Comprehensive Magnetic Resonance in Peripheral Arterial Disease.3

The goal is to test the ability to detect improved calf muscle perfusion and energetics in
PAD patients in a randomized controlled trial of home exercise therapy. Eighty patients will
be randomized to a 12 week home exercise program or no program (control). Patients will be
studied before and after program completion with MRI/MRS, calf muscle biopsy for capillary
density, and exercise performance measures. Arterial spin labeling peak exercise calf muscle
perfusion will be used as the primary endpoint in the most symptomatic leg. All will undergo
ASL, peak exercise PCr recovery kinetics, calf muscle biopsy, and functional measures
including treadmill exercise, VO2 testing, and 6-minute walk. Correlations will be examined
between changes in perfusion and energetics with changes in capillary density, peak VO2, and
functional capacity from before to after completion of home exercise therapy.

Inclusion Criteria:

- Documented ABI 0.5-0.9

- Ability to walk on treadmill

Exclusion Criteria:

- Lower extremity vascular surgery, angioplasty or lumbar sympathectomy within 3 months
of enrollment

- Critical limb ischemia

- Known or suspected peripheral neuropathy, heel cord contracture and foot deformity

- Other conditions that limit walking, e.g. lung disease or arthritis

- Active coronary artery disease such as unstable angina, significant left main disease
or three vessel coronary artery disease (>70% stenosis, unprotected by grafts) or
recent (<2 months) myocardial infarction,

- BMI > 40,

- Known contraindication to MRI (intracardiac pacer, defibrillator, certain intracranial
aneurysm clips, intraocular or cochlear implants, claustrophobia, etc.)

- Allergy to lidocaine or xylocaine (local anesthetic)