In-hospital brain natriuretic peptide and N-terminal prohormone brain natriuretic peptide variations are predictors of short-term and long-term outcome in acute decompensated heart failure

Acute decompensated heart failure is one of the most important causes of hospitalisation worldwide. Natriuretic peptides have shown their usefulness in the diagnosis and management of heart failure. Their variations during hospitalisation also appear useful to predict outcomes. In particular, data from the literature demonstrate that reduction from admission to discharge of brain natriuretic peptide and N-terminal prohormone brain natriuretic peptide in these patients is a predictor of future cardiovascular events.

Th ese results from Noveanu and colleagues' paper are in accordance with data reported by our group [8]. We demonstrated that a reduction of BNP >46% at hospital discharge coupled with a BNP absolute value <300 pg/ml resulted in a very powerful negative prognostic value for future cardiovascular outcomes in patients hospitalised with ADHF [8].
Other studies demonstrated the usefulness of repeated measurements of natriuretic peptides during hospitalisation in predicting survival of ADHF patients [8][9][10][11]. BNP variations during hospitalisation could give prognostic information, particularly at discharge, and could also suggest a qualitative variation of treatment (intensifi cation or decrement of drugs) on the basis of natriuretic peptide levels.
Noveanu and colleagues have also demonstrated that the prognostic accuracy of BNP was comparable at 24 hours with 48 hours and with discharge [1]. Th e authors suggested that BNP at 24 hours could be suitable to assess prognosis and to vary treatment in order to decrease mortality in patients with constant elevated levels of BNP. Th is suggestion is in accordance again with data from our laboratory, where we showed that a drop of BNP >25% at 24 hours was a strong negative prognostic factor for future cardiovascular events [8], suggesting

Abstract
Acute decompensated heart failure is one of the most important causes of hospitalisation worldwide. Natriuretic peptides have shown their usefulness in the diagnosis and management of heart failure. Their variations during hospitalisation also appear useful to predict outcomes. In particular, data from the literature demonstrate that reduction from admission to discharge of brain natriuretic peptide and N-terminal prohormone brain natriuretic peptide in these patients is a predictor of future cardiovascular events.

© 2010 BioMed Central Ltd
In-hospital brain natriuretic peptide and N-terminal prohormone brain natriuretic peptide variations are predictors of short-term and long-term outcome in acute decompensated heart failure intensifi ed treatment in patients who did not decrease their BNP >25% at 24 hours.
Rapid change in BNP levels seems to refl ect an adequate response to heart failure therapy, and could be considered very important for early risk stratifi cation and therapy guidance. A lack of this response, assuming optimal medical treat ment, implies a more complex and therapy-refractory disease, associated with an adverse long-term outcome. Accordingly, if this change in BNP level does not occur, treatment intensifi cation should be the consequence. In patients with a comparable decrease in BNP levels (roughly 30% between admission and 24 hours), we would expect a favourable outcome; however, future prospective studies need to evaluate a distinct cut-off point to allow more precise recommendations [12].
Moreover, from the data of Noveanu and colleagues, BNP and NT-proBNP seem to show a diff erent response to treatment due to their diff erent kinetics. Th is diff erence is probably due to the slower decrease of NT-proBNP during treatment in ADHF patients in comparison with BNP [9][10][11][12]. Compared with NT-proBNP, BNP could be more useful to determine initial clinical stabilisation of ADHF patients, and to assess clinical improvement in hospitali sation as we also demonstrated [13]. NT-proBNP could be used to assess initial diagnosis but is of limited help for repeat measurements during hospitalisation because its variations are not as sensitive and rapid as those of BNP [9][10][11][12]14].
In conclusion, in patients admitted to the emergency department for ADHF, serial measurements of BNP and NT-proBNP are useful because they show a similar powerful predictive role for mortality in the short term and in the long term. Interestingly, patients' BNP and NT-proBNP varia tions could help the physician to vary the thera peutic approach during the initial hours of hospitalisation in order to obtain favourable outcomes.
Nevertheless, when considering hospital readmissions after discharge it seems that the variation of the two biomarkers during hospitalisation at various time points is of no utility. Logeart and colleagues showed that only predischarge BNP was a strong predictor of death, and also of readmissions for heart failure with a cut-off point of 350 ng/ml [10]. Previously published studies presuming this fi nding -including Cheng and colleagues using BNP [15] or Bettencourt and colleagues using NT-proBNP [16] -used combined endpoints consisting of all-cause mortality and readmission for heart failure.
Although the results of Noveanu and colleagues' study are to be considered of importance for the role of natriuretic peptides in prognostic stratifi cation for patients with ADHF, multicentre studies on a larger number of patients should be carried out to better elucidate the real value of natriuretic peptides in avoiding readmission after hospital discharge in heart failure patients.