title: Effect of compensated renal dysfunction on approved heart failure markers: direct comparison of brain natriuretic peptide (BNP) and N-terminal pro-BNP.
abstract: Brain natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) are markers of heart failure. Although renal dysfunction may increase plasma concentrations, the magnitude of this effect has not been assessed in a head-to-head comparison between the clinically approved tests. We assessed the effect of compensated renal dysfunction on BNP (Triage BNP; Biosite) and NT-proBNP (elecsys proBNP; Roche) in 469 randomly selected stable outpatients after myocardial infarction (MI; Monitoring Trends and Determinants in Cardiovascular Diseases [MONICA] register Augsburg) who were characterized with respect to renal function (glomerular filtration rate [GFR]; Cockroft method) and left ventricular (LV) ejection fraction (EF) and mass (2D echocardiography). BNP and NT-proBNP were elevated in MI patients with LV dysfunction (LVD; EF <35%) compared with MI patients with preserved EF ( >45%; BNP 139+/-27 pg/mL versus 75+/-6; NT-proBNP 816+/-237 pg/mL versus 243+/-20; both P <0.03). Among all MI patients, the prevalence of renal dysfunction (GFR <85 mL/min) was 24%. BNP and NT-proBNP were significantly elevated in MI patients with renal dysfunction (BNP 132+/-17 pg/mL versus 68+/-4 without renal dysfunction; NT-proBNP 535+/-80 pg/mL versus 232+/-19; both P <0.05), and both markers were correlated with GFR in univariate and multivariate analyses (all P <0.01). When binary cut-off values were stratified according to the absence or presence of renal dysfunction (BNP 75 pg/mL and 125 pg/mL, respectively; NT-proBNP 100 pg/mL and 350 pg/mL, respectively), the predictive power of both markers for the detection of LVD increased substantially. BNP and NT-proBNP are almost similarly influenced by mild-to-moderate renal dysfunction. Renal dysfunction is a potential cause of elevated marker concentrations in the absence of LVD, and cut-off concentrations should be stratified according to renal function.
authors.affiliation: Klinik und Poliklinik für Innere Medizin II, University of Regensburg, Germany. andreas.luchner@klinik.uni-regensburg.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Luchner
authors.forename: Christian
authors.initials: C
authors.lastname: Hengstenberg
authors.forename: Hannelore
authors.initials: H
authors.lastname: Löwel
authors.forename: Günter A J
authors.initials: GA
authors.lastname: Riegger
authors.forename: Heribert
authors.initials: H
authors.lastname: Schunkert
authors.forename: Stephan
authors.initials: S
authors.lastname: Holmer
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000097:blood*; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000209:etiology
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain