[1] Duke Univ, Sch Med, Duke Clin Res Inst, Durham, NC USA
[2] Duke Univ, Sch Med, Dept Med, Durham, NC 27706 USA
[3] Novartis Pharmaceut, E Hanover, NJ USA
[4] Mayo Clin, Dept Hlth Sci Res, Rochester, MN USA
[5] Indiana Univ Sch Med, Indianapolis, IN 46202 USA
[6] Univ Calif Los Angeles, Ahmanson UCLA Cardiomyopathy Ctr, Los Angeles, CA USA