameter≥2mm.

Optical Coherence Tomography Findings in Bioresorbable Vascular Scaffolds Thrombosis

BACKGROUND

Everolimus-eluting bioresorbable vascular scaffolds have been developed to improve late outcomes after coronary interventions. However, recent registries raised concerns regarding an increased incidence of scaffold thrombosis (ScT). The mechanism of ScT remains unknown.

METHODS AND RESULTS

The present study investigated angiographic and optical coherence tomography findings in patients experiencing ScT. Fifteen ScT (14 patients, 79% male, age 59±10 years) occurred at a median of 16 days (25%-75% interquartile range: 1-263 days) after implantation. Early ScT (<30 days) occurred in 8 cases (53%). Possible causal factors in these patients included insufficient platelet inhibition in 2 cases and procedural factors (scaffold underexpansion, undersizing, or geographical miss) in 4 cases. No obvious cause could be found in 2 early ScT. In late (>1 month) and very late (>1 year) ScT (respectively, 5 and 2 cases), 5 scaffolds showed intimal neovessels or marked peristrut low-intensity areas. Scaffold fractures were additionally found in 2 patients, and scaffold collapse was found in 1 patient with very late ScT. Extensive strut malapposition was the presumed cause for ScT in 1 case. One scaffold did not show any morphological abnormality. Thrombectomy specimens were analyzed in 3 patients and did not demonstrate increased numbers of inflammatory cells.

CONCLUSIONS

The mechanisms of early ScT seem to be similar to metallic stents (mechanical and inadequate antiplatelet therapy). The predominant finding in late and very late ScT is peristrut low-intensity area.

"Assessment of effectiveness and security in high pressure postdilatation of bioresorbable vascular scaffolds during percutaneous coronary intervention. Study in a contemporary, non-selected cohort of Spanish patients"

OBJECTIVES

To determine security and benefits of high pressure postdilatation (HPP) of bioresorbable vascular scaffolds (BVS) in percutaneous coronary intervention (PCI) of complex lesions whatever its indication is.

BACKGROUND

Acute scaffold disruption has been proposed as the main limitation of BVS when they are overexpanded. However, clinical implications of this disarray are not yet clear and more evidence is needed.

METHODS

A total of 25 BVS were deployed during PCI of 14 complex lesions after mandatory predilatation. In all cases HPP was performed with NC balloon in a 1:1 relation to the artery. After that, optical coherence tomography (OCT) analyses were performed.

RESULTS

Mean and maximal postdilatation pressure were 17±3.80 and 20 atmospheres (atm) respectively. Postdilatation balloon/scaffold diameter ratio was 1.01. A total of 39,590 struts were analyzed. Mean, minimal and maximal scaffold diameter were respectively: 3.09±0.34mm, 2.88±0.31mm and 3.31±0.40mm. Mean eccentricity index was 0.13±0.05. ISA percentage was 1.42% with a total of 564 malapposed struts. 89 struts were identified as disrupted, which represents a percentage of disrupted struts of 0.22%. At 30days, none of our patients died, suffered from stroke, stent thrombosis or needed target lesion revascularization (TLR).

CONCLUSIONS

NC balloon HPP of BVS at more than 17atm (up to 20atm) is safe during PCI and allows to achieve better angiographic and clinical results.

Bioresorbable vascular scaffolds-time to vanish?

The fully bioabsorbable vascular scaffold (BVS) has been developed to reduce late adverse events after coronary stenting such as device thrombosis. The device consists of polylactic acid, which is gradually absorbed within the first few years after its implantation. The initial experience with the device in low-risk patients presenting with simple lesions was satisfying and generated optimism among interventional cardiologists by promising better patient outcomes. However, the unrestricted use of the device in patients presenting with a higher baseline risk and more complex lesions came at the cost of alarmingly high rates of early device thrombosis. The performance of the device largely depends on an optimal implantation technique, which differs from that employed with metallic drug-eluting stents due to the device's distinct physical propensity. Mid-term outcomes in large-scale randomized clinical trial were disappointing. Although its non-inferiority compared to metallic everolimus-eluting stents was formally met, there was a clear trend towards an increased occurrence of myocardial infarction and device thrombosis during the first year after device implantation. However, the BVS's putative advantages are expected to manifest themselves at long-term, that is 3 to 5 years after the device has been implanted. Evidence pertaining to these long-term outcomes is eagerly awaited.

Bioresorbable vascular scaffolds in patients with acute myocardial infarction: a new step forward to optimized reperfusion?

Bioresorbable vascular scaffolds (BVS) represent a disruptive technology that has caused a new revolution in interventional cardiology. BVS appear to be particularly appealing in patients presenting with an acute myocardial infarction (MI). The available evidence on the value of BVS implantation in this challenging scenario is very promising but still limited. Results come from preliminary small observational studies, prospective registries that include a control group, and from scarce randomized clinical trials with surrogate mechanistic or angiographic primary end-points. Further studies, powered for clinical endpoints, are required to establish the relative safety and efficacy of BVS vs. new-generation metallic drug-eluting stents (DES) in patients with ST-segment elevation acute MI.