Outcomes of Carotid Revascularization versus Optimal Medical Treatment Alone for Asymptomatic Carotid Stenosis: Inverse-Probability-of-Treatment Weighting Using Propensity Scores

Background: The benefits and necessity of revascularization for asymptomatic carotid stenosis remains under debate. This study aimed to determine the more durable and beneficial alternative between carotid revascularization and optimal medical treatment (OMT) alone for asymptomatic carotid stenosis. Methods: We performed a retrospective analysis of patients with asymptomatic severe carotid stenosis at a tertiary institution between 1994 and 2017. We compared revascularization (carotid endarterectomy [CEA] and carotid artery stenting [CAS]) with OMT alone by using inverse-probability-of-treatment weighting with propensity scores to account for selection bias. The primary end point was a composite of any stroke, myocardial infarction, and death within 30 days, plus ipsilateral stroke thereafter. Results: A total of 1089 patients were included in the analysis (56% CEA, 25% CAS, 19% OMT alone). Patients who underwent CAS consistently showed greater risk regarding the primary composite end point compared with those who received OMT alone (hazard radio [HR] 3.32, 95% confidence interval 1.014–10.868; P = 0.047), but the CEA group showed no significant difference (HR 1.19, 95% confidence interval 0.385–4.584; P = 0.761). The CAS group had the greatest rates of any stroke within 30 days (4.0%, P = 0.0006) and ipsilateral stroke thereafter (3.68%, P = 0.0009). There was no death within 30 days. In the long-term outcomes, neither CEA nor CAS showed significant differences in HR compared with OMT alone. Conclusions: Our study suggests that for stroke prevention in asymptomatic severe carotid stenosis, CAS might be inferior to the other 2 options regarding early outcomes. However, further investigation is required regarding the efficacy and durability of OMT alone.