FIGURE 1.

Inclusion criteria for the switch and control groups. Key: CHD, congenital heart disease; ERA, endothelin receptor antagonist; PAH, pulmonary arterial hypertension; PDE5‐i, phosphodiesterase type‐5 inhibitor; review window = May 1, 2014 to May 1, 2021. * Patients excluded as the planned switch did not follow local practice: switch done at the same time without interval assessment in view of compliance issues (1); unable to undergo assessments (1); and prolonged switch period of 18 months (1).