[1] Mayo Coll Med, Div Cardiovasc Dis, Rochester, MN 55902 USA
[2] Mayo Coll Med, Dept Internal Med, Rochester, MN 55902 USA
[3] Goethe Univ Frankfurt, Div Cardiovasc Dis, D-6000 Frankfurt, Germany
[4] Goethe Univ Frankfurt, Dept Internal Med, D-6000 Frankfurt, Germany