For instance, in patients with preoperative NT-proBNP 2,609 pg/ml, CysC 1.00 mg/L, and current smoker, without hypertension, heart failure, previous myocardial infarction, and cerebrovascular disease, 27.6% (95% CI: 17.7%–40.2%) of them would experience postoperative AKI. Here, NPPB is linked to heart failure.