B-type natriuretic peptide (BNP) is more sensitive to rapid hemodynamic changes in acute heart failure than N-terminal proBNP

BackgroundWe examined whether B-type natriuretic peptide (BNP) and its precursor fragment, N-terminal proBNP (NT-proBNP), can serve as non-invasive markers of hemodynamic response to treatment in acute heart failure in a prospective observational study.Methods29 unselected, consecutive patients (mean age: 61.6, 39–83 years; 25 males, 4 females) in urgent need for positive inotropic support and invasive hemodynamic monitoring by a Swan-Ganz catheter. Positive hemodynamic response to treatment was defined as ≥ 25% decrease in pulmonary artery occlusion pressure after 24 h. Hemodynamics were recorded simultaneously with blood sampling for BNP and NT-proBNP testing before and 24 h after initiation of inotropic support. BNP (Bayer Diagnostics) and NT-proBNP (Roche Diagnostics) were measured by commercial immunoassays.ResultsBoth markers were markedly elevated. However, there were no close correlations (r < 0.43, p < 0.05) of BNP or NT-proBNP with hemodynamic parameters at baseline or 24 h thereafter. Only BNP showed a significant (p = 0.023) decrease compared to baseline values in hemodynamic responders. The area under receiver operating characteristics curve for relative changes of BNP for the prediction of hemodynamic response was 0.76.ConclusionsOur preliminary results indicate that BNP is more sensitive to acute hemodynamic changes than NT-proBNP. This study also highlights limitations of both markers as surrogates of hemodynamics in critically ill acute heart failure patients.