1Division of Cardiology, Department of Medicine, Duke University School of Medicine, Durham, NC. (H.J.W., R.J.M.)
2Duke Clinical Research Institute, Durham, NC (H.J.W., R.J.M.).
3Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest School of Medicine, Winston-Salem, NC. (D.W.K., M.B.N., B.U.)
4Department of Medicine, Thomas Jefferson University, Philadelphia, PA (D.J.W., G.R.R.).
5Department of Neurology, Wake Forest School of Medicine, Winston-Salem, NC. (P.W.D.)
6Departments of Medicine and Orthopaedic Surgery, Duke University School of Medicine, Durham, NC. (A.M.P.)