Prenatal Delineation of Coronary Anatomy in Dextro-Transposition of Great Arteries

BACKGROUND: Dextro-transposition of the great arteries (D-TGA) is the second-most common cyanotic congenital heart disease with variable coronary artery anatomy. The arterial switch procedure has revolutionized outcomes for this defect, with coronary anatomy being a key determinant of both short- and long-term outcomes following surgical repair. The assessment of coronary anatomy is usually undertaken in the postnatal period by transthoracic echocardiography, with assessment prenatally not being well studied. We sought to assess the feasibility of delineating the coronary arteries on fetal echocardiograms in a small cohort of patients followed prenatally. METHODS: This was a retrospective review of fetuses with D-TGA from 2008 to 2018. Patients with prenatal diagnosis of D-TGA were reviewed for the assessment of coronary artery anatomy. Details of coronary artery anatomy diagnosed prenatally were compared with postnatal transthoracic echocardiograms and intraoperative findings. RESULTS: Thirty-four fetuses with findings of D-TGA on prenatal echocardiograms were reviewed. 14/34 fetuses had attempted delineation of coronary artery anatomy, with average gestational age of 28 weeks (range 23–31 weeks) at the time of diagnosis. Two-dimensional and color Doppler imaging of the coronary arteries on both short and long axis images were performed, with complete delineation being possible in ~ 86% of fetuses. These findings were confirmed postnatally. CONCLUSIONS: Fetuses with D-TGA can have variable coronary artery anatomy which drives postnatal outcomes. Our study describes a cohort of patients with D-TGA wherein coronary artery anatomy was assessed. We demonstrate that coronary artery evaluation is feasible prenatally with optimal imaging techniques, being more successful after 25 weeks' gestation. The potential knowledge of dangerous variants can help with referral to centers of excellence for appropriate postnatal management and facilitate prenatal care accordingly.