The results showed that there was a significant correlation between IBI and CI-AKI (c = 0.007, SE = 0.002); after adding FBG and NT-poBNP respectively to the model of IBI and CI-AKI, there was still a significant correlation between IBI and CI-AKI (c'FBG = 0.006, SE = 0.002; c'BNP = 0.006, SE = 0.002); there was a significant correlation between IBI and FBG, NT-poBNP (aFBG = 0.010, SE = 0.002; aBNP = 0.005, SE = 0.001); there was a significant correlation between FBG, NT-poBNP and CI-AKI (bFBG = 0.112, SE = 0.035; bBNP = 0.409, SE = 0.103). Here, NPPB is linked to acute kidney injury.