Background: The present study aimed to investigate the effect of high-dose atorvastatin on advanced soft atherosclerotic plaque in the rabbit common carotid artery.

Materials and Methods: In this experimental study, the common carotid arteries in 17 rabbits were injured through perivascular liquid nitrogen followed by a 1.5% cholesterol-rich diet for eight weeks. The animals were randomly divided into three groups including A: a cholesterol-rich diet (8 weeks), B: control and discontinuation of cholesterol-rich diet (12 weeks) and C: high-dose atorvastatin administration (5 mg/kg/day) and discontinuation the cholesterol-rich diet (12 weeks). Blood volume flow and blood mean velocity were measured by color Doppler ultrasonography. Moreover, mean wall thickness and percentage of luminal cross-sectional area of stenosis were measured by B-mode ultrasonography and histological methods in the stenotic region of the common carotid artery.

Results: Results showed a significant reduction in the serum lipid parameters, peak systolic blood pressure, blood mean pressure, blood mean velocity, mean value for wall thickness and the percentage of luminal cross-sectional area of stenosis. Moreover, results showed a significant increase in the peak diastolic blood pressure and blood volume flow in group C compared with the other groups (P<0.05).

Conclusion: The pleiotropic and lipophilic effects of high-dose atorvastatin accompanied by discontinuation of cholesterol-rich diet can cause to exterminate the microvessels, improve the fibro-lipid lesion in the soft plaque and significantly dilate the luminal cross-sectional area of stenosis.