Value of natriuretic peptides in assessment of patients with possible new heart failure in primary care.
BACKGROUND
The reliability of a clinical diagnosis of heart failure in primary care is poor. Concentrations of natriuretic peptides are high in heart failure. This population-based study examined the predictive value of natriuretic peptides in patients with a new primary-care diagnosis of heart failure.


METHODS
Concentrations of plasma atrial (ANP and N-terminal ANP) and B-type (BNP) natriuretic peptides were measured by radioimmunoassay in 122 consecutive patients referred to a rapid-access heart-failure clinic with a new primary-care diagnosis of heart failure. On the basis of clinical assessment, chest radiography, and transthoracic echocardiography, a panel of three cardiologists decided that 35 (29%) patients met the case definition for new heart failure. ANP and NT-ANP results were available for 117 patients (34 with heart failure) and BNP results for 106 (29 with heart failure).


RESULTS
Geometric mean concentrations of natriuretic peptides were much higher in patients with heart failure than in those with other diagnoses (29.2 vs 12.4 pmol/L for ANP; 63.9 vs 13.9 pmol/L for BNP; 1187 vs 410.6 pmol/L for NT-ANP; all p < 0.001). At cut-off values chosen to give negative predictive values for heart failure of 98% (ANP > or = 18.1 pmol/L, NT-ANP > or = 537.6 pmol/L, BNP > or = 22.2 pmol/L), the sensitivity, specificity, and positive predictive value for ANP were 97%, 72%, and 55%; for NT-ANP 97%, 66%, and 54%; and for BNP 97%, 84%, and 70%. Addition of ANP or NT-ANP concentration or both did not improve the predictive power of a logistic regression model containing BNP concentration alone.


CONCLUSIONS
In patients with symptoms suspected by a general practitioner to be due to heart failure, plasma BNP concentration seems to be a useful indicator of which patients are likely to have heart failure and require further clinical assessment.
Cowie
M R
MR
Imperial College School of Medicine, National Heart and Lung Institute, London, UK.
Struthers
A D
AD
Wood
D A
DA
Coats
A J
AJ
Thompson
S G
SG
Poole-Wilson
P A
PA
Sutton
G C
GC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009320:Atrial Natriuretic Factor / Q000097:blood*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D011863:Radioimmunoassay; D015203:Reproducibility of Results
D009320:Atrial Natriuretic Factor