Aim: To evaluate morphological and functional characteristics of an atherosclerotic plaque (ASP) in patients with marked carotid atherosclerosis.

Materials and methods: Forty patients (25 males, age 68.9±6.6 years) with marked carotid atherosclerosis (stenosis ≥ 70%, based on ultrasound DS, MSCT and MRI data) were examined before carotid endarterectomy (16 cases with history of cerebral stroke, CS – Group 1; 24 cases without – Group2). All the patients were asymptomatic (no acute cerebrovascular events in the last 6 months). Histochemical examination of the excised carotid ASP was performed in 21 cases (9 cases in Group 1 and 12 cases in Group 2).

Results: Incidence of unstable carotid ASP in groups with and without history of CS was respectively: 50% vs. 23%, p=0.02 (DS data); 25% and 25%, p>0.5 (MRI). Patients with and without history of CS have respectively: ischemic heart disease, IHD (43.5% vs. 68.8% of cases, p=0.03); history of myocardial infarction, MI (25.1% vs. 8.7%; p=0.01). Carotid ASP was unstable in 71.4% of cases (n=16) and stable – in 28.6% (n=6) based on histochemical examination data. As compared to histochemical examination data (conventional "gold standard”) sensitivity and specificity were respectively: 67% and 83% for DS; 93% and 67% for MRI.

Conclusions: Asymptomatic patients with marked carotid atherosclerosis have unstable ASP (detected by DS), IHD and history of MI significantly more often in cases with history of CS than without it. Compared with histochemical examination data MRI was the most sensitive method of unstable carotid plaque detection, while DS was the most specific one.