我们已证明辛伐他汀可部分通过改善瓣膜病人的高密度脂蛋白（HDL）功能来保护体外循环心脏手术的血管功能和心肌，进一步证明瓣膜性心脏病患者及心脏体外循环手术后产生的循环微粒（MPs）可损伤血管功能。但辛伐他汀是否也通过改善MPs功能来保护体外循环心脏手术的血管功能仍未清楚。我们预实验结果提示围手术期使用辛伐他汀患者的MPs刺激氧自由基的作用减弱，由此我们提出辛伐他汀可部分通过改善MPs的功能来保护体外循环心脏手术的血管功能。本研究拟提取病人的MPs，通过细胞培养和血管舒张功能试验，观察MPs对血管舒张功能的影响，测定与血管舒张功能相关的自由基、蛋白活动的变化。旨在获得辛伐他汀通过改善MPs功能来保护体外循环心脏手术的血管功能的可靠依据，阐明辛伐他汀在围手术期对心脏保护作用的新机制，为以后临床围手术期使用辛伐他汀保护体外循环心脏手术的血管和心肌提供科学依据。

We have demonstrated that the cardioprotective effects of simvastatin in cardiopulmonary bypass cardiac surgery are, at least in part, due to the improvement of HDL function. We demonstrated that valvular heart disease during cardiac surgery produced by MPs can impair endothelium-dependent vasodilation function. That is unkown if simvastatin also improve vascular function during cardiopulmonary bypass cardiac surgery. Our preliminary data showed that oxygen free radicals were reduced by MPs stimulation. Therefore, we hypothesize that simvastatin can protect vascular function through improving MPs impair cardiac surgery with cardiopulmonary bypass in the part. MPs will be isolated from patient, incubated with vascular endothelial cells and vasodilation function experiment. The endothelium-dependent vasodilation, the vascular endothelial function related free radicals and protein activity will be measured. The aims of this study is to obtain the direct evidences of simvastatin can protect vascular function through improving MPs impair cardiac surgery with cardiopulmonary bypass and illustrate the cardioprotective effects of simvastatin in perioperation. Findings from this study may provide scientific evidences that simvastatin protect vascular and myocardium during cardiac surgery with cardiopulmonary bypass in the future of clinical.