1. Scottish Pulmonary Vascular UnitGolden Jubilee National HospitalGlasgowUK
2. Sheffield Pulmonary Vascular Disease UnitRoyal Hallamshire HospitalSheffieldUK
3. National Heart and Lung InstituteImperial College LondonHammersmith HospitalLondonUK
4. Pulmonary Vascular Disease UnitPapworth HospitalCambridgeUK
5. Northern Pulmonary Vascular UnitFreeman HospitalNewcastleUK
6. National Pulmonary Hypertension UnitMater Misericordiae University HospitalDublinIreland
7. Pulmonary Hypertension UnitRoyal Free HospitalLondonUK
8. Royal Brompton Pulmonary Hypertension and Adult Congenital Heart CentreLondonUK