NPPB and congestive heart failure: Recently, assessment of the concentration of natriuretic peptides especially NT-proBNP in urine, as a non-invasive and simple test is suggested in CHF patients and several studies have evaluated its diagnostic and prognostic value.15-21 However, studies of urinary NT-proBNP are limited, particularly studies using fresh, unfrozen samples.22 This evaluation could be useful in certain circumstances.