Abstract 10816: Progression of Atherosclerotic Neointima as a Cause of Late Phase In-Stent Restenosis after Bare-Metal Stent Implantation
Background: Recent studies have shown the progression of neoatherosclerosis within the stented segment in the late phase after bare-metal stent (BMS) implantation. We hypothesized that atherosclerotic change might also be responsible for in-stent restenosis (ISR) in the late phase after BMS implantation.
Methods: This study consisted of a total of 52 consecutive patients with in-stent restenosis (ISR) after BMS implantation. According to the duration from stent implantation to the diagnosis of ISR, ISR lesions were classified as the early phase (5 to 8 months), the moderate phase (9 to 12months) or the late phase (more than 13 months). To compare the tissue characterization of neointima among three phases, integrated backscatter intravascular ultrasound (IB-IVUS) was performed for volumetric analysis within the stented segment.
Results: Twenty-six ISR lesions were classified as the early phase, 13 ISR lesions as the moderate phase and 13 ISR lesions as the late phase. On IB-IVUS analysis, the percentage of lipid tissue was significantly higher and that of fibrous tissue was significantly lower in the late phase compared to early or moderate phases (Lipid: 25.9 ± 9.9% vs. 17.0 ± 8.1%, 17.1 ± 6.2%; p=0.007 by ANOVA. Fibrous: 71.5 ± 9.1 vs. 79.9 ± 7.7, 80.6 ± 5.2; p=0.005 by ANOVA). However, there were no significant differences in tissue characterization between early and moderate phases.
Conclusion: We could identify the increased percentage of lipid tissue and the decreased percentage of fibrous tissue in the late phase compared to early or moderate phases, suggesting atherosclerotic neointima as a cause of late phase ISR after BMS implantation.
- © 2012 by American Heart Association, Inc.