Fetal Echocardiographic Dimension Indices: Important Predictors of Postnatal Coarctation.
Fricke K, Liuba P, Weismann CG. Pediatr Cardiol. 2020 Dec 23. doi: 10.1007/s00246-020-02509-6. PMID: 33355680
Take Home Points:
- Fetuses that developed CoA postnatally (34%) exhibited significantly smaller Z-scores of left cardiac structures from the mitral valve to the aortic isthmus.
- The most sensitive and specific predictors were:
- A carotid-subclavian artery index (CSAI) of < 0.78 (92.3% sensitivity, 96.8% specificity)
- A product of isthmus-to-duct ratio in the three-vessel trachea view (3VT) and the mitral-to-tricuspid valve ratio (I/D3VTxMV/TV) of < 0.37 (100% sensitivity, 94.6% specificity).
Commentary from Dr. Manoj Gupta (New York, USA), section editor of Pediatric & Fetal Cardiology Journal Watch: In this retrospective study, the authors are trying to reliably identify quantitative fetal echocardiographic predictors of postnatal CoA.
The authors measured the following ratios between left and right cardiac structures: left-to-right ventricular (LV/RV) width and length ratios and mitral-to-tricuspid valve (MV/TV) dimension ratio examined in the four-chamber view; aortic-to-pulmonary valve (AoV/PV) ratio; ascending-to-descending aorta (Ao asc/DAo) ratios measured in the outflow tract and sagittal views; and isthmus aortae-to-arterial duct (I/D) diameter ratios examined in the three-vessel trachea (3VT) and sagittal views. In addition, the carotid-subclavian artery index (CSAI) was also calculated, defined as the ratio of the aortic arch diameter at the left subclavian artery, to the distance between the left carotid artery and the left subclavian artery.
A bidirectional or retrograde flow in the aortic arch (p < 0.001) or bidirectional or left–right shunt across the interatrial communication (p = 0.002) was linked to postnatal CoA. Fetuses with a postnatally confirmed CoA exhibited significantly smaller left cardiac structures from the mitral valve to the aortic isthmus when adjusted for gestational age. Borderline left ventricular hypoplasia, a hypoplastic aortic arch, or posterior shelf are known predictors for postnatal CoA.
The authors validated the CSAI and I/D3VTxMV/TV indices prospectively in 16 fetuses with prenatal suspicion of CoA born in 2019, four of which developed CoA postnatally.
A CSAI < 0.78 detected postnatal development of CoA with a sensitivity of 100% and a specificity of 91.7%. The I/D3VTxMV/TV < 0.37 exhibited both a 100% sensitivity and specificity.
Cut-off points, sensitivity, and specificity for highly significant continuous parameters: