Patients with Carotid Intraplaque Hemorrhage Have Higher Incidence of Cerebral Microbleeds

Aims: Carotid intraplaque hemorrhage (IPH) is considered a marker of plaque vulnerability. Cerebral microbleeds (CMBs) are recognized on magnetic resonance imaging (MRI) in patients with cerebrovascular disease. Any connection between carotid IPH and CMBs remains scantly investigated. This study aimed to determine whether the histologic evidence of carotid IPH is related to CMBs. Methods: We retrospectively enrolled 101 consecutive patients undergoing carotid endarterectomy with symptomatic (ischemic stroke, TIA, and amaurosis fugax) or asymptomatic ipsilateral carotid artery disease. The presence and the extent (%) of IPH were identified on carotid plaques stained with Movat Pentachrome. CMBs were localized on T2*-weighted gradient-recalled echo or susceptibility-weighted imaging sequence on brain MRI before surgery. The degree of carotid stenosis was measured by neck CTA. Results: IPH was identified in 57 (56.4%) patients, and CMBs were found in 24 (23.7%) patients. CMBs were more commonly observed in patients with carotid IPH compared to those without [19 (33.3%) vs 5 (11.4%); P=0.010]. The carotid IPH extent was significantly higher in patients with CMBs than in those without [9.0 % (2.8-27.1%) vs 0.9% (0.0-13.9%); P=0.004] and was associated with the number of CMBs (P=0.004). Logistic regression analysis demonstrated an independent association between carotid IPH extent and the presence of CMBs [OR 1.051 (95% CI 1.012-1.090); P=0.009]. Additionally, patients with CMBs had a lower degree of ipsilateral carotid stenosis compared to those without [40% (35-65%) vs 70% (50-80%); P=0.049]. Conclusions: CMBs may be potential markers of the ongoing process of carotid IPH, especially in those with nonobstructive plaques.