The relationship between carotid atherosdemsis, characterization of plaque, position and ischemic stroke： a retrospective casecontrol study

Objective To investigate the relationship between the carotid intima-media thickness （IMT）, the characterization of atherosclerotic plaque as well as the degree of carotid stenosis and ischemic stroke. Methods The patients with first-ever acute ischemic stroke （ischemic stroke group） detected by color Doppler ultrasonography and the outpatients and hospitalized patients without ischemic stroke in the same period （control group） were collected retrospectively. The demographic data, vascular risk factors, and characterization of atherosclerotic plaque were compared between the two groups. Ischemic stroke group was divided into stroke subtype groups according to the TOAST classification. Their characteristics of carotid atherosclerosis were compared. Results A total of 200 patients with lust-ever acute ischemic stroke and 200 patients without ischemic stroke were included in the study. The carotid IMT in the ischemic stroke group was significantly thicker than that in the control group （left side： 1.04± 0.22mmvs. 0.69± 0.13mm, t= 7.34, P〈 0.01; right side： 1.05± 0. 21 mm vs. 0. 71 ± 0. 16 mm, t = 7. 43, P 〈 0. 01 ）. The proportions of the patients with moderate and severe stenosis were significantly higher （moderate stenosis： 38% vs. 14% ,X^2 = 7. 64, P 〈 0. 01 ; severe stenosis： 27% vs. 6%, X^2 = 7. 93, P 〈 0. 01 ）, and the proportion of patients with mild stenosis was no significant difference. The detection rate of carotid plaque in the ischemic stroke group was significantly higher than that in the control group （87. 0% vs. 31.5% ,X^2 =7. 01, P 〈0. 01）. The numbers of unstable plaque （lipid soft plaque, flat plaque, and mixed plaque） in the ischemic stroke group were 301 （65.3%）, and significantly more than 65 （31.7%） in the control group （X^2 =6. 30, P〈0. 01）. There was no significant difference in the distribution of carotid plaque between the two groups. The plaques were most common at the carotid artery bifurcation. Compared with those in other stroke subtypes, such as cardioem- bolism, small-vessel occlusion, stroke of other determined etiology, and stroke of undetermined etiology, the carotid IMT （left side： F=22. 34, P〈0. 01; right side： F =21.41, P 〈0. 01）, and the proportion of lipid soft plaque 0（2 =7. 93,P 〈0. 01）, carotid severe stenosis （X^2 =6. 83, P 〈 0. 01）, carotid occlusion （X^2 = 14. 00,P 〈0. 01） in stroke patients with large-artery atherosclerosis were significantly increased. Conclusions Carotid IMT, the numbers of unstable plaque as well as the degree of carotid stenosis were associated with the occurrence of ischemic stroke. Key words: Atherosclerosis;  Carotid stenosis;  Stroke;  Brain ischemia;  Risk Factors;  Ultrasonography, Doppler;  Risk factors