[Study of diagnostic criteria of intima-media thickening and effects of drugs on peripheral arteries].

OBJECTIVE: To establish the diagnostic criteria of intima-media thickening (IMT) of the carotid artery, femoral artery and thoracic aorta in normal subjects and evaluate the effects of drugs on IMT in patients with atherosclerosis with high-frequency ultrasound imaging.

METHODS: 259 normal subjects and 102 patients with atherosclerosis (AS) were studied. 134 normal subjects were examined by transesophegeal echocardiography. 102 patients with AS were randomly divided into 4 groups:simvastatin group, probucol group, captopril group, and placebo group. The values of IMT, including IMT of the normal segment (IMT(A)) and the maximal IMT of each artery (IMT(B)) of the carotid and femoral arteries, and thoracic aorta, the mean maximal IMT of the 4 arteries (IMT(C)), and the single maximal IMT among the 4 arteries (IMT(D)) were measured. The examinations were repeated in 3 years after treatments.

RESULTS: In carotid, and femoral arteries and thoracic aorta, IMT increased with aging. The IMT values of the carotid and femoral arteries and thoracic aorta were 0.63 mm +/- 0.15 mm, 0.68 mm +/- 0.21 mm, 1.02 mm +/- 0.22 mm respectively with the upper limits of 0.93 mm, 1.10 mm, and 1.46 mm respectively. IMT(A) increased 0.023 mm per year. The progression value of IMT(D) in all therapeutic groups were significantly lower than that of the control group (all P < 0.05).

CONCLUSION: It is suggested that the IMT > 0.93 mm, > 1.10 mm, and > 1.46 mm is be defined as indicators of IMT in carotid and femoral arteries and thoracic aorta respectively. Drug therapy can decrease the progression of atherosclerosis but has no effects on the IMT in normal segment of arteries. High frequency ultrasound technique is reliable in monitoring the progression or regression of atherosclerosis in peripheral arteries.