Abstract 18127: The Relationship Between Nonuniform Strut Distribution and Neointimal Coverage After Everolimus-eluting Bioresorbable Scaffolds Implantation
Objects: The number and distribution of stent struts have been reported to affect neointimal coverage of metalic drug-eluting stent (DES). According to previous reports, the thick struts of everolimus-eluting bioresorbable scaffolds (BRS) created areas of low endothelial shear stress, which may contribute to neointimal formation. The aim of the present study is to investigate the relationship between the distribution of BRS struts and neointimal coverage.
Methods: 43 patients (50 lesions) underwent follow-up optical coherence tomography (OCT) 11.8 ± 2.6 months after BRS implantation. Cross sectional area (CSA) of OCT images were analyzed at 1-mm intervals. Scaffold area and neointimal thickness were evaluated. Additionally, scaffold eccentricity (SE) was defined as follows: SE = [maximum (Max) diameter - minimum(Min) diameter]/ Max diameter. Furthermore, to assess the impact of the strut distribution, CSAs of BRS were divided into four regions. The average neointimal thickness (ANT) and the number of strut in each region were measured. The number of strut in each region was classified into 1, 2, 3 and ≥4. Further, the ANT acquired in each area was divided by ANT of all struts in the same CSA to describe an unevenness score, and its Max and Min values were defined as Max-unevenness score and Min-unevenness score.
Results: Mean scaffold diameter and length were 3.17±0.37 and 19.9±5.2 mm. In almost all cases, pre- (90%) and post- (80%) dilatation were performed at initial percutaneous coronary intervention. There was a significant difference in the unevenness score among regions with differenrt strut numbers (unevenness score=1,04±0.34 in regions with 1 strut (N=400); 0.97±0.25 in regions with 2 struts (N=616); 1.00±0.25 in regions with 3 struts (N=894);1.04±0.20 in regions with ≥4 struts (N=938); p=0.01). Furthermore, a significant correlation was observed between SE and the dispersion of neointimal coverage in each CSA, which was expressed as Max-unevenness score - Min- unevenness score (N=792, R=0.10, p=0.02).
Conclusion: Unlike metallic DES, crowding of struts as well as spare distribution of struts is associated with increased neointimal proliferation after BRS implantation. In addition, SE might be associated with uneven neointimal coverage.
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.