Effect of high-dose atorvastatin therapy accompanied by discontinuation of cholesterol-rich diet on color-doppler ultrasonography parameters of atherosclerotic carotid artery

Aim: Atherosclerosis is the underlying reason for nearly all causes of coronary artery disease and peripheral arterial disease and many cases of stroke. Carotid color-Doppler ultrasonography is a popular tool for evaluating atherosclerosis of the carotid artery. The aim of this study was to generate a rabbit model of carotid arterial atherosclerotic stenosis and the subsequent investigating the effect of high-dose atorvastatin therapy on color-Doppler ultrasonography parameters in this model.

Methods: Carotid fibro-lipid plaque with severe stenosis (>70%) and neovascularization was induced at the right common carotid artery of New Zealand white rabbits by perivascular severe cold injury using liquid nitrogen before being fed a 1.5% cholesterol-rich diet. After eight weeks, the histopathology showed advanced atherosclerosis formation, resulting in vessel wall thickening and stenosis formation. The animals treated by high- dose atorvastatin (5 mg/kg/day) administration accompanied by discontinuation of cholesterol-rich diet. Different variables such as PSV (Peak Systolic Velocity), EDV (End Diastolic Velocity), MV (Mean Velocity), RI (Resistance Index), PI (Pulsatility Index), VF (Volume Flow) were studied in the treatment group compared with other groups using color-Doppler ultrasonography.

Results: Results from color-Doppler ultrasonography, showed a significant reduction in the mean value for PSV, EDV, MV, RI and a significant increase VF at the stenotic region in the treatment group compared with the other groups (P< 0.05).

Conclusions: Changes in color-Doppler ultrasonography parameters in the treatment group, as mentioned in the results section, show that lipid- lowering therapy by high-dose atorvastatin in combination with discontinuation of cholesterol-rich diet, can cause to atherosclerotic plaque regression.