Carotid atherosclerosis and risk for ischemic stroke in patients with atrial fibrillation on oral anticoagulant treatment

Abstract

Background and aims: Whether carotid atherosclerosis is associated with an increased risk for ischemic stroke in patients with atrial fibrillation (AF) on anticoagulant treatment is undefined. To explore this association, patients with AF on treatment with vitamin K antagonists were included in a multicenter, prospective study.

Methods: At inclusion in the study, patients underwent Doppler-ultrasonography for the assessment of carotid atherosclerosis and then were prospectively followed. Ischemic stroke or transient ischemic attack (TIA) were the primary study outcomes; death and its causes were reported.

Results: Overall, 587 patients were included in the study. At ultrasonography, 380 patients had carotid atherosclerosis (64.7%) and 45 internal carotid (ICA) stenosis ≥50% (7.7%). During a mean follow-up of 41 ± 15 months, 30 patients had an ischemic stroke or TIA (1.49% per patient-year, 95% CI 0.96-2.03) and 81 patients died (4.01% per patient-year, 95% CI 3.16-4.86). Carotid atherosclerosis was associated with a significant increase in the risk for the composite of ischemic stroke or TIA or death after adjusting for CHA₂DS₂VASc (6.0% vs. 3.1% patient-year; HR 1.60, 95% CI 0.99-2.59; p = 0.05). ICA ≥50% was associated with a not significant increase in the risk of ischemic stroke or TIA (2.05% vs. 1.45% patient-year; HR 1.39, 95% CI 0.42-4.58) or all-cause death (6.1% vs. 3.8% patient-year; HR 1.66, 95% CI 0.83-3.32).

Conclusions: In patients with AF, carotid atherosclerosis is a predictor for the composite of cerebrovascular events or death while on anticoagulant therapy. In patients with AF and carotid atherosclerosis, the clinical benefit of a more intense antithrombotic treatment should be evaluated.

Keywords: Anticoagulants; Atrial fibrillation; Carotid atherosclerosis; Carotid stenosis; Stroke.