Everolimus-eluting Bioresorbable Vascular Scaffold Research Articles

Serial In Vivo Intravascular Ultrasound-Based Echogenicity Changes of Everolimus-Eluting Bioresorbable Vascular Scaffold During the First 12 Months After Implantation: Insights From the ABSORB B Trial

This study sought to investigate quantitative and homogeneity differential echogenicity changes of the ABSORB scaffold (1.1) during the first year after implantation. The imaging of the ABSORB bioresorbable vascular scaffold degradation by intravascular ultrasound (IVUS) has previously demonstrated diminishing gray-level intensity of the struts over time that can be evaluated by IVUS-based differential echogenicity. The first generation of ABSORB (1.0) showed a 50% reduction in hyperechogenicity at 6 months and restoration of the pre-ABSORB implantation values at 2 years. The second generation of ABSORB (1.1), investigated in the ABSORB B trial, was modified to prolong the duration of luminal scaffolding. A total of 63 patients were examined by IVUS immediately post-implantation and at 6-month (Cohort B1, n = 28) or 12-month (Cohort B2, n = 35) follow-up. IVUS-based tissue composition analysis software was used to quantify changes in hyperechogenicity over time in the scaffolded regions. Relative changes in hyperechogenicity were calculated as: 100 × (% hyperechogenicity at follow-up - % hyperechogenicity at baseline)/% hyperechogenicity at baseline. At 6- and 12-month follow-up, there was a 15% (from 22.58 ± 9.77% to 17.42 ± 6.69%, p = 0.001) and 20% (from 23.51 ± 8.57% to 18.25 ± 7.19%, p < 0.001) reduction in hyperechogenicity, respectively, compared with post-implantation values. No difference in hyperechogenicity changes were observed between the proximal, medial, or distal part of the scaffolded segment. Quantitative differential echogenicity changes of the ABSORB scaffold (1.1) during the first 12 months after implantation are lower compared with those previously observed with its first generation (1.0), confirming the value of the manufacturing changes and suggesting a slower degradation rate of the scaffold.

Analysis of 1 year virtual histology changes in coronary plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Serial intravascular ultrasound virtual histology (IVUS-VH) after implantation of metallic stents has been unable to show any changes in the composition of the scaffolded plaque overtime. The everolimus-eluting ABSORB scaffold potentially allows for the formation of new fibrotic tissue on the scaffolded coronary plaque during bioresorption. We examined the 12 month IVUS-VH changes in composition of the plaque behind the struts (PBS) following the implantation of the ABSORB scaffold. Using IVUS-VH and dedicated software, the composition of the PBS was analyzed in all patients from the ABSORB Cohort B2 trial, who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA), immediately post-ABSORB implantation and at 12 month follow-up. Paired IVUS-VH data, recorded with s5i system, were available in 17 patients (18 lesions). The analysis demonstrated an increase in mean PBS area (2.39 ± 1.85 mm2 vs. 2.76 ± 1.79 mm2, P = 0.078) and a reduction in the mean lumen area (6.37 ± 0.90 mm2 vs. 5.98 ± 0.97 mm2, P = 0.006). Conversely, a significant decrease of 16 and 30% in necrotic core (NC) and dense calcium (DC) content, respectively, were evident (median % NC from 43.24 to 36.06%, P = 0.016; median % DC from 20.28 to 11.36%, P = 0.002). Serial IVUS-VH analyses of plaque located behind the ABSORB struts at 12-month demonstrated an increase in plaque area with a decrease in its NC and DC content. Larger studies are required to investigate the clinical impact of these findings.

TCT-25: Bioresorbable Everolimus Eluting Vascular Scaffold in Small Vessels One year results

TCT-25: Bioresorbable Everolimus Eluting Vascular Scaffold in Small Vessels One year results

TCT-238: Proximal & Distal Maximal Luminal Diameters (Dmax) as a Guide to Appropriate Deployment of the Everolimus-Eluting Bioresorbable Vascular Scaffold: A Substudy of the ABSORB Cohort B & On-Going ABSORB EXTEND Single Arm Study

TCT-238: Proximal & Distal Maximal Luminal Diameters (Dmax) as a Guide to Appropriate Deployment of the Everolimus-Eluting Bioresorbable Vascular Scaffold: A Substudy of the ABSORB Cohort B & On-Going ABSORB EXTEND Single Arm Study

TCT-651: Assessment of the bioresorption process utilising intravascular ultrasound derived echogenicity analyses and vasomotion testing of the ABSORB bioresorbable everolimus-eluting vascular scaffold. A substudy of the ABSORB Cohort B trial

TCT-651: Assessment of the bioresorption process utilising intravascular ultrasound derived echogenicity analyses and vasomotion testing of the ABSORB bioresorbable everolimus-eluting vascular scaffold. A substudy of the ABSORB Cohort B trial

Proximal and distal maximal luminal diameters as a guide to appropriate deployment of the ABSORB everolimus‐eluting bioresorbable vascular scaffold

Due to the limited distensibility of the everolimus-eluting bioresorbable vascular scaffold (ABSORB) compared to metallic platform stents, quantitative coronary arteriography (QCA) is a mandatory requirement for ABSORB deployment in the on-going ABSORB EXTEND Single-Arm Study. Visual assessment of vessel size in the ABSORB Cohort B study often lead to under and over-sizing of the 3 mm ABSORB in coronary vessels (recommended range of the vessel diameter ≥ 2.5 mm and ≤ 3.3 mm), with an increased risk of spontaneous incomplete scaffold apposition post ABSORB deployment. We report whether mandatory QCA assessment of vessel size pre-implantation, utilizing the maximal luminal diameter (Dmax) and established interpolated reference vessel diameter (RVD) measurements, has improved device/vessel sizing. Pre-implantation post-hoc QCA analyses of all 101 patients from ABSORB Cohort B (102 lesions) and first consecutive 101 patients (108 lesions) from ABSORB EXTEND were undertaken by an independent core-laboratory; all patients had a 3 mm ABSORB implanted. Comparative analyses were performed. Within ABSORB Cohort B, a greater number of over-sized vessels (> 3.3 mm) were identified utilizing the Dmax compared to the interpolated RVD (17 vessels, 16.7% vs. 3 vessels, 2.9%; P = 0.002). Comparative analyses demonstrated a greater number of appropriate vessel-size selection (75 vessels, 69.4% vs. 48 vessels, 47.1%; P = 0.001), a trend towards a reduction in implantation in small (< 2.5 mm) vessels (29 vessels, 26.9% vs. 40 vessels, 39.2%; P = 0.057) and a significant decrease in the implantation in large (> 3.3 mm) vessels (4 vessels, 3.7% vs. 17 vessels, 16.7%; P = 0.002) in ABSORB EXTEND. Bland-Altman plots suggested a good agreement between operator and core-laboratory calculated Dmax measurements. The introduction of mandatory Dmax measurements of vessel size prior to ABSORB implantation significantly reduced the under-sizing of the 3.0 mm scaffold in large vessels validating the use of this technique in vessel sizing prior to ABSORB implantation.

Bioresorbable Polymeric Vascular Scaffolds

The everolimus-eluting bioresorbable vascular scaffold (BVS, Abbott Vascular, Santa Clara, CA) is an exciting advance in percutaneous coronary intervention (PCI), providing a temporary coronary scaffold for at least 3 months and being resorbed by about 2 years.1–3 Along with patient preference, potential advantages over metallic stents include restored vasomotion, reduced late thrombosis, and unimpaired imaging with computed tomography and magnetic resonance. However, advances in interventional devices may bring new challenges in the early days of the technology. A 78-year-old man with recent-onset angina was enrolled in the ABSORB Trial Cohort B Group 1.3 An obtuse marginal coronary artery branch measuring by quantitative angiography 3.5 mm upstream and 3.0 mm downstream from a stenosis was predilated with a 2.5-mm balloon. A 3.0×18 mm Revision 1.1 ABSORB BVS (Figure 1) was deployed at 16 atm, and the scaffold was postdilated with a 3.25-mm noncompliant balloon at 24 atm (expected diameter, 3.5 mm). Although the angiographic appearances were good, there was malapposition of the proximal half of the scaffold shown by intravascular ultrasound (IVUS), and more clearly seen with optical coherence tomography (OCT) (Figure 1). After further inflations with a compliant 3.5-mm balloon to 16 atm (expected diameter, 4.0 mm), the angiographic appearances remained satisfactory. However, repeat IVUS and OCT showed persisting strut malapposition, including sections where the struts lay …

Three-Dimensional Reconstruction of the Post-Dilated ABSORB Everolimus-Eluting Bioresorbable Vascular Scaffold in a True Bifurcation Lesion for Flow Restoration

A 68-year-old male patient presented to our catheterization laboratory with a non–ST-segment elevation myocardial infarction. Coronary angiography suggested a significant true bifurcation lesion in the mid left anterior descending (LAD) artery, appearing to involve the second diagonal side branch

Evaluation of the Second Generation of a Bioresorbable Everolimus-Eluting Vascular Scaffold for the Treatment of De Novo Coronary Artery Stenosis: 12-Month Clinical and Imaging Outcomes

The first generation of the bioresorbable everolimus drug-eluting vascular scaffold showed signs of shrinkage at 6 months, which largely contributed to late luminal loss. Nevertheless, late luminal loss was less than that observed with bare metal stents. To maintain the mechanical integrity of the device up to 6 months, the scaffold design and manufacturing process of its polymer were modified.Quantitative coronary angiography, intravascular ultrasound with analysis of radiofrequency backscattering, and as an optional assessment, optical coherence tomography (OCT) were performed at baseline and at a 6-month follow-up. Forty-five patients successfully received a single bioresorbable everolimus drug-eluting vascular scaffold. One patient had postprocedural release of myocardial enzyme without Q-wave occurrence; 1 patient with OCT-diagnosed disruption of the scaffold caused by excessive postdilatation was treated 1 month later with a metallic drug-eluting stent. At follow-up, 3 patients declined recatheterization, 42 patients had quantitative coronary angiography, 37 had quantitative intravascular ultrasound, and 25 had OCT. Quantitative coronary angiography disclosed 1 edge restenosis (1 of 42; in-segment binary restenosis, 2.4%). At variance with the ultrasonic changes seen with the first generation of bioresorbable everolimus drug-eluting vascular scaffold at 6 months, the backscattering of the polymeric struts did not decrease over time, the scaffold area was reduced by only 2.0% with intravascular ultrasound, and no change was noted with OCT. On an intention-to-treat basis, the late lumen loss amounted to 0.19±0.18 mm with a limited relative decrease in minimal luminal area of 5.4% on intravascular ultrasound. OCT showed at follow-up that 96.8% of the struts were covered and that malapposition of at least 1 strut, initially observed in 12 scaffolds, was detected at follow-up in only 3 scaffolds. Mean neointimal growth measured by OCT between and on top of the polymeric struts equaled 1.25 mm(2), or 16.6% of the scaffold area.Modified manufacturing process of the polymer and geometric changes in the polymeric platform have substantially improved the medium-term performance of this new generation of drug-eluting scaffold to become comparable to those of current drug eluting stents.URL: http://clinicaltrials.gov. Unique identifier: NCT00856856.

6-Month Clinical Outcomes Following Implantation of the Bioresorbable Everolimus-Eluting Vascular Scaffold in Vessels Smaller or Larger Than 2.5 mm

We investigated the 6-month clinical outcomes after implantation of second-generation 3.0-mm bioresorbable everolimus-eluting vascular scaffolds (BVS) in small coronary vessels (<2.5 mm). BVS are a novel approach to treating coronary lesions and are untested in small vessels. The ABSORB Cohort B Trial is a multicenter, single-arm, prospective, open-label trial assessing the performance of the second-generation BVS, in which 101 patients were enrolled. The pre-procedural reference vessel diameter (RVD) was assessed by quantitative coronary angiography during post hoc analysis. The vessel size was overestimated, by visual assessment, in 41 patients before implantation of 3.0-mm BVS in vessels with a pre-procedural RVD <2.5 mm. The study population was divided into 2 groups, group I (n = 41) with RVD <2.5 mm and group II (n = 60) with RVD ≥2.5 mm. The composite endpoint of ischemia-driven major adverse cardiac events, defined as ischemia-driven target lesion revascularization, myocardial infarction, or cardiac death, was assessed. Of the 45 patients scheduled for 6-month coronary angiography, 42 patients had the procedure performed, with intravascular ultrasound undertaken in 40 of these patients. At 6 months, no significant differences in ischemia-driven major adverse cardiac events (3 of 41 [7.3%] cases vs. 2 of 60 [3.3%] cases; p = 0.3933) were observed in the small- and large-vessel groups, respectively. No cardiac deaths or episodes of in-scaffold thromboses were seen. Angiographic and intravascular ultrasound follow-up demonstrated no differences in late lumen loss (0.16 ± 0.18 mm vs. 0.21 ± 0.17 mm; p = 0.3525) or percentage lumen area stenosis (17.6 ± 6.0% vs. 19.8 ± 8.5%; p = 0.3643). The second-generation 3.0-mm BVS appears to be safe in small vessels, with similar clinical and angiographic outcomes compared with those of large vessels.

Evaluation with in vivo optical coherence tomography and histology of the vascular effects of the everolimus-eluting bioresorbable vascular scaffold at two years following implantation in a healthy porcine coronary artery model: implications of pilot results for future pre-clinical studies

To quantify with in vivo OCT and histology, the device/vessel interaction after implantation of the bioresorbable vascular scaffold (BVS). We evaluated the area and thickness of the strut voids previously occupied by the polymeric struts, and the neointimal hyperplasia (NIH) area covering the endoluminal surface of the strut voids (NIHEV), as well as the NIH area occupying the space between the strut voids (NIHBV), in healthy porcine coronary arteries at 2, 3 and 4 years after implantation of the device. Twenty-two polymeric BVS were implanted in the coronary arteries of 11 healthy Yucatan minipigs that underwent OCT at 2, 3 and 4 years after implantation, immediately followed by euthanasia. The areas and thicknesses of 60 corresponding strut voids previously occupied by the polymeric struts and the size of 60 corresponding NIHEV and 49 NIHBV were evaluated with both OCT and histology by 2 independent observers, using a single quantitative analysis software for both techniques. At 3 and 4 years after implantation, the strut voids were no longer detectable by OCT or histology due to complete polymer resorption. However, analysis performed at 2 years still provided clear delineation of these structures, by both techniques. The median [ranges] areas of these strut voids were 0.04 [0.03–0.16] and 0.02 [0.01–0.07] mm2 by histology and OCT, respectively. The mean (±SD) thickness by histology and OCT was 220 ± 40 and 120 ± 20 μm, respectively. The median [ranges] NIHEV by histology and OCT was 0.07 [0.04–0.20] and 0.03 [0.01–0.08] mm2, while the mean (±SD) NIHBV by histology and OCT was 0.13 ± 0.07 and 0.10 ± 0.06 mm2. Our study indicates that in vivo OCT of the BVS provides correlated measurements of the same order of magnitude as histomorphometry, and is reproducible for the evaluation of certain vascular and device-related characteristics. However, histology systematically gives larger values for all the measured structures compared to OCT, at 2 years post implantation.

3-Dimensional reconstruction of a bifurcation lesion with double wire after implantation of a second generation everolimus-eluting bioresorbable vascular scaffold

The everolimus-eluting bioresorbable vascular scaffold (BVS) is one of the latest innovations in bioresorbable technology and has been investigated in the ABSORB Cohort A and B studies [1]. The next generation BVS (BVS revision 1.1) is currently being investigated in the ongoing international, multicentre ABSORB EXTEND single arm study. Herein we present a case study from the ABSORB EXTEND single arm study involving the double wiring of a bifurcation lesion. We demonstrate 3-Dimensional (3-D) reconstructions of the main branch (MainB) and side branch (SideB), constructed using dedicated software from their respective using two-Dimensional (2-D) frequency domain optical coherence tomography (FD-OCT) images.

Reproducibility of Shin’s method for necrotic core and calcium content in atherosclerotic coronary lesions treated with bioresorbable everolimus-eluting vascular scaffolds using volumetric intravascular ultrasound radiofrequency-based analysis

Although Virtual Histology intravascular ultrasound (VH-IVUS) is increasingly used in clinical research, the reproducibility of plaque composition remains unexplored in significant coronary artery and stented lesions. The purpose of this study was to assess the reproducibility of necrotic core and calcium content in atherosclerotic coronary lesions that were treated with a bioresorbable everolimus-eluting vascular scaffold (BVS) using a new measurement method (Shin's method) by VH-IVUS. Eight patients treated with a BVS (Abbott Vascular, Santa Clara, CA, USA) were analyzed with serial VH-IVUS assessments, i.e., pre- and post-stenting, and at 6 months and 2 years follow-up. A total of 32 coronary segments were imaged to evaluate the reproducibility of volumetric VH-IVUS measurements. In Shin's method, contours are drawn around the IVUS catheter (instead of the lumen) and vessel. Overall, in the imaged coronary segment, for necrotic core and dense calcium volumes, the relative intra-observer differences were 0.30 ± 0.22, 0.19 ± 0.16% for observer 1 and 0.45 ± 0.41, 0.36 ± 0.47% for observer 2, respectively. The inter-observer relative differences of necrotic core and dense calcium volumes were 0.51 ± 0.79 and 0.56 ± 1.01%, respectively. The present study demonstrates a good reproducibility for both, intra-observer and inter-observer measurements using Shin's method. This method is suitable for the measurement of necrotic core and dense calcium using VH-IVUS in longitudinal studies, especially studies on bioresorbable scaffolds, because the degradation process will be fully captured independently of the location of the struts and their greyscale appearance.

Morphological and functional evaluation of the bioresorption of the bioresorbable everolimus-eluting vascular scaffold using IVUS, echogenicity and vasomotion testing at two year follow-up: a patient level insight into the ABSORB A clinical trial

The aim of this study was to describe vaso-reactivity (by Acetylcholine and Methergine tests) at 2 year follow-up in parallel with the individual changes in the echogenicity characteristics of the polymer struts of the everolimus eluting bioresorbable vascular scaffold (BVS), from post-treatment to 2 year follow-up, in patients enrolled in the ABSORB Cohort A study. Intravascular ultrasound assessment was performed with a phased array catheter (EagleEye, Volcano Corporation, Cordova, CA, USA) with automated pullback at 0.5 mm per second. The % ratio at 6 months and 2 years [(Scaffold Area post PCI- Lumen Area)/Scaffold Area post PCI] was calculated as a measure of scaffold shrinkage. The % change of hyperechogenicity was defined as: ([post-procedural hyperechogenicity] - [2 year follow up hyperechogenicity])/[post-procedural hyperechogenicity]) × 100. The vasomotion test with intracoronary acetylcholine (10(-6) M) or intravenous methergine (0.4 mg) was performed at 2 years. Overall nine patients received all these analyses and were enrolled in the present analysis. A 50-96% reduction in hyperechogenicity was observed between baseline and 2 years, which corresponded to a change in vasoreactivity between 2 and 22%. A vasoconstriction of the scaffolded segment was observed in the 5 patients, who underwent the methergine test, with a mean decrease in lumen diameter after methergine of 9 ± 7% (P = 0.06), while vasodilatation occurred in the 4 patients who underwent the acetylcholine test with a mean increase in lumen diameter after acetylcholine of 8 ± 5% (P = 0.125). Bioresorption of the BVS is accompanied by re-establishment of both endothelial and non-endothelial dependent vasomotion.

A comparative assessment by optical coherence tomography of the performance of the first and second generation of the everolimus-eluting bioresorbable vascular scaffolds

The first generation of the everolimus-eluting bioresorbable vascular scaffold (BVS 1.0) showed an angiographic late loss higher than the metallic everolimus-eluting stent Xience V due to scaffold shrinkage. The new generation (BVS 1.1) presents a different design and manufacturing process than the BVS 1.0. This study sought to evaluate the differences in late shrinkage, neointimal response, and bioresorption process between these two scaffold generations using optical coherence tomography (OCT). A total of 12 lesions treated with the BVS 1.0 and 12 selected lesions treated with the revised BVS 1.1 were imaged at baseline and 6-month follow-up with OCT. Late shrinkage and neointimal area (NIA) were derived from OCT area measurements. Neointimal thickness was measured in each strut. Strut appearance has been classified as previously described. Baseline clinical, angiographic, and OCT characteristics were mainly similar in the two groups. At 6 months, absolute and relative shrinkages were significantly larger for the BVS 1.0 than for the BVS 1.1 (0.98 vs. 0.07 mm² and 13.0 vs. 1.0%, respectively; P = 0.01). Neointimal area was significantly higher in the BVS 1.0 than in the BVS 1.1 (in-scaffold area obstruction of 23.6 vs. 12.3%; P < 0.01). Neointimal thickness was also larger in the BVS 1.0 than in the BVS 1.1 (166.0 vs. 76.4 µm; P < 0.01). Consequently, OCT, intravascular ultrasound, and angiographic luminal losses were higher with the BVS 1.0 than with the BVS 1.1. At 6 months, strut appearance was preserved in only 2.9% of the BVS 1.0 struts, but remained unchanged with the BVS 1.1 indicating different state of strut microstucture and/or their reflectivity. The BVS 1.1 has less late shrinkage and less neointimal growth at 6-month follow-up compared with the BVS 1.0. A difference in polymer degradation leading to changes in microstructure and reflectivity is the most plausible explanation for this finding.

Intracoronary Optical Coherence Tomography and Histology at 1 Month and 2, 3, and 4 Years After Implantation of Everolimus-Eluting Bioresorbable Vascular Scaffolds in a Porcine Coronary Artery Model

Background— With the use of optical coherence tomography (OCT), alterations of the reflectance characteristics of everolimus-eluting bioresorbable vascular scaffold (BVS) struts have been reported in humans. In the absence of histology, the interpretation of the appearances of the struts by OCT remains speculative. We therefore report OCT findings with corresponding histology in the porcine coronary artery model immediately after and at 28 days and 2, 3, and 4 years after BVS implantation. Methods and Results— Thirty-five polymeric BVS (3.0×12.0 mm) were singly implanted in the main coronary arteries of 17 pigs that underwent OCT and were then euthanized immediately (n=2), at 28 days (n=2), at 2 years (n=3), at 3 years (n=5), or at 4 years (n=5) after implantation. All BVS-implanted arteries in these animals were evaluated by histology except for 5 arteries examined at 2 years with gel permeation chromatography to assess the biodegradation of the polymeric device. Fourteen arteries with BVS from an additional 6 pigs were examined by gel permeation chromatography at 1 (n=1), 1.5 (n=2), and 3 (n=2) years. Corresponding OCT and histology images were selected with the distal and proximal radiopaque markers used as landmarks. At 28 days, by OCT, 82% of struts showed sharply defined, bright reflection borders, best described as a box-shaped appearance. Histologically, all struts appeared intact with no evidence of resorption. At 2 years, by OCT, 60±20 struts were discernible per BVS with 80.4% of the strut sites as a box-shaped appearance. Despite their defined appearance by OCT, by histology, these structures appeared to be composed of proteoglycan, with polymeric material being at such low level as to be no longer quantifiable by chromatography. At 3 years, by OCT, recognizable struts decreased to 28±9 struts per BVS: 43.7% showed dissolved black box; 34.8%, dissolved bright box; 16.1%, open box; and 5.4%, preserved box appearance. Histology shows that connective tissue cells within a proteoglycan-rich matrix replaced the areas previously occupied by the polymeric struts and coalesced into the arterial wall. At 4 years, by OCT, 10±6 struts were recognizable as either dissolved black or dissolved bright box. In histology, these struts are minimally discernible as foci of low-cellular-density connective tissue. Relative to the prediction of histological type by OCT appearance, the preserved box appearance of OCT corresponds well with 2-year histology (86.4%), whereas the dissolved bright and black box appearances correspond to 3-year histology (88.0% and 90.7%, respectively). Struts indiscernible by OCT correspond to the integrated strut footprints seen at 4 years (100%). Conclusions— Struts that are still discernible by OCT at 2 years are compatible with largely bioresorbed struts, as demonstrated by histological and gel permeation chromatography analysis. At 3 and 4 years, both OCT and histology confirm complete integration of the struts into the arterial wall.

Assessment of the serial changes of vessel wall contents in atherosclerotic coronary lesion with bioresorbable everolimus-eluting vascular scaffolds using Shin’s method: an IVUS study

Although serial changes in necrotic core and calcium are regarded as surrogates for the bioresorption process in patients treated with the bioresorbable everolimus-eluting vascular scaffolds (BVS), these temporal changes have not yet been fully investigated. Shin's method may be offer a more suitable technique for this analysis because it includes all the contents of both the lumen and vessel wall. The purpose of this study was to assess the serial changes of necrotic core and dense calcium content in coronary lesions that were treated with a BVS implant using Virtual Histology intravascular ultrasound (VH-IVUS) analyzed using Shin's method. A total of 29 patients (92 coronary segments) were imaged to evaluate the serial changes in necrotic core and dense calcium using Shin's method. Lesions treated with a BVS implant were analyzed with serial VH-IVUS assessments, i.e., pre- and post-stenting, and at 6months and 2years follow-up. In Shin's method contours are drawn around the IVUS catheter (instead of delineating the lumen) and the vessel. The mean necrotic core area decreased by 6.9% from post-stenting to 6months (1.71±1.03mm² vs. 1.36±0.91mm², P=0.027), and by 20.5% (1.71±1.03mm² vs. 1.20±0.70mm², P=0.003) from post-steting to 2years; while the mean dense calcium areas decreased by 27.2% (1.07±0.55mm² vs. 0.78±0.64mm², P=0.039) from post-stenting and 2years. At 2years, absolute necrotic core and dense calcium content were significantly decreased as compared to post-stenting values. The present study demonstrates that the bioresorption process in patients who undergoing BVS device implantation can be assessed using VH-IVUS analysed using Shin's method.

A Comparison of the Conformability of Everolimus-Eluting Bioresorbable Vascular Scaffolds to Metal Platform Coronary Stents

The aim of this study was to assess the differences in terms of curvature and angulation of the treated vessel after the deployment of either a metallic stent or a polymeric scaffold device. Conformability of metallic platform stents (MPS) is the major determinant of geometric changes in coronary arteries caused by the stent deployment. It is not known how bioresorbable polymeric devices perform in this setting. This retrospective study compares 102 patients who received an MPS (Multi-link Vision or Xience V, Abbott Vascular, Santa Clara, California) in the SPIRIT FIRST and II trials with 89 patients treated with the Revision 1.1 everolimus-eluting bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) from cohort B of the ABSORB (A bioabsorbable everolimus-eluting coronary stent system) trial. All patients were treated with a single 3 × 18 mm device. Curvature and angulation were measured with dedicated software by angiography. Both the MPS and BVS groups had significant changes in relative region curvature (MPS vs. BVS: 28.7% vs. 7.5%) and angulation (MPS vs. BVS: 25.4% vs. 13.4%) after deployment. The unadjusted comparisons between the 2 groups showed for BVS a nonsignificant trend for less change in region curvature after deployment (MPS vs. BVS: 0.085 cm(-1) vs. 0.056 cm(-1), p = 0.06) and a significantly lower modification of angulation (MPS vs. BVS 6.4° vs. 4.3°, p = 0.03). By multivariate regression analysis, the independent predictors of changes in curvature and angulation were the pre-treatment region curvature, the pre-treatment region angulation, and the used device. Bioresorbable vascular scaffolds have better conformability than conventional MPS. The clinical significance of the observed differences will require further investigation.

Temporal changes of coronary artery plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Implantation of a coronary stent results in a mechanical enlargement of the coronary lumen with stretching of the surrounding atherosclerotic plaque. Using intravascular ultrasound virtual-histology (IVUS-VH) we examined the temporal changes in composition of the plaque behind the struts (PBS) following the implantation of the everolimus eluting bioresorbable vascular scaffold (BVS). Using IVUS-VH and dedicated software, the composition of plaque was analyzed in all patients from the ABSORB B trial who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA) post-treatment and at 6-month follow-up. This dedicated software enabled analysis of the PBS after subtraction of the VH signal generated by the struts. The presence of necrotic core (NC) in contact with the lumen was also evaluated at baseline and follow-up. IVUS-VH data, recorded with s5i system, were available at baseline and 6-month follow-up in 15 patients and demonstrated an increase in both the area of PBS (2.45±1.93mm(2) vs. 3.19±2.48mm(2), P=0.005) and the external elastic membrane area (13.76±4.07mm(2) vs. 14.76±4.56mm(2), P=0.006). Compared to baseline there was a significant progression in the NC (0.85±0.70mm(2) vs. 1.21±0.92mm(2), P=0.010) and fibrous tissue area (0.88±0.79mm(2) vs. 1.15±1.05mm(2), P=0.027) of the PBS. The NC in contact with the lumen in the treated segment did not increase with follow-up (7.33 vs. 6.36%, P=0.2). Serial IVUS-VH analysis of BVS-treated lesions at 6-month demonstrated a progression in the NC and fibrous tissue content of PBS.

TCT-37: ABSORB Cohort B Trial: 9 Months Clinical Results of the Evaluation of the Bioresorbable Everolimus-Eluting Vascular Scaffold (BVS) in the Treatment of Patients with de Novo Native Coronary Artery Lesions

TCT-37: ABSORB Cohort B Trial: 9 Months Clinical Results of the Evaluation of the Bioresorbable Everolimus-Eluting Vascular Scaffold (BVS) in the Treatment of Patients with de Novo Native Coronary Artery Lesions