NPPB and hydrops fetalis: From these data, the authors derived the following optimal strategy for the implementation of NT-proBNP in acute dyspnea: for the exclusion of acute HF, a general age-independent cut-point of 300 pg/mL should be used, while for diagnosis of HF, age-dependent cut-points were more useful than a single cut-point: namely NT-proBNP > 450 pg/ml for patients < 50 years, > 900 pg/ml for patients in between 50 and 75 years, and NT-proBNP > 1800 for patients > 75 years.