1. Pulmonary Vascular Diseases Unit, National Pulmonary Hypertension Service, Royal Papworth Hospital, Cambridge CB2 0AY, UK
2. National Pulmonary Hypertension Service, Hammersmith Hospital, London W12 0HS, UK
3. Sheffield Pulmonary Vascular Disease Unit, Royal Hallamshire Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S10 2JF, UK
4. Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, NIHR Biomedical Research Centre, Sheffield S10 2RX, UK
5. Medical Affairs Department, Janssen-Cilag Ltd., High Wycombe HP12 4EG, UK
6. Scottish Pulmonary Vascular Unit, Golden Jubilee National Hospital, Glasgow G81 4DY, UK