The relation between repeated 6-minute walk test performance and outcome in patients with chronic heart failure.
OBJECTIVE
To assess the prognostic implications of the 6-minute walk test (6-MWT) distance measured twice, one year apart, in a large sample of patients with chronic heart failure (CHF) followed for an extended period (>8 years from baseline).


METHODS
Patients undertook a 6-MWT at baseline and at one year, and were followed up for 8 years from baseline.


RESULTS
Six hundred patients (median [inter-quartile range, IQR]) (age 78 [72-84] years; 75% males; body mass index 27 [25-31] kg·m(-2); left ventricular ejection fraction 34 [26-38] %) were included. At baseline, median 6-MWT distance was 232 (60-386) m. There was no significant change in 6-MWT distance at one year (change -12m; P=0.533). During a median follow-up of 8.0 years in survivors, 396 patients had died (66%). Four variables were independent predictors of all-cause mortality in a multivariable Cox model (adjusted for body mass index, age, QRS duration, left ventricular ejection fraction); increasing NT pro-BNP, decreasing 6-MWT distance at 1 year, decreasing haemoglobin, and increasing urea.


CONCLUSIONS
Distance walked during the 6-MWT is an independent predictor of all-cause mortality in patients with CHF. In survivors, the 6-MWT distance is stable at 1 year. The 6-MWT distance at 1 year carries similar prognostic information.
Department of sport, health & exercise science, university of Hull, 003 Don building, Cottingham road, Kingston-upon-Hull, HU7 6RX, United Kingdom. Electronic address: L.Ingle@hull.ac.uk.
L
L
Ingle
National heart & lung institute, Royal Brompton & Harefield hospitals, Imperial college, London, United Kingdom.
J G
JG
Cleland
Department of academic cardiology, Hull York medical school, Castle Hill hospital, Kingston-upon-Hull, HU16 5JQ, United Kingdom.
A L
AL
Clark
D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality* / Q000503:physiopathology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011379:Prognosis; D015996:Survival Rate; D014508:Urea / Q000097:blood; D016138:Walking / Q000502:physiology*
D006454:Hemoglobins; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D014508:Urea
6-minute walk test; Chronic heart failure; Insuffisance cardiaque; Repeat testing; Risk; Risque; Test de marche de 6minutes; Tests répétés