1. University of Minnesota Medical Center, Cardiovascular Division, Department of Medicine, 420 Delaware St MMC 508, Minneapolis, MN, USA
2. Virginia Commonwealth University Medical Center, 1250 E. Marshall Street, Richmond, VA, USA
3. Houston Methodist Hospital, 6550 Fannin St Suite 1901, Houston, TX, USA
4. Duke University Medical Center, Duke Medical Pavilion, 10 Medicine Circle, Rm IE-58 Durham, NC 27710, USA