Risk factors for cerebral embolization after carotid artery stenting with embolic protection: a diffusion-weighted magnetic resonance imaging study in 837 consecutive patients.

BACKGROUND Meta-analyses of randomized trials have shown an increased risk of periprocedural stroke after carotid artery stenting (CAS) compared with carotid endarterectomy, which may differ in specific patient subgroups. Knowledge of risk factors for cerebral embolic lesions during CAS may impact treatment decisions for the individual patient, but these factors have not been extensively studied. We aimed to identify factors predictive for cerebral ischemic lesions during embolic protected CAS. METHODS AND RESULTS Preprocedural and postprocedural diffusion-weighted magnetic resonance imaging was performed for evaluation of new cerebral ischemic lesions in 728 (86.9%) of 837 consecutive patients undergoing CAS with cerebral embolic protection. Multivariable logistic regression analyses were performed to identify factors predictive for embolic lesions. New ischemic lesions were found in 32.8% of patients. Age, hypertension, lesion length, lesion eccentricity, and aortic arch type III were significantly associated with new ischemic lesions; calcified lesions were negatively associated. In 25% of these patients embolic lesions were also found in the contralateral hemisphere. Predictive factors for contralateral lesions were age, >50% stenosis of the contralateral internal carotid artery, and an aortic arch type II, with a trend for aortic arch type III. CONCLUSIONS Age, hypertension, lesion morphology, and aortic arch type were predictive for procedural-related cerebral embolic lesions during embolic protected CAS. Age, significant contralateral carotid stenosis, and complex aortic arch type were predictive for bilateral ischemic lesions. The clinical implications of ischemic lesions are not yet fully understood.