Head-to-Head Comparison of the Neointimal Response Between Metallic and Bioresorbable Everolimus-Eluting Scaffolds Using Optical Coherence Tomography

The metallic everolimus drug-eluting stents (DES) and polymeric everolimus bioresorbable vascular scaffolds (BVS) are coated with the same antiproliferative drug. It is uncertain if, during the bioresorption process, the neointimal response of everolimus BVS differs from that of everolimus DES. A total of 31 lesions treated with a single everolimus BVS, and 19 lesions treated with everolimus DES and imaged with optical coherence tomography at 1 year, were investigated. Neointimal response was assessed as a percentage of uncovered struts, neointimal thickness, in-stent/scaffold area obstruction, and pattern of neointima. Both scaffolds presented with similar neointimal response. However, the everolimus BVS presented with a trend toward higher proportion of intraluminal masses than everolimus DES did. Objectives This study sought to compare the neointimal response of metallic everolimus drug-eluting stents (DES) and polymeric everolimus bioresorbable vascular scaffolds (BVS) by optical coherence tomography at 1 year. Background DES decrease the risk of restenosis by reducing the neointimal response. However, DES may impair strut coverage, and this has been associated with late stent/scaffold thrombosis. BVS may overcome the risk of stent/scaffold thrombosis when completely resorbed. It is unknown if, during the bioresorption process, the neointimal response of the everolimus BVS (Absorb, Abbott Vascular, Santa Clara, California) differs from that of the metallic everolimus DES (Xience, Abbott Vascular). Methods A total of 19 lesions were treated with a single everolimus DES, and 31 lesions were treated with everolimus BVS and imaged with optical coherence tomography at 1 year. Neointimal response was assessed as percentage of uncovered struts, neointimal thickness, in-stent/scaffold area obstruction, and pattern of neointima. Results At 1 year, no significant differences in the angiographic lumen loss were seen for the everolimus DES and everolimus BVS (0.18 ± 0.20 mm vs. 0.29 ± 0.36 mm; p = 0.42). optical coherence tomography analysis of 951 cross sections and 8,385 struts demonstrated similar rates of uncovered struts (5.3% everolimus DES vs. 4.5% everolimus BVS; p = 0.11), mean neointimal thickness (120.6 ± 46.0 μm vs. 136.1 ± 71.4 μm; p = 0.82) and in-stent/scaffold area obstruction (12.5 ± 7.1% vs. 13.6 ± 9.7%; p = 0.91), respectively. There was a trend of higher heterogenic tissue pattern of neointima (21.1% vs. 6.5%; p = 0.12) and less intraluminal masses (0% vs. 12.9%; p = 0.10) with everolimus DES than with everolimus BVS. Conclusions The everolimus BVS (Absorb) demonstrated a similar neointimal response as the everolimus DES (Xience). However, the presence of intraluminal masses at 12 months in a small proportion of patients warranted watchful follow-up of these cases.