Coronary events after arterial switch operation for transposition of the great arteries

Background - Transfer of the coronary arteries is a crucial step during the arterial switch operation (ASO) for transposition of the great arteries. This retrospective study aims to assess the incidence and risk factors of coronary events after ASO and sensitivity of noninvasive tests in the diagnosis of the coronary obstruction. Methods and Results - Between 1982 and 2001, 1304 newborn and infants had an ASO and the 1 198 hospital survivors had a 59-month mean follow-up. Coronary events occurred in 94 patients (7.2%; 95% CI, 6 to 9). Survival without coronary events were 92.7, 91, and 88.2% at 1, 10, and 15 years, respectively. The incidence was bimodal: high early and slow later. Multivariate analysis showed correlation with type B or C coronary pattern and major operative events (P<0.0001 and P=0.0024). In a subset of 324 patients who underwent a coronary artery angiography, lesions were observed in 22 patients (6.8%; 95% CI, 5 to 10). Multivariate analysis showed correlation with only type B or C coronary pattern (OR=20.8, P=0.0002). All of these patients had electrocardiogram and echocardiogram, 174 patients also had a treadmill test, and 115 patients had a myocardial scintigraphy. The association of these tests had the highest diagnosis sensitivity, 75%. Conclusion - After ASO, coronary events are not rare, occurring most often early and are an important cause of death. Coronary repair can be needed lately. Noninvasive tests are not sensitive enough to detect significant delayed coronary artery stenosis and coronary artery angiography should be performed.