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

Background: We 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. Methods: 29 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. Results: Both 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. Conclusions: Our 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. (c) 2007 Elsevier B.V. All rights reserved.