[1] Permanente Med Grp Inc, Div Cardiol, 2238 Geary Blvd,8th Floor, San Francisco, CA 94114 USA
[2] Kaiser Permanente Northern Calif, Div Res, Oakland, CA USA
[3] Yale Univ, Sch Med, Ctr Outcomes Res & Evaluat, New Haven, CT USA
[4] Duke Univ, Med Ctr, Div Cardiol, Durham, NC 27710 USA
[5] Duke Clin Res Inst, Durham, NC USA
[6] Univ Calif Los Angeles, Ahmanson UCLA Cardiomyopathy Ctr, Ronald Reagan UCLA Med Ctr, Div Cardiol, Los Angeles, CA 90024 USA
[7] Univ Colorado, Div Cardiol, Anschutz Med Campus, Aurora, CO USA