The importance of admission and discharge BNP assessment in patients hospitalized for acutely decompensated chronic systolic heart failure

IntroductionThe assessment of B-type natriuretic peptide (BNP) plasma levels is not only useful for the differential diagnosis of acute dyspnea, but also for the prognostic stratification of patients with heart failure. However, available studies that have addressed monitoring of hospitalized patients are burdened with significant limitations: (1) measurement of plasma BNP levels only at admission or at discharge, (2) lack of details regarding the cause of heart failure, and (3) small sample size. Therefore, we conducted a prospective study of all patients presenting to our hospital with acutely decompensated chronic systolic heart failure.AimTo determine the importance of admission and discharge values of BNP and its changes during hospitalization for identification of patients with acutely decompensated chronic systolic heart failure at higher risk of unfavorable course of the disease.MethodsA prospective monocentric study determining plasma BNP levels at admission and at discharge in patients hospitalized for acutely decompensated chronic systolic heart failure. Patients: 130 consecutive patients, 77% men, mean age 70 years, body mass index (BMI) 27.8 kg/m²; etiology of chronic heart failure—65.9% ischemic heart disease, 29.5% dilated cardiomyopathy, 4.6% others; signs and symptoms at admission—peripheral edema 58.9%, pulmonary rates 88.3%, orthopnea 53.1%, median of admission BNP 1101 pg/ml, median of discharge BNP 650 pg/ml, median left ventricular ejection fraction 26.5%, average length of hospitalization 9 days.ResultsDuring the follow-up (mean 15 months) the total mortality rate reached almost 40% and the annual mortality of our cohort was 29%. The most common causes of death included progression of heart failure and acute coronary syndromes. To evaluate the long-term risk of mortality, we used time-dependent ROC curves for the definition of cut-off values of BNP at admission and discharge. The relationship of BNP levels and the survival of patients was assessed using the hazard ratio (HR) calculated by the Cox proportional hazards model. BNPs at admission and at discharge with a cut-off value of 1699 pg/ml and 434.5 pg/ml are significant prognostic factors for patients hospitalized for acutely decompensated chronic systolic heart failure with a HR 2.79 and 3.29, respectively. During the follow-up, more than half of the patients required readmission to the hospital. The most common reasons for rehospitalization were cardiovascular causes.ConclusionBNP levels at admission and at discharge are an important predictive factor of survival in patients with acutely decompensated chronic systolic heart failure.