NPPB and hydrops fetalis: We have previously reported that risk prediction models derived from large-scale registries in Western countries, namely, the GWTG-HF and the Meta-analysis Global Group in Chronic Heart Failure risk scores, performed modestly when they were applied to Japanese patients with AHF, and that incorporating BNP levels into the models potentially improved their prognostic abilities [12,23], which concurred with the findings from several studies from different countries [8,9].