1. Cardiovascular Division/Department of Internal Medicine and Department of Laboratory Medicine and Pathology, Mayo Clinic and Mayo Medical School, Rochester, MN
2. Department of Laboratory Medicine and Pathology, University of Minnesota School of Medicine and Hennepin County Hospital, Minneapolis, MN
3. Cardiology Division/Department of Internal Medicine, Harvard Medical School and Brigham and Womens Hospital, Boston, MA
4. Department of Cardiology and Uppsala Clinical Research Center (UCR), Uppsala University Hospital, Uppsala, Sweden
5. Medizinische Klinik, Abteilung für Innere Medizin III, Universitätsklinikum Heidelberg, Germany