Coronary complications are inadequately evaluated by resting echocardiography, and stress imaging in asymptomatic patients is not sensitive. It is unclear that coronary ab- normalities will present de novo or that those present in childhood will progress. However, because patients did not receive an arterial switch before the late 1980s, the long-term natural history of the coronary arteries after arterial switch is still unknown. This is particularly true regarding the impact of risks for concomitant ac- quired coronary artery disease in patients whose coro- nary substrate is not normal. At this time, investigation and management of suspected coronary abnormalities in adults with the arterial switch for TGA should largely be symptom-driven and in accordance with existing guidelines for acquired coronary artery diseases. Several residua and sequelae in adults after arte- rial switch merit consideration of reoperation. Severe RVOT obstruction (Table 22) not amenable or respon- sive to percutaneous treatment is an indication for re- operation; lesser degrees of obstruction can be consid- ered an indication for intervention if greater degrees of exercise are desired. Pulmonary valve replacement or repair is often considered when severe PR is present and there is significant RV dilation or RV dysfunction. Coronary ostial stenosis late after arterial switch may be repaired by coronary artery bypass graft surgery or ostial arterioplasty techniques. The threshold aortic di- ameter at which dissection/rupture risk exceeds the risk of operation is not known, and consequently the threshold for prophylactic operation for neoaortic root dilation is undefined. See Section 3.3 for recommendations on who should perform surgeries, cardiac catheterization, and other procedures in these patients; Section 3.4 for rec- ommendations on diagnostic evaluation; and Table 30 for routine testing and follow-up intervals. Recommendation-Specific Supportive Text 1. 