Long-term Prognosis Associated With Acute Kidney Injury After Cardiac Surgery

Objective To study the relationship between long-term prognosis and acute kidney injury (AKI) during hospitalization after cardiac surgery.Methods The paitients were seleted in Fudan University of Zhongshan Hospital from April2009to February2011,who underwent cardiac surgery,and their clinical information were collected before the operation. AKI was defined by the AKIN classification.The paitients was divided into two groups:one was acute kindey injury group/the another was non-acute kidney injury group,then follow up whether the patients died or had the advanced chronic kidney disease(including the the stage4and5of chronic kidney disease). Long-term survival was analyzed with Kaplan-Meier method and a risk-adjusted Cox proportional hazards regression model.Results There were1770patients enrolled in this study.After heart surgery,the non-acute kidney injury patients accouted for59.6%,and the acute kidney injury paitiets accouted for40.4%,in which stage I,stage2,stage3accouted for26.7%,7.2%,6.5%respectively.the2-year survival rate of the patients with acute kidney injury was lower than the non-acute kidney injury patients(83.2%VS93.6%,p<0.001);the2-year survival rate of the patients with stage1,stage2,stage3of acute kidney injury was89.2%,79.5%,62.6%respectively, p<0.001;the2-year survival rate of the patients with complete renal recovery, patial recovery,no recovery after AKI was88.8%,67.8%,5.3%, respectively,p<0.001. Survival was worse among patients with AKI and was proportional to its severity, with an adjusted hazard ratio(AHR) of1.75(95%CI1.21to2.51) for the stagel,1.88(95%CI1.50to2.36) for the stage2,and1.95(95%CI1.72to2.22) for the stage3compared with patients without AKI. Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of1.81(95%CI1.29to2.54) compared with patients without AKI. Compared with patients without AKI, the incidence of2-years of advanced chronic kidney disease was higher (6.7%vs0.2%, p<0.001), with an adjusted hazard ratio of31.22(95%CI7.55to129.11).Conclusions Compared with the patients without AKI,the2-year survival rate of the patients with AKI after cardiac surgery was worse and was proportional to its severity;the situation of the renal recovery effect the2-year survival rate,even if Patients with complete renal recovery after AKI still increased the hazard ratio for death.the incidence of2-years of advanced chronic kidney disease after cardic operations in acute kidney injury patients was significantly higher than in patients with non-acute kidney injury.lmproved renal protection and closer postdischarge follow-up of renal function should be warranted to improve the patients long-term prognosis.