NPPB and heart failure: Natriuretic peptides are routinely used in the diagnosis of heart failure, although doubt remains about the most appropriate cut-off levels required to optimise diagnostic accuracy.20 The European Society of Cardiology (ESC) advocates an NT-proBNP threshold of 125 pg/ml,8 below which heart failure can be ruled out, whereas the National Institute for Health and Care Excellence (NICE) in England (where the study took place) recommends a much higher NT-proBNP threshold of 400 pg/ml.4