1. Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital (E.A., M.C.B., S.A.S.), Harvard Medical School, Boston.
2. Center for Excellence in Vascular Biology, Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital (E.A.), Harvard Medical School, Boston.
3. Division of Cardiology, Cardiac Ultrasound Laboratory, Massachusetts General Hospital (R.A.L.), Harvard Medical School, Boston.
4. Imperial College London, United Kingdom (M.H.Y.).