Symptomatic low-grade carotid stenosis with intraplaque hemorrhage and expansive arterial remodeling is associated with a high relapse rate refractory to medical treatment.

Background: Carotid plaque characteristics influence future risk of stroke considerably. However, the severity of stenosis does not accurately reflect plaque burden in patients with expansive arterial remodeling.

Objective: To determine the therapeutic outcome of symptomatic carotid low-grade stenosis with vulnerable plaque based on magnetic resonance imaging (MRI) characterization.

Methods: We studied 25 (male, n = 23; age, 74.2 ± 5.6 years) of 29 consecutive patients with symptomatic carotid low-grade stenosis (<50%) and both high-signal plaque and expansive remodeling on T1-weighted MRIs. The remaining 4 were excluded because of impending stroke. A single antithrombotic and statin were administered, and recurrent ischemic stroke was treated with dual antithrombotics. We considered carotid endarterectomy when recurrence was refractory to aggressive medical treatment.

Results: During a 31.3 ± 16.4-month follow-up, 11 of the 25 patients developed a total of 30 recurrent ischemic events (46.0% per patient-year). The patients' characteristics did not differ significantly between the groups with and without recurrence (n = 11 and n = 14, respectively). Seven of 11 patients in the recurrence group treated with carotid endarterectomy remained free of ischemic events during a postoperative follow-up of 19.1 ± 14.6 months.

Conclusion: Symptomatic low-grade carotid stenosis with vulnerable plaque confirmed by MRI was associated with a high rate of stroke recurrence that was refractory to aggressive medical treatment. However, carotid endarterectomy was safe and effective for such patients. Plaque characterization by MRI has the potential for more accurate stroke risk stratification in the management of carotid low-grade stenosis.