Influence of renal function on N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients admitted for dyspnoea in the Emergency Department: comparison with brain natriuretic peptide (BNP).
BACKGROUND
Renal dysfunction influences the optimum brain natriuretic peptide (BNP) threshold for a diagnosis of cardiac-related dyspnoea, but this has not been demonstrated for N-terminal pro-brain natriuretic peptide (NT-proBNP). We studied the influence of renal function on NT proBNP and BNP concentrations in dyspnoeic patients admitted by night to the Emergency Department (ED).


METHODS
NT-proBNP, BNP, and creatinine levels were measured in blood samples collected routinely from 381 patients; estimated glomerular filtration rate (eGFR) was calculated.


RESULTS
Cardiac-related dyspnoea was found in 115 patients (30.2%). NT-proBNP and BNP values were elevated in patients with cardiac-related dyspnoea (6823+/-6569 vs. 2716+/-4838 pg/ml, and 642+/-329 vs. 243+/-267 pg/ml, p<0.0001, respectively). Log-transformed NT-proBNP and BNP values were correlated to eGFR values. Mean NT-proBNP and BNP values stratified by ED diagnosis increased in line with eGFR categories, but in each category both peptide concentrations remained elevated in cardiac-related dyspnoea when compared with non-cardiac-related dyspnoea (p<0.05). NT-proBNP (and BNP) cut-off points rose as a function of eGFR categories: from 1360 (and 290) pg/ml in patients with eGFR 60-89 ml/min/1.73 m2, to 6550 (and 515) pg/ml in patients with eGFR 15-29 ml/min/1.73 m2.


CONCLUSIONS
Renal function influences the optimal cut-off points of NT-proBNP and BNP for the diagnosis of cardiac-related dyspnoea.
Department of Biochemistry, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, 27 rue du Faubourg Saint-Jacques, 75679 Paris cedex 14, France. camille.gobeaux@cch.ap-hop-paris.fr
Camille
C
Chenevier-Gobeaux
Yann-Erick
YE
Claessens
Simon
S
Voyer
Dominique
D
Desmoulins
O G Jean-Charles
OG
Ekindjian
D000368:Aged; D000369:Aged, 80 and over; D004417:Dyspnea / Q000097:blood* / Q000503:physiopathology*; D004635:Emergency Medicine; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain