1. From the Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA (Z.M.G., W.O., B.D.M., C.S., D.M.K., R.L.W., P.R.F., H.C.H.); Section of Heart Failure/Transplant and Pulmonary Hypertension, Allegheny General Hospital, Pittsburgh, PA (A.R.).