Abstract 11390: Exercise Intensity, Minutes Walked for Exercise, and Improved Walk Performance in Peripheral Artery Disease: The Lite Randomized Clinical Trial

Abstract

Introduction: Recent evidence showed that among people with peripheral artery disease (PAD), walking exercise conducted at a pace inducing ischemic leg symptoms improved six-minute walk distance (6MW), while walking exercise conducted at a pace without ischemic leg symptoms had no effect on 6MW. This report describes associations of walking exercise intensity and minutes walked for exercise among participants with PAD with the change in 6MW. Method & Results: In the LITE clinical trial, 305 participants with PAD (69±4 years, 181 (59%) Black, 146 (48%) female) were randomized to: 1) walking exercise conducted at a pace without ischemic leg symptoms (low-intensity: LI), 2) walking exercise conducted at a pace eliciting ischemic leg symptoms (high-intensity: HI), or 3) an attention-control group for 12-months. Participants in both exercise groups were asked to walk in or around the home for up to five days/week for up to 50 minutes/session. Measurements of walking intensity and exercise minutes per week were determined individually for each participant in each exercise group using an Accelerometer. Participants in each exercise group were categorized into quartiles according to exercise minutes per week and exercise intensity, respectively (4 th quartile indicated greatest minutes or intensity). Within the LI and HI groups, more minutes of exercise per week were associated with greater 6MW improvement [(LI: 4 th vs 1 st Q: +54 m, 95%CI:16, 92; P=0.018), (HI: 4 th vs 1 st Q: +54 m, 95% CI: 12, 96; P=0.010), Table 1]. Within the LI group, but not the HI group, greater exercise intensity was associated with greater 6MW improvement [(LI: 4 th vs 1 st Q: +80 m, 95% CI: 31, 128; P=0.002), Table 1]. Conclusion: While high intensity exercise improves 6MW in PAD, exercising for a greater duration offers greater benefit. Additionally, there is benefit in exercising at low intensity, focusing on increased duration of exercise, if patients are unable to exercise at high intensity.