Abstract 2790: Aggressive Atorvastatin Decreases Wall Shear Stress In The Carotid Artery

Abstract

Introduction: Both wall shear stress (WSS) and inflammation play an important role in atherosclerotic plaque initiation and progression. Lipid-lowering therapy has been shown to be effective in stabilizing them by reducing plaque inflammation. However, its effect on WSS remains unknown. Therefore, the role of high- and low-dose lipid-lowering therapy using an HMG Co A reductase inhibitor - atorvastatin on WSS in carotid artery was investigated. Methods: Twenty-six patients included in the ATHEROMA study were assessed using phase-contrast magnetic resonance imaging (MRI). All patients demonstrated plaque inflammation by intraplaque accumulation of ultrasmall super paramagnetic particles of iron oxide (USPIO) on at baseline. They were randomized in a double-blinded manner to either 10mg or 80mg atorvastatin daily for 12 weeks. WSS at common carotid artery (CCA), maximum (MS) stenosis and internal carotid artery (ICA) were assessed from in vivo phase contrast MRI at both 0 and 12 weeks. Results: There were no significant differences in WSS in CCA, MS and ICA between the two groups at baseline. At 12 weeks, WSS in CCA and MS at end diastole were significantly lower in the 80mg group than those in the 10mg group (p=0.03 and 0.04 respectively). Significant reductions of WSS in all the three locations were observed in the 80mg group at 12 weeks (p= 0.01, 0.04 and 0.04 respectively) whereas no significant change was seen in the 10mg dose group. Conclusions: Aggressive lipid-lowering therapy is associated with a significant reduction in WSS. This suggests that reduction in WSS may be associated with reduction in plaque inflammatory burden and vice-versa. Lipid-lowering therapy may not only reduce inflammation but also improve the hemodynamics.