Angiographic and optical coherence tomography insights into bioresorbable scaffold thrombosis: single-center experience

Outcomes of the two generations of bioresorbable scaffolds (Magmaris vs. Absorb) in acute coronary syndrome in routine clinical practice

BACKGROUND

Acute coronary syndrome (ACS) as a clinical manifestation of coronary artery disease (CAD) remains a significant cause of mortality and morbidity, as reported worldwide annually. The second generation of drug-eluting stents (DES) is a gold standard in percutaneous interventions in ACS patients however, permanent caging of the vessel with metallic DES has some drawbacks. Bioresorbable vascular scaffolds (BRS) were designed as a temporal vessel-supporting technology allowing for anatomical and functional restoration. Nevertheless, following the initial encouraging reports, numerous concerns about the safety of BRS occurred.

METHODS

In this study, a 1-year performance of 193 patients with magnesium BRS - Magmaris (Biotronik, Berlin, Germany) was evaluated in comparison to 160 patients with polymer BRS - Absorb (Abbott-Vascular, Chicago, USA) in the non-ST-segment elevation-ACS setting.

RESULTS

The Magmaris, when compared to Absorb showed a significantly lower rate of primary endpoint (death from cardiac causes, myocardial infarction, stent thrombosis) as well as target lesion failure in 30-day and 1 year follow-up. In the Absorb group, a significantly higher rate of stent thrombosis was observed.

CONCLUSIONS

Data from the present study suggests encouraging safety a profile and more favorable clinical outcomes of Magnesium BRS in comparison to the polymer Absorb - BRS.

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.

Intravascular ultrasound predictors of long-term outcomes following ABSORB bioresorbable scaffold implantation: A pooled analysis of the ABSORB III and ABSORB Japan trials

BACKGROUND

The long-term prognostic impact of IVUS findings following Absorb BVS implantation remains uncertain. This study aimed to identify the IVUS predictors of long-term clinical outcomes following ABSORB bioresorbable vascular scaffold (BVS) implantation from the pooled IVUS substudy cohorts of the ABSORB III and Japan trials.

METHODS

A total of 298 lesions in 286 patients were enrolled with 2:1 randomization to ABSORB BVS vs. cobalt-chromium everolimus-eluting stents. This sub-analysis included 168 lesions of 160 patients in the Absorb arm whose post-procedural quantitative IVUS were available. The primary endpoint of this analysis was device-oriented composite endpoint (DOCE) of target lesion failure, including cardiac death, target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization. The median follow-up duration was 4.9 [3.1-5.0] years.

RESULTS

During follow-up, DOCE occurred in 10.1% of lesions treated with Absorb BVS. Among several post-procedural IVUS indices associated with DOCE, non-uniform device expansion (defined as uniformity index = minimum / maximum device area) (hazard ratio 0.47 per 0.1 increase [95%CI 0.28 to 0.77]; p = 0.003) and residual reference plaque burden (hazard ratio 4.01 per 10% increase [95%CI 1.50 to 10.77]; p = 0.006) were identified as independent predictors of DOCE by Cox multivariable analysis.

CONCLUSIONS

Nonuniform device expansion and substantial untreated residual plaque in reference segments were associated with long-term adverse events following BVS implantation. Baseline imaging to identify the appropriate device landing zone and procedural imaging to achieve uniform device expansion if possible (e.g. through post-dilatation) may improve clinical outcomes of BVS implantation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01751906 (ABSORB III); NCT01844284 (ABSORB Japan).

Scaffold underexpansion and late lumen loss after bioresorbable scaffold implantation: Insights from ABSORB JAPAN trial

Background

Device underexpansion is associated with late adverse outcomes after bioresorbable vascular scaffold (BVS) implantation. This study, representing official IVUS results of the ABSORB Japan trial, aimed to characterize IVUS findings, focusing specifically on acute device expansion, and to investigate its impact on late lumen loss (LLL) with Absorb-BVS compared with cobalt-chromium everolimus-eluting stents (CoCr-EES).

Methods

ABSORB Japan enrolled 148 patients (2:1 randomization) in the IVUS cohort. Serial IVUS was prescheduled at post-procedure and 3 years. Acute device expansion was evaluated with respect to the degree and uniformity of the implanted device.

Results

Overall, Absorb-BVS showed smaller and more nonuniform device expansion at post-procedure, compared with CoCr-EES, which was particularly prominent in small-vessel lesions. In serial analysis, Absorb-BVS showed unique associations of smaller device expansion (r = 0.40, p = 0.001) and more nonuniformity (r = 0.29, p = 0.007) at post-procedure with greater LLL at 3 years, primarily attributable to greater negative remodeling (r = 0.39, p = 0.006). In contrast, acute device expansion showed no relation with subsequent lumen change in CoCr-EES. In Absorb-BVS, ischemic-driven target lesion or vessel revascularization (ID-TLR or ID-TVR) at 3 years occurred more frequently in small- versus large-vessel lesions (12.5% vs. 0%, p = 0.04 for ID-TLR and 15.6% vs. 2.3%, p = 0.08 for ID-TVR). Conversely, Absorb BVS had no target lesion nor vessel failure, even in small-vessel lesions, when adequate device expansion was achieved at post-procedure.

Conclusions

Unlike CoCr-EES, underexpansion was associated with greater negative remodeling and LLL in Absorb-BVS. This may in part account for the poorer outcomes of Absorb-BVS than CoCr-EES when under-expanded.

Bioresorbable Vascular Scaffolds Versus Drug-Eluting Stents for Diffuse Long Coronary Narrowings

Clinical benefits of bioresorbable vascular scaffold (BVS) implantation for long coronary lesions were not sufficiently evaluated. The efficacy and safety of BVS and metallic everolimus-eluting stent (EES) were compared for the treatment of long coronary narrowings. A total of 341 patients with diffuse long lesions (requiring device length ≥28 mm) were randomized to receive either BVS (n = 171) or EES (n = 170) implantation. The primary endpoint was major adverse cardiovascular events which included death from cardiac cause, myocardial infarction, device thrombosis, or ischemia-driven target-lesion revascularization at 12 months. The trial was terminated early because the manufacturer stopped supplying BVS. The mean lesion length was 32.2 ± 13.1 mm in the BVS group and 35.3 ± 13.0 mm in the EES group. The 12-month follow-up was completed in 332 patients (97.4%). At 12 months, the primary endpoint events occurred in 2 patients (1.2%) in the BVS group and in 4 patients (2.4%) in the EES group (hazard ratio = 0.49, 95% confidence interval = 0.09 to 2.67, p = 0.398). Definite or probable device thrombosis occurred in 1 patient (0.6%) in the BVS group and 1 patient (0.6%) in the EES group (hazard ratio = 1.00, 95% confidence interval = 0.06 to 15.94, p = 0.998). In conclusion, in patients with long native coronary artery disease, significant differences between BVS and EES were not observed regarding the primary composite endpoint of death from cardiac cause, myocardial infarction, device thrombosis, or target-lesion revascularization at 12 months. However, due to the early termination of this trial and a low number of events, the results cannot be considered clinically relevant (clinicalTrials.gov Identifier: NCT02796157).

Comparison of the everolimus-eluting bioresorbable vascular scaffold versus the everolimus-eluting metallic stent in real-world patients with ST-segment elevation myocardial infarction

INTRODUCTION

Despite the withdrawal of the ABSORB bioresorbable vascular scaffold (BVS) from clinical use, continuous observation of BVS-treated patients is necessary. In the vast majority of clinical trials, patients with ST-segment elevation myocardial infarction (STEMI) were excluded from the analysis.

AIM

To compare the early and long-term outcomes of the BVS with the everolimus-eluting metallic stent (EES) in patients with STEMI.

MATERIAL AND METHODS

Consecutive patients treated with BVS or EES in our center were screened. For analysis, only patients with STEMI were enrolled. The primary endpoint was a comparison of the target lesion failure at 12 and 24 months. The secondary endpoints encompass occurrence of the patient-oriented cardiovascular endpoint (PoCE), stent thrombosis (ST), device, and procedural success.

RESULTS

Between 2012 and 2016, 2,137 patients were hospitalized for STEMI. Of these, 123 patients received the BVS (163 scaffolds; 151 lesions), whereas in 141 patients the EES (203 stents; 176 lesions) was implanted. The median follow-up was 931 ±514 days. The primary endpoint at 12 months occurred in 9.7% in the BVS group and in 8.5% in the EES group (hazard ratio (HR) = 2.61; 95% confidence interval (CI): 0.90-7.56; p = 0.076). At 24 months the incidence of the primary endpoint was 15.2% in the BVS group and 14.9% in the EES group (HR = 2.46; 95% CI: 0.85-7.07; p = 0.095). The rates of PoCE, ST, device, and procedural success were also comparable in both groups.

CONCLUSIONS

STEMI patients treated with the BVS showed statistically similar rates of primary and secondary endpoints compared with the EES.

Intracoronary Imaging for Assessment of Vascular Healing and Stent Follow-up in Bioresorbable Vascular Scaffolds

Bioresorbable Vascular Scaffolds (BVS) are polymer-based materials implanted in the coronary arteries in order to treat atherosclerotic lesions, based on the concept that once the lesion has been treated, the material of the implanted stent will undergo a process of gradual resorption that will leave, in several years, the vessel wall smooth, free of any foreign material and with its vasomotion restored. However, after the first enthusiastic reports on the efficacy of BVSs, the recently published trials demonstrated disappointing results regarding long-term patency following BVS implantation, which were mainly attributed to technical deficiencies during the stenting procedure. Intracoronary imaging could play a crucial role for helping the operator to correctly implant a BVS into the coronary artery, as well as providing relevant information in the follow-up period. This review aims to summarize the role of intracoronary imaging in the follow-up of coronary stents, with a particular emphasis on the role of intravascular ultrasound and optical coherence tomography for procedural guidance during stent implantation and also for follow-up of bioabsorbable scaffolds.

Optical Coherence Tomography for Coronary Bioresorbable Vascular Scaffold Implantation: A Randomized Controlled Trial

BACKGROUND

We investigated whether optical coherence tomography (OCT) guidance would reduce nonoptimal bioresorbable vascular scaffold (BVS) deployment.

METHODS

This was a randomized controlled trial. Patients who required percutaneous coronary intervention for ischemic heart disease were recruited from 2 centers in Korea. The enrolled patients were randomly assigned to receive either OCT-guided BVS (Absorb; Abbott Vascular) implantation or angiography-guided BVS implantation using an optimized technique. The primary outcome was nonoptimal deployment, which was a composite outcome of the following parameters assessed by OCT: a minimal scaffold area <5 mm², residual area stenosis >20%, incomplete apposition of the scaffold struts >5%, major edge dissection, or scaffold disruption. The secondary outcome was a procedural complication defined by the occurrence of no reflow, coronary perforation, or flow-limiting dissection.

RESULTS

Between September 2016 and January 2018, 88 patients (90 lesions) were assigned to OCT guidance, while 88 patients (89 lesions) were assigned to angiography guidance. The recruitment was prematurely terminated in March 2018 because the manufacturer stopped supplying BVS. Postprocedural OCT data were available for 88 lesions with OCT guidance and for 88 lesions with angiography guidance. There was nonoptimal BVS deployment postprocedurally in 35.2% of patients in the OCT-guidance group and in 38.6% in the angiography-guidance group (absolute difference, -3.7% [95% CI, -19.0% to 11.6%]; P=0.64). There were no procedural complications in either group.

CONCLUSIONS

OCT-guided BVS implantation did not reduce the incidence of nonoptimal deployment compared to that of angiography-guided BVS implantation (using optimized techniques).

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02894697.

Three-year clinical and two-year multimodality imaging outcomes of a thin-strut sirolimus-eluting bioresorbable vascular scaffold: MeRes-1 trial

AIMS

Although the proof of concept of the bioresorbable vascular scaffold (BRS) is well documented, device-related adverse outcomes with first-generation BRS indicate longer-term surveillance. The current study provides insights into the safety and performance of the MeRes100, a novel second-generation sirolimus-eluting BRS, beyond one-year up to three-year follow-up (FU).

METHODS AND RESULTS

A total of 108 enrolled patients with de novo coronary artery lesions who underwent implantation of MeRes100 as part of the first-in-human MeRes-1 trial were followed up clinically beyond one year at two and three years and with multiple modality imaging at six months and two years. At three-year FU, the cumulative major adverse cardiac events rate was 1.87%, in the form of two ischaemia-driven target lesion revascularisations. No scaffold thrombosis was reported. Between six months and two years at quantitative coronary angiography, in-segment late lumen loss (LLL) (0.15±0.22 mm vs. 0.23±0.32 mm; p=0.18) and in-scaffold LLL (0.13±0.22 mm vs. 0.24±0.34 mm; p=0.10) changed insignificantly. IVUS subset analysis revealed a non-significant reduction in mean lumen area (6.17±1.28 mm2 vs. 5.47±1.50 mm2; p=0.21) and minimum lumen area (5.14±1.19 mm2 vs. 4.05±1.42 mm2; p=0.10) at two years compared to post-procedural measurements. OCT subset analysis demonstrated 99.24±2.27% neointimal strut coverage.

CONCLUSIONS

The extended outcomes of the MeRes-1 trial demonstrated sustained efficacy and safety of the MeRes100 BRS with maintained lumen patency up to two years by multimodality imaging and no very late scaffold thrombosis up to three-year clinical FU.The MeRes-1 trial is registered at the Clinical Trials Registry-India. CTRI Number: CTRI/2015/04/005706.

Everolimus- vs. novolimus-eluting bioresorbable scaffolds in patients with acute coronary syndrome

BACKGROUND

Limited data exist on bioresorbable scaffolds (BRS) in patients with acute coronary syndrome (ACS). The aim of the present study was to evaluate novolimus-eluting BRS (DESolve) as interventional treatment for patients with ACS, and to compare its 12-month outcomes with the everolimus-eluting bioresorbable scaffolds (Absorb).

METHODS

In this retrospective study, patients with ACS (including unstable angina pectoris, ST-segment elevation myocardial infarction, or non-ST-segment elevation myocardial infarction) treated with either the Absorb or the DESolve BRS were evaluated in a 1:1 matched-pair analysis. Major adverse cardiac events (MACE), including death, myocardial infarction, and target lesion revascularization, were evaluated as a major endpoint. The occurrence of scaffold thrombosis was also assessed.

RESULTS

A total of 102 patients were eligible for this analysis. The rate of MACE at 12 months was comparable between the Absorb and the DESolve group (8.3% vs. 6.8%, p = 0.738). The occurrence of target lesion revascularization (6.2% vs. 4.7%; p = 0.700) and scaffold thrombosis (4.1% vs. 2.1%; p = 0.580) was comparable as well. All instances of scaffold thrombosis occurred within 30 days of the index procedure.

CONCLUSION

In this study, similar 12-month event rates were observed for both BRS types after implantation for the treatment of ACS.

Procedural findings and early healing response after implantation of a self-apposing bioresorbable scaffold in coronary bifurcation lesions

We aimed to evaluate feasibility, early healing and self-correcting properties of the Desolve 150 bioresorbable scaffold (BRS) implanted in bifurcation lesions, using the simple, provisional side branch (SB) stenting technique. BIFSORB pilot was a proof-of-concept study enrolling 10 patients with stable angina pectoris and a bifurcation lesion with SB ≥ 2.5 mm and less than 50% diameter stenosis. Procedure and 1-month outcome was evaluated by optical coherence tomography (OCT) to assess scaffold performance and healing patterns. Nine patients were treated with Desolve 150 BRS and one delivery to the target bifurcation failed. Thrombus formation in the jailed SB ostium was seen in three cases, but was completely resolved at 1-month. OCT confirmed acute self-correcting properties. No clinical events were reported after six months. Scaffold diameter by OCT increased in the proximal main vessel from 3.09 ± 0.16 mm to 3.34 ± 0.18 mm (p = 0.01) and in distal main vessel from 2.82 ± 0.26 mm to 3.02 ± 0.29 mm (p < 0.01) at one-month follow-up. SB ostial diameter stenosis improved from 42 ± 15% to 34 ± 12% (p = 0.01). Malapposition was effectively reduced after 1 month from 4.1 (1.4; 6.1)% to 0.1 (0; 0.6)% (p = 0.002). Treatment of bifurcation lesions using Desolve 150 BRS was feasible except for a delivery failure and unsettling thrombus formation behind jailing SB struts, which was completely resolved at 1-month. Self-correcting and even self-expanding properties were confirmed.

Long-term safety of bioresorbable scaffolds: insights from a network meta-analysis including 91 trials

AIMS

The aim of this study was to investigate the long-term safety and efficacy of biodegradable scaffolds and metallic stents.

METHODS AND RESULTS

We analysed a total of 91 randomised controlled trials with a mean follow-up of 3.7 years in 105,842 patients which compared two or more coronary metallic stents or biodegradable scaffolds and reported the long-term clinical outcomes (≥2 years). Network meta-analysis showed that patients treated with the Absorb bioresorbable vascular scaffold (BVS) had a significantly higher risk of definite or probable scaffold thrombosis (ScT) compared to those treated with metallic DES. The risk of very late ScT was highest with the Absorb BVS among comparators. Pairwise conventional meta-analysis demonstrated that the elevated risk of ScT with Absorb BVS compared to cobalt-chromium everolimus-eluting stents was consistent across the time points of ≤30 days (early), 31 days - 1 year (late) and >1 year (very late) ScT. In addition, target lesion failure rates were significantly higher in the Absorb BVS cohort, driven by both increased risk of target vessel myocardial infarction and ischaemia-driven target lesion revascularisation.

CONCLUSIONS

Absorb BVS implantation was associated with increased risk of long-term and very late ScT compared to current-generation metallic DES. The risk of ScT occurred with a rising trend beyond one year.

Clinical outcomes of bioresorbable vascular scaffolds implanted with routine versus selective optical coherence tomography guidance: results from a single-centre experience

AIMS

We aimed to investigate the effects of an initial learning period with mandatory optical coherence tomography (OCT) guidance for the implantation of everolimus-eluting bioresorbable vascular scaffolds (BVS).

METHODS AND RESULTS

We analysed procedural and clinical outcomes of all BVS implantations at a single centre where OCT guidance was mandatory in the initial rollout (OCT-mandatory) phase. We compared these data with the later phase where use of OCT was at operator discretion (OCT-selective or angiography). We implanted 406 BVS in 306 vessels (201 OCT, 105 angiography) in 272 patients. Follow-up duration was 38±10 months. Annualised rates of device-oriented cardiac events (DOCE) and scaffold thrombosis (ScT) were 1.4% and 0.4%, respectively. The risks of DOCE (HR 1.06, 95% CI: 0.33-3.34; p=0.71) and ScT (HR 0.48, 95% CI: 0.07-3.85; p=0.49) were not significantly different when comparing the OCT and angiography groups.

CONCLUSIONS

Routine use of OCT to guide and optimise BVS implants results in very acceptable outcomes. Further, the benefits of such an early OCT-mandatory "learning" period persist after cessation of routine OCT usage when imaging is not routinely used. A period of mandatory OCT usage for BVS implants may therefore be beneficial in improving patient outcomes with these devices.

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

Background

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

Methods

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

Results

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

Conclusion

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

Trial registration NTR5447. Registered 05 October 2015, retrospectively registered

Long-term follow-up of BVS from a prospective multicenter registry: Impact of a dedicated implantation technique on clinical outcomes

OBJECTIVES

The aim of this study was to evaluate the impact of a consistent and dedicated implantation strategy on long-term outcomes after implantation of bioresorbable vascular scaffold (BVS) in a real-world cohort of patients with a high prevalence of complex lesions.

BACKGROUND

Bioresorbable vascular scaffolds may result in a reduced incidence of late and very-late scaffold thrombosis (ScT) after the complete reabsorption of the scaffold, but this hypothesis is hampered by data from RCTs that showed a higher than expected incidence of late events. However, these studies did not adopt a dedicated implantation technique, that proved to be fundamental in reducing the incidence of adverse events.

METHODS

573 consecutive patients (912 lesions) treated with bioresorbable scaffolds between May 2012 and December 2014 were enrolled in 3 high-volume centers that used a dedicated implantation strategy from the beginning. Primary endpoints were target-lesion failure (TLF) and definite and probable ScT. Secondary endpoints included myocardial infarction, target-lesion and target-vessel revascularization.

RESULTS

The registry enrolled a high complexity subset of lesions (69.4% of type B2 or C lesions; 10.3% of severe calcific lesions; 26.1% of bifurcations). Predilatation was performed in almost all cases (99.2%); intracoronary imaging was liberally adopted (37.3%). Mean scaffold length was 42.9 ± 27.4 mm per patient, and post-dilation with a 1:1 high-pressure (22 ± 3.5 atm) balloon was performed in 99.9% of lesions. Median follow-up (available for 98.6% of patients) was 981 days (IQR 802-1133). Overall incidence of ScT was reassuringly low: three thrombotic events occurred during the first year (0.5%), while only one event ensued in the second year of follow-up, and ScT rate remained stable thereafter up to the fourth year (0.7%). Cumulative TLF rates at 1, 2, 3 and 4 years were 3.0%, 6.0%, 7.8% and 12.2%.

CONCLUSIONS

These long-term results from a complex "real-world" population appear to be reassuring as regards to the incidence of ScT and TLF when BVS are implanted by experienced operators with a dedicated implantation technique.

Appropriate use criteria for optical coherence tomography guidance in percutaneous coronary interventions : Recommendations of the working group of interventional cardiology of the Netherlands Society of Cardiology

Introduction

Optical coherence tomography (OCT) enables detailed imaging of the coronary wall, lumen and intracoronary implanted devices. Responding to the lack of specific appropriate use criteria (AUC) for this technique, we conducted a literature review and a procedure for appropriate use criteria.

Methods

Twenty-one of all 184 members of the Dutch Working Group on Interventional Cardiology agreed to evaluate 49 pre-specified cases. During a meeting, factual indications were established whereupon members individually rated indications on a 9-point scale, with the opportunity to substantiate their scoring.

Results

Twenty-six indications were rated ‘Appropriate’, eighteen indications ‘May be appropriate’, and five ‘Rarely appropriate’. Use of OCT was unanimously considered ‘Appropriate’ in stent thrombosis, and ‘Appropriate’ for guidance in PCI, especially in distal left main coronary artery and proximal left anterior descending coronary artery, unexplained angiographic abnormalities, and use of bioresorbable vascular scaffold (BVS). OCT was considered ‘Rarely Appropriate’ on top of fractional flow reserve (FFR) for treatment indication, assessment of strut coverage, bypass anastomoses or assessment of proximal left main coronary artery.

Conclusions

The use of OCT in stent thrombosis is unanimously considered ‘Appropriate’ by these experts. Varying degrees of consensus exists on the appropriate use of OCT in other settings.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1143-z) contains supplementary material, which is available to authorized users.

Optical coherence tomographic analysis of drug-eluting in-stent restenosis at different times: A STROBE compliant study

The imaging characteristics of drug-eluting in-stent restenosis (ISR) at different times varied; however, the mechanism had not yet been elucidated.To analyze the imaging characteristics of drug-eluting ISR at different time points by optical coherence tomography (OCT) and investigate the cause of the stent treatment failure.A total of 70 patients with drug-eluting ISR undergoing OCT were enrolled (intimal hyperplasia ≥50% of stent area) and implanted with drug-eluting stents. According to stent implantation time, the patients were divided into 2 groups: early in-stent restenosis group (E-ISR group) (group A, n = 35, stent age ≤12 months) and late in-stent restenosis group (L-ISR group) (group B, n = 35, stent age ≥24 months). A qualitative analysis of the restenosis tissue included the nature of restenosis tissue (homogeneous and heterogeneous), neoatherosclerosis, thin-cap fibroatheroma (TCFA), and microvessels.The ratio of ≥75% cross-sectional area stenosis between the L-ISR and E-ISR groups was (60.00% vs 34.28%, P < .05). The heterogeneous intima, neoatherosclerosis, TCFA, and microvessels were more prevalent in the L-ISR group as compared to the E-ISR group (71.43% vs 45.71%, P < .05; 48.57% vs 22.86%, P < .05; 25.71% vs 5.71%, P < .05; 22.86% vs 2.86%, P < .05, respectively).The morphological characteristics of L-ISR were significantly different from those in the E-ISR; the former was closer to the atherosclerotic plaque, which provided a new approach for the treatment of drug-eluting ISR.

Local Flow Patterns After Implantation of Bioresorbable Vascular Scaffold in Coronary Bifurcations - Novel Findings by Computational Fluid Dynamics

BACKGROUND

Development of methods for accurate reconstruction of bioresorbable scaffolds (BRS) and assessing local hemodynamics is crucial for investigation of vascular healing after BRS implantation.Methods and Results:Patients with BRS that crossed over in a coronary bifurcation were included for analysis. Reconstructions of the coronary lumen and BRS were performed by fusion of optical coherence tomography and coronary angiography generating a tree model (TM) and a hybrid model with BRS (TM-BRS). A virtual BRS model with thinner struts was created and all 3 models were analyzed using computational fluid dynamics to derive: (1) time-average shear stress (TASS), (2) TASS gradient (TASSG), which represents SS heterogeneity, and (3) fractional flow reserve (FFR). Reconstruction of the BRS was successful in all 10 patients. TASS and TASSG were both higher by TM-BRS than by TM in main vessels (difference 0.27±4.30 Pa and 10.18±27.28 Pa/mm, P<0.001), with a remarkable difference at side branch ostia (difference 13.51±17.40 Pa and 81.65±105.19 Pa/mm, P<0.001). With thinner struts, TASS was lower on the strut surface but higher at the inter-strut zones, whereas TASSG was lower in both regions (P<0.001 for all). Computational FFR was lower by TM-BRS than by TM for both main vessels and side branches (P<0.001).

CONCLUSIONS

Neglecting BRS reconstruction leads to significantly lower SS and SS heterogeneity, which is most pronounced at side branch ostia. Thinner struts can marginally reduce SS heterogeneity.

Association of stent-induced changes in coronary geometry with late stent failure: Insights from three-dimensional quantitative coronary angiographic analysis

BACKGROUND

The relationship between vessel angulation and large changes in vessel geometry after stent implantation and the occurrence of stent failure still remains unclear. We sought to investigate the association of the change in the coronary bending angle after stenting and the risk for late stent failure by three-dimensional quantitative coronary angiography (3D QCA).

METHODS

The bending angle in coronary lesions that presented with late stent failure and those without stent failure was computed during the cardiac cycle, before and after stenting using a recently developed 3D QCA software.

RESULTS

A total of 40 lesions with stent failure (cases) were successfully matched to 47 lesions without stent failure (controls).The mean duration to follow-up coronary angiography was 1,011 days in cases and 1,109 days in the control group (P = 0.14). In stent failure, the systolic bending angle after stenting was smaller (14.45° [12.18, 17.68] versus 18.20° [14.00, 20.30], P = 0.01), while the stent-induced change in systolic bending angle was significantly larger (4.15° [1.13, 7.20] versus 1.80° [-1.90, 4.40], P = 0.004). Multivariable logistic regression analysis suggested that systolic bending angle after stenting (odds ratio: 0.88; 95% CI: 0.79-0.99; P = 0.03), and decrease in systolic bending angle after stenting (odds ratio: 1.13; 95% CI: 1.02-1.26; P = 0.03) were predictors of stent failure.

CONCLUSIONS

Our study suggests that a change in the natural tortuous course of the coronaries by stent implantation with the decrease in coronary bending angle is a potentially major contributor in stent failure.

Impact of calcium on procedural and clinical outcomes in lesions treated with bioresorbable vascular scaffolds - A prospective BRS registry study

BACKGROUND

There is limited data on the impact of calcium (Ca) on acute procedural and clinical outcomes in patients with lesions treated with bioresorbable vascular scaffolds (BRS). We sought to evaluate the effect of calcium on procedural and clinical outcomes in a 'real world' population.

METHODS

Clinical outcomes were compared between patients with at least 1 moderately or heavily calcified lesion (Ca) and patients with no/mild calcified lesions (non-Ca) enrolled in our institutional BRS registry.

RESULTS

455 patients (N) with 548 lesions (L) treated with 735 BRS were studied. Patients in the Ca group (N=160, L=200) had more complex (AHA B2/C lesion: 69.0% in Ca vs 14.9% in non-Ca, p<0.001) and significantly longer lesions (27.80±15.27 vs 19.48±9.92mm, p<0.001). Overall device success rate was 99.1% with no significant differences between the groups. Despite more aggressive lesion preparation and postdilation compared to non Ca, acute lumen gain was significantly less in Ca lesions (1.50±0.66 vs 1.62±0.69mm, p=0.040) with lower final MLD (2.28±0.41 vs 2.36±0.43, p=0.046). There were no significant differences in all-cause mortality, total definite scaffold thrombosis (ST), target lesion revascularization and myocardial infarction between the 2 groups. Late ST was more frequent in the Ca group compared to non Ca group (late ST: 2.1 vs 0%, p=0.02).

CONCLUSIONS

Clinical outcomes after BRS implantation in calcified and non-calcified lesions were similar. A remarkable difference in timing of thrombosis was observed, with an increased rate of late thrombosis in calcified lesions.

"Bringing on the light" in a complex clinical scenario: Optical coherence tomography-guided discontinuation of antiplatelet therapy in cancer patients with coronary artery disease (PROTECT-OCT registry)

BACKGROUND

Cancer patients with recently placed drug-eluting stents (DESs) often require premature dual antiplatelet therapy (DAPT) discontinuation for cancer-related procedures. Optical coherence tomography (OCT) can identify risk factors for stent thrombosis such as stent malapposition, incomplete strut coverage and in-stent restenosis and may help guide discontinuation of DAPT.

METHODS

We conducted a single-center prospective study in cancer patients with recently placed (1-12 months) DES who required premature DAPT discontinuation. Patients were evaluated with diagnostic coronary angiogram and OCT. Individuals with appropriate stent strut coverage, expansion, apposition, and absence of in-stent restenosis or intraluminal masses were considered low risk and transiently discontinued DAPT to allow optimal cancer therapy. Patients who did not meet all these criteria were considered high risk and underwent further endovascular treatment when appropriate and bridging with low-molecular weight heparin. The incidence of adverse cardiovascular events was assessed after the procedure and at 12 months.

RESULTS

A total of 40 patients were included. Twenty-seven patients (68%) were considered low risk by OCT criteria and DAPT was transiently discontinued. Thirteen patients (32%) were considered high risk with one or more OCT findings: uncovered stent struts (4 patients, 10%); stent underexpansion (3 patients, 8%); malapposition (8 patients, 20%); in-stent restenosis (2 patients, 5%). The high-risk patients with uncovered stent struts and malapposition underwent additional stent dilatation. There were no cardiovascular events in the low-risk group. One myocardial infarction occurred in the high-risk group. Fourteen non-cardiac deaths were registered before 12 months due to cancer progression or cancer therapy.

CONCLUSION

OCT imaging allows identification of low-risk cancer patients with DES placed who may safely discontinue DAPT and proceed with cancer-related surgery or procedures.

Thirty-Day and One-Year Clinical Outcomes of Bioresorbable Vascular Scaffold Implantation: A Single-Center Experience

Background

Available data on the use of the Bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, CA) in real-world patients is limited, particularly in Asian populations. The aim of this study was to assess clinical outcomes of patients treated with a BVS in real-world practice in Taiwan.

Methods

This study focused on 156 patients with coronary artery disease and a total of 249 lesions who received BVS implantation from October 2012 to October 2015. The study's primary endpoint was major adverse cardiac event (MACE), such as a myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), definite or possible scaffold thrombosis, cardiovascular death, and all-cause mortality during the thirty-day follow-up period. The secondary endpoint was MACE during the one-year follow-up period. Additionally, the composite clinical secondary endpoint was target lesion failure (TLF), which was called device-oriented composite endpoint.

Results

The average age of the patients was 60.34 ± 10.15 years, and 81.4% were male. The average of Syntax score was 12.42 ± 8.77 points. 44.2 % lesions were type B2 or C. At 31 days, one patient experienced a MACE (1/156) the composite of two TLF (2/249) with ST elevation MI, which was related to scaffold thrombosis. At one-year, 5.1 % (8/156) of the patients experienced a MACE and 3.6% (9/249) of the lesions experienced a TLF. There was no cardiovascular or all-cause mortality in the 30-day follow-up. The one-year cardiovascular and all-cause mortality rates were each 1.3%, respectively. Diabetes, ostial lesion, bifurcation lesion, and non-standard dual anti-platelet therapy (DAPT) were the strong associations of one-year TLF.

Conclusions

Even with difficult and complex lesions of patients in this study, acceptable outcomes were achieved with low definite or possible scaffold thrombosis rates after BVS implantation. And despite anatomical issues, it is important to complete standard DAPT.

Automated Segmentation of Bioresorbable Vascular Scaffold Struts in Intracoronary Optical Coherence Tomography Images

Bioresorbable vascular scaffolds (BVS), the next step in the continuum of minimally invasive vascular interventions present new opportunities for patients and clinicians but challenges as well. As they are comprised of polymeric materials standard imaging is challenging. This is especially problematic as modalities like optical coherence tomography (OCT) become more prevalent in cardiology. OCT, a light-based intracoronary imaging technique, provides cross-sectional images of plaque and luminal morphology. Until recently segmentation of OCT images for BVS struts was performed manually by experts. However, this process is time consuming and not tractable for large amounts of patient data. Several automated methods exist to segment metallic stents, which do not apply to the newer BVS. Given this current limitation coupled with the emerging popularity of the BVS technology, it is crucial to develop an automated methodology to segment BVS struts in OCT images. The objective of this paper is to develop a novel BVS strut detection method in intracoronary OCT images. First, we preprocess the image to remove imaging artifacts. Then, we use a K-means clustering algorithm to automatically segment the image. Finally, we isolate the stent struts from the rest of the image. The accuracy of the proposed method was evaluated using expert estimations on 658 annotated images acquired from 7 patients at the time of coronary arterial interventions. Our proposed methodology has a positive predictive value of 0.93, a Pearson Correlation coefficient of 0.94, and a F1 score of 0.92. The proposed methodology allows for rapid, accurate, and fully automated segmentation of BVS struts in OCT images.

Hybrid Percutaneous Coronary Intervention With Bioresorbable Vascular Scaffolds in Combination With Drug-Eluting Stents or Drug-Coated Balloons for Complex Coronary Lesions

Bioresorbable vascular scaffolds (BVS) have become an attractive option in the percutaneous coronary intervention field due to the potential advantages associated with the complete resorption process that occurs within a few years. However, current-generation BVS have several limitations including thicker struts, reduced radial strength, and limited expansion capability when compared with drug-eluting stents (DES). As a result, complex coronary disease often contains BVS-inappropriate/unfavorable segments. This does not necessarily mean that BVS use must be completely avoided, and minimizing the length of permanent metallic caging may still be advantageous. Operators should fully understand the limitations of current BVS, and when to consider a hybrid strategy of BVS in combination with DES or drug-coated balloons.

Antiplatelet Therapy After Implantation of Bioresorbable Vascular Scaffolds: A Review of the Published Data, Practical Recommendations, and Future Directions

The introduction of bioresorbable vascular scaffolds (BVS) for clinical use has raised a number of questions on whether current dual-antiplatelet therapy (DAPT) recommendations after drug-eluting stent (DES) implantation, mostly deriving from data on second-generation DES, are also applicable to this completely different technology. This article aims to review the technical shortcomings of BVS-the most extensively studied fully bioresorbable coronary stent-and its contemporary rates of scaffold thrombosis, with a focus on recommendations for DAPT duration.

Evaluation of potential substrates for restenosis and thrombosis in overlapped versus edge-to-edge juxtaposed bioabsorbable scaffolds: Insights from a computed fluid dynamic study

BACKGROUND/PURPOSE

Multiple BRSs and specifically the Absorb scaffold (BVS) (Abbott Vascular, Santa Clara, CA USA) have been often used to treat long diffuse coronary artery lesions. We evaluate by a computational fluid dynamic(CFD) study the impact on the intravascular fluid rheology on multiple bioabsorbable scaffolds (BRS) by standard overlapping versus edge-to-edge technique.

METHODS/MATERIALS

We simulated the treatment of a real long significant coronary lesion (>70% luminal narrowing) involving the left anterior descending artery (LAD) treated with a standard or edge-to-edge technique, respectively. Simulations were performed after BVS implantations in two different conditions: 1) Edge-to-edge technique, where the scaffolds are kissed but not overlapped resulting in a luminal encroachment of 0.015cm (150μm); 2) Standard overlapping, where the scaffolds are overlapped resulting in a luminal encroachment of 0.030cm (300μm). After positioning the BVS across the long lesion, the implantation procedure was performed in-silico following all the usual procedural steps.

RESULTS

Analysis of the wall shear stress (WSS) suggested that at the vessel wall level the WSS were lower in the overlapping zones overlapping compared to the edge-to-edge zone (∆=0.061Pa, p=0.01). At the struts level the difference between the two WSS was more striking (∆=1.065e-004 p=0.01) favouring the edge-to-edge zone.

CONCLUSIONS

Our study suggested that at both vessel wall and scaffold struts levels, there was lowering WSS when multiple BVS were implanted with the standard overlapping technique compared to the "edge-to-edge" technique. This lower WSS might represent a substrate for restenosis, early and late BVS thrombosis, potentially explaining at least in part the recent evidences of devices poor performance.

Everolimus-eluting bioresorbable vascular scaffold in daily clinical practice: A single-centre experience

Background

Recent evidence has raised concerns regarding the safety of the everolimus-eluting bioresorbable vascular scaffold (E-BVS) (Absorb, Abbott Vascular, Santa Clara, CA, USA). Following these data, the use of this device has diminished in the Netherlands; however, daily practice data are limited. Therefore we studied the incidence of safety and efficacy outcomes with this device in daily clinical practice in a single large tertiary centre in the Netherlands.

Methods

All E‑BVS treated patients were included in this analysis. The primary endpoint was target lesion failure (TLF), a composite of cardiac death, target vessel non-fatal myocardial infarction (TV-MI) and clinically-driven target lesion revascularisation (TLR). The secondary endpoint was the incidence of definite scaffold thrombosis.

Results

Between October 2013 and January 2017, 105 patients were treated with 147 E‑BVS. This population contained 42 (40%) patients with diabetes mellitus and 43 (40.9%) undergoing treatment for acute coronary syndrome, and thus represents a high-risk patient cohort. Mean follow-up was 19.8 months. Intravascular imaging guidance during scaffold implantation was used in 64/105 (43.5%) patients. The primary endpoint (TLF) occurred in 3 (2.9%) patients. All-cause mortality and cardiac mortality occurred in 2 (2%) and 0 (0%) patients respectively. TV-MI occurred in 2 patients (1.9%): both were periprocedural and not related to the BVS implantation. TLR occurred in 1 patient (1.0%) during follow-up. No definite scaffold thrombosis occurred during follow-up.

Conclusion

This single-centre study examining the real-world experience of E‑BVS implantation in a high-risk population shows excellent procedural safety and long-term clinical outcomes.

Neoatherosclerosis development following bioresorbable vascular scaffold implantation in diabetic and non-diabetic swine

Background

DM remains a risk factor for poor outcome after stent-implantation, but little is known if and how DM affects the vascular response to BVS.

Aim

The aim of our study was to examine coronary responses to bioresorbable vascular scaffolds (BVS) in swine with and without diabetes mellitus fed a ‘fast-food’ diet (FF-DM and FF-NDM, respectively) by sequential optical coherence tomography (OCT)-imaging and histology.

Methods

Fifteen male swine were evaluated. Eight received streptozotocin-injection to induce DM. After 9 months (M), 32 single BVS were implanted in epicardial arteries with a stent to artery (S/A)-ratio of 1.1:1 under quantitative coronary angiography (QCA) and OCT guidance. Lumen, scaffold, neointimal coverage and composition were assessed by QCA, OCT and near-infrared spectroscopy (NIRS) pre- and/or post-procedure, at 3M and 6M. Additionally, polarization-sensitive (PS)-OCT was performed in 7 swine at 6M. After sacrifice at 3M and 6M, histology and polymer degradation analysis were performed.

Results

Late lumen loss was high (~60%) within the first 3M after BVS-implantation (P<0.01 FF-DM vs. FF-NDM) and stabilized between 3M and 6M (<5% change in FF-DM, ~10% in FF-NDM; P>0.20). Neointimal coverage was highly heterogeneous in all swine (DM vs. NDM P>0.05), with focal lipid accumulation, irregular collagen distribution and neointimal calcification. Likewise, polymer mass loss was low (~2% at 3M, ~5% at 6M;P>0.20) and not associated with DM or inflammation.

Conclusion

Scaffold coverage showed signs of neo-atherosclerosis in all FF-DM and FF-NDM swine, scaffold polymer was preserved and the vascular response to BVS was not influenced by diabetes.

Intravascular imaging in coronary artery disease

Although it is the method used by most interventional cardiologists to assess the severity of coronary artery disease and guide treatment, coronary angiography has many known limitations, particularly the fact that it is a lumenogram depicting foreshortened, shadowgraph, planar projections of the contrast-filled lumen rather than imaging the diseased vessel itself. Intravascular imaging-intravascular ultrasound and more recently optical coherence tomography-provide a tomographical or cross-sectional image of the coronary arteries. These techniques are clinically useful to answer questions such as whether the stenosis is clinically relevant; the identification of the culprit lesion; or whether the plaque (or patient) is at high risk of future adverse events. They can also be used to optimise stent implantation to minimise stent-related adverse events, provide answers to the likelihood of distal embolisation or peri-procedural myocardial infarction during stent implantation, and provide reasons for stent thrombosis or restenosis. This review considers the usefulness of intravascular imaging in day-to-day practice.

Randomised comparison of a bioresorbable everolimus-eluting scaffold with a metallic everolimus-eluting stent for ischaemic heart disease caused by de novo native coronary artery lesions: the 2-year clinical outcomes of the ABSORB II trial

AIMS

The one-year randomised data of the ABSORB II trial showed that the everolimus-eluting bioresorbable scaffold and the everolimus-eluting metallic stent were comparable for the composite secondary clinical outcomes of patient-oriented composite endpoint (PoCE) and device-oriented composite endpoint (DoCE)/target lesion failure (TLF), MACE and TVF. This report describes the two-year clinical outcomes of the ABSORB II trial.

METHODS AND RESULTS

Patients were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting bioresorbable scaffold (Absorb; Abbott Vascular, Santa Clara, CA, USA) or treatment with an everolimus-eluting metallic stent (XIENCE; Abbott Vascular). The trial enrolled 501 patients. Clinical follow-up at two years was available in 320 patients in the Absorb BVS arm and 160 patients in the XIENCE arm. At two years, the PoCE for the Absorb and XIENCE arms was 11.6% and 12.8% (p=0.70) and the DoCE/TLF was 7.0% and 3.0% (p=0.07), respectively. The hierarchical ID-MACE rate was 7.6% vs. 4.3% (p=0.16) and the rate of TVF was 8.5% vs. 6.7% (p=0.48). The definite/probable thrombosis rate was 1.5% in the Absorb arm vs. 0% in the XIENCE arm (p=0.17). Thirty-six percent and 34% of patients remained on DAPT at two years, respectively. Ninety-two percent of patients in both arms remained on aspirin.

CONCLUSIONS

Two-year clinical results demonstrate sustained low rates of PoCE, MACE, DoCE and TVF with the Absorb BVS as compared to the XIENCE stent.

Mid-term and long-term safety and efficacy of bioresorbable vascular scaffolds versus metallic everolimus-eluting stents in coronary artery disease: A weighted meta-analysis of seven randomised controlled trials including 5577 patients

AIMS

Mid- and long-term safety and efficacy of the Absorb bioresorbable vascular scaffold (BVS) have been studied in randomised trials; however, most were not individually powered for clinical endpoints. We performed a weighted meta-analysis comparing mid- and long-term outcomes in patients treated with the BVS compared with the Xience metallic stent.

METHODS AND RESULTS

Randomised trials comparing the BVS and Xience were identified by searching MEDLINE, EMBASE and conference abstracts. Seven trials were included (BVS n = 3258, Xience n = 2319) with follow-up between 1-3 years. The primary outcome of target lesion failure occurred more frequently in BVS compared with Xience [OR 1.34; 95% CI 1.11-1.62, p = 0.003]. Overall definite or probable device thrombosis occurred more frequently with the BVS [OR 2.86; 95% CI 1.88-4.36, p < 0.001] and this extended beyond 1 year of follow-up [OR 4.13; 95% CI 1.99-8.57, p < 0.001]. Clinically indicated or ischaemia driven target lesion revascularisation [OR 1.43; 95% CI 1.11-1.83, p = 0.005] and myocardial infarction (all MI) [OR 1.64; 95% CI 1.20-2.23, p = 0.002] were more frequently seen in the BVS compared with Xience. Rates of target vessel failure [OR 1.15; 95% CI 0.91-1.46, p = 0.25] and cardiac death [OR 0.91; 95% CI 0.57-1.46, p = 0.71] were not significantly different between BVS and Xience.

CONCLUSION

This meta-analysis shows a higher rate of target lesion failure and an almost threefold higher rate of device thrombosis in BVS compared with Xience, which extends beyond the first year. Device thrombosis did not lead to an overall increased (cardiac) mortality.

Bioresorbable Scaffolds versus Metallic Stents in Routine PCI

BACKGROUND

Bioresorbable vascular scaffolds were developed to overcome the shortcomings of drug-eluting stents in percutaneous coronary intervention (PCI). We performed an investigator-initiated, randomized trial to compare an everolimus-eluting bioresorbable scaffold with an everolimus-eluting metallic stent in the context of routine clinical practice.

METHODS

We randomly assigned 1845 patients undergoing PCI to receive either a bioresorbable vascular scaffold (924 patients) or a metallic stent (921 patients). The primary end point was target-vessel failure (a composite of cardiac death, target-vessel myocardial infarction, or target-vessel revascularization). The data and safety monitoring board recommended early reporting of the study results because of safety concerns. This report provides descriptive information on end-point events.

RESULTS

The median follow-up was 707 days. Target-vessel failure occurred in 105 patients in the scaffold group and in 94 patients in the stent group (2-year cumulative event rates, 11.7% and 10.7%, respectively; hazard ratio, 1.12; 95% confidence interval [CI], 0.85 to 1.48; P=0.43); event rates were based on Kaplan-Meier estimates in time-to-event analyses. Cardiac death occurred in 18 patients in the scaffold group and in 23 patients in the stent group (2-year cumulative event rates, 2.0% and 2.7%, respectively), target-vessel myocardial infarction occurred in 48 patients in the scaffold group and in 30 patients in the stent group (2-year cumulative event rates, 5.5% and 3.2%), and target-vessel revascularization occurred in 76 patients in the scaffold group and in 65 patients in the stent group (2-year cumulative event rates, 8.7% and 7.5%). Definite or probable device thrombosis occurred in 31 patients in the scaffold group as compared with 8 patients in the stent group (2-year cumulative event rates, 3.5% vs. 0.9%; hazard ratio, 3.87; 95% CI, 1.78 to 8.42; P<0.001).

CONCLUSIONS

In this preliminary report of a trial involving patients undergoing PCI, there was no significant difference in the rate of target-vessel failure between the patients who received a bioresorbable scaffold and the patients who received a metallic stent. The bioresorbable scaffold was associated with a higher incidence of device thrombosis than the metallic stent through 2 years of follow-up. (Funded by Abbott Vascular; AIDA ClinicalTrials.gov number, NCT01858077 .).

Comparison of a Drug-Free Early Programmed Dismantling PDLLA Bioresorbable Scaffold and a Metallic Stent in a Porcine Coronary Artery Model at 3-Year Follow-Up

BACKGROUND

Arterial Remodeling Technologies bioresorbable scaffold (ART-BRS), composed of l- and d-lactyl units without drug, has shown its safety in a porcine coronary model at 6 months. However, long-term performance remains unknown. The aim of this study was to evaluate the ART-BRS compared to a bare metal stent (BMS) in a healthy porcine coronary model for up to 3 years.

METHODS AND RESULTS

Eighty-two ART-BRS and 66 BMS were implanted in 64 Yucatan swine, and animals were euthanatized at intervals of 1, 3, 6, 9, 12, 18, 24, and 36 months to determine the vascular response using quantitative coronary angiography, optical coherence tomography, light and scanning electron microscopy, and molecular weight analysis. Lumen enlargement was observed in ART-BRS as early as 3 months, which progressively increased up to 18 months, whereas BMS showed no significant difference over time. Percentage area stenosis by optical coherence tomography was greater in ART-BRS than in BMS at 1 and 3 months, but this relationship reversed beyond 3 months. Inflammation peaked at 6 months and thereafter continued to decrease up to 36 months. Complete re-endothelialization was observed at 1 month following implantation in both ART-BRS and BMS. Scaffold dismantling started at 3 months, which allowed early vessel enlargement, and bioresorption was complete by 24 months.

CONCLUSIONS

ART-BRS has the unique quality of early programmed dismantling accompanied by vessel lumen enlargement with mild to moderate inflammation. The main distinguishing feature of the ART-BRS from other scaffolds made from poly-l-lactic acid may result in early and long-term vascular restoration.

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.

Optimal duration of dual anti-platelet therapy after percutaneous coronary intervention: 2016 consensus position of the Italian Society of Cardiology

Definition of the optimal duration of dual anti-platelet therapy (DAPT) is an important clinical issue, given the large number of patients having percutaneous coronary intervention (PCI), the costs and risks of pharmacologic therapy, the consequences of stent thrombosis, and the potential benefits of DAPT in preventing ischaemic outcomes beyond stent thrombosis. Nowadays, the rationale for a prolonged duration of DAPT should be not only the prevention of stent thrombosis, but also the prevention of ischaemic events unrelated to the coronary stenosis treated with index PCI. A higher predisposition to athero-thrombosis may persist for years after an acute myocardial infarction, and even stable patients with a history of prior myocardial infarction are at high risk for major adverse cardiovascular events. Recently, results of pre-specified post-hoc analyses of randomized clinical trials, including the PEGASUS-TIMI 54 trial, have shed light on strategies of DAPT in various clinical situations, and should impact the next rounds of international guidelines, and also routine practice. Accordingly, the 2015 to 2016 the Board of the Italian Society of Cardiology addressed newer recommendations on duration of DAPT based on most recent scientific information. The document states that physicians should decide duration of DAPT on an individual basis, taking into account ischaemic and bleeding risks of any given patient. Indeed, current controversy surrounding optimal duration of DAPT clearly reflects the fact that, nowadays, a one size fits all strategy cannot be reliably applied to patients treated with PCI. Indeed, patients usually have factors for both increased ischaemic and bleeding risks that must be carefully evaluated to assess the benefit/risk ratio of prolonged DAPT. Personalized management of DAPT must be seen as a dynamic prescription with regular re-evaluations of the risk/benefit to the patient according to changes in his/her clinical profile. Also, in order to derive more benefit than harm from new treatments, a multi-parametric approach using several risk scores of the ischaemic and bleeding risks might improve the process of risk factor characterization. In patients with high ischaemic risk, particularly those with a history of myocardial infarction, the benefits of extended DAPT (particularly with ticagrelor up to 3 years) are likely to outweigh the risks.