Stiffness of aortic arch and carotid arteries increases in ApoE-knockout mice with high-fat diet: Evidence from echocardiography

Arterial stiffness is an effective predictor of atherosclerosis. Measurement of pulse-wave velocity (PWV) is a gold-standard approach to study arterial stiffness. This study aims to examine arterial stiffness and heart functions via echocardiography at an early stage of atherosclerosis. A model of atherosclerosis in ApoE-knockout (ApoE-/-) mice fed on high-fat diet (HFD) was used, with normal chow diet (ND) as a control. Stiffness of aortic arch and carotid arteries and left ventricular (LV) systolic/diastolic functions were measured by echocardiography. The plasma cholesterol levels and atherosclerotic plaque areas in the aortas were measured. The PWV values of aortic arch and carotid arteries were compared at 2, 4, 6 and 8 weeks with different diets. Compared with ND mice, PWV values in aortic arch and carotid arteries were significantly increased in HFD mice after 8 weeks (Aortic arch: 516.65 ± 216.89 cm/s vs. 192.53 ± 71.71 cm/s; Carotid arteries: 514.26 ± 211.01 cm/s vs. 188.03 ± 75.14 cm/s, respectively; both P < 0.01) accompanied by the decrease in LV systolic/diastolic functions. These were well correlated with the increase in plasma cholesterol levels. Echo-based PWV measurement in the aortic arch was found more sensitive to predict atherosclerosis than in the carotid arteries in ApoE-/-mice. Measuring aortic arch PWV via echocardiography could represent a new diagnostic strategy for early detection of atherosclerosis.