1. Jefferson Vascular Center, Departments of Medicine and Surgery, Thomas Jefferson University, Philadelphia, PA, USA
2. Cardiovascular Division, Vascular Medicine Section, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
3. Departments of Biostatistics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
4. Cardiology, Hematology and Vascular Surgery, New York University School of Medicine, New York, NY, USA