NPPB and hydrops fetalis: Contrary to the above-mentioned studies in which the single plasma NT-proBNP level could predict morbidity and mortality in a more extended follow-up period (six months or longer) in relatively stable or chronic HF patients, Januzzi et al. [13] found that a higher presenting NT-proBNP (>5180 ng/L) could only predict mortality in a shorter follow-up period (76 days) in acute HF patients.