[1] Univ Calif Los Angeles, David Geffen Sch Med, Harbor UCLA Med Ctr, St Johns Cardiovasc Res Ctr, Torrance, CA 90502 USA
[2] Univ Calif Los Angeles, Olive View Med Ctr Sylmar, Los Angeles, CA USA
[3] Greater Los Angeles VA Healthcare, Los Angeles, CA USA
[4] Kaiser Permanente Med Ctr, Div Cardiol, Los Angeles, CA 90034 USA