Shuttle versus six-minute walk test in the prediction of outcome in chronic heart failure

We prospectively analysed the potential usefulness of a symptom-limited wal k test: the shuttle walk test (SWT), in the prediction of major cardiac eve nts in 46 consecutive patients with chronic heart failure (NYHA class II-IV , ejection fraction <0.40) and compared it with that of a time-limited walk test, the six-minute walk test (6-MT). After a mean follow-up of 17 months (range, 8-28 months), 15 of 46 patients (33%) experienced a major cardiac event, defined as a cardiac death, urgent transplantation, or hospital admi ssion for continuous inotropic or mechanical support. Distance walked in th e SWT was shown to be a predictor of outcome at one year of follow-up (P=0. 03), but distance ambulated in the 6-MT was not (P=0.07). In multivariate a nalysis, percentage of age-gender predicted peak oxygen uptake was the best predictor of major cardiac events. When patients were divided into tertile s according to performance in both walk tests, there was an overall differe nce in event-free survival at 12 months among SWT tertiles (P=0.004), but n ot among 6-MT tertiles (P=0.09). A low performance in the SWT (distance amb ulated <450 m) allowed identification of a subgroup of patients with a high risk for major cardiac events at short-term. We conclude that, in patients with chronic heart failure, distance ambulated in the SWT predicts event-f ree survival at one year better than that in the 6-MT. (C) 2000 Elsevier Sc ience Ireland Ltd. All rights reserved.