Prospective assessment of myocardial deformation in fetuses with suspected aortic coarctation

Prenatal identification of true aortic coarctation (CoA) remains challenging as evidenced by high false-positive rates. Myocardial deformation has been proposed to improve prediction of postnatal outcome. This prospective study aimed to determine whether fetal myocardial deformation analysis can differentiate true CoA from false-positive cases throughout gestation.

All fetuses with a prenatal suspicion of isolated CoA were prospectively recruited at our fetal cardiology services. Cases were classified as true CoA or false-positives based on their postnatal diagnosis. Speckle-tracking echocardiography was performed longitudinally to assess left and right ventricular global longitudinal strain (GLS), strain rate, and segmental strain throughout gestation. Measurements were compared between true CoA and false-positive cases.

Thirty-eight fetuses were included (19 true CoA, 19 false-positives). True CoA cases exhibited smaller left-sided cardiac dimensions, including the aortic valve (mean Z-score -3.2 vs. -1.6, p<0.001), aortic isthmus (-3.5 vs. -1.7, p=0.001), and mitral valve (-4.9 vs. -3.1, p<0.001), whereas right-sided cardiac dimensions were comparable (pulmonary valve Z-score 3.0 vs. 2.6, p=0.64; arterial duct Z-score 1.9 vs. 3.2, p=0.61). No clinically relevant differences in myocardial deformation parameters were observed between groups, with similar left ventricular GLS (-20.1% vs. -20.5%, p=0.57), right ventricular GLS (-20.0% vs. -19.1%, p=0.13), strain rates and segmental strain.

Fetal myocardial deformation analysis does not provide additional predictive value for postnatal outcome in prenatally suspected isolated CoA. Conventional assessment of cardiac dimensions and flow patterns remains the cornerstone of prenatal CoA diagnosis, yet current imaging modalities cannot provide sufficient diagnostic certainty to safely triage perinatal management.