Background: B-type natriuretic peptide (BNP) and the amino-terminal fragment of the BNP prohormone (NT-proBNP) are markers for functional cardiac impairment and are elevated in heart failure (HF). Aim of the present study was to perform a head-to-head comparison of the diagnostic utility of BNP and NT-proBNP in symptomatic and asymptomatic structural heart disease.
Methods: We prospectively classified 180 consecutive subjects according to ACC/AHA guidelines. Blood concentrations of BNP and NT-proBNP were determined by two fully automated chemiluminescent assays (Bayer and Roche method). Diagnostic utilities were tested by ROC analyses and logistic regression.
Results: ROC curves of BNP and NT-proBNP in patients with symptomatic HF (n=43) and asymptomatic subjects (n=137) did not differ significantly (AUC 0.930 vs. 0.918, p=0.650), but comparison of patients with asymptomatic structural heart disease (n=56) and subjects without structural disorder of the heart (n=81) revealed different AUCs for the respective assays (0.735 vs. 0.839, p=0.009). In the population studied, age, sex and renal function had no impact on the diagnostic performance of both tests when compared by logistic regression models.
Conclusions: Both assays facilitate diagnosis of symptomatic and asymptomatic structural heart disease. BNP and NT-proBNP may be equally useful as an aid in the differential diagnosis of probable signs or symptoms of HF. In contrast, NT-proBNP might be a more discerning marker of early cardiac dysfunction than BNP.