Risk-adjusted 30-day outcomes of carotid stenting and endarterectomy: results from the SVS Vascular Registry.

OBJECTIVE: As the first operational societal registry of carotid procedures, the Outcomes Committee of the Society for Vascular Surgery (SVS) developed the Vascular Registry (VR) in response to the Centers for Medicare and Medicaid Services' (CMS) National Coverage Decision on carotid artery stenting (CAS). Although CMS requires data submission only on CAS, the VR collects similar data on carotid endarterectomy (CEA) to allow comparison of outcomes, as well as potential for expansion to other procedures.
METHODS: SVS-VR on-line provider-reported data include baseline through follow-up visits to better understand long-term risks and benefits associated with CAS and CEA. The primary outcomes are combined death, stroke, and myocardial infarction (MI). An independent data coordinating center maintains the database, which is Health Insurance Portability and Accountability Act (HIPAA)-compliant and auditable.
RESULTS: As of December 26, 2007, 6403 procedures with discharge data were entered by 287 providers at 56 centers on 2763 CAS patients (1450 with 30-day outcomes, 52.5%) and 3259 CEA patients (1368 with 30-day outcomes, 42%). Of the total cohort, 98% of CEA and 70.7% of CAS (P < .001) were performed for atherosclerotic disease. Restenosis accounted for 22.3% and post-radiation induced stenosis in 4.5% of CAS patients. Preprocedure lateralizing neurologic symptoms were present in a greater proportion of CAS patients (49.2%) than CEA patients (42.4%, P < .001). CAS patients also had higher preprocedure prevalence of coronary artery disease (CAD), MI, congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and cardiac arrhythmia. For CAS, death/stroke/MI at 30 days was 7.13% for symptomatic patients and 4.60% for asymptomatic patients (P = .04). For CEA, death/stroke/MI at 30 days was 3.75% in symptomatic patients and 1.97% in asymptomatic patients (P = .05). After risk-adjustment for age, history of stroke, diabetes, and American Society of Anesthesiologists (ASA) grade (ie, factors found to be significant confounders in outcomes using backwards elimination), logistic regression analysis suggested better outcomes following CEA. There were no statistically significant differences when examining CAS outcomes based on center volume. CAS in atherosclerotic disease had significantly worse outcomes than in nonatherosclerotic stenosis. When CAS and CEA were compared in the treatment of atherosclerotic disease only, the difference in outcomes between the two procedures was more pronounced, with death/stroke/MI 6.42% after CAS vs 2.62% following CEA, P < .0001.
CONCLUSION: Following best possible risk adjustment of these unmatched groups, symptomatic and asymptomatic CAS patients had significantly higher 30-day postprocedure incidence of death/stroke/MI when compared with CEA patients. The initial 1.5 years of data collection provide proof of concept that a specialty society based VR can succeed in meeting regulatory and scientific goals. With continued enrollment and follow-up, analysis of SVS-VR will supplement randomized trials by providing real-world comparisons of CAS and CEA with sufficient numbers to serve as an outcome assessment tool of important patient subsets and across the spectrum of peripheral vascular procedures.