Ulcerated Carotid Plaques with Ultrasonic Echolucency Are Causatively Associated with Thromboembolic Cerebrovascular Events

Abstract

The presence of ulcerated carotid plaques is a risk factor for ischemic stroke, which is associated with thromboembolism. We evaluated the relationship between ulcerated carotid plaques and cerebrovascular events in patients with acute ischemic stroke or transient ischemic attack. We extracted 48 consecutive patients with ulcerated carotid plaques from a cohort of 1111 patients with acute ischemic stroke or transient ischemic attack. All patients were evaluated by carotid ultrasonography and diffusion-weighted magnetic resonance imaging. We defined thromboembolic events by excluding potential cardiac sources of embolism, stroke in posterior circulation, contralateral lesions, and single and small (<1.5 cm) subcortical lesions, and we considered the remaining patients with cortical lesions or multiple or large subcortical lesions as having experienced a thromboembolic cerebrovascular event. We compared ultrasonographic findings in the patients with and those without a thromboembolic cerebrovascular event. A relationship with thromboembolic events was suspected in 10 patients (21%) with ulcerated carotid plaques. The proportion of smokers was significantly higher in the group of patients with a thromboembolic event (90% vs 53%; P = .03). Logistic regression demonstrated a significant association between thromboembolic events and the presence of echolucent ulcerated plaques (odds ratio, 9.34, 95% confidence interval, 1.65-53.0), even though maximum intima-media thickness and other variables of ulcerated plaques (eg,depth of ulcers, thickness of the plaque, or the degree of stenosis) did not differ significantly between the 2 groups. Our findings indicate that although cerebrovascular events are closely associated with echolucent ulcerated carotid plaques, the prevalence of thromboembolism was not very high (∼20%) in our cohort of Japanese patients with ulcerated carotid plaques.