Randomized Comparison Between Everolimus-Eluting Bioresorbable Scaffold and Metallic Stent: Multimodality Imaging Through 3 Years

Objectives: The aim of this study was to investigate the vascular responses and fates of the scaffold after bioresorbable vascular scaffold (BVS) implantation using multimodality imaging. Background: Serial comprehen

Two-year clinical, angiographic, and serial optical coherence tomographic follow-up after implantation of an everolimus-eluting bioresorbable scaffold and an everolimus-eluting metallic stent: insights from the randomised ABSORB Japan trial

We sought to investigate two-year clinical and serial optical coherence tomography (OCT) outcomes after implantation of a fully bioresorbable vascular scaffold (BVS) or a cobalt-chromium everolimus-eluting stent (CoCr-EES). In the ABSORB Japan trial, 400 patients were randomised in a 2:1 ratio to BVS (N=266) or CoCr-EES (N=134). A pre-specified OCT subgroup (N=125, OCT-1 group) underwent angio-graphy and OCT post procedure and at two years. Overall, the two-year TLF rates were 7.3% and 3.8% in the BVS and CoCr-EES arms (p=0.18), respectively. Very late scaffold thrombosis (VLST) beyond one year was observed in 1.6% (four cases: all in non-OCT-1 subgroups) of the BVS arm, while there was no VLST in the CoCr-EES arm. In three cases, OCT at the time of or shortly after VLST demonstrated strut discontinuities, malapposition and/or uncovered struts. However, the vessel healing by two-year OCT was nearly complete in both BVS and CoCr-EES arms with almost fully covered struts, and minimal malapposition. The flow area by two-year OCT was smaller in the BVS arm than in the CoCr-EES arm, mainly due to tissue growth inside the device. However, there were no differences between the BVS and CoCr-EES with regard to the quality of homogenous tissues growing inside the devices. The rate of TLF was numerically higher in the BVS arm than in the CoCr-EES arm, although this difference was not statistically significant. VLST was observed only in the BVS arm at a rate of 1.6% between one and two years. Further studies are mandatory to investigate the risk of BVS relative to metallic stents for VLST, and the underlying mechanisms of BVS VLS

Randomized Comparison Between Everolimus-Eluting Bioresorbable Scaffold and Metallic Stent: Multimodality Imaging Through 3 Years

Objectives: The aim of this study was to investigate the vascular responses and fates of the scaffold after bioresorbable vascular scaffold (BVS) implantation using multimodality imaging. Background: Serial comprehensive image assessments after BVS implantation in the context of a randomized trial have not yet been reported. Methods: In the ABSORB Japan trial, 400 patients were randomized to a BVS (n = 266) or a cobalt-chromium everolimus-eluting stent (n = 134). Through 3 years, patients underwent serial angiography and intravascular ultrasound or optical coherence tomography (OCT). Results: Luminal dimension at 3 years was consistently smaller with the BVS than with the cobalt-chromium everolimus-eluting stent (mean angiographic minimal luminal diameter 2.04 ± 0.63 mm vs. 2.40 ± 0.56 mm, mean difference −0.37 mm [95% confidence interval: −0.50 to −0.24 mm]; p < 0.001), mainly because of smaller device area (6.13 ± 2.03 mm2 vs. 7.15 ± 2.16 mm2, mean difference −1.04 mm2 [95% confidence interval: −1.66 to −0.42 mm2]; p < 0.001), and larger neointimal area (2.10 ± 0.61 mm2 vs. 1.86 ± 0.64 mm2, mean difference 0.24 mm2 [95% confidence interval: 0.06 to 0.43 mm2]; p = 0.01) by OCT. BVS-treated vessels did not show previously reported favorable vessel responses, such as positive vessel remodeling, late luminal enlargement, and restoration of vasomotion, although the OCT-based healing score was on average zero (interquartile range: 0.00 to 0.00). At 3 years, intraluminal scaffold dismantling (ISD) was observed in 14% of BVS. On serial OCT, ISD was observed in 6 lesions at 2 years, where the struts had been fully apposed at post-procedure, while ISD was observed in 12 lesions at 3 years, where 8 lesions were free from ISD on 2-year OCT. In 5 cases of very late scaffold thrombosis, strut discontinuities were detected in all 4 cases with available OCT immediately before reintervention. Conclusions: In this multimodality serial imaging study, luminal dimension at 3 years was smaller with the BVS than with the cobalt-chromium everolimus-eluting stent. ISD, suspected to be one of the mechanisms of very late BVS thrombosis, was observed in a substantial proportion of cases at 3 years, which developed between post-procedure and 2 years and even beyond 2 years. (AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 [Absorb™ BVS] in Japanese Population [ABSORB JAPAN]; NCT01844284