Abstract 18936: OFDI is a Better Predictor of Above Strut Coverage than IVUS in Stented Human Coronary Arteries Studied Ex-Vivo
Background: The risk of late stent thrombosis remains a major concern where its incidence is dependent on a lack of strut coverage (Circulation 2007;115;2435–2441). Therefore, assessment of covered struts by imaging modalities at follow-up is considered to be an important surrogate to help stratify the patient's future risk for thrombotic events.
Methods: Stented vessels (n=12) from 9 hearts examined at autopsy underwent ex-vivo optical frequency domain imaging (OFDI system, Terumo Corp, Tokyo, Japan) with intravascular ultrasound (IVUS system, Terumo Corp, Tokyo, Japan) where 100 pairs of acquired images were co-registered with histopathology, which served as a control for comparative measurements. Morphometric analysis was performed for determination of cross-sectional neointimal area (mm2) and neointimal thickness (mm). The number of total struts per section and uncovered struts were also assessed and the ratio of uncovered to total struts per section (RUTSS) was calculated. To further evaluate the utility of OFDI to detect covered versus uncovered struts, a detailed analysis was performed on a subset of histologic sections (n=6) with at least 1 uncovered strut where a total of 47 covered and 16 uncovered struts were identified.
Results: Measurement of neointimal area by OFDI and IVUS showed a excellent correlation with histopathology (OFD: R=0.92; IVUS: R=0.87, P<0.0001). On the contrary, the correlation with minimum neointimal thickness by IVUS waned (R=0.66, P<0.0001) while this relationship was maintained in OFDI (R=0.91, P<0.0001). Similarly, RUTSS analysis in IVUS showed a poor correlation (R=0.54, P<0.0001) while OFDI demonstrated superiority (R=0.91, P<0.0001). Overall identification of strut coverage by OFDI demonstrated a sensitivity of 95.7% and specificity of 81.3%.
Conclusions: OFDI is most promising in detecting strut coverage in intracoronary stents and potentially assessing the future risk of late stent thrombosis.
- © 2010 by American Heart Association, Inc.