i. Ambulation limited by co-morbid condition other than claudication, for example:1. severe coronary artery disease; 2. angina pectoris; 3. chronic lung disease;4. neurological disorder such as hemiparesis;5. arthritis, or other musculoskeletal conditions including amputation ii. Poorly-controlled hypertension (SBP greater than 180 mm Hg) iii.Poorly-controlled diabetes mellitus iv. Other active significant medical problems such as cancer, known chronic renal disease (serum creatinine greater than 2.0 mg/dl within 60 days or renal replacement therapy), known chronic liver disease or anemia, active substance abuse, or known history of dementia