A novel diagnostic model for fetal coarctation of the aorta with ventricular septal defect

Background: Our study aimed to develop a novel diagnostic model for fetal coarctation of the aorta with ventricular septal defect(CoA/VSD). Methods and results: We respectively included 70 fetuses with suspected CoA/VSD(January 2017-June 2023). After birth, 26 fetuses (26/47, 55.3 %) were confirmed to be true-positive CoA/VSD (TP-CoA/VSD), 21 cases had only VSDs without CoA, namely false-positive CoA/VSD (FP-CoA/VSD), and the remaining 23 fetuses were excluded due to additional major malformations, multiple pregnancies or other reasons. Large VSDs and doubly committed subarterial VSDs were more prevalent in true coarctation fetuses(all p < 0.05). Among morphological parameters of echocardiography, the aortic isthmus (AoI)/VSD ratio had the highest area under the curve (AUC) of 0.81 (95 % CI: 0.68-0.94, p < 0.001) and cutoff value of <= 0.67. Three new diagnostic models were constructed by adding different functional variables, namely left ventricular longitudinal strain(LVLS), LV ejection fraction, and LV fractional area of change to the morphological variable AoI/VSD ratio. The diagnostic model of AoI/VSD ratio and LVLS had the highest AUC of 0.96 (95 % CI: 0.86-1.00; p < 0.001). In addition, risk stratification revealed a high risk of prenatal CoA/VSD when the risk probability was greater than 0.80, which required early medical counseling and intervention. Conclusions: In fetuses suspected with having CoA/VSD, myocardial strains of both ventricles were lower in true CoA group. Additionally, a diagnostic model of new morphological parameter AoI/VSD ratio and functional variable LVLS, was highly valuable in diagnosing fetal CoA/VSD.