Attendance at Supervised Exercise Sessions and Walking Outcomes in Peripheral Artery Disease: Results From 2 Randomized Clinical Trials.

Background Supervised exercise therapy (SET) is the first-line therapy for walking impairment in peripheral artery disease (PAD). This study evaluated the association between attendance at SET and improved walking performance, compared with a control group, in PAD. Methods and Results Data from 2 randomized clinical trials of SET for PAD were combined. In each trial, participants were randomized to 3 times weekly supervised treadmill exercise or an attention control group for 6 months (maximum, 77 exercise sessions). Participants randomized to SET were categorized into tertiles, according to the proportion of exercise sessions they attended. Results adjusted for age, sex, race, baseline walking performance, comorbidities, and other potential confounders. A total of 272 participants with PAD (mean age, 67.9±9.3 years; 44% women; 61% Black race) were included. For participants randomized to SET, tertiles of attendance rates at exercise sessions were as follows: 11% to 68% (N=45), 69% to <85% (N=46), and ≥85% (N=46). Compared with control, mean improvement in 6-minute walk was significantly greater in each SET tertile: mean (95% CI) for tertile 1, 27.9 m (1.3-54.4 m; P =0.04), tertile 2, 38.2 m (12.2-64.2 m; P =0.001), and tertile 3, 56.9 m (29.9-83.8 m; P <0.0001). Among participants randomized to SET, greater SET attendance was associated with greater improvement in 6-minute walk distance (overall P for trend=0.025). Compared with control, improvement in maximal treadmill walking time was greater in each SET attendance tertile: tertile 1 (3.3 minutes [95% CI, 1.7-4.8 minutes]; P <0.0001), tertile 2 (3.8 minutes [95% CI, 2.3-5.3 minutes]; P <0.0001), and tertile 3 (5.4 minutes [95% CI, 3.9-7.0 minutes]; P :<0.0001). Among participants randomized to SET, greater attendance at SET was not significantly associated with greater improvement in maximal treadmill walking time (overall P for trend=0.064). Conclusions Among people with PAD randomized to SET, better attendance at exercise sessions was associated with significantly greater 6-minute walk improvement. Among all participants with PAD, even relatively low SET attendance was associated with significantly greater improvement in walking performance, compared with a control group who did not exercise. Registration URL: https://clinicaltrials.gov/ct2/show/NCT01408901. URL: https://clinicaltrials.gov/ct2/show/NCT00106327.