1. Department of Medicine, West Virginia University, Morgantown, WV, USA
2. Department of Medicine, John H. Stroger J. Hospital of Cook County, Chicago, IL, USA
3. Department of Internal Medicine, East Carolina University, Greenville, SC, USA
4. Keele Cardiovascular Research Group, Keele University, Stoke-on-Trent, Staffordshire, UK
5. Department of Cardiology, Royal Stoke University Hospital, Stoke-on-Trent, Staffordshire, UK
6. Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, MD, USA