1. Department of Pulmonary Circulation and Thromboembolic Diseases and Cardiology, Centre of Postgraduate Medical Education, European Health Centre, ECZ-Otwock, Poland (A.T.).
2. Biostatistics, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland (M.B., B.H.).
3. Department of Pneumology, University Hospitals Leuven, Belgium (M.D.).
4. Pulmonary Center, Boston University School of Medicine, MA (H.W.F.).
5. University of Giessen and Marburg Lung Center, Germany, member of the German Center of Lung Research, and Department of Medicine, Imperial College London, United Kingdom (H.-A.G.).
6. Clinicial Department of Cardiology and Angiology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic (P.J.).
7. Canada Respirology Division, London Health Sciences Centre, ON (S.M.).
8. Global Medical Affairs, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland (L.P.).
9. Cardiopulmonary Department, Ignacio Chávez National Heart Institute, Mexico City, Mexico (T.P.).
10. Epidemiology & Observational Studies, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland (D.R.).
11. Division of Pulmonary and Critical Care Medicine, University of California, San Diego Medical School (L.J.R.).
12. Division of Cardiology, CARE Hospitals, Hyderabad, India (B.K.S.S.).
13. APHP Centre de Référence de l'Hypertension Pulmonaire, Service de Pneumologie et Soins Intensifs, Université Paris-Sud, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France (G.S., O.S.).
14. INCOR Heart Institute, University of Sao Paulo, Brazil (R.S.).
15. Department of Biostatistics, Harvard University, Boston, MA (L.-J.W.).
16. University of California Los Angeles (R.C.).
17. Division of Cardiovascular Diseases, Allegheny General Hospital, Pittsburgh, PA (R.B.).