Comparison of the clinical utility of atrial and B type natriuretic peptide measurement for the diagnosis of systolic dysfunction in a low-risk population.
BACKGROUND
Measurement of B type natriuretic peptide and its N terminal prohormone (NTproBNP) can now be performed routinely by automated high-throughput immunoassays. The study compared measurement of NTproBNP with measurement of N terminal pro-atrial natriuretic peptide (NTproANP) for detection of ventricular systolic dysfunction in primary care.


METHODS
734 subjects aged >45 years (349 men and 385 women, median age 58 years, range 45-89, interquartile range 51-67 years) from seven representative general practices attended for echocardiography with determination of ejection fraction and completed a questionnaire. Blood samples were collected into gel serum separation tubes (Becton-Dickinson, Franklin Lakes, New Jersey, USA), the serum separated and aliquots stored frozen at -70 degrees C until analyses. Samples were analysed for NTproBNP (Roche Diagnostics, Lewes, UK; coefficient of variation (CV) 3.2-2.4%) and for NTproANP (Biomedica, Vienna, Austria; CV 5.6-10.1%). Echocardiography was used as the diagnostic "gold standard", with ventricular systolic dysfunction defined as abnormal when there was an ejection fraction of <or=40%. Patients were dichotomised by ejection fraction from 50% to 30%, and receiver operating characteristic curves constructed and the area under the curve (AUC) compared.


RESULTS
At 40% ejection fraction, NTproANP and NTproBNP showed AUCs of, respectively, 0.738 (0.601-0.875) and 0.973 (0.958-0.989), p<0.004.


CONCLUSIONS
NTproBNP is superior to NTproANP for detection of systolic dysfunction.
Galasko
Gavin
G
Department of Cardiovascular Medicine, Northwick Park Hospital, Harrow, Middlesex, UK.
Collinson
Paul O
PO
Barnes
Sophie C
SC
Gaze
David
D
Lahiri
Arjivit
A
Senior
Roxy
R
D000368:Aged; D000369:Aged, 80 and over; D009320:Atrial Natriuretic Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D012372:ROC Curve; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis*
D015415:Biomarkers; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor