1. Division of Cardiovascular Diseases, Department of Internal Medicine, Vanderbilt University Medical Center , Nashville, TN , USA
2. Carl J. and Ruth Shapiro Cardiovascular Center, Brigham and Women's Hospital , Boston, MA , USA
3. Department of Cardiovascular Diseases, Providence St. Vincent Medical Center , Portland, OR , USA
4. Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center , 6431 Fannin St., MSB 1.229 E, Houston, TX 77030 , USA
5. Baylor Scott and White The Heart Hospital Plano , Plano, TX , USA