1. Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
2. Department of Medicine, Brown University, Rhode Island Hospital, Providence, Rhode Island, USA.
3. Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA.
4. Division of Cardiology, Department of Internal Medicine, Columbia University Medical Center, New York, New York, USA.
5. Northside Cardiovascular Institute, Atlanta, Georgia, USA.
6. Barts Heart Center, St Bartholomew's Hospital and William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.