Variation in coronary anatomy in adult patients late after arterial switch operation: a computed tomography coronary angiography study.

Background: The arterial switch operation is the current treatment for transposition of the great arteries. Long-term outcome mainly depends on the patency of the transferred coronary arteries. This study assessed the presence of abnormal coronary findings and neoaortic root dilation late after arterial switch operation.

Methods: In 30 adult patients after arterial switch operation (22 men, 22 ± 3 years), computed tomography angiography was performed to assess the coronary anatomy and abnormal coronary findings, defined as significant stenosis, interarterial coronary course, and acute angled coronary origins. Neoaortic root dimensions and coronary takeoff height were also assessed.

Results: The most common coronary anatomy pattern was found in 24 of 30 patients. Variant anatomy patterns were seen in 6 patients (5 with aberrant circumflex artery, 1 with a single ostium). The prevalence of abnormal coronary findings was higher in patients with variant coronary pattern as compared with patients with common coronary pattern (100% and 29%, respectively; p = 0.003). In particular, an acute angle of the coronary origin was frequently observed. In patients with an acute angle, larger dimensions of the aortic annulus (p = 0.016) and the sinus of Valsalva (p = 0.002) were observed. Moreover, a higher takeoff of the right (p = 0.030) and left (p = 0.002) coronary ostium was noted in patients with acute angles.

Conclusions: Abnormal coronary findings were frequently observed in adult patients after arterial switch operation, especially in patients with a variant coronary anatomy pattern. Neoaortic root dilation and a higher coronary takeoff may explain part of the pathophysiology. Long-term follow-up is needed to determine the clinical significance of these findings.