1. From the Department of Medicine (E.M.H., L.E.H.), Research Unit-Section of General Internal Medicine, Boston University School of Medicine, Mass; the Department of Medicine (J.D.), Cardiology Division, University of Pittsburgh, Pa; the Department of Medicine (C.E.-M.), University of Virginia, Charlottesville, Va; and the Department of Medicine (C.S., S.R.), Massachusetts General Hospital, Boston, Mass.