Abstract

Abstract Objective: Symptomatic carotid stenosis is associated with a 3‐fold risk of early stroke recurrence compared to other stroke subtypes. Current carotid imaging techniques rely on estimating plaque‐related lumen narrowing but do not evaluate intraplaque inflammation, a key mediator of plaque rupture and thromboembolism. Using combined 18 F‐fluorodeoxyglucose positron‐emission tomography (FDG‐PET)/computed tomography, we investigated the relation between inflammation‐related FDG uptake and stroke recurrence. Methods: Consecutive patients with a recent (median, 6.5 days; interquartile range, 4–8) stroke, transient ischemic attack (TIA), or retinal embolism and ipsilateral carotid stenosis (≥50%) were included. FDG uptake was quantified as mean standardized uptake values (SUVs, g/ml). Patients were followed prospectively for stroke recurrence. Results: Sixty patients were included (25 stroke, 29 TIA, 6 retinal embolism). Twenty‐two percent (13 of 60) had stroke recurrence within 90 days. FDG uptake in ipsilateral carotid plaque was greater in patients with early recurrent stroke (mean SUV, 1.85g/ml; standard deviation [SD], 0.44 vs 1.58g/ml; SD, 0.32, p = 0.02). On life‐table analysis, 90‐day recurrence rates with mean SUV greater than a 2.14g/ml threshold were 80% (95% confidence interval [CI], 41.8–99.2) versus 22.9% (95% CI, 12.3–40.3) with SUV ≤2.14g/ml (log‐rank, p < 0.0001). In a Cox regression model including age and degree of stenosis (50–69% or ≥70%), mean plaque FDG uptake was the only independent predictor of stroke recurrence (adjusted hazard ratio, 6.1; 95% CI, 1.3–28.8; p = 0.02). Interpretation: In recently symptomatic carotid stenosis, inflammation‐related FDG uptake was associated with early stroke recurrence, independent of the degree of stenosis. Plaque FDG‐PET may identify patients at highest risk for stroke recurrence, who may be selected for immediate revascularization or intensive medical treatment. ANN NEUROL 2012