Marc Semigran is Associate Professor of Medicine, Harvard Medical School; Director, Heart Failure and Transplant Service, Massachusetts General Hospital; Attending Physician, Cardiac Catheterization, Laboratory, Medical Services, Coronary Care Unit, and Cardiology Consultation Service, Massachusetts General Hospital, Boston, Massachusetts, USA. He is a member of fellow of several organizations, including the American College of Physicians, the American College of Cardiology, the American Heart Association, the International Society of Heart and Lung Transplantation, and the Working Group of Transplant Cardiologists. Dr. Semigran is a reviewer for several publications, including the American Journal of Cardiology, Anesthesia, Journal of the American College of Cardiology, New England Journal of Medicine, Journal of the American College of Cardiology, Arthritis and Rheumatism, Circulation, and the Journal of Heart and Lung Transplantation. He also contributed to the first edition of Heart Failure. Jordan T. Shin is Professor of Medicine, Harvard Medical School and Assistant Physician, Massachusetts General Hospital, Boston, Massachusetts, USA. He is a member of numerous organizations, including the Massachusetts Medical Society, the American Medical Association, American College of Cardiology, the American Association for the Advancement of Science, Member, the American Heart Association, and the Heart Failure Society of America.