Duration of Supervised Exercise Necessary for Meaningful Improvement in Peripheral Artery Disease

Background Supervised treadmill exercise improves walking performance in people with lower extremity peripheral artery disease, but benefits are not immediate. This study identified the time course of attaining meaningful improvement in 6‐minute walk distance and patient‐reported outcome measures during a 6‐month supervised exercise intervention in people with peripheral artery disease. Methods Participants with peripheral artery disease were randomized to supervised treadmill exercise 3 time weekly or a nonexercise control group for 6 months. Six‐minute walk distance (large clinically important difference: 20 meters) and the Walking Impairment Questionnaire distance score (0–100 scale, 100 is best, clinically important difference: 5 points) were measured at the 6‐week, 12‐week, and 26‐week follow‐up using a mixed‐effects model for repeated measures. Results Of 210 randomized participants (mean age, 67.0±8.6 years, 82 [39%] women, 141 [66%] Black), 200 (95%) completed at least 1 follow‐up visit. Compared with controls, supervised exercise significantly improved 6‐minute walk distance by 13.0 m ( P =0.049) at the 6‐week, 31.8 m ( P <0.001) at the 12‐week, and 33.9 m ( P <0.001) at the 26‐week follow‐up. Compared with controls, supervised exercise increased the Walking Impairment Questionnaire distance score by +2.63 ( P =0.37) at the 6‐week, +6.59 ( P =0.049) at the 12‐week, and +2.37 ( P =0.49) at the 26‐week follow‐up. Conclusions In people with peripheral artery disease, >6 weeks of supervised treadmill exercise was necessary to attain a large meaningful gain in 6‐minute walk, and large meaningful gains were measurable by week 12 of supervised exercise. Meaningful improvement in participant reported walking ability was first observed at the 12‐week follow‐up, but this statistically significant benefit was gone by the 26‐week follow‐up. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01408901.