Effects Branch PA Stenting d-TGA, ToF and TA

The goal of this randomized controlled trial is to identify the effects of percutaneous interventions for branch PA stenosis on exercise capacity in patients with d-TGA, ToF and TA. The main question\[s\] it aims to answer are: The primary study objective is to identify the effects of percutaneous interventions for branch PA stenosis on exercise capacity in patients with d-TGA, ToF and TA. The secondary objectives are 1) to assess the effects of percutaneous interventions for branch PA stenosis on RV function and 2) to define early markers for RV function and adaptation to improve timing of these interventions. Participants will undergo the same series of examinations at baseline and approximately 6 months follow-up (within 6 week time-range) as part of standard care: conventional transthoracic echocardiogram (TTE), cardiopulmonary exercise testing (CPET) and conventional Cardiac Magnetic Resonance (CMR) including a low dose dobutamine stress MRI to assess RV functional reserve. The low dose dobutamine stress MRI will be performed in the interventional group from the UMC Utrecht/WKZ and Erasmus MC because the LUMC and AUMC do not have a suitable infrastructure for the low dose dobutamine stress MRI and this cannot be achieved throughout the duration of this study. The baseline CMR in the interventional group will be performed as close as possible prior to the intervention but maximal 4 weeks prior to the intervention. In addition, the intervention group will undergo standard RV pressure measurements during the intervention. Quality of life (QoL) questionnaires will be obtained at baseline and 2 weeks post intervention (intervention group) or a similar time range in the control group, which is based on experts opinion. TTE, CPET and conventional CMR will be performed within 2-4 years follow-up to assess the long-term effects of percutaneous PA interventions. Researchers will compare the difference in VO2 max (% predicted) between the interventional group (TGA, ToF or TA patients with a class II indication for a PA intervention who will undergo a percutaneous intervention for a PA stenosis) and the control group (TGA, ToF or TA patients with a class II indication for a PA intervention who will undergo conservative management)