Monte S Willis1, Eunice S Lee, David G Grenache. 1. Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC 27599-7525, United States.
Abstract
BACKGROUND: Concentrations of the amino-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) are increased in the blood of patients with heart failure. Understanding the variables that influence the concentrations of NT-proBNP is required to refine its clinical use criteria. The effect of anemia on plasma concentrations of NT-proBNP was investigated. METHODS: Hemoglobin and NT-proBNP were measured in blood specimens collected from 209 adult patients without heart failure or renal disease. RESULTS: The median NT-proBNP concentration of patients with anemia was significantly higher than in those without anemia (82 vs. 232 ng/l, p<0.0001). Anemic patients were also 3 times more likely to have an NT-proBNP concentration that exceeded age-specific cutoffs recommended by the assay manufacturer (odds ratio 3.1, 95% CI 1.7 to 5.4, p<0.0001). CONCLUSIONS: Decreased concentrations of hemoglobin are sufficient to produce serum concentrations of NT-proBNP above diagnostic cutoffs in anemic patients without heart failure independent of gender, body mass index, glomerular filtration rate, left ventricular hypertrophy, and valve disease. The impact of this finding on the clinical use and interpretation of the test needs to be examined.
BACKGROUND: Concentrations of the amino-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) are increased in the blood of patients with heart failure. Understanding the variables that influence the concentrations of NT-proBNP is required to refine its clinical use criteria. The effect of anemia on plasma concentrations of NT-proBNP was investigated. METHODS: Hemoglobin and NT-proBNP were measured in blood specimens collected from 209 adult patients without heart failure or renal disease. RESULTS: The median NT-proBNP concentration of patients with anemia was significantly higher than in those without anemia (82 vs. 232 ng/l, p<0.0001). Anemicpatients were also 3 times more likely to have an NT-proBNP concentration that exceeded age-specific cutoffs recommended by the assay manufacturer (odds ratio 3.1, 95% CI 1.7 to 5.4, p<0.0001). CONCLUSIONS: Decreased concentrations of hemoglobin are sufficient to produce serum concentrations of NT-proBNP above diagnostic cutoffs in anemicpatients without heart failure independent of gender, body mass index, glomerular filtration rate, left ventricular hypertrophy, and valve disease. The impact of this finding on the clinical use and interpretation of the test needs to be examined.
Authors: Mazhar A Afaq; Azadeh Shoraki; Oleg Ivanov; Janardhan Srinivasan; Lawrence Bernstein; Stuart W Zarich Journal: J Clin Med Res Date: 2011-07-26