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.

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.

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.

Outcomes of bioresorbable vascular scaffolds versus everolimus-eluting stents by coronary complexity: a sub-analysis of the AIDA trial.

AIMS: We aimed to evaluate the impact of the complexity of coronary disease as assessed by the SYNTAX score (SXscore) on the clinical outcomes in the AIDA trial. METHODS AND RESULTS: In the AIDA trial, we compared Absorb versus XIENCE in routine clinical practice. Clinical outcomes were stratified by SXscore tertiles: SXlow (SXscore ≤8), SXmid (SXscore >8 and ≤15) and SXhigh (>15). The SXscore was available in 1,661 of the 1,845 (90%) patients. The event rate of TVF was numerically lower in Absorb compared to XIENCE (3.7% versus 5.6%; p=0.257) in the SXlow tertile, numerically higher in Absorb in the SXmid tertile (11.4% versus 9.3%, p=0.421) and similar in the SXhigh tertile (15.5% versus 15.6%; p=0.960). The rates of definite/probable device thrombosis in Absorb versus XIENCE were significantly higher in the SXmid tertile (3.3% versus 0.8%, p=0.043) and in the SXhigh tertile (3.7% versus 0.8%, p=0.006). CONCLUSIONS: We found no significantly different rates of TVF between Absorb and XIENCE patients. Absorb-treated patients in the SXmid and SXhigh tertiles had an increased risk of device thrombosis when compared to XIENCE-treated patients. The rates of device thrombosis in the SXlow tertile, while still higher for Absorb, are more acceptable than in the SXmid and SXhigh score tertiles.

Clinical outcomes at 2 years of the Absorb bioresorbable vascular scaffold versus the Xience drug-eluting metallic stent in patients presenting with acute coronary syndrome versus stable coronary disease-AIDA trial substudy.

BACKGROUND: Patients with acute coronary syndrome (ACS) might represent a specific subgroup, in which bioresorbable scaffold implantation in percutaneous coronary intervention (PCI), might lead to better outcomes when compared to conventional treatment with metallic drug eluting stents. In this prespecified subgroup analysis of the Amsterdam Investigator-Initiated Absorb Strategy All-Comers (AIDA) trial, we evaluated the clinical outcomes of Absorb bioresorbable vascular scaffold (BVS) versus Xience everolimus eluting stent (EES) treated patients presenting either with or without ACS. METHODS AND RESULTS: We classified AIDA patients on the basis of clinical presentation of ACS or of no-ACS. The rate of the 2-year primary endpoint of target vessel failure (TVF) was similar after treatment with Absorb BVS or Xience EES in ACS patients (10.2% versus 9.0% respectively; P = 0.49) and in no-ACS patients (11.7% versus 10.7%, respectively; P = 0.67) Definite or probable device thrombosis occurred more frequently with Absorb BVS compared to Xience EES in ACS patients (4.3% versus 1.7%, respectively, P = 0.03) as well as in no-ACS patients (2.4% versus 0.2%, respectively; P = 0.002). There were no statistically significant interactions between clinical presentation and randomized device modality for TVF (P = 0.80) and for the endpoint of definite or probable device thrombosis (P = 0.17). CONCLUSION: In the AIDA trial, the 2-year outcomes of PCI with Absorb BVS versus Xience EES were consistent in ACS and no-ACS patients: similar rates for TVF and consistently higher rates of definite or probable stent thrombosis under Absorb BVS versus Xience EES. There were no statistically significant interactions between clinical presentation and randomized device modality.

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.

Complete two-year follow-up with formal non-inferiority testing on primary outcomes of the AIDA trial comparing the Absorb bioresorbable scaffold with the XIENCE drug-eluting metallic stent in routine PCI.

AIMS: The aim of this report of the AIDA trial is to provide full two-year outcomes for the primary endpoint of target vessel failure (TVF) and an update on device thrombosis. METHODS AND RESULTS: AIDA was a single-blind, multicentre, investigator-initiated, non-inferiority, randomised (1:1) clinical trial. At complete two-year follow-up, the primary endpoint of TVF had occurred in 100 patients in the Absorb BVS arm versus 90 patients in the XIENCE EES arm (HR 1.12, 95% CI: 0.94-1.49; psuperiority=0.436). Estimated two-year Kaplan-Meier event rates of TVF were 11.0% and 9.9%, respectively (95% CI: -0.9%-3.0%; pnon-inferiority=0.003). Definite or probable device thrombosis at two years occurred in 30 patients in the Absorb BVS arm and in eight patients in the XIENCE EES arm. Kaplan-Meier estimates of device thrombosis were 3.3% in the Absorb BVS arm and 0.9% in the XIENCE EES arm (HR 5.22, 95% CI: 2.00-13.59; p<0.001). CONCLUSIONS: AIDA formally met its criterion for non-inferiority of Absorb BVS versus XIENCE EES in terms of the combined endpoint of TVF. The Absorb BVS, however, was associated with higher rates of scaffold thrombosis and target vessel myocardial infarction at complete two-year follow-up.

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.

AIMS: Specific implantation strategies have been proposed for the Absorb bioresorbable vascular scaffold (Absorb BVS) to optimise outcomes. We aimed to analyse whether the occurrence of definite scaffold thrombosis (ScT) and target lesion revascularisation (TLR) in Absorb-treated AIDA patients was influenced by scaffold implantation techniques. METHODS AND RESULTS: Absorb BVS implantation in 1,074 lesions was graded according to definitions of optimal implantation based on predilatation, sizing, and post-dilatation (PSP). Lesion-oriented outcomes (definite ScT and TLR) that occurred during a median follow-up of 707 days were related to the presence or absence of PSP. Of 1,074 lesions, 158 (14.7%) lesions met PSP criteria. The most prevalent reason for not meeting PSP criteria was inadequate sizing: 863 (94.2%). Definite ScT occurred in four of 158 PSP-treated lesions compared with 27 of 916 non PSP-treated lesions, with two-year KM estimates of 3.0% vs. 4.1% and an HR of 1.14 (p=0.811). TLR occurred in eight of 158 PSP-treated lesions compared with 61 of 916 non PSP-treated lesions, with KM estimates of 5.6% vs. 7.1% and an HR of 1.29 (p=0.492). CONCLUSIONS: In AIDA, lesions that underwent scaffold implantation according to an optimised Absorb BVS implantation technique did not have lower rates of ScT and TLR compared to scaffold-treated lesions that did not meet PSP criteria.

Scaffold thrombosis following implantation of the ABSORB BVS in routine clinical practice: Insight into possible mechanisms from optical coherence tomography.

OBJECTIVES: To identify potential underlying mechanisms of early and (very) late scaffold thrombosis (ScT) by optical coherence tomography (OCT), in a frame-by-frame analysis. BACKGROUND: The absorb scaffold is associated with an increased risk of ScT compared with metallic stents. Several potential causes of bioresorbable ScT have been identified, however the precise etiology still remains unclear. METHODS: Between February 2013 and February 2016, 13 patients presenting with definite ScT underwent OCT imaging. After guidewire passage or balloon inflations, OCT images were acquired. Pullbacks were assessed offline at each 1 mm longitudinal interval within the treated segment and the 5 mm segments adjacent to both edges. Primary cause of ScT was assessed by reviewing medical records, baseline angiographic films, and OCT pullback and angiographic films at time of ScT. RESULTS: 13 patients, with 14 thrombotic lesions presented either with early ScT (i.e., ≤30 days) or very (late) (i.e., >30 days). Analysis demonstrated a significantly smaller in-scaffold maximal lumen diameter in the early cases (2.75 ± 0.85 mm vs. 3.00 ± 0.46 mm; P = 0.033) and a nonsignificant smaller minimal scaffold diameter (2.44 ± 0.62 mm vs. 2.58 ± 0.37 mm P = 0.097). Per-strut analysis demonstrated significantly more malapposed scaffold struts in (very) late cases (6% versus 0.6%, P < 0.001). Assessment of the predominate cause showed underexpansion as the dominant factor in the early cases, while malapposition was predominantly seen in the (very)late cases. CONCLUSIONS: OCT performed in patients presenting with Absorb ScT demonstrated that malapposition of scaffold struts was more prominent in patients presenting with (very) late ScT, while underexpansion was more frequent in the early cases.

First-in-Man Trial of SiO2 Inert-Coated Bare Metal Stent System in Native Coronary Stenosis　- The AXETIS FIM Trial.

BACKGROUND: A novel bare metal stent with an SiO2coating was developed to prevent excessive neointimal hyperplasia by inertization of the metallic stent surface. The efficacy of the device was demonstrated in a preclinical model. The aim of this first-in-man trial was to assess the safety and feasibility of the new device.Methods and Results:This prospective non-randomized single-arm trial was designed to enroll 35 patients with a de novo coronary lesion. Quantitative coronary angiography and optical coherence tomography (OCT) were performed at the baseline procedure and at the 6-month follow-up. Stent implantation was performed with OCT guidance according to optimal stent implantation criteria. The trial was terminated upon the advice of the data safety monitoring board after enrolling 14 patients due to the high incidence of re-intervention. Optimal OCT implantation criteria were achieved in only 8.3% of lesions. At 6 months, angiographic in-stent late lumen loss as the primary endpoint was 0.77±0.44 mm, and binary restenosis occurred in 33.3% of lesions. At the 6-month OCT, neointimal volume obstruction was 32.8±15.6% with a neointimal thickness of 237±117 µm. At 12 months, the device-oriented composite endpoint (defined as cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularization rate) was 33.3%. CONCLUSIONS: In contrast with the preclinical study, the Axetis stent did not efficiently suppress neointimal hyperplasia in humans in this trial.

Evaluation of the MiStent sustained sirolimus eluting biodegradable polymer coated stent for the treatment of coronary artery disease: does uniform sustained abluminal drug release result in earlier strut coverage and better safety profile?

INTRODUCTION: Treatment of coronary artery disease has made strides over the last decades. Development of drug eluting stents (DES), coated with a polymer layer and an anti-proliferative drug to reduce neointimal hyperplasia, has reduced the incidence of in-stent-restenosis relative to treatment with bare metal stents. Patients treated with first generation DES more likely suffer from (very) late events which can be cause by the permanent presence of a polymer. Therefore second generation DES with more biocompatible coatings, and third generation DES, with very thin struts coated with biodegradable polymers, were developed. Areas covered: The MiStent SES is one of these third generation DES and is designed to limit the duration of polymer exposure, optimize coronary vessel healing and more precisely and consistently control drug elution to improve safety and clinical outcomes. This review provides a detailed description of the technique behind the MiStent SES, and describes the pre-clinical and clinical trials conducted with this device to date. Expert commentary: Recent clinical trials have shown non-inferiority of very thin strut biodegradable polymer coated DES compared to durable polymer coated DES, whilst maintaining an excellent safety profile. Longer follow-up, to see the real potential benefits of these devices, is mandatory however.

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 .).

The IMPACT Study (Influence of Sensor-Equipped Microcatheters on Coronary Hemodynamics and the Accuracy of Physiological Indices of Functional Stenosis Severity).

BACKGROUND: The Navvus pressure sensor-equipped microcatheter allows to measure functional stenosis severity over a work-horse guidewire and is used as a more feasible alternative to regular sensor-equipped wires. However, Navvus is larger in diameter than contemporary sensor-equipped guidewires and may, thereby, influence functional measurements. The present study evaluates the hemodynamic influence of the Navvus microcatheter. METHODS AND RESULTS: In patients with intermediate coronary stenosis, coronary pressure and flow velocity were measured using a dual sensor-equipped guidewire before and after introduction of Navvus. Patients were randomized to microcatheter-first or guidewire-first measurement. The primary end point was the difference in hyperemic stenosis resistance index between measurements before and after introduction of Navvus. Measurements were completed in 28 patients (28 stenoses). Mean hyperemic stenosis resistance was 0.37±0.19 Hg/cm/s for wire-only assessment and 0.48±0.26 Hg/cm/s after Navvus introduction (P<0.001). Bland-Altman analysis documented a mean bias of +0.11 Hg/cm/s (limits of agreement: -0.13 to 0.36), proportional to mean hyperemic stenosis resistance (Spearman ρ =0.61; P=0.001). Passing-Bablok analysis revealed absence of a constant difference but significant proportional difference between the methods. Mean fractional flow reserve was 0.86±0.06 for wire-only assessment and 0.82±0.07 after Navvus introduction (P<0.001). Bland-Altman analysis documented a mean bias of -0.033 (limits of agreement: -0.09 to 0.03), proportional to mean fractional flow reserve (Spearman ρ =0.40; P=0.036). Passing-Bablok analysis revealed significant constant and proportional differences between methods. Similar results were documented for resting indices of stenosis severity. CONCLUSIONS: Introduction of the Navvus microcatheter leads to clinically relevant stenosis severity overestimation in intermediate stenosis.

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.

Bioresorbable drug-eluting scaffolds for treatment of vascular disease.

INTRODUCTION: Theoretical advantages of fully bioresorbable scaffold (BRS) stem from transient vessel support without rigid caging. Therefore, it could reduce long-term adverse events associated with the presence of foreign materials. AREAS COVERED: This article will provide an overview of: drug-eluting BRS for various applications in the treatment of vascular disease; The mechanisms of active agent release from such scaffolds; currently available drug-eluting BRS and their future applications are also discussed. EXPERT OPINION: The current BRS have been developed in order to achieve optimal vascular patency while providing long-term safety. The clinical efficacy and safety of BRS in coronary treatment have been reported as equal to that of the current metallic drug eluting stents in simple lesions. The application of BRS can potentially be expanded to other vascular beds. The research in bioengineering for the appropriate materials should not only focus on biocompatibility but also should be tailored according to the sites of implantation, which may require different strength and supporting period. The ultimate goal in this field is to develop a biocompatible device that provides equivalent and complementary therapy to other devices, and is able to disappear when the mechanical support and drug delivery are no longer required.

Coronary Artery Vessel Healing Pattern, Short and Long Term, After Implantation of the Everolimus-Eluting Bioresorbable Vascular Scaffold.

BACKGROUND: Although the Absorb bioresorbable vascular scaffold is increasingly used in daily clinical practice for the treatment of coronary artery disease, the exact vascular healing pattern and the resorption process in humans is unknown because histological data are derived only from animal studies. METHODS AND RESULTS: We have obtained 4 autopsies (5 scaffolds) since August 2013. Duration of bioresorbable vascular scaffold implantation ranged from 3 to 501 days. All autopsies and histological assessments were performed by dedicated cardiovascular pathologists. At 1 week after bioresorbable vascular scaffold implantation, struts were covered with a fine layer of fibrin and platelets. At 113 days, the scaffold struts were fully covered with smooth muscle cells. Hyaline eosinophilic and proteoglycan material infiltrating the scaffold struts was observed at 501 days after implantation. At all time points, we observed the presence of multinuclear foreign body giant cells adjacent to the scaffold struts. CONCLUSIONS: Resorption and healing processes after bioresorbable vascular scaffold implantation in human patients mirror those observed in porcine models. The presence of multinucleated foreign body giant cells at both short- and long-term follow-up needs further investigation and may be related to a low-grade absorptive inflammatory response to the polymer.

The future of BRS in bifurcations.

Bioresorbable scaffolds (BRS) provide a new tool for percutaneous treatment of coronary stenosis. Initially, relatively simple coronary artery lesions were treated with this novel technology; nowadays, we have gained more experience with a wide variety of lesions, including bifurcation lesions. Data are limited in terms of the use of BRS in coronary bifurcation lesions, although it has been demonstrated that over time the bioresorbable struts are replaced by a tissue bridge resembling a "neo-carina". Furthermore, data are emerging about the endothelial shear stress (ESS) alterations and blood flow patterns after scaffold implantation. It is likely that ESS and blood flow determinations will guide correct future bifurcation techniques. In the future, BRS with thinner struts and more resistant to fracture are likely to improve bifurcation treatment with BRS.