Abstract: Objective:To assess the value of brain natriuretic peptide(BNP) in diagnosis of asymptomatic heart failure(AHF), and to study the relationship between BNP and heart failure.Methods:One hundred and forty subjects were divided into AHF group(50 cases),congestive heart failure(CHF) group(50 cases) and healthy control(40 cases).The plasma BNP was measured, and echocardiogram was performed in all the cases.Exercise treadmill testing was carried on in the patients with AHF and the healthy controls,and the plasma BNP was determined immediately after exercise testing.Multi-variable correlation analysis was used to determine the relationship between BNP and different variables;receiver operating characteristic curves were used to assess the diagnostic accuracy of BNP in detecting AHF.Results:The plasma BNP concentration in CHF group was significantly higher than that in AHF group and control group(P<0.01),but there was no significant difference between AHF group and control group(P>0.05).After exercise testing,the BNP(△BNP) in AHF group increased significantly compared with that in control group(P<0.01).Multi-variable correlation analysis showed that BNP concentrations were positively related to NYHA functional classifications(r=0.534,P<0.01) and negatively related to LVEF(P<0.01).The area under the curve before and after exercise testing and △BNP were 0.653(P<0.05),0.724(P<0.01) and 0.831(P<0.01),respectively.If the value of △BNP was 58.90 pg/ml,the sensitivity and specificity would be 80% and 75% in detecting AHF.Conclusions:BNP is a sensitive and specific diagnostic marker of CHF.Natriuretic peptide concentration is negatively correlated with LVEF and positively with NYHA functional classifications.Plasma BNP can reflect the changes of cardiac function,and can be used to assess the severity of heart failure.BNP combined with exercise testing may enhance the diagnosis of AHF.