The pooled sensitivity of 0.67 (95% credible interval [CI] = 0.56–0.77), specificity of 0.55 (95% CI = 0.45–0.64), area under the summary receiver operating characteristic curve of 0.65 (95% CI = 0.60–0.69), positive likelihood ratio of 1.5 (95% CI = 1.2–1.8), negative likelihood ratio of 0.60 (95% CI = 0.46–0.79), and diagnostic odds ratio of 2 (95% CI = 2–4) suggested that patients with higher preoperative NT-proBNP levels (pg/mL) are at higher risk of developing acute kidney injury after cardiac surgery. This evidence concerns the gene NPPB and acute kidney injury.