Study: NCT01408901

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Supervised Treadmill Exercise Therapy
Description: Exercise intervention will be delivered three times weekly for 26 weeks. In the first week, participants will be asked to exercise 15 minutes per session (excluding rest periods). Walking exercise duration will be increased to 25 minutes minutes per session during week 2. Week 3 and 4 sessions will also be 25 minutes long, but the intensity will be increased either to produce leg symptoms or at a target rate of perceived exertion (RPE)of 12-14 on the Borg's 6-20 scale. For weeks 5-8, walking duration will be increased to 40 to 50 minutes while maintaining intensity. For weeks 9-26, exercise duration will continue to be 40 to 50 minutes but we will increase intensity up to a maximum of 4.0 miles per hour at 10% grade.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Supervised Treadmill Exercise Therapy
Description: Exercise intervention will be delivered three times weekly for 26 weeks. In the first week, participants will be asked to exercise 15 minutes per session (excluding rest periods). Walking exercise duration will be increased to 25 minutes minutes per session during week 2. Week 3 and 4 sessions will also be 25 minutes long, but the intensity will be increased either to produce leg symptoms or at a target rate of perceived exertion (RPE)of 12-14 on the Borg's 6-20 scale. For weeks 5-8, walking duration will be increased to 40 to 50 minutes while maintaining intensity. For weeks 9-26, exercise duration will continue to be 40 to 50 minutes but we will increase intensity up to a maximum of 4.0 miles per hour at 10% grade.

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: Health education sessions (Control)
Description: Participants randomized to the attention control group will attend weekly one-hour educational sessions at Northwestern University for six months. These educational sessions are on topics of interest to the typical PAD patient and are led by physicians and other health care workers. Topics include Medicare Part D, nutritional supplements, C-reactive protein, and hypertension. Sessions do not include information about exercise.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Health education sessions (Control)
Description: Participants randomized to the attention control group will attend weekly one-hour educational sessions at Northwestern University for six months. These educational sessions are on topics of interest to the typical PAD patient and are led by physicians and other health care workers. Topics include Medicare Part D, nutritional supplements, C-reactive protein, and hypertension. Sessions do not include information about exercise.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: granulocyte macrophage colony stimulating factor (GM-CSF)
Description: The dose of GM-CSF will be 250 ug/M\^2 subcutaneously three times weekly for two weeks.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: granulocyte macrophage colony stimulating factor (GM-CSF)
Description: The dose of GM-CSF will be 250 ug/M\^2 subcutaneously three times weekly for two weeks.