1. Division of Cardiovascular Medicine; Brigham and Women's Hospital; Boston MA USA
2. Department of Cardiology, Herlev and Gentofte Hospital; University of Copenhagen; Denmark
3. Cardiology Division; Northwestern University Feinberg School of Medicine; Chicago IL USA
4. Cardiovascular Division; VA Medical Center; Minneapolis MN USA
5. Sarver Heart Center; University of Arizona College of Medicine; Tucson AZ USA
6. Cardiology Division; University of Michigan School of Medicine; Ann Arbor MI USA