Application of NT-proBNP and BNP measurements in cardiac care: a more discerning marker for the detection and evaluation of heart failure.

BACKGROUND: Measurement of brain natriuretic peptide (BNP) has become a potent diagnostic aid as a means of identifying patients with systolic or diastolic dysfunction. Due to better stability in circulating blood, we reasoned that measurement of N-terminal proBNP (NT-proBNP) may be a more discerning marker for the detection and evaluation of chronic heart failure.

METHODS: The relationships between plasma concentrations of NT-proBNP and BNP, and aetiology, New York Heart Association (NYHA) classification, and left ventricular ejection fraction (LVEF) were analyzed in 105 patients with chronic heart failure. Sixty-seven healthy volunteers were studied as the controls.

RESULTS: Both NT-proBNP and BNP showed progressive increases (P<0.001) in proportion to the NYHA classification; the increment of NT-proBNP was larger than that of BNP. Elevated NT-proBNP significantly correlated with BNP (r=0.737, P<0.001). Receiver operating characteristics analysis to detect LVEF<40% showed similar values (area under the curve, AUC: NT-proBNP 0.754 vs. BNP 0.770), however, AUC to detect LVEF<50% tended to be greater for NT-proBNP than that for BNP (NT-proBNP 0.820 vs. BNP 0.794).

CONCLUSION: NT-proBNP may be a more discerning marker for the detection and evaluation of heart failure than BNP.