Echolucent internal carotid artery plaques are a risk factor for stroke

Atherosclerotic changes in carotid arteries are responsible for 10-20% of strokes. The aim of our study was to examine how the ultrasonic morphology of carotid arteries influences the occurrence of ischaemic stroke (IS).

Ultrasonography of the carotid arteries was performed with a 7-MHz duplex-type scanner Acuson 128XP/10C. We examined 200 consecutive acute IS patients and 100 sex- and age-matched control subjects. Morphology of atheromatic plaques was evaluated with the assessment of degree of stenosis, surface regularity and echogenicity of the plaques. The predictive value of potential prognostic variables in the assessment of the risk of IS was tested using regression models.

The most frequent site of atherosclerotic changes was the internal carotid artery (ICA) (right ICAs: 34.5% in IS group vs. 19% in controls, p=0.005; left ICAs: 26.5% vs. 16%, p=0.04). Plaques in ICAs were significantly more severe in IS patients than in controls. Echolucent plaques were observed in the IS group in 11% of right and 5.5% of left ICAs, whereas in controls we found echolucent plaques in only 2% in left ICAs. IS occurrence was independently predicted by: hypertension, congestive heart failure, current smoking status, haemodynamically significant and echolucent plaques in ICAs.

Echolucent plaques in ICAs are an independent risk factor for ischaemic stroke even if they have no impact on haemodynamics of blood flow. Clear characterization of plaques in CAs, especially vulnerable plaques, together with estimation of the degree of stenosis, may improve the selection of patients for invasive secondary prevention methods.