OBJECTIVE: To evaluate the diagnostic value of B-type natriuretic peptide (BNP) in the diagnosis of left heart failure (HF) or left ventricular systolic dysfunction. METHODS: Samples of peripheral venous blood were collected from 243 consecutive patients with left HF and 111 normal controls (control group, CG) to measured BNP level with fluorescence immunoassay method. The patients with left HF were divided into 2 groups: those with the left ventricular ejection fraction (LVEF) </= 40% (n = 111) and those with the LVEF > 40% (n = 132) according to the level of LVEF; or into 2 groups: compensated heart failure group (CHF group, at NYHA grade I - II, n = 110) and decompensated heart failure group (DHF group, at NYHA grade III - IV, n = 133) according to the New York Heart Association (NYHA) functional class. RESULTS: The plasma level of BNP of the left HF group was 292.0 ng/L, significantly higher than that of the CG (17.9 ng/L, P < 0.001). The plasma BNP of the group with the LVEF </= 40% was 471.0 ng/L, significantly than that of the group with the LVEF > 40% (138.5 ng/L, P < 0.001). The plasma BNP of the DHF group was 579.0 ng/L, significantly higher than that of the of the CHF group (84.8 ng/L, P < 0.001). The values of area under the curve (AUC) of receiver operator characteristic curve were all > 0.9 in the diagnosis of presence of HF (AUC = 0.927), HF with the LVEF </= 40% (AUC = 0.989), and DHF (AUC = 0.991), and in the differential diagnosis between CHF and DHF (AUC = 0.941). When 90.0 pg/ml was used as cutoff value to diagnose left HF, heart failure with the LVEF </= 40%, and decompensation, the positive predictive value (PPV) were 98.9%, 98.1%, and 98.5% respectively, and the negative predictive value (NPV) were 64.5%, 94.0%, and 96.5% respectively. When 50.0 pg/ml was used as the cutoff value to diagnose HF with the LVEF > 40% and compensated heart failure, the PPV were 88.0% and 84.7%, the NPV were 72.6% and 72.1% respectively. CONCLUSION: The diagnostic value of BNP is high for the diagnosis of more severely impaired LVEF and decompensated heart failure with 90.0 pg/ml as the cutoff value, and if 50.0 pg/ml is used as the cutoff value, the value is also good for the diagnosis of HF with the LVEF > 40% and compensated heart failure.
OBJECTIVE: To evaluate the diagnostic value of B-type natriuretic peptide (BNP) in the diagnosis of left heart failure (HF) or left ventricular systolic dysfunction. METHODS: Samples of peripheral venous blood were collected from 243 consecutive patients with left HF and 111 normal controls (control group, CG) to measured BNP level with fluorescence immunoassay method. The patients with left HF were divided into 2 groups: those with the left ventricular ejection fraction (LVEF) </= 40% (n = 111) and those with the LVEF > 40% (n = 132) according to the level of LVEF; or into 2 groups: compensated heart failure group (CHF group, at NYHA grade I - II, n = 110) and decompensated heart failure group (DHF group, at NYHA grade III - IV, n = 133) according to the New York Heart Association (NYHA) functional class. RESULTS: The plasma level of BNP of the left HF group was 292.0 ng/L, significantly higher than that of the CG (17.9 ng/L, P < 0.001). The plasma BNP of the group with the LVEF </= 40% was 471.0 ng/L, significantly than that of the group with the LVEF > 40% (138.5 ng/L, P < 0.001). The plasma BNP of the DHF group was 579.0 ng/L, significantly higher than that of the of the CHF group (84.8 ng/L, P < 0.001). The values of area under the curve (AUC) of receiver operator characteristic curve were all > 0.9 in the diagnosis of presence of HF (AUC = 0.927), HF with the LVEF </= 40% (AUC = 0.989), and DHF (AUC = 0.991), and in the differential diagnosis between CHF and DHF (AUC = 0.941). When 90.0 pg/ml was used as cutoff value to diagnose left HF, heart failure with the LVEF </= 40%, and decompensation, the positive predictive value (PPV) were 98.9%, 98.1%, and 98.5% respectively, and the negative predictive value (NPV) were 64.5%, 94.0%, and 96.5% respectively. When 50.0 pg/ml was used as the cutoff value to diagnose HF with the LVEF > 40% and compensated heart failure, the PPV were 88.0% and 84.7%, the NPV were 72.6% and 72.1% respectively. CONCLUSION: The diagnostic value of BNP is high for the diagnosis of more severely impaired LVEF and decompensated heart failure with 90.0 pg/ml as the cutoff value, and if 50.0 pg/ml is used as the cutoff value, the value is also good for the diagnosis of HF with the LVEF > 40% and compensated heart failure.