1. Division of Cardiology, Department of Medicine (L.K.T., A.R.G., R.C.G., P.N.T., M.Y., M.A.F., P.C.C., V.K.T.), and Division of Cardiothoracic Surgery, Department of Surgery (K.T., H.T., Y.N.), Columbia University College of Physicians and Surgeons, New York, NY.