The utility of the 6-minute walk test as a measure of frailty in older adults with heart failure

Patients with heart failure (HF) are at increased risk for frailty, and identification is challenging. The authors assessed the distance on the 6-minute walk test (6MWT) as a measure of frailty in 60 older HF patients (ejection fraction <= 40%) compared with frailty phenotype (FP). Scores were dichotomized to frail (F) or nonfrail (NF), and the results of 6MWT were dichotomized to low endurance (LE) or normal endurance (NE). FP and 6MWT results were in moderate agreement ( kappa=0.57, confidence interval [CI], 0.36-0.79; age-adjusted kappa=0.54, 95% CI, 0.33-0.76); 25% of participants were classified as FILE, and 55% were classified as NF/NE. Discordance was asymmetric (McNemar P=.006); 18% of participants were NF/LE. There were no differences between the NF/LE and other groups in age, sex, body mass index, or physical activity level. Results in the NF/LE group differed front those in the NF/NE group by a slower 8-foot walking speed (P=.02), weaker grip strength (P=.056), and worse renal function (P=.01) and from those in the FILE group by faster 8-foot walking speed (P<.001). The 6MWT may be useful to identify frailty and those in transition to frailty.