Ultrasonic Echolucent Carotid Plaques Predict Future Strokes

Abstract

Background-We tested prospectively the hypothesis that stroke development can be predicted by echolucency of carotid atherosclerotic plaques in previously symptomatic and asymptomatic patients. Methods and Results-We followed incidence of ipsilateral ischemic strokes for 4.4 years in 111 asymptomatic and 135 symptomatic patients with Ն50% relevant carotid artery stenosis. At inclusion, echogenicity of carotid plaques and degree of stenosis were evaluated with high-resolution B-mode ultrasound with computer-assisted image processing and Doppler ultrasound, respectively. We observed 44 ipsilateral ischemic strokes. In symptomatic patients, relative risk of ipsilateral ischemic stroke for echolucent versus echorich plaques was 3.1 (95% CI, 1.3 to 7.3), whereas for 80% to 99% versus 50% to 79% stenosis, the relative risk was 1.4 (95% CI, 0.7 to 3.0). Relative to symptomatic patients with echorich 50% to 79% stenotic plaques, those with echorich 80% to 99% stenotic plaques, echolucent 50% to 79% stenotic plaques, and echolucent 80% to 99% stenotic plaques had relative risks of ipsilateral ischemic strokes of 3.1 (95%CI, 0.7 to 14), 4.2 (95% CI, 1.2 to 15), and 7.9 (95% CI, 2.1 to 30), equivalent to absolute risk increases of 11%, 18%, and 28%. This was not observed in previously asymptomatic patients. Conclusions-Echolucent

Comparacoes preliminares entre a histologia virtual ultrassonografica in vivo e os achados histopatologicos da placa carotidea produto de endarterectomia

“…In contrast, calcium and blood had no significant correlations (R=0.04 and R=0. 19). GSM values ranged from 20 to 69 and were in agreement with plaque characteristics in both USVH and conventional histology, as the plaques with a low GSM were classified as more lipidic.…”

“…GSM is the mid-point in the histogram generated by the pixels of the ultrasound image distributed according to brightness or echogenicity. According to Nicolaides 18 , an echogenic plaque has a GSM greater than 32, although a more recent study found that the cut-off point to define plaques with high lipid contents should be 14 19 . Other authors have suggested a much higher cut-off point (74, for example) to separate plaques into echogenic and echolucent 20 .…”

Long-term treatment with low-dose metoprolol CR/XL is associated with increased plaque echogenicity: The Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS)

“…Several lines of evidence suggest that this could possibly reflect a stabilizing effect on the lesion. Previous studies have shown that echogenic plaques have a more stable phenotype and are associated with a lower risk for development of clinical events [6,7].…”

“…The possibility to assess carotid plaque morphology in terms of echogenicity expressed as gray scale median (GSM) on ultrasound images has been explored during recent years. The results of these studies indicate that echolucent plaques are associated with an increased risk for ischemic cerebrovascular events independent of degree of stenosis [6,7]. Echolucent plaques have been shown to contain more lipids [8], macrophages [9], and elastin [10] in comparison to more echogenic lesions.…”

Carotid atherosclerotic plaque characterisation by measurement of ultrasound sound speed in vitro at high frequency, 20MHz

“…It found that the RRs of ipsilateral cerebrovascular events for the predominantly echolucent and wholly echolucent groups were 3.5 (95% CI, 1.0 -12.4) and 3.6 (95% CI, 0.8 -16.8) respectively compared to the echogenic plaques (Mathiesen, Bonaa, & Joakimsen 2001). A further study (Grønholdt et al 2001) looked at the RR of ischaemic stroke, as opposed to cerebrovascular events, between the two groups and found it to be 3.1 (95% CI, 1.3 -7.3).…”