Abstract 13995: Comparison of Angiographic Patterns and Tissue Characterizations of In-stent Neointimal Hyperplasia by Integrated Backscatter Intravascular Ultrasound Between Drug-Eluting Stents and Bare-Metal Stents
Background: The mechanism of in-stent restenosis (ISR) after drug-eluting stent implantation remains unclear. The aim of this study was to analyze tissue characterizations of in-stent neointimal hyperplasia in sirolimus-eluting stents (SES) and bare-metal stents (BMS) using integrated backscatter intravascular ultrasound (IB-IVUS) and to determine whether there are any differences between SES and BMS.
Methods: We evaluated angiographic patterns of ISR and tissue characterizations of in-stent neointimal hyperplasia in 44 ISR lesions of 40 consecutive patients previously treated with SES (n=17) or BMS (n=27). For IB-IVUS analysis of tissue characterizations, in-stent neointimal hyperplasia was evaluated by two-dimensional (at the narrowest cross-section) and three-dimensional analyses (within the stented segment). IB values on the regions of interest were classified into 3 categories: lipid, −130<IB<-49dB; fibrous, −49<IB<-29dB; calcified, −29<IB<-11dB. On the basis of these categories, color-coded map of in-stent neointimal hyperplasia was constructed and the proportions of each category were compared between SES and BMS.
Results: In the angiographic patterns of ISR, diffuse ISR was more commonly observed in BMS group than in SES group (81.5% vs.11.8%, p<0.001), whereas focal ISR was commonly observed in SES group than in BMS group (88.2% vs. 18.5%, p<0.001). In both two- and three-dimensional analyses of in-stent neointimal hyperplasia, the proportions of lipid content were significantly larger in SES group compared to BMS group (2D, 21.2% vs.13.0%, p=0.004; 3D, 22.0% vs. 15.2%, p=0.006). On the other hand, the proportions of fibrous content were significantly smaller in SES group compared to BMS group (2D, 75.4% vs. 84.7%, p<0.001; 3D, 74.7% vs. 81.6%, p=0.002).
Conclusions: We could identify the differences between SES and BMS in angiographic patterns of ISR and tissue characterizations of in-stent neointimal hyperplasia, suggesting that the mechanism of restenosis in SES may be different from that in BMS.
- © 2010 by American Heart Association, Inc.