1. From the Departments of Medicine and Pulmonary Hypertension Program (J.N., G.S., I.P., L.W., A.H., E.D.M.), Surgery (J.N., I.M.R., D.B.R.), and Pathology (B.C.), University of Alberta and Mazankowski Alberta Heart Institute, Edmonton, Canada; and Department of Medicine, University of Pittsburgh, Pittsburgh, PA (H.C.C.).