NPPB and hydrops fetalis: In a recent study, Tung and colleagues have shown in 216 patients with underlying chronic obstructive pulmonary disease (COPD), that NT-proBNP was very useful for correctly identifying or excluding acute HF in this challenging patient population, superior to clinical judgment for this indication.66 Importantly, in this analysis, NT-proBNP also detected previously unsuspected HF in 22 patients with prior obstructive airway disease, an important diagnosis to make, in order to reduce the potential hazard associated with the dual diagnosis of pulmonary and cardiac insufficiency.