All variables considered potential predictors of mortality in HF patients (age, sex, body mass index, systolic blood pressure, rhythm, heart rate, ejection fraction, NYHA class, etiology, urea, creatinine, sodium, hemoglobin, B-type natriuretic peptide (BNP), lactate and HF medications) were included in univariable COX regression model. Here, NPPB is linked to hydrops fetalis.