Clinical features and long-term outcomes of symptomatic low- grade carotid stenosis

Objective: In symptomatic low-grade stenosis, most of the reports did not clarify the long-term outcome. This study aims to clarify the clinical features and long-term out-comes of symptomatic low-grade stenosis cases. Materials and methods: We included 123 symptomatic patients with low-grade (<50%) carotid stenosis. The relative plaque signal intensity (rSI) and expansive remodeling rate (ERR) were measured using carotid magnetic resonance imaging (MRI). Antiplatelet therapy and treatment for atherosclero-sis risk factors were administered in all cases. Carotid endarterectomy (CEA) was per-formed when ischemic symptoms appeared, or the percent stenosis progressed despite medical treatment. Results: The mean percent stenosis, rSI, and ERR on admission were 22.3, 1.70, and 2.01, respectively. The mean volume of the hyperintense plaque on carotid MRI was 641.4 +/- 540 mm3. Sixty percent of cases involved intraplaque hemor-rhage and expansive remodeling. During a mean follow-up of 52 months, recurrence of ischemic events was confirmed in 45 cases (36.6%). Of the 67 cases performed follow-up MRI, 34 cases (50%) had an increased volume of T1-hyperintense plaque. CEA or carotid artery stenting was performed in 49 cases. During a mean follow-up of 57.8 months after CEA, two cases of death (fatal intracerebral hemorrhage and asphyxia) and one case of brain stem lacunar infarction were observed, but ipsilateral ischemic events were not. Conclusion: Most of the symptomatic patients with low-grade stenosis had both intraplaque hemorrhage and expansive remodeling and presented a high risk of recurrence and stenosis progression. CEA may have preventive effects against ische-mic events in low-grade stenosis.