Safety and Efficiency Study of Loading Dose Atorvastatin in Cardiac Surgery

Acute kidney injury occurs up to 30% in cardiac surgery which influenced patients' mid-term and long-term outcomes. Furthermore, evidence shows patients who initiate renal placement therapy in hospital have higher mortality and morbility. The pathologies of Cardiac surgery-associated acute kidney injury (CSA-AKI) is not clear yet ,many researches find cardiopulmonary bypass is an independent risk factor in developing AKI, and inflammatory bursts during cardiopulmonary bypass (CPB) may play an important role in CSA-AKI.

Statins are reported to have anti-inflammatory reaction in many researches. In Some multicenter RCTS, Statins are reported to reduce myocardial infarction,atrial fibrillation and have renoprotective effects due to pleiotropic effects in percutaneous coronary intervention. While in the cardiac surgery settings, the renoprotective effect of statin is still controversial. The investigators believe the differences between surgery and PCI may contribute to the discrepancy. The investigators plan to test the renoprotective effect of atorvastatin in a randomized,double-blind control manner and try to explore the mechanism of this protective effect.

The investigators hypothesise loading dose atorvastatin pretreatment in elective coronary artery bypass grafting surgery may attenuate inflammatory response in CPB and therefore reduce postoperative AKI or help recovery from AKI.

The investigators randomize patients into two arms, the Atorvastatin group takes Atorvastatin 80mg 12h before surgery with another 40mg 2h before operation, the control arm takes placebo in the same regime. The investigators plan to compare the inflammatory cytokines at different time points and the incidence of AKI between the two groups. The investigators hope Atorvastatin group can decrease AKI incidence and has a lower level of inflammatory cytokines, what's more, the two have a good correlation in the time frame.