Carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. Unlike CEA, CAS is performed by a wide variety of specialists including vascular surgeons (VS), interventional cardiologists (IC), and interventional radiologists (IR). This study compares the indications, in-patient mortality rate, and in-patient stroke rate for patients undergoing CAS, according to operator specialty.
The State In-patient Databases from New York and Florida, made available by the Healthcare Cost and Utilization Project, were reviewed by International Classification of Disease (ICD)-9-CM codes to identify all patients treated with CAS for the years 2005 and 2006. This cohort was then stratified according to operator specialty defined by procedures performed by each operator over the years surveyed. Primary endpoints were in-patient death and stroke. Propensity score matching adjusting for indication, demographics, and comorbidities was employed to evaluate the influence of operator type on outcomes.
During the study period, 4001 CAS procedures were performed. All primary analyses compared VS (n = 1350) to non-VS (n = 2651). Patient characteristics were similar, except VS treated fewer patients with CAD (44.2% vs 50.9%, P < .001) and valvular disease (6.3% vs 8.6%, P = .01) and more patients with chronic lung disease (19.4% vs 15.9%, P = .01). Each group performed an equal proportion of CAS for symptomatic disease (8.1% vs 9.0%, P = .32). Univariate analysis revealed no difference in mortality (0.9% vs 0.5%, P = .13) or stroke (1.3% vs 1.5%, P = .73). Propensity score matched analysis also demonstrated no difference in mortality (0.7% vs 0.4%, P = .48) or stroke (1.1% vs 1.7%, P = .27). Subgroup analysis comparing VS, IC, and IR showed no significant difference in mortality or stroke, but demonstrated that of the three specialties, IC treated the smallest proportion of symptomatic patients. The proportion of CAS performed by VS differed significantly by state (New York 46%, Florida 19%, P < .01).
Despite a paucity of level 1 evidence for CAS in asymptomatic patients and current Centers for Medicare and Medicaid Services (CMS) policy limiting reimbursement for CAS to only high-risk symptomatic patients, VS and non-VS are treating primarily asymptomatic patients. Perioperative rates of stroke and death are equivalent between VS, IC, and IR. Regional variation of operator type is substantial, and despite similar outcomes, <50% of CAS is performed by VS.