Transfemoral Carotid Artery Stents Should Be Used with Caution in Patients with Asymptomatic Carotid Artery Stenosis

Abstract

Significant national variation exists in defining the degree of stenosis that requires intervention in patients with asymptomatic carotid artery stenosis (ACAS). We aimed to evaluate the risk of perioperative and 2-year stroke and death in ACAS patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS) for severe versus very severe stenosis in a contemporary population. All patients undergoing CEA or transfemoral CAS for ACAS in the Vascular Quality Initiative (2005-2017) were included. Degree of stenosis was defined as the highest recorded on any imaging method. Univariable and multivariate logistic regression analyses were performed to assess risk of stroke, stroke/death, and major adverse cardiac events (MACE) at 30 days; and Cox proportional hazard, life tables, and Kaplan-Meier estimates were implemented to evaluate ipsilateral stroke and stroke/death at 2 years postoperatively in patients undergoing CEA versus CAS for severe (60-79%) and very severe (≥80%) stenosis adjusting for baseline characteristics. A total of 53,337 ACAS patients were examined (severe stenosis=17,586; 33.%), of which 11.5% (n=6,127) underwent CAS. The crude incidence of 30-day stroke/death was significantly higher for CAS versus CEA in the very severe stenosis group (2.0% vs. 1.2%, P<0.001), but not in the severe stenosis group (1.7% vs. 1.3%, P=0.17). MACE was not significantly different for CAS versus CEA in either group (P≥0.64). On multivariable analysis, CAS was associated with a persistently higher risk of 30-day stroke or death compared to CEAin patients with very severe stenosis (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.26-2.13). The 30-day composite stroke/death risk for patients undergoing CEA was similar for severe versus very severe stenosis (OR 1.07, 95% CI 0.89-1.28), but there was a trend toward higher risk of perioperative stroke in the severe stenosis group (OR 1.23, 95% CI 0.97-1.56). Two-year outcomes were similar; the crude annualized incidence rates of stroke and stroke/death were higher for CAS versus CEA in both the severe (stroke: incidence rate ratio [IRR] 1.62, 95% CI 1.00-2.55; stroke/death: IRR 1.53, 95% CI 1.11-1.64) and very severe stenosis (stroke: IRR 1.97, 95% CI 1.44-2.65; stroke/death: IRR 1.51, 95% CI 1.34-1.68) groups (all, P≤0.04). On multivariable Cox proportional hazards analysis, CAS was associated with a higher risk of stroke or death compared to CEA in patients with both severe (hazard ratio [HR] 1.40, 95% CI 1.15-1.70) and very severe stenosis (HR 1.62, 95% CI 1.37-1.90). More than one-third of patients undergoing carotid revascularization for ACAS had 60-79% stenosis. Having lower degree of stenosis is not protective against stroke and death for either CEA or CAS at either 30 days or 2 years postoperatively. We believe that optimal medical management should be the first line in stroke prevention for asymptomatic patients with severe (60-79%) carotid stenosis.