1. Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD
2. Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE
3. Department of Internal Medicine, Division of Cardiology, The Warren Alpert Medical School of Brown University, Providence, RI
4. Keele Cardiovascular Research Group, Institute of Applied Clinical Sciences, University of Keele, Stoke-on-Trent, UK