Abstract 13548: Determination of Indication for Carotid Artery Stenting using Signal Intensity Ratio Evaluated by Magnetic Resonance Imaging-Comparative Study with Carotid Artery Stenting and Carotid Endarterectomy-
Background: Carotid tissue components are associated with an incidence of embolic complications after carotid artery stenting (CAS) or carotid endarterectomy (CEA). The aim of study was to elucidate the relationship between tissue components and the incidence of new embolic lesions after CAS and CEA.
Methods: We performed CAS in 56 patients and CEA in 25 patients with carotid stenosis. We also performed quantitative analyses of plaque characteristics in carotid arteries using T1 weighted black-blood magnetic resonance imaging (BB-MRI) before CAS and CEA. Signal intensity ratio (SIR) was defined as the ratio of signal intensity evaluated by BB-MRI in carotid plaques to that of sternocleidomastoid muscle. According to the criteria we and other investigators previously reported, the SIR was defined as “high”, when the SIR was ≥1.25. New ipsilateral silent ischemic lesions (NISIL) were evaluated by diffusion-weighted imaging of MRI comparing before and after CAS and CEA.
Results: Forty-three plaques were classified as high SIR plaques. There were two minor strokes (2.5%) in high SIR group treated with CAS, whereas there was no stroke in high SIR group treated with CEA. In the high SIR group, the incidence of NISIL was higher in CAS group than CEA group (CAS vs CEA: 61% vs 13%, p=0.007), whereas there were no significant differences in the incidence of NISIL in the plaques with SIR <1.25 (CAS vs CEA; 21% vs 0%). In multivariate logistic regression analysis, the independent predictors of NISIL were CAS procedure (p = 0.002), and the SIR (p = 0.021). The positive and negative predictive values of SIR for NISIL were 61% and 79%.
Conclusions: Embolic complications occur more frequently after CAS than after CEA when SIR of carotid plaques ≥1.25. CEA should be selected when the SIR of carotid plaques is ≥1.25. Noninvasive quantitative tissue characterization in carotid plaques using BB-MRI is useful to determine the indication of CAS.
- © 2010 by American Heart Association, Inc.