1 Department of Medicine, Cardiovascular Medicine Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: ssolomon@rics.bwh.harvard.edu.
2 Department of Medicine, Cardiovascular Medicine Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark.