[1] Univ Iowa, Dept Internal Med, Cardiovasc Div, Iowa City, IA USA
[2] Imperial Coll London, Sch Publ Hlth, London, England
[3] Univ Minnesota, Dept Internal Med, Cardiovasc Div, Minneapolis, MN USA
[4] HCA Healthcare, Dept Internal Med, Cardiovasc Div, Kansas City, KS USA
[5] Texas Tech Univ, Dept Internal Med, Cardiovasc Div, Hlth Sci Ctr Lubbock, Lubbok, TX USA
[6] Texas Tech Univ, Hlth Sci Ctr Lubbock, Dept Internal Med, Lubbock, TX USA
[7] Texas Tech Univ, Hlth Sci Ctr, Sch Med, Lubbock, TX USA
[8] Baylor Scott & White Univ, Dept Emergency Med, Temple, TX USA
[9] Univ Texas Hlth Sci Ctr Houston, Dept Internal Med, Houston, TX USA
[10] Texas Tech Hlth Sci Ctr Lubbock, Dept Internal Med, Pulm Crit Care Div, Lubbock, TX USA
[11] Univ Iowa, Dept Internal Med, Cardiovasc Div, 200 Hawkins Dr,E 315 GH, Iowa City, IA 52242 USA