N-terminal pro-brain natriuretic peptide, kidney disease and outcome in patients with chronic heart failure.
BACKGROUND
In patients with chronic heart failure (CHF), N-terminal pro-brain natriuretic peptide (NT-proBNP) provides relevant prognostic information, but its usefulness in the presence of kidney disease has been questioned.


METHODS
We prospectively enrolled 142 patients with stable CHF and a wide spectrum of renal function (estimated glomerular filtration rates [eGFRs] ranging from 17.1 to 100.3 ml/min/1.73 m2). Chronic kidney disease, defined as eGFR < 60 ml/min/1.73 m2, was present in 63 patients (44%). NT-proBNP measurements were carried out on a bench-top analyzer (Elecsys 2010). Cardiac death or urgent cardiac transplantation were considered as a combined study end-point.


RESULTS
During a follow-up of 383 +/- 237 days, 19 patients underwent a cardiac event (cardiac death, n = 17; urgent cardiac transplantation, n = 2). By multivariate Cox analysis, including clinical and laboratory variables, NT-proBNP and serum hemoglobin were independent prognostic predictors. In patients with NT-proBNP > 1,129 pg/ml, outcome was significantly worse compared to patients with NT-proBNP < 1,129 pg/ml (event-free survival rate 67% vs 94% in those with NT-proBNP < 1,129 pg/ml, p = 0.001). By linear regression analysis, NT-proBNP levels were related to New York Heart Association (NYHA) functional class (R = 0.41, p < 0.001), and inversely related to eGFR (R = -0.29, p = 0.001) and to left ventricular ejection fraction (R = -0.43, p < 0.001).


CONCLUSIONS
In CHF patients with and without kidney disease, NT-proBNP provides independent prognostic information. In such patients, NT-proBNP levels are not only reflective of a reduced clearance (i.e., a lower eGFR) but also of the severity of the underlying structural heart disease.
Bruch
Christian
C
Department of Cardiology and Angiology, Hospital of the University of Münster, Münster, Germany. bruchc@uni-muenster.de
Reinecke
Holger
H
Stypmann
Jörg
J
Rothenburger
Markus
M
Schmid
Christof
C
Breithardt
Günter
G
Wichter
Thomas
T
Gradaus
Rainer
R
D000328:Adult; D000368:Aged; D002303:Cardiac Output, Low / Q000097:blood* / Q000401:mortality / Q000503:physiopathology*; D002908:Chronic Disease; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007674:Kidney Diseases / Q000097:blood* / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain