Long-term coronary artery outcome after arterial switch operation for transposition of the great arteries

Objective: To analyse the long-term patency of coronary arteries after neonatal arterial switch operation (ASO). Methods: A retrospective study of the operative reports, follow-up and postoperative catheterisation data of 119 patients, who underwent the great arteries (TGA) repair since 1991, has been carried out. Patient population: Among the 133 survivors of the 137 ASOs performed between 1991 and 2007, 119 patients have been studied by routine control cardiac catheterisation and form the study population. Median time between repair and the coronary angiography was 2.9 ± 1.9 years. A comparison between the eight patients (6.7% out of the entire study population), known to have postoperative coronary obstructions (group I) and the rest of the cohort with angiographic normal coronary vessels (group II) was performed by univariate analysis of variance and logistic regression models. One patient had surgical plasty of the left coronary main stem with subsequent percutaneous angioplasty, three patients had primary coronary stent implantation and four patients had no further intervention at all. In group I, all but one patient denied symptoms of chest pain and echocardiography failed to show any difference between the two groups in terms of left ventricular systolic function (ejection fraction group I 61 ± 2% vs 62 ± 6% of group II, p = 1.0). Results: The association of coronary obstruction with complex native coronary anatomy (Yacoub type B to E) was evident at both univariate (62% of group I vs 22% of group II, p = 0.04) and logistic regression (p = 0.007, odds ratio (OR) 8.1) models. The type of coronary reimplantation (i.e., coronary buttons on punch vs trap-door techniques) was similar between the two groups (punch reimplantation in 25% of patients of group I vs 31% of group II, p = 0.1) as was the relative position of the great vessels (aorta anterior in 100% of patients of group I vs 96% of group II; univariate, p = 0.1). Conclusions: The late outcome in terms of survival and functional status after ASO is excellent. Nevertheless, the risk of a clinically silent late coronary artery obstruction of the reimplanted coronary arteries warrants a prolonged follow-up protocol involving invasive angiographic assessment.