Utility of Walk Tests in Evaluating Functional Status Among Participants in an Outpatient Cardiac Rehabilitation...

Although walk tests are frequently used in cardiac rehabilitation (CR), no prior study has evaluated the capacity of these measures to predict peak oxygen uptake during exercise testing ((Equation is included in full-text article.)O2peak). This study evaluated the interrelationship of objective measures of exercise performance (walk and exercise testing) among patients entering CR as well as a novel measure of functional status assessment for use in CR.

Forty-nine patients (33 males) referred to an outpatient CR program were evaluated with objective measures of ambulatory functional status (peak oxygen uptake [(Equation is included in full-text article.)O2peak], 6-minute walk test [6MWT], and 60-ft walk test [60ftWT]).

All measures of functional status were moderately to highly intercorrelated (r values from 0.50 to 0.88; P values < .05). The relationship among measures differed by sex, but not by age or diagnosis. Among men, results were generally consistent with the full sample. Among women, the magnitude of correlations was generally lower and there was no relationship between (Equation is included in full-text article.)O2peak and other measures.

Measures of functional status, including (Equation is included in full-text article.)O2peak, 6MWT, and 60ftWT, were highly correlated among CR patients, suggesting the plausibility of using them interchangeably to fit the needs of the patient and testing environment. Among women, walk tests may not be appropriate substitutes for (Equation is included in full-text article.)O2peak. Because of the brevity of the 60ftWT, it may be particularly useful for measuring functional status in patients with greater symptoms and those with comorbidities limiting walking.