Although an ASD seems an easily correctable defect, patients with a repaired ASD have a poorer prognosis than patients in a control group, especially in the presence of PAH, which confers an eightfold increased probability of functional limitations. In the Euroheart survey PAH was present in 12% of patients with a closed ASD. Whether it is useful to treat mild to moderate pulmonary vascular disease after repair of an ASD with specific PAH treatment in order to have a positive effect on exercise capacity and even outcome outcome still needs to be evaluated.