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

OBJECTIVE: 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.

METHODS: 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 vs. CAS for severe (60-79%) and very severe (≥80%) stenosis adjusting for baseline characteristics.

RESULTS: 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 vs. 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 vs. 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 CEA in patients with very severe stenosis [OR 1.64 (95% CI: 1.26-2.13)]. The 30-day composite stroke/death risk for patients undergoing CEA was similar for severe vs. 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 vs. 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 [HR 1.40 (95% CI 1.15-1.70)] and very severe stenosis [HR 1.62 (95% CI 1.37-1.90)].

CONCLUSION: 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.