1. University of Texas Southwestern Medical Center, Dallas (K.P., Y.L., M.A.A., N.M., I.T., S.B.).
2. Veterans Affairs North Texas System, Dallas (K.P., C.P., M.A.A., N.M., I.T., S.B.).
3. Texas Tech University Health Sciences Center, Amarillo School of Medicine (F.E.).
4. Methodist Health System Dallas, TX (C.P.).
5. University of Texas at Austin Dell Medical School (P.M.).
6. University of California San Diego Sulpizio Cardiovascular Center, La Jolla (M.P.).
7. Ballad Health/Holston Valley Medical Center, Kingsport, TN (C.M.).
8. Georgetown University Medical Center, Washington, DC (A.B.).
9. Minneapolis Heart Institute, MN (E.S.B.).
10. Case Western Reserve University and Harrington Heart and Vascular Institute, University Hospitals, Cleveland, OH (M.H.S.).