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

Safety and efficacy of new-generation coronary bioresorbable scaffolds

INTRODUCTION

The concept of bioresorbable scaffolds (BRS) was born with the aim to reduce the rate of late and very late cardiac events related to drug-eluting stents. However, first-generation BRS failed to prove their short-term safety and efficacy. Based on data derived from early investigations, new-generation BRS have been developed and tested in preliminary studies. The present review's focus was to summarize the mechanical characteristics of these new scaffolds and the clinical evidence of their safety and efficacy.

EVIDENCE ACQUISITION

This systematic review was performed following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). PUBMED, Google Scholar, and Biomed central databases were analyzed. Only papers published in English and in peer-reviewed journals were selected to summarize current evidence about new generation BRS, with CE mark approval. Overall, 23 studies were included.

EVIDENCE SYNTHESIS

Data obtained from selected studies assessing the safety and efficacy of new generation BRS are encouraging. This is thanks to the progressive development of scaffolds with a different backbone structure and struts thickness that guarantee higher radial strength, flexibility, and resistance to fracture. These characteristics led to low rates of major adverse cardiac events and device-oriented composite endpoint at follow-up.

CONCLUSIONS

New-generation BRS have a good safety profile in stable patients with simple lesions, supported by a meticulous implantation technique. The first studies were performed on a small population with short-term follow-up, therefore new randomized clinical trials and registries are needed to expand the preliminary findings.

Structural and Functional Evaluation of Coronary Arteries Treated With ABSORB Bioresorbable Vascular Scaffold at 5-Year Follow-Up

Although complete bioresorbable vascular scaffold (BVS) resorption has been demonstrated at 5-year follow-up, whether corresponding vasomotor function restoration occurs remains unknown. The objective was to simultaneously assess the structural healing response along with vasomotor responses at 5-year follow-up of BVS implantation. We studied consecutive patients treated with ABSORB-BVS at 5-year follow-up (n = 31), who were recruited from a multicenter registry and were contacted to undergo a research protocol-driven repeat coronary angiogram involving intracoronary optical coherence tomography (OCT) and invasive coronary endothelial function testing. Epicardial endothelium-dependent vasomotion was defined as any vasodilatation after intracoronary acetylcholine (ACh), whereas endothelium-independent vasomotion was defined as any vasodilatation after intracoronary nitroglycerine (NTG), using quantitative coronary angiography. The mean implantation time point was 60.5 ± 4.6 months. OCT imaging demonstrated complete scaffold resorption in all patients. New coronary lesions (stenosis >50%) were found in 5 patients (16.1%), 3 of them underwent ad hoc percutaneous revascularization (9.7%). Intracoronary ACh (27 patients) and NTG testing (30 patients) was performed. Quantitative coronary angiography analysis demonstrated vasoconstriction after ACh administration and lack of response to NTG in BVS segments (mean lumen diameter = 2.00 ± 0.61 mm at baseline vs 1.74 ± 0.70 mm post-ACh, p <0.001; 2.05 ± 0.54 mm at baseline vs 2.03 ± 0.50 mm post-NTG, p = 0.69). OCT lumen analysis demonstrated similar vasoconstrictive responses to ACh (mean lumen area = 5.31 ± 2.26 mm² at baseline vs 5.12 ± 2.55 mm² post-ACh, p = 0.007) but had a vasodilatory response to NTG (5.96 ± 2.35 mm² at baseline vs 6.17 ± 2.55 mm² post-NTG, p<0.001). In conclusion, complete ABSORB-BVS resorption was demonstrated at 5-year follow-up. However, this healing response was associated with endothelium-dependent vasomotor dysfunction within the BVS segment.

Effects of aggressive predilatation, sizing, and postdilatation strategy for coronary bioresorbable vascular scaffolds implantation

BACKGROUND

The results of the recent Amsterdam Investigator-Initiated Absorb Strategy All-Comers trial showed that the predilatation, sizing, and postdilatation (PSP) technique did not lower the long-term rates of scaffold thrombosis and adverse events. We evaluated the impact of aggressive PSP bioresorbable vascular scaffold (BRS) implantation on the short- and long-term clinical outcomes.

METHODS

From June 2014 to December 2016, 150 patients with BRS implantation were enrolled and received successful percutaneous coronary intervention (PCI), of whom 104 received aggressive PSP technique (high-pressure predilatation and lesion preparation in addition to the traditional PSP technique). Short- and long-term outcomes were compared.

RESULTS

All patients underwent successful PCI and BRS implantation with final Thrombolysis in Myocardial Infarction grade 3 flow. The baseline and procedure characteristics were similar in both groups. Debulking techniques were used in 13 (8.7%) patients. Intracoronary imaging modalities were used in 73 (48.7%) patients. After BRS implantation, no adverse events were observed within 30 days in both groups. During the mean follow-up period of 2.98 ± 0.77 years, 12 (8.0%) patients experienced major adverse cardiovascular events (MACEs), including one cardiovascular death (0.6%), three nonfatal myocardial infarction (2.0 %), and 11 target-vessel revascularization (7.3 %). Multivariate Cox regression analysis showed that aggressive PSP remained an independent protective factor for MACEs. Moreover, the use of intracoronary imaging and rotablation atherectomy was associated with better clinical outcomes.

CONCLUSION

Lesion preparation by aggressive PSP in BRS implantation was associated with better long-term clinical outcomes.

Long-term clinical outcomes of everolimus-eluting bioresorbable scaffolds versus everolimus-eluting stents: final five-year results of the AIDA randomised clinical trial

BACKGROUND

Absorb bioresorbable vascular scaffold (BVS)-related events have been reported between 1 and 3 years - the period of active scaffold bioresorption. Data on the performance of the Absorb BVS in daily clinical practice beyond this time point are scarce.

AIMS

This report aimed to provide the final five-year clinical follow-up of the Absorb BVS in comparison with the XIENCE everolimus-eluting stent (EES). In addition, we evaluated the effect of prolonged dual antiplatelet therapy (DAPT) administration on events in the scaffold group.

METHODS

AIDA was a multicentre, investigator-initiated, non-inferiority trial, in which 1,845 unselected patients with coronary artery disease were randomly assigned to either the Absorb BVS (n=924) or the XIENCE EES (n=921). Target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction or target vessel revascularisation, was the primary endpoint. Scaffold thrombosis cases were matched with controls and tested for the effect of prolonged DAPT.

RESULTS

Up to five-year follow-up, there was no difference in TVF between the Absorb BVS (17.7%) and the XIENCE EES (16.1%) (hazard ratio [HR] 1.31, 95% confidence interval [CI]: 0.90-1.41; p=0.302). Definite or probable device thrombosis (DT) occurred in 43 patients (4.8%) in the scaffold group compared to 13 patients (1.5%) in the stent group (HR 3.32, 95% CI: 1.78-6.17; p<0.001). DT between 3 and 4 years occurred six times in the Absorb arm versus three times in the XIENCE arm. Between 4 and 5 years, the incidence was three versus two, respectively. Of those three DT in the scaffold group, two occurred in XIENCE EES-treated lesions. The odds ratio of scaffold thrombosis in patients on DAPT compared to off DAPT throughout five-year follow-up was 0.36 (95% CI: 0.15-0.86).

CONCLUSIONS

The excess risk of the Absorb BVS on late adverse events, in particular device thrombosis, in routine PCI continues up to 4 years and seems to plateau afterwards. Clinical Trial Registration ClinicalTrials.gov: NCT01858077.

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

OBJECTIVES

To identify potential differences in 2-year outcome between patients who underwent coronary revascularization using bioresorbable vascular scafffolds (BVS) in stable coronary artery disease (CAD) and acute coronary syndromes (ACS).

BACKGROUND

Data from randomized trials suggest a significantly higher event rate following coronary revascularization using everolimus-eluting BVS as compared to new generation drug eluting stents. Whether particular patient subgroups are at increased risk for scaffold thrombosis and target lesion failure (TLF) has not clearly been demonstrated.

METHODS

German-Austrian ABSORB RegIstRy is a prospective all-comer multi-center observational study of consecutive patients who were considered for coronary revascularization with BVS. We compared 1499 patients with stable CAD to 1594 patients with ACS. Endpoints were major adverse cardiac events (MACE), TLF, and scaffold thrombosis.

RESULTS

While single vessel disease was more prevalent in ACS (46% vs. 37%, p < 0.0001), lesion complexity (B2/C stenosis 37% vs. 36%, bifurcation 2.4% vs. 3.4%, p < 0.05), number of implanted scaffolds/patient (1.34 vs. 1.43), scaffold length (18 vs. 18 mm) or the rate of high pressure postdilatation (68% vs. 70%) did not differ between ACS and stable CAD. Two-year MACE rates were 11.6% in ACS and 11.4% in stable CAD, TLF occurred in 7.0% versus 7.4% and target vessel revascularization in 8.8 versus 10.2% (n.s. for all). Definite scaffold thrombosis rates were not significantly different (ACS 1.9% vs. stable CAD 2.1%).

CONCLUSION

Real-world 2-year event rates after coronary revascularization with BVS are not significantly different between individuals with ACS as compared to stable CAD.

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

Background

In this prespecified AIDA‐trial sub‐study we investigate the clinical performance of absorb bioresorbable vascular scaffold (BVS) compared to Xience everolimus‐eluting stent (EES) in routine percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) at complete 3‐year follow‐up.

Methods and results

All 1,845 randomized patients were subdivided by medical history with DM or without DM. Of the 924 Absorb BVS patients, 171 (18.5%) patients had DM, of which 65 (38.0%) were treated with insulin (iTDM). Of the 921 Xience EES patients, 153 (16.6%) patients had DM, of which 45 (29.4%) were insulin‐treated diabetes mellitus (iTDM). Target vessel failure (TVF), composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization, occurred in 18.7% of diabetic patients treated with Absorb patients versus in 18.0% patients treated with Xience EES (p = .840). In nondiabetics the rates of TVF were 12.3% in Absorb BVS versus 11.0% in Xience EES (p = .391). Definite/probable device thrombosis occurred more frequently in Absorb BVS compared to Xience EES in both diabetic and nondiabetic patients (4.8% versus 0.7%; p = .028 and 3.2% vs. 0.5%; p < .001, respectively).

Conclusions

In routine PCI practice, both Absorb BVS and Xience EES have worse clinical outcomes in diabetic patients as compared to nondiabetic patients. Throughout all clinical presentations, Absorb BVS was associated with higher rates of device thrombosis at 3‐year follow‐up.

Advances in IVUS/OCT and Future Clinical Perspective of Novel Hybrid Catheter System in Coronary Imaging

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed and improved as both diagnostic and guidance tools for interventional procedures over the past three decades. IVUS has a resolution of 100 μm with a high tissue penetration and capability of assessing the entire structure of a coronary artery including the external elastic membrane, whereas OCT has a higher resolution of 10–20 μm to assess endoluminal structures with a limited tissue penetration compared to IVUS. Recently, two companies, CONAVI and TERUMO, integrated IVUS and OCT into a single catheter system. With their inherent strength and limitations, the combined IVUS and OCT probes are complementary and work synergistically to enable a comprehensive depiction of coronary artery. In this review, we summarize the performance of the two intracoronary imaging modalities—IVUS and OCT—and discuss the expected potential of the novel hybrid IVUS–OCT catheter system in the clinical field.

A paradox in sex-specific clinical outcomes after bioresorbable scaffold implantation: 2-year results from the AIDA trial

BACKGROUND

Females are underrepresented in clinical trials evaluating new stent technologies whilst results may differ between the sexes. Females are known to have smaller, more tortuous coronary arteries and have generally more comorbidities. On the other hand, they may have smaller plaque burden. This subgroup-analysis sought to assess sex-specific outcomes after Absorb bioresorbable vascular scaffold (BVS) or XIENCE everolimus-eluting stent (EES) implantation.

METHODS

The AIDA trial was an investigator-initiated, non-inferiority, all-comers trial, in which 1845 patients were randomly assigned to either Absorb BVS or XIENCE EES. Baseline clinical, angiography and procedural variables, as well as 2-year clinical outcomes were analyzed by sex and device modality.

RESULTS

Of the 1845 randomized patients, 475 (25.7%) were females. The 2-year rates of target vessel failure (TVF) with Absorb BVS versus XIENCE EES in females were 6.4% versus 10.6% (HR 0.59; 95% CI: 0.31-1.11; p = 0.10) and in males 12.7% versus 9.7% (HR 1.34; 95% CI: 0.98-1.85; p = 0.07). Males treated with Absorb BVS were at higher risk for TVF compared to females treated with Absorb BVS (HR 2.06; 95% CI 1.21-3.53; p = 0.007). Definite/probable device thrombosis occurred in females with Absorb BVS versus XIENCE EES in 1.6% versus 1.4% (HR 1.15; 95% CI: 0.26-5.12; p = 0.86) and in males 3.9% versus 0.7% (HR 5.55; 95% CI: 2.11-14.35; p < 0.001). A statistical significant interaction between sex and device was present for TVF (p = 0.02), but was not seen for definite/probable device thrombosis (p = 0.08).

CONCLUSIONS

In this subgroup analysis, Absorb BVS used in routine practice tends to result in better clinical outcomes in females compared to males.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSION

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

The influence of implantation techniques on lesion oriented-outcomes in Absorb BVS and Xience EES lesions treated in routine clinical practice at complete three year follow-up: AIDA trial QCA substudy

It has been hypothesized that dedicated optimized Absorb BVS implantation techniques might mitigate the risk of adverse events such as target vessel failure and device thrombosis. In this explorative AIDA trial QCA substudy, we sought to investigate the influence of implantation techniques on lesion-oriented outcomes in both the Absorb BVS and Xience EES arm at complete 3-year follow-up. The current analysis includes 2152 study lesions treated with at least one study device, of which the baseline angiogram was suited for offline QCA analysis, including Dmax analysis. The lesion-oriented composite outcome (LOCE) of this analysis was a composite of definite device thrombosis, target lesion revascularization and target-vessel myocardial infarction. In Absorb BVS, the Lesion-oriented composite endpoint (LOCE) occurred numerically less in correctly QCA sized vessels when compared to incorrectly sized vessels 8.5% (58/696) versus 11.1% (39/358), p = 0.151. In Xience EES, LOCE had occurred more frequently in incorrectly sized devices according to device diameter/RVD matching; 2.2% (4/187) in correctly sized devices versus 7.1% (63/911) in incorrectly sized devices (p = 0.014). In this AIDA trial QCA substudy, rates of LOCE were significantly lower in Xience EES treated lesions in which devices were correctly sized according to the definitions of device diameter/RVD matching.

The relationship of pre-procedural Dmax based sizing to lesion level outcomes in Absorb BVS and Xience EES treated patients in the AIDA trial

Due to expansion limits of the Absorb bioresorbable scaffold a meticulous implantation with correct sizing is required. We sought to investigate the clinical outcomes based on the sizing of the device related to the maximal lumen diameter measured by quantitative coronary angiography in Absorb BVS and Xience EES treated lesions in the AIDA trial. Sizing of Absorb bioresorbable vascular scaffold (BVS) and Xience everolimus eluting stent (EES) was graded according to the definitions of device non-oversize and device oversize on pre-procedural angiography. Lesion-oriented outcomes (LOCE) (device thrombosis, TLR and TVMI) that occurred during 2 years follow-up were related to device non-oversized or oversized status. In the Absorb BVS group, LOCE occurred in 48 (7.4%) lesions in the oversized group and in 32 (8.2%) lesions in the non-oversized group (HR 0.91; 95% CI 0.58-1.42; p = 0.681), whereas TLR occurred in 34 (5.3%) lesions and in 23 lesions (5.9%), respectively (HR 0.89; 95% CI 0.52-1.51; p = 0.666). Definite scaffold thrombosis occurred in 11 (1.7%) device oversized treated lesions against 16 (4.1%) device non-oversized treated lesions (HR 0.41; 95% CI 0.19-0.89; p = 0.020). There were no differences in event rates between oversized and non-oversized groups in lesions treated with Xience EES. There was no significant difference in LOCE between oversized and non-oversized treated Absorb BVS and Xience EES treated lesions. Non-oversized Absorb BVS implantation was associated with a higher risk of scaffold thrombosis at complete 2 years follow-up. The majority of very late scaffold thrombosis occurred in properly sized devices.