Celina M Yong1, Jason J Han2, Muthiah Vaduganathan3. 1. Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California; Palo Alto VA Healthcare System, Palo Alto, California. Electronic address: cyong@stanford.edu. 2. Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania. 3. Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.