1. Pulmonary Division, Lausanne University Hospital, University of Lausanne, 1011 Lausanne, Switzerland
2. Division of Respiratory Medicine, Department of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
3. Division of Cardiology, Cardiovascular Department, Lausanne University Hospital, University of Lausanne, 1011 Lausanne, Switzerland
4. Pulmonary Division, Geneva University Hospital, 1211 Geneva, Switzerland