[1] Stanford Univ, Sch Med, Stanford Cardiovasc Inst, Stanford, CA 94305 USA
[2] Stanford Univ, Sch Med, Dept Med, Div Cardiol, Stanford, CA 94305 USA
[3] Stanford Univ, Sch Med, Dept Radiol, Stanford, CA 94305 USA
[4] Stanford Univ, Sch Med, Inst Stem Cell Biol & Regenerat Med, Stanford, CA 94305 USA