[BNP and dyspnea: proposition of a diagnostic strategy based on two cut-off]

The purpose of this study was to evaluate the cut-off value of brain natriuretic peptide (BNP) assayed with AxSYM BNP assay (Abbott). 86 patients have been included (mean age of 66 years). The clinical sensibility was 100% at 100 ng/L versus 80% at 250 ng/L. The clinical specificity was 66% at 100 ng/L versus 92% at 250 ng/L. The positive predictive value was 80% at 100 ng/L versus 92% at 250 ng/L. The negative predictive value was 100% at 100 ng/L versus 88% at 250 ng/L. The double cut-off strategy is more suitable to diagnose a dyspnea of cardiac origin than the usual strategy based on a single cut-off.value. With such a strategy, the two cut-off strategy improve the diagnosis of 9% in the total population.