Abstract 6105: Clinical Impact of In-Vivo Coronary Stent Fracture as a Cause of In-Stent Restenosis: its Morphological Characteristics Provided By Multislice Computed Tomography
Some cases have been reported concerning in-vivo coronary stent fracture as an alternative cause of in-stent restenosis (ISR) to neointimal hyperplasia. Conventional cine-angiogram is apt to miss clear visualization of stent structure, whereas multislice computed tomography (MSCT) has potential to depict stent structure more precisely. The aim of this study is to investigate the frequency and morphological characteristics of coronary stent fracture, as well as its impact on ISR. We performed MSCT coronary angiography for 290 consecutive patients post coronary stenting, and 488 lesions were included in the analysis. Stent fracture was defined as spontaneous injury to structure of stent strut without any artificial process. Correlation of fracture rate with each of the following parameters was evaluated: stented vessel, multiple stenting, overlap, bending and severe calcification of the native vessel. ISR rate was also compared between fractured and non-fractured groups. Among 488 stented sites, fracture was detected in 38 sites (8%). ISR rate was significantly higher in fractured group (26% vs. 8%, p < 0.0001). The right coronary artery showed a significantly higher fracture rate than the left coronary artery (15% vs. 6%, p < 0.0001). Multiple stenting and overlap were significantly higher in fracture rate than single stenting (18% vs. 4% and 22% vs. 2%, both p < 0.0001). Vessel bending had a significantly higher fracture rate (27% vs. 7%, p = 0.0056), while severe calcification had no significant difference. Fracture was detected in 8% of stented sites, which is more likely to induce ISR. MSCT allows precise detection of stent fracture.