Background:The incidence of late coronary artery abnormalities after arterial switch operation (ASO) for d-loop transposition of the great arteries may be underestimated.
Methods and Results:We retrospectively reviewed coronary artery morphology in 40 of 97 patients who survived the first year after ASO. Seven asymptomatic patients developed significant late coronary artery abnormalities. One patient died suddenly at home with severe left coronary artery (LCA) ostial stenosis at age 3.8 years. The second patient collapsed during exercise at age 9.6 years due to ventricular fibrillation and severe LCA ostial stenosis despite prior negative exercise stress test (EST) and myocardial perfusion imaging (MPI). The third patient was found to have moderate ostial stenosis of the LCA with negative EST and MPI. The fourth patient with exercise-induced ST-T depression and myocardial perfusion defect was shown to have complete LCA occlusion with collateral vessel formation. Three other patients had complete proximal obliteration of either of the coronary arteries with collateral supply. An additional 4 asymptomatic patients had trivial-mild narrowing of the LCA on routine selective coronary angiogram.
Conclusions:Incidence of late coronary stenosis or occlusion was not infrequent after ASO (11.3%) and presented usually without preceding symptoms and often after negative non-invasive screening. We advocate routine coronary imaging in all patients after ASO before they participate in competitive sports. 2373 Late Coronary Problems After ASO Laboratory). MPI was performed with technetium-99 m sestamibi injection, and perfusion imaging was obtained before and after exercise. Studies were read by a radiologist specialized in nuclear medicine. All cardiac catheterizations and angiograms were reviewed by W.R., Director of the Cardiac Catheterization Laboratory. All study results and original images were presented and carefully discussed in a weekly Multidisciplinary Case Conference at Nemours Cardiac Center for final consensus among the group, which included all attending cardiologists, intensivists, surgeons, and anesthesiologists prior to any critical decisions being made.