Coronary artery complications are the main reason for early mortality after an arterial switch operation. Late complications are relatively rare, and there is no consensus regarding the need or indications for routine follow-up coronary artery evaluations or the best first-line assessment modality. The aim of this study was to present the long-term post-operative frequency of coronary abnormalities in asymptomatic patients with transposition of the great arteries discovered by coronary CT angiography and potential “red flags” revealed by other examinations.

A group of 50 consecutive asymptomatic patients who underwent routine long-term coronary artery evaluation after an arterial switch operation according to our institutional protocol were qualified for this study. This routine in-hospital visit included a detailed medical interview, electrocardiography, echocardiography, Holter electrocardiography examinations, and laboratory and cardiopulmonary exercise tests. Patients who showed significant abnormalities were qualified for perfusion scintigraphy.

Unfavourable coronary abnormalities were detected in 30 patients (60%) and included ostial stenosis, muscular bridge, coronary fistula, interarterial course, proximal kinking, high ellipticity index, proximal acute angulation (<30 degree) of the left coronary artery, and proximal acute angulation of the right coronary artery. These features could not be predicted based on the medical interviews, surgical reports, or non-invasive screening test results.

Complex coronary configurations with potentially dangerous coronary features are common in patients with transposition after an arterial switch operation. Such high-risk patients cannot be identified indirectly, and coronary CT angiography provides accurate information that is useful for post-operative management.