Steps to assessing heart failure

In an era when high-tech procedures are becoming increasingly common in cardiology, it’s refreshing to see continued interest in one of the lowest-tech diagnostic/prognostic procedures currently available: the 6-minute walk test. This simple and low-cost method of estimating functional status in patients with chronic congestive heart failure has been used by several groups of investigators, beginning with the report of Guyatt et al in 1985¹ and including Roul et al in 1998² to demonstrate a direct relationship between reduced walk duration (less than 300 meters) and prognosis in chronic heart failure.

The most recent report by Dr. Lee Ingle from the United Kingdom adds to this database. Ingle and colleagues used a study group of 1077 patients over the age of 60 and evaluated both the 1-year reproducibility and the sensitivity of the test. As the authors point out, one of the useful features of the test is that the mode of exercise—good, old fashioned walking—is very familiar to patients. Furthermore, the test design can be duplicated easily in different settings and even crosses geographic boundaries without a problem!

Aside from the 1-year reproducibility issue (which the investigators found to be 7%, an excellent correlation), Ingle poses some other “new” questions about the test in the current study, questions dealing with self-perceived changes regarding symptoms of heart failure. In other words, now that we have an objective test of functional status, can we relate that to how the patient judges his or her improvement (or worsening) of heart failure symptoms? Using a questionnaire supplied to patients (the EuroHeart Failure Survey, found in the article, which grades 6 symptom-related questions from 1-6 with “1” unimpaired and “6” greatly impaired), Ingle found that patients with improved symptoms not only walked farther (a direct correlation not seen with the unchanged or worsened test result sub-groups) but had a better self perception of this im­provement as documented on the questionnaire.

The current study, by focusing on self-perceived symptoms of heart failure, breaks new ground and the clinical implications of Ingle’s report are persuasive: this simple 6-minute walk test is not only reproducible but is an objective correlate to changes in symptoms of heart failure.