Different trajectories and significance of B-type natriuretic peptide, congestion and acute kidney injury in patients with heart failure

The exact relationship existing among congestion status, brain natriuretic peptide (BNP) changes and acute kidney injury (AKI) has not been elucidated in patients with acute heart failure (AHF). The aims of this study are: to investigate the relation and prognostic role of BNP, AKI and clinical congestion after discharge; to define the exact BNP cut off value or a BNP in-hospital reduction to identify patients with higher risk during vulnerable post-discharge phase. We consecutively enrolled 157 patients with a diagnosis of AHF. BNP and creatinine were measured in all patients, and degree of failure was assessed. AKI was defined as a creatinine increase ≥0.3 mg/dL or eGFR reduction ≥20% during hospitalization. All patients were followed for 1 and 3 months. Of 146 included patients, 110 patients (75%) displayed effective decongestion, 116 (79%) showed a BNP decrease ≥30%, and 28 (19%) developed in-hospital AKI. BNP in-hospital decrease ≥30% was found more often in patients who showed good decongestion in comparison to patients in persistent failure (63 vs 22%; p < 0.001). The ROC curve analyses at 3 months show that both BNP reduction of 30% between admission and discharge and decongestion at discharge identifies patients with a reduced incidence of cardiovascular events (AUC = 0.79, confidence interval 0.68-0.90, sensibility 90%, sensitivity 50% p < 0.001). Kaplan-Meier survival plots show a better outcome in patients with a BNP decrease ≥30% and good decongestion at discharge (p = 0.03). BNP reduction in AHF is associated with decongestion. BNP reduction associated with decongestion at discharge is a favorable prognostic indicator at 90-day survival irrespective of the AKI occurrence.