Abstract 12458: Proximal Stent Edge Location on Thin Cap Fibroatheroma is a Predictor of In-Stent Restenosis -Optical Coherence Tomography Study
Background: In-stent restenosis (ISR) after percutaneous coronary intervention (PCI) remains a clinically important problem. Previous studies have shown that stent under-expansion and inadequate lesion coverage are the predictors of ISR, but relation between baseline tissue characteristics of coronary lesion and ISR remains unknown. Using optical coherence tomography (OCT), we evaluated the morphological characteristics of coronary segments at both side of stent edges immediately after stent implantation, and evaluated their influence on the development of ISR after 6 to 13 months.
Methods: We retrospectively evaluated 134 culprit coronary lesions in 114 patients (65.8 y/o) with OCT-guided stent implantation (18 bare metal stents; 116 drug eluting stents). ISR was defined as a luminal stenosis greater than 50% within the stent or within 5mm of its edges. OCT tissue characteristics were studied within 5mm proximal and distal segment of each stent edge after stent implantation. The lesions were divided into two groups based on the presence or absence of ISR at follow-up angiography (8.6 months).
Result: ISR was found in 26 (19.4%) lesions. There was no difference in clinical background and angiographic parameters in baseline and after stent implantation. As to OCT findings after stent implantation, the incidence of tissue protrusion was more frequently observed in ISR group than non-ISR group (92.3 vs. 73.2%, P=0.0375), but the incidence of edge dissection and malaposition were similar between the two groups. As to OCT tissue characteristic, thin-cap fibroatheroma (TCFA) at proximal stent edge was only more frequently observed in ISR group than non-ISR group (15.4 vs. 0.9%, p≤0.001). Lipid arc at distal stent edge location was significantly larger in ISR group than non-ISR group (227 ± 79 vs. 155 ± 63 degree, p≤0.05). In analysis adjusted for the existence of protrusion, TCFA was an independent predictor of ISR (OR: 15.6, 95% CI: 2.16-314.2, p≤0.01).
Conclusion: TCFA at proximal stent edge was a powerful predictor of ISR after stent implantation. Although mechanism should be further elucidated, placement of proximal stent edge on TCFA should be avoided.
- © 2013 by American Heart Association, Inc.