Effects of lipid-lowering by simvastatin on human atherosclerotic lesions - A longitudinal study by high-resolution, noninvasive magnetic resonance imaging

Background-This study was designed to investigate the effects of lipid-lowe ring by simvastatin on human atherosclerotic lesions. Methods and Results-Eighteen asymptomatic hypercholesterolemic patients wit h documented aortic and/or carotid atherosclerotic plaques were selected fo r the study. A total of 35 aortic and 25 carotid artery plaques were detect ed. Serial black-blood MRI of the aorta and carotid artery of the patients was performed at baseline and 6 and 12 months after lipid-lowering therapy with simvastatin. The effects of the treatment on atherosclerotic lesions w ere measured as changes in lumen area, vessel wall thickness, and vessel wa ll area, a surrogate of atherosclerotic burden. Simvastatin induced a signi ficant (P <0.01) reduction in total and LDL cholesterol levels at 6 weeks t hat was maintained thereafter. At 6 months, no changes in lumen area, vesse l wall thickness, or vessel wall area were observed. However, at 12 months, significant reductions in vessel wall thickness and vessel wall area, with out chan ges in lumen area, were observed in both aortic and carotid arteri es (P <0.001). Conclusions-This in vivo human study demonstrates that effective and mainta ined lipid-lowering therapy by simvastatin is associated with a significant regression of atherosclerotic lesions Our observation suggests that statin s induce vascular remodeling, as manifested by reduced atherosclerotic burd en without changes in the lumen.