1 Adult Congenital Heart Centre & National Centre for Pulmonary Hypertension, Royal Brompton Hospital, Harefield NHS Foundation Trust, London, UK. Electronic address: montanaro@rbht.nhs.uk.
2 Adult Congenital Heart Centre & National Centre for Pulmonary Hypertension, Royal Brompton Hospital, Harefield NHS Foundation Trust, London, UK; National Heart and Lung Institute, Imperial College School of Medicine, London, UK.
3 National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Surgical Division of Adult Congenital Heart Disease Centre, Royal Brompton Hospital, Harefield NHS Foundation Trust, London, UK.