title: The 6-minute walk is associated with frailty and predicts mortality in older adults with heart failure.
abstract: Heart failure (HF) may contribute to the development of functional decline and frailty in older adults. Sixty HF patients with an ejection fraction ≤ 40% evaluated in 2004 and 2005 were reevaluated in 2008. Six-minute walk distance (6MW), frailty score, and biomarkers (25-hydroxyvitamin D, C-reactive protein, and interleukin-6 [IL-6]) were measured. Participants were categorized at baseline and follow-up into 3 groups: nonfrail/normal endurance (NF/NE), nonfrail/low endurance (NF/LE) and frail/low endurance (F/LE). Survival time was assessed according to frailty/endurance status and associated predictors of mortality. Forty-three men, 17 women (mean age, 78 ± 12 years) were contacted. At follow-up, 20 had died, 20 participated, and 20 did not participate. There were no changes in frailty/endurance status over time (McNemar;P=.19). Deaths occurred in 18% of NF/NE, 45% of NF/LE, and 60% of F/LE persons. The NF/NE group had greater survival rates than the NF/LE (  P=.032) and F/LE (  P=.014) groups. The 6MW and frailty score were independently predictive of mortality, with hazard ratios of 0.82 (95% confidence interval, 0.72-0.94) and 1.64 (95% confidence interval, 1.19-2.26), respectively, as was New York Heart Association class and IL-6. Backward stepwise Cox regression revealed that 6MW and frailty each were associated with mortality (P=.005) and highly correlated. Physical function is an important predictor of mortality in older adults with HF. The 6MW may be useful as a measure of frailty.
authors.affiliation: Department of Medicine, Harrington McLaughlin Heart and Vascular Institute, University Hospitals ⁄ Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106, USA. rebecca.boxer@case.edu
authors.forename: Rebecca
authors.initials: R
authors.lastname: Boxer
authors.forename: Alison
authors.initials: A
authors.lastname: Kleppinger
authors.forename: Amir
authors.initials: A
authors.lastname: Ahmad
authors.forename: Kristin
authors.initials: K
authors.lastname: Annis
authors.forename: David
authors.initials: D
authors.lastname: Hager
authors.forename: Anne
authors.initials: A
authors.lastname: Kenny
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D051341:Dependent Ambulation; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D016330:Frail Elderly; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D010359:Patient Readmission; D015203:Reproducibility of Results; D012107:Research Design; D012307:Risk Factors; D013318:Stroke Volume; D016019:Survival Analysis; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014807:Vitamin D; D002097:C-Reactive Protein; C104450:25-hydroxyvitamin D