Acquired anomalies of the coronary arteries after arterial switch operation. Usefulness of coronary computed tomography angiography and impact on follow-up.

INTRODUCTION: Mortality and morbidity in patients with transposition of the great arteries after an arterial switch operation depends mainly on the status of coronary perfusion. Coronary computed tomography angiography (CCTA) provides accurate information on coronary morphology, however its use in these patients is not yet routine procedure. OBJECTIVE: We sought to assess its accuracy to identify acquired coronary anomalies in this population, compared to conventional angiography in a subset of patients, and assess its impact on postoperative management. METHODS: Retrospective analysis of clinical data on transposition of the great arteries in patients who underwent CCTA between January 2013 and September 2017. RESULTS: Between January 2013 and September 2017, 18 patients underwent CCTA. Seven patients (39%) disclosed iatrogenic coronary lesions (stenosis 1; kinking 2, occlusion 1; filiform coronary 3). The exam was performed in 78% of patients due to suggestion of myocardial ischemia (symptoms or altered exams). Only 16% needed to undergo additional exams, and in four patients the CCTA result modified therapeutic management. Conventional coronary angiography was also performed in 10 patients (55%), and in three cases, the results were discordant with underestimation or non-identification of coronary lesions on conventional angiography. The medium radiation dose used was 2.4 mSv and no complications after CT were reported. CONCLUSION: CCTA accurately identified iatrogenic postoperative coronary lesions and it has proven to be superior to conventional angiography in this population. It should be performed routinely in this group of patients, even in the absence of symptoms.