[1] Stanford Univ, Div Cardiovasc Med, Stanford, CA 94305 USA
[2] Beth Israel Deaconess Med Ctr, Dept Med, Boston, MA 02215 USA
[3] Stanford Univ, Dept Med, Stanford, CA 94305 USA
[4] Stanford Univ, Dept Radiol, Stanford, CA 94305 USA
[5] Stanford Univ, Dept Pathol, Stanford, CA 94305 USA
[6] Hamburg Heart Ctr, Dept Cardiothorac Surg, Hamburg, Germany