1. From the Winters Center For Heart Failure Research, Department of Medicine, Veterans Administration Medical Center, and the Methodist Hospital, and Baylor College of Medicine, Houston, Tex (B.B., G.T.-A., D.L.M.); the Cardiovascular Institute of the University of Pittsburgh Medical Center Health System, Pittsburgh, Pa (O.Z.S., A.M.F.); and Immunex Corporation, Seattle, Wash (M.S.W., J.W.).