VALUE OF NATRIURETIC PEPTIDES IN ASSESSMENT OF PATIENTS WITH POSSIBLENEW 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 dia gnosis of heart failure. Methods Concentrations of plasma atrial (ANP and N-terminal ANP) and B-type (BNP) natriuretic peptides were measure d 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). Findings Ge ometric mean concentrations of natriuretic peptides were much higher i n 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 pm ol/L for NT-ANP; all p<0.001). At cut-off values chosen to give negati ve predictive values for heart failure of 98% (ANP greater than or equ al to 18.1 pmol/L, NT-ANP greater than or equal to 537.6 pmol/L, BNP g reater than or equal to 22.2 pmol/L), the sensitivity, specificity, an d 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. Interpr etation In patients with symptoms suspected by a general practitioner to be due to heart failure, plasma BNP concentration seems to be a use ful indicator of which patients are likely to have heart failure and r equire further clinical assessment.