The exclusion of patients with severe PAH from ASD closure may eventually be obviated by PA vasodilator and remodeling therapy with prostaglandins, endothelin blockers, and PDE-5 inhibitors. Because of the complexity of the hemodynamics in such patients, collabo- ration between ACHD and pulmonary hyperten- sion providers is important. Pretreatment with PAH therapies and pulmonary arterial remodeling agents, with a demonstrated reduction in pulmo- nary arterial resistance of >20%, portends a fa- vorable prognosis after ASD closure.S4.1.1-26 9. Morbidity and mortality are prohibitively high when surgical repair is attempted in patients with open shunts, such as ASD when Eisenmenger syndrome is present.S4.1.1-21,S4.1.1-22 4.1.2. Anomalous Pulmonary Venous Connections Recommendations for Anomalous Pulmonary Venous Connections Referenced studies that support recommendations are summarized in Online Data Supplement 27. 