Participation in this study will last a minimum of 2 years and a maximum of 5 years. All participants will first undergo baseline assessments that will include a medical history, vascular and physical exam, electrocardiograph (EKG), magnetic resonance imaging (MRI) scan, 3D ultrasound, blood pressure measurement test in the legs, treadmill walking distance test, urine test, blood draw, and questionnaires. A portion of the blood draw will be used for DNA analysis and genetic testing.