Preprocedural Carotid Plaque Echolucency as a Predictor of In-Stent Intimal Restenosis after Carotid Artery Stenting

Objectives: In-stent intimal restenosis (ISR) caused by neointimal hyperplasia can develop <24 months after carotid artery stenting (CAS). The utility of plaque imaging by carotid ultrasonography (US) or magnetic resonance imaging (MRI) has been investigated for the prediction of ipsilateral stroke. We aimed to investigate whether these imaging techniques are useful for detecting carotid plaques prone to ISR. Materials and Methods: We examined 133 patients (mean age of 72.1 +/- 8.4 years old) that received CAS at a single hospital from 2014 to 2018. A pre-CAS carotid plaque evaluation was performed by carotid angiography, duplex carotid US, and black-blood carotid artery MRI (BB-MRI). The mean stenosis rate was 71.0 +/- 12.3% by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. Follow-up carotid angiography was performed 6 months after CAS in all patients according to a predefined protocol. ISR was defined as in-stent intimal hyperplasia more than 50% stenosed based on the NASCET criteria. The selection of the stent type was at the discretion of the treating physician. Predictors of ISR were determined by multivariate logistic regression analysis. Results: Follow-up angiography demonstrated ISR in 33 patients (24.8%). In 44 patients, more than two stents were deployed. Univariate logistic regression analyses demonstrated echolucent lesion, floating plaque, complete occlusive or pseudo-occlusive lesion, and closed-cell stent use as significantly associated with ISR (>50%). Multivariate logistic regression analysis demonstrated that echolucent lesion (OR 4.667, 95% CI 1.849-11.779) and closed-cell stent use (OR .378, 95% CI .148-.968) were significantly associated with ISR. Conclusions: Preprocedural plaque characterization by carotid US appeared to be useful to predict ISR 6 months after CAS.