Abstract 18189: Neointimal Response to Everolimus-eluting Bioresorbable Scaffolds Implanted at Bifurcating Coronary Segments: An Optical Coherence Tomography Study
Background: Previous studies have described different patterns of neointimal coverage between the outer wall and inner wall at coronary bifurcations lesions (BL) treated with metallic drug-eluting stents (DES) due to endothelial shear stress. Everolimus-eluting bioresorbable scaffolds (BRS) have thicker struts and could therefore have a stronger influence on endothelial shear stress compared to DES. However, the neointimal coverage of BL treated with BRS has not been adequately studied. We sought to evaluate the vascular response to BRS struts deployed at BL using optical coherence tomography (OCT).
Methods: 50 patients (64 lesions) underwent follow-up OCT 11.0 ± 2.1 months after BRS implantation. Cross-sectional area of BL with a side branch more than 1mm using OCT was analyzed every 200μm. All images were divided into 3 regions according to shear stress: the 1/2 circumference of the vessel opposite to the ostium (OO), side branch ostium (SO), and the vessel wall adjacent to the ostium (AO). %uncovered strut of all struts and the averaged neointimal thickness (NIT) in 3 regions were evaluated. Additionally, to assess the impact of the side branch size on neointimal proliferation in BL, we calculated the ratio of the diameter of side branch ostium (Ds) to the diameter of main branch (Dm) (Ds/Dm) and divided patients into two groups based on median value of Ds/Dm of 0.318 as follow: large ratio side branch group (LRSB, n=32) and small ratio side branch group (SRSB, n=32).
Results: Mean BRS diameter and length were 3.01±0.37 and 20.7±5.5mm. Mean diameter of all side branches was 1.69±0.51mm. In all patients, there was a significant difference in NIT among 3 regions (OO, 121±66 vs. AO, 96±32 vs. SO, 82±43μm, p=0.03). A significant difference was shown in %uncovered strut among 3 regions (OO, 0.45 vs. AO, 1.5 vs. SO, 4.7%, p=0.03). Further, in LRSB group, there was a significant difference in NIT among 3 regions (OO, 130±63 vs. AO, 92±38 vs. SO, 75±39 μm, p=0.01), and a significant difference was shown in %uncovered strut among 3 regions (OO, 0.37 vs. AO, 2.0 vs. SO, 8.8%, p=0.01).
Conclusion: Different patterns of neointimal coverage are observed between the outer wall and inner wall of BL treated with BRS. Neointimal coverage is least at and adjacent to large side branches.
Author Disclosures: T. Sato: None. M. Abdel-Wahab: None. M. El-Mawardy: None. R. Tölg: None. G. Richardt: None.
- © 2015 by American Heart Association, Inc.