The decision whether to repair congenital heart defects in patients with raised pulmonary vascular resistance to alleviate pulmonary hypertension is a complex one. The degree of pulmonary vascular disease is of paramount importance. Operating on patients with pulmonary vascular resistance above a certain threshold runs the risk of postoperative persistent pulmonary hypertension and a worse long-term prognosis. This review focuses on patients deemed "borderline inoperable" or "inoperable" due to pulmonary vascular disease and asks whether they can be "converted to an operable status" with pulmonary arterial hypertension-specific drugs that potentially modify the pulmonary vascular lesions and resistance.