Prenatal prediction of Shone's complex. The role of the degree of ventricular disproportion and speckle-tracking analysis

Objectives: Shone's complex (SC) is characterized by sequential obstructions of left ventricular (LV) inflow and outflow. It can be associated with poor long-term prognosis when compared to Simple-Aortic Coarctation (S-CoA). We aimed to assess whether the degree of ventricular disproportion and 2D-speckle-tracking echocardiography (2D-STE) could improve the accuracy of prenatal prediction of SC.

Methods: 75 consecutive fetuses were retrospectively enrolled from January 2010 to June 2021. Fetuses were divided into 4 groups (Group 1: SC; Group 2: S-CoA; Group 3: False Positive-Coarctation of the Aorta [FP-CoA]; group 4: controls). Comparisons for echocardiographic measures and myocardial deformation indices were performed. A receiver operating characteristic (ROC) analysis was performed on the MV/TV (mitral valve/tricuspid valve ratio) and LV GLS (global longitudinal strain) values to identify cut-offs to separate group 1 and 2 fetuses.

Results: SC fetuses showed a significant reduction in MV/TV when compared to S-CoA and FP-CoA fetuses (p<0.001). LV GLS in SC fetuses was significantly reduced compared to S-CoA fetuses (-13.3 ± 2.1% vs. -17.0 ± 2.2%, p=0.001). A cut-off value of 0.59 for MV/TV and -15.35% for LV GLS yielded a sensitivity of 76 and 82% and a specificity of 71 and 83% respectively in separating SC vs. S-CoA fetuses.

Conclusions: SC fetuses showed a more severe degree of ventricular disproportion and a lower LV GLS compared to S-CoA, FP-CoA and control fetuses. MV/TV and GLS are both predictors of SC. These findings may improve the quality of prenatal parental counselling.