N-terminal pro-brain natriuretic peptide and exercise capacity in chronic heart failure: data from the Heart Failure and a Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION) study.
OBJECTIVE
To examine the relationship between N-terminal pro-brain natriuretic peptide (NT-proBNP) and exercise capacity in a large contemporary cohort of patients with chronic heart failure.


BACKGROUND
Natriuretic peptides such as NT-proBNP are important biomarkers in heart failure. The relationship between NT-proBNP and exercise capacity has not been well studied.


METHODS
We analyzed the relationship between baseline NT-proBNP and peak oxygen uptake (peak VO(2)) or distance in the 6-minute walk test in 1383 subjects enrolled in the HF-ACTION study. Linear regression models were used to analyze the relationship between NT-proBNP and peak Vo(2) or distance in the 6-minute walk test in the context of other clinical variables. Receiver operator curve analysis was used to evaluate the ability of NT-proBNP to accurately predict a peak VO(2) <12 mL/kg per minute.


RESULTS
NT-proBNP was the most powerful predictor of peak VO(2) (partial R(2) = 0.13, P < .0001) of 35 candidate variables. Although NT-proBNP was also a predictor of distance in the 6-minute walk test, this relationship was weaker than that for peak VO(2) (partial R(2) = 0.02, P < .0001). For both peak VO(2) and distance in the 6-minute walk test, much of the variability in exercise capacity remained unexplained by the variables tested. Receiver operator curve analysis suggested NT-proBNP had moderate ability to identify patients with peak VO(2) <12 mL/kg per minute (c-index, 0.69).


CONCLUSIONS
In this analysis of baseline data from HF-ACTION, NT-proBNP was the strongest predictor of peak VO(2) and a significant predictor of distance in the 6-minute walk test. Despite these associations, NT-proBNP demonstrated only modest performance in identifying patients with a low peak VO(2) who might be considered for cardiac transplantation. These data suggest that, although hemodynamic factors are important determinants of exercise capacity, much of the variability in exercise performance in heart failure remains unexplained by traditional clinical and demographic variables.
Duke Clinical Research Institute, Durham, NC 27705, USA. michael.felker@duke.edu
G Michael
GM
Felker
David
D
Whellan
William E
WE
Kraus
Robert
R
Clare
Faiez
F
Zannad
Mark
M
Donahue
Kirkwood
K
Adams
Robert
R
McKelvie
Ileana L
IL
Piña
Christopher M
CM
O'Connor
D000368:Aged; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D015331:Cohort Studies; D003625:Data Collection / Q000706:statistics & numerical data; D005080:Exercise Test / Q000706:statistics & numerical data*; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood* / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D010446:Peptide Fragments / Q000097:blood; D011379:Prognosis; D011498:Protein Precursors / Q000097:blood* / Q000502:physiology; D012372:ROC Curve; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology
D015415:Biomarkers; D010446:Peptide Fragments; D011498:Protein Precursors; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain