EP09.46: Biventricular remodelling in tetralogy of Fallot starts from fetal life

To define the pattern of cardiovascular remodelling and function in fetuses with tetralogy of Fallot (ToF) by conventional echocardiography and its correlation with postnatal outcome. A multicentric prospective study (2011-2023) was conducted at BCNatal and University hospital of Gießen and Marburg. ToF cases were matched to healthy fetuses followed at BCNatal. A 2D comprehensive echocardiography was performed at third trimester to evaluate cardiac morphometry and function. Potential associations between echocardiographic parameters and postnatal outcome were evaluated. We included 63 ToF fetuses (5 with pulmonary atresia) and 66 controls. Pregnancies with ToF fetuses presented a higher rate of pre-eclampsia (6.35%) and postnatally confirmed fetal growth restriction (19.1%). ToF fetuses showed lower cardiac sphericity index with biventricular hypertrophy which was associated with prolonged tricuspid and mitral filling time fractions, Moreover, cardiac index was increased at expenses of a higher aortic output with higher aortic valve z-score. The length of stay in the neonatal intensive care unit showed a negative association with pulmonary valve z-scores, pulmonary peak systolic velocity, and pulmonary-aortic valve ratio. ToF is associated with cardiovascular remodelling and from prenatal life with a biventricular hypertrophy pattern with prolonged filling. Further studies are needed to correlate these findings with postnatal echocardiography. Controls (n = 66)