Role of plasma B type natriuretic peptide concentration in the diagnosis and predicting prognosis of patients with heart failure

Objective To study the role of plasma B type natriuretic peptide(BNP)concentration in the diagnosis and predicting prognosis of patients with heart failure(HF).Methods Plasma BNP concentration was measured with immunofluorescenee assay in 90 patients with dyspnea.Left ventricular ejection fraction(LVEF)and pulmonary capillary wedge pressure(PCWP)were determined by eehoeardiography and Swan-Ganz catheter respectively in these patients at the same time.The gradation of HF was based on the criteria of cardiac function classification setted by New York Heart Association(NYHA).The HF patients were classified into 2 groups according to BNP concentration measured just before the discharge:patients with BNP＜400 ng/L and BNP≥400 ng/L.The re-admisslon rate within 30 days because of the HF between the two groups was compared.Results Plasma BNP levels were higher in the patients with left heart failure than those in the non-heart failure patients[(569±222)ng/L vs.(52±10)ng/L,P＜0.01],and BNP levels were increased in accordance with the severity of HF.The sensitivity,specificity,and negative predictive values of plasma BNP levels≥100 ng/L for predicting HF were 94.7%,91.7% and 96.7%,respectively.Plasma BNP levels were positively related to PCWP(r=0.55,P＜0.01),and negatively related to LVEF(r=-0.62,P＜0.01).There was no significant difference of plasma BNP levels between patients with different causes of HF.The re-admission rate within 30 days after discharge was notably high if the plasma BNP concentrations were over 400 ng/L.Conclusion Plasma BNP concentration can be regarded as a valuable marker for diagnosis and predicting prognosis of patients with HF.