[The clinical value of B-type natriuretic peptide in the diagnosis of left 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.


CONCLUSIONS
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.
Zhao
Xue-Yan
XY
Department of Cardiology, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
Yang
Yue-Jin
YJ
Zhang
Jian
J
Dang
Ai-Min
AM
Ni
Xin-Hai
XH
Huang
Jie
J
Kang
Sheng
S
Ma
Wei-Hua
WH
Zhao
Dong-Yun
DY
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015200:Fluoroimmunoassay; D006333:Heart Failure / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000032:analysis*; D011237:Predictive Value of Tests; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000378:metabolism
D020097:Natriuretic Peptide, Brain