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 (
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 [
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
O2peak and other measures.
Measures of functional status, including
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
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.
This study evaluated the interrelationship of functional status measures among cardiac rehabilitation (CR) patients. In men, but not women, walk test measures were associated with peak oxygen uptake. The 60-ft walk test was validated in CR patients and may be useful for evaluating patients with more severe symptoms.
Department of Psychology, The Ohio State University, Columbus.
Correspondence: Charles F. Emery, PhD, Department of Psychology, The Ohio State University, 1835 Neil Ave, Columbus, OH 43210 (Emery.firstname.lastname@example.org).
The authors declare no conflicts of interest.