Evaluating improvement across rehabilitation in peripheral artery disease patients: a comparison between the 6-minute walk test and maximal treadmill graded exercise test

Abstract

Peripheral artery disease (PAD) is a debilitating disease that increases mortality and negatively affects quality of life. The primary non-invasive therapeutic step after diagnosis is supervised exercise therapy (SET). A commonly used tool to measure outcomes in PAD patients is a symptom limited maximal graded exercise test (GXT) performed on a treadmill. A possible alternative to the GXT is the 6-minute walk test (6MWT). Patients with diagnosed PAD completed a symptom-limited maximal treadmill GXT and 6MWT pre and post SET. Primary outcome measures for the tests included GXT total walking time and 6MWT total distance. Four patients (3 male, 1 female) completed the study. No statistically significant difference was observed for the treadmill GXT or 6MWT from pre to posttest (p >0.05). Percent change from pre to post for the treadmill GXT and 6MWT were compared against one another. No significant difference was found between the percent change on the two tests (p>0.05). There was a moderate correlation between the treadmill GXT and 6MWT (r = 0.73). The GXT and 6MWT showed similar trends in improvement from pre to post SET. The present study supports the use of either the treadmill GXT or 6MWT to assess outcomes in PAD patients.