Preoperative Serum Fibrinogen Is Associated With Acute Kidney Injury After Cardiac Valve Replacement Surgery

Objective:Acute kidney injury(AKI)is a common complication after open cardiac surgery,which is associated with a longer hospital stay and higher risk of short-term and long-term mortality.We aimed to explore the association between preoperative serum fibrinogen level and risk of postoperative AKI in patients undergoing cardiac valve replacement surgery.Methods:Patients who underwent cardiac valve replacement surgery from January2011 to September 2015 in the First Affiliated Hospital,Zhejiang University School of Medicine were recruited.The relationship between preoperative fibrinogen and postoperative AKI was evaluated by multivariate logistic regression,and the improvement effect of fibrinogen on AKI risk assessment was evaluated by net reclassification improvement(NRI).The primary outcome was AKI,defined as AKI stage-1 or higher based on the Kidney Disease: Improving Global Outcomes Guidelines.Results : A total of 3459 patients were included and 510 patients developed postoperative AKI after operation(14.74%).Serum fibrinogen was independently associated with AKI(OR=1.211,95% CI 1.080 to 1.358,p=0.001)after adjusting for age,sex,hypertension,diabetes,cerebrovascular disease,obesity,emergency surgery,type of surgery,left ventricular ejection fraction,estimated glomerular filtration rate,hemoglobin and international standardized ratio.The receiver operator characteristic curve for the outcome of AKI,after the addition of serum fibrinogen,had a c-statistic increasing from 0.72 to 0.73(p<0.001).This translated to a substantially improved AKI risk classification with a NRI of 0.178(p<0.001).Conclusions:Preoperative serum fibrinogen levels were associated with the risk of postoperative AKI after cardiac valve replacement surgery and were helpful to improve preoperative risk assessment.