Atheromatous Plaques at the Origin of the Left Subclavian Artery in Patients with Ischemic Stroke

Abstract

Background: Atheromatous plaques of the aortic arch that extend to the origin of its branches may cause stroke. The frequency and clinical implications of plaque at the origin of the left subclavian artery (LSCA) in patients with recent ischemic stroke were investigated. Methods: We studied 347 consecutive patients (223 men, 69 ± 12 years) who developed symptomatic ischemic stroke and underwent transesophageal echocardiography (TEE). Results: The origin of the LSCA was identified in 303 of 347 patients (87.3%). Plaque ≧1.0 mm was detected in 108 of the 303 patients (35.6%), ranging between 1.0 and 6.1 mm (median, 2.5 mm). Patients having thicker plaque (≧2.5 mm) were older (p = 0.012) and more commonly took antiplatelets prior to stroke (p = 0.038) than patients with no plaque and those with thinner plaque (<2.5 mm). Of the aortic arch findings detected on TEE, maximum intima-media thickness (IMT) was the highest (p < 0.001) in patients with thicker plaque, and large plaque (≧4.0 mm) (p = 0.017), ulcerative plaques (p < 0.001), and spontaneous echo contrasts (p = 0.001) were identified most commonly in patients with thicker plaque. The frequency of infarcts involving the posterior circulation was similar among the three groups. After multivariate adjustment, maximum IMT of the aortic arch was independently related to thicker plaque at the LSCA origin (OR = 1.24, 95% CI = 1.03–1.51, p = 0.024, per 1-mm increase). Conclusions: Atheromatous plaque at the origin of the LSCA was present in approximately one third of patients with a recent ischemic stroke. High IMT at the aortic arch was independently related to the presence of thick plaque at the LSCA origin. The present study does not support the concept that plaque at the LSCA origin may be associated with posterior circulation infarction.