Symptomatic carotid stenosis and stroke risk in patients with transient ischemic attack according to the tissue-based definition

Abstract

Background and Purpose: Symptomatic carotid stenosis (sCS), a common cause of transient ischemic attack (TIA), is correlated with higher stroke risk. We investigated the frequency and associated factors of sCS in patients with TIA and the association between sCS and stroke risk following TIA. Methods: Over a three-year period (2011–2013), 861 consecutive patients with TIA, who were admitted to the Department of Neurology at the University of Lübeck, Germany, were included in a monocenter study and prospectively evaluated. Diagnosis of TIA was in accordance with the tissue-based definition (transient neurological symptoms without evidence of infarction by brain imaging). Results: Of 827 patients (mean age, 70 ± 13.2 years; 49.7% women), 64 patients (7.7%; 95% confidence interval [CI], 5.9%–9.7%) exhibited sCS and 3 patients (0.3%) showed an occlusion of the corresponding internal carotid artery. Logistic regression revealed that sCS was associated with male sex (odds ratio [OR], 2.7; 95% CI, 1.2–3.6; p = 0.012), amaurosis fugax (OR, 8.1; 95% CI, 3.4–19–4; p < 0.001), unilateral weakness (OR, 3.4; 95% CI, 1.9–6.1; p < 0.001), symptom duration less than 1 h (OR, 2.0; 95% CI, 1.1–3.4; p = 0.019) and previous stroke (OR, 2.7; 95% CI, 1.5–4.7; p = 0.001). During hospitalization (mean, 6.6 days), five patients (0.6%; 95% CI, 0.1%–1.2%) suffered from stroke. The stroke risk was higher in patients with sCS than in those without sCS (6.3% vs. 0.1%; p < 0.001), whereas the recurrent TIA risk (2.6%) did not differ between the groups (4.7% vs. 2.5%; p = 0.29). Conclusion: SCS appears to be associated with a higher risk of stroke in patients with TIA defined according to the tissue-based definition.