Early Outcomes After Carotid Artery Stenting Compared With Endarterectomy for Asymptomatic Carotid Stenosis

Background and Purpose-Despite the absence of definitive data from randomized clinical trials on the comparative effectiveness of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) for asymptomatic carotid stenosis, the use of CAS has been expanding and seems to be displacing the use of CEA in some parts of the United States. Methods-We used comprehensive hospital discharge data from January 2010 to December 2012 to identify patients who had CEA or CAS for asymptomatic carotid stenosis at all academic medical centers that participate in the University HealthSystem Consortium. In-hospital death and postoperative stroke after CAS and after CEA were compared using multivariable logistic regression, propensity score matching, and a grouped-treatment approach using multilevel mixed-effects models to adjust for baseline characteristics of patients selected for these procedures. Results-We identified 17 716 patients with asymptomatic carotid stenosis treated with CEA and 3962 treated with CAS at 186 University HealthSystem Consortium hospitals. Postoperative stroke or in-hospital death was more frequent after CAS (4.0% versus 1.5%; P<0.001), and patients with CAS were more likely to have these adverse outcomes even after adjusting for baseline characteristics using multivariable analysis (odds ratio [OR], 2.5; 95% confidence interval [CI], 2.1-3.1; P<0.001) and propensity score matching (OR, 2.5; 95% CI, 1.9-3.4; P<0.001). In a multilevel mixed-effects model, hospitals that performed a higher proportion of all carotid revascularization cases using CAS had significantly higher rates of adverse outcomes (OR, 3.7; 95% CI, 1.8-7.6; P<0.001) after adjusting for patient-level variables. Conclusions-For asymptomatic carotid stenosis, CAS is associated with a substantially higher risk of postoperative stroke or in-hospital death than CEA even after adjustment for baseline differences in hospital and patient characteristics.