Association Between Risk Factor For Atherosclerosis And Mechanical Forces In Carotid Artery In Subjects With Cerebral Infarction

Background and purpose:Mechanical stresses on the arterial wall participate in the pathogenesis of atherosclerosis as local factors. The relationship between local mechanical forces and risk factors for atherosclerosis in subjects with cerebral infarction were investigated.Methods: Mechanical forces on the the arterial wall were evaluated in the common carotid artery and internal carotid artery in 40 cerebral infarction patients with risk factors for atherosclerosis including hypertension, diabetes mellitus, dyslipidemia and smoking, as well as 32 age- and sex-matched normal controls. Circumferential wall tension and shear stress were evaluated with Laplace's law and a poiseuillean parabolic model of velocity distribution. Circumferential wall strain was also evaluated as mechanical force. We compared the mechanical forces in the two groups. The degree of carotid atherosclerosis asymmetry in the patients was also to be evaluated.Results:Mechanical forces in subjects with risk factors were characterized by low wall shear stress, high circumferential wall tension, and reduce strain. Systolic blood pressure was significantly negatively associated with shear stress and circumferential wall strain. HDL cholesterol showed a significantly positive correlation with shear stress and a negative correlation with circumferential wall tension. Fasting blood glucose was significantly negatively associated with shear stress, while smoking showed a negative correlation with shear stress and apositive correlation with wall tension. Accumulation of risk factors was associated with further deterioration of mechanical forces. Low shear stress was expressed in the side with infarction or where atherosclerotic plaques were located than the contralateral side artery.Conclusions:These findings suggest that risk factors for atherosclerosis were associated with alteration of mechanical forces. Consequent alteration in mechanical forces could be underlying local mechanism for the progression of atherosclerosis. The side of cerebral infarction show low shear stress than the contralateral. Wall shear stress is lower in the carotid arteries where plaques are present than in plaque-free arteries.