Stroke and death after carotid endarterectomy and carotid artery stenting with and without high risk criteria.

OBJECTIVE: Centers for Medicare and Medicaid Services (CMS) reimbursement criteria for carotid artery stenting (CAS) require that patients be high surgical risk or enrolled in a clinical trial. This may bias comparisons of CAS and carotid endarterectomy (CEA). We evaluate mortality and stroke following CAS and CEA stratified by medical high risk criteria.
METHODS: The Nationwide Inpatient Sample (2004-2007) was queried by ICD-9 code for CAS and CEA with diagnosis of carotid artery stenosis. Medical high risk criteria were identified for each patient including patients undergoing a coronary artery bypass and/or valve repair (CABG/V) during the same admission. Symptom status was defined by history of stroke, transient ischemic attack (TIA), and/or amarosis fugax. The primary outcome was postoperative death, stroke (complication code 997.02), and combined stroke or death, stratified by high risk vs non-high risk status and symptom status.
RESULTS: Patient totals of 56,564 (10.5%) CAS and 482,394 (89.5%) CEA were identified. Half of the patients in each group were high risk. CABG/V was performed less commonly with CAS than CEA (2.8% vs 4.0%, P < .001). Patients undergoing CAS were more likely symptomatic than those undergoing CEA (13.1% vs 9.4%, P < .001). Mortality was higher after CAS than CEA for both high risk and non-high risk patients. Stroke was also higher after CAS for both high risk and non-high risk patients. Combined stroke or death was higher after CAS again for both high risk (asymptomatic 1.5% vs 1.2%, P < .05, symptomatic 14.4% vs 6.9%, P < .001) and non-high risk (asymptomatic 1.8% vs 0.6%, P < .001, symptomatic 11.8% vs 4.9%, P < .001). Combined stroke or death for patients undergoing CABG/V during the same admission was similar for CAS and CEA (4.8% vs 3.2%, P = .19). Multivariate predictors of combined stroke or death adjusted for age and gender included CAS vs CEA (odds ratio [OR] 2.4, P < .001), symptom status (OR 6.8, P < .001), high risk (OR 1.6, P < .001), and earlier year of procedure (OR 1.1, P < .01).
CONCLUSIONS: In the United States from 2004 to 2007, CAS has a higher risk of stroke and death than CEA after adjustment for medical high risk criteria. Further analysis with prospective assessment of risk factors is needed to guide appropriate patient selection for CEA and CAS in the general population.