In-Stent Stenosis or Occlusion After Carotid Artery Stenting in Patients Treated With Anticoagulants vs Antiplatelet Therapy.

INTRODUCTION

Rise in anticoagulant use increases the likelihood that patients undergoing carotid artery stenting (CAS) are on anticoagulants. This complicates postprocedural antithrombotic management, as dual antiplatelet therapy is standard to reduce stent-related complications. To mitigate bleeding risks, patients on anticoagulants often briefly receive a single antiplatelet agent instead. Based on clinical practice, we hypothesized this regimen may increase in-stent stenosis, potentially raising the risk of recurrent ipsilateral transient ischemic attack or ischemic stroke.

DESIGN

Single-center, retrospective cohort study at a tertiary referral center.

METHODS

Patients with significant carotid artery stenosis treated with CAS (May 2005 to September 2024) were categorized into the anticoagulant (with or without antiplatelet therapy) or antiplatelet group (mono therapy or dual therapy). Primary outcome was in-stent stenosis at short-term (30 days to 8 weeks) and mid-term (1 year) follow-ups. Secondary outcomes included 30-day composite of thromboembolic and bleeding complications, reintervention, and other procedure-related adverse events. For the sensitivity analysis, multiple imputation was performed to address missing data.

RESULTS

Among 327 patients, 274 (83.8%) received antiplatelets and 53 (16.2%) anticoagulants. In-stent stenosis rates did not differ at short term (2.1% vs 2.8%, P = 1.00) but were higher in the anticoagulant group at mid-term (21.6% vs 7.4%, P = .01; adjusted odds ratio [OR] 3.29, 95% confidence interval [CI] 1.16-9.39), with more symptomatic cases (10.5% vs 1.0%, P = .01). All occurred in direct oral anticoagulant (DOAC) users, 75% also on single antiplatelet therapy. However, sensitivity analysis yielded a non-significant association (OR 1.29, 95% CI 0.54-3.07, P = .56). Secondary outcomes showed no significant differences.

CONCLUSION

Anticoagulant use, specifically DOACs, appears associated with increased mid-term (symptomatic) in-stent stenosis in the primary analysis. However, this association was attenuated in the sensitivity analysis. Prospective studies are warranted to guide post-CAS antithrombotic therapy in anticoagulated patients.Clinical ImpactAs the number of patients undergoing carotid artery stenting while receiving oral anticoagulation continues to rise, clinicians face uncertainty regarding optimal post-procedural antithrombotic therapy. This study identifies a potential association between anticoagulant use, particularly direct oral anticoagulants, and increased mid-term carotid in-stent stenosis. Confirmation in prospective studies is required. The innovation of this study lies in addressing an important evidence gap in carotid intervention practice, providing the first comparison of in-stent stenosis outcomes between anticoagulant- and antiplatelet-treated patients.