[1] Vet Affairs Med Ctr, Dept Med, 50 Irving St NW, Washington, DC 20422 USA
[2] George Washington Univ, Dept Med, Washington, DC USA
[3] Uniformed Serv Univ Hlth Sci, Dept Med, Washington, DC USA
[4] Georgetown Univ, Dept Med, Washington, DC USA
[5] MedStar Washington Hosp Ctr, Dept Med, Washington, DC USA
[6] Univ Maryland, Sch Med, Dept Med, Div Cardiovasc Med, Baltimore, MD 21201 USA
[7] Vet Affairs Med Ctr, Dept Med, Sect Cardiol, Baltimore, MD USA
[8] Med Univ South Carolina, Dept Med, Div Cardiol, Charleston, SC 29425 USA
[9] Ralph H Johnson Vet Affairs Med Ctr, Dept Med, Sect Cardiol, Charleston, SC USA
[10] Univ Calif San Francisco, Dept Med, Div Cardiol, San Francisco, CA 94143 USA
[11] Natl & Kapodistrian Univ Athens, Dept Med, Div Cardiol, Athens, Greece
[12] Univ Alabama Birmingham, Dept Biostat, Birmingham, AL 35294 USA
[13] Univ Alabama Birmingham, Dept Med, Birmingham, AL 35294 USA
[14] Univ Calif Los Angeles, Dept Med, Div Cardiol, Los Angeles, CA 90024 USA