Fetal RFOF Mimics CoA: The Predictive and Differential Value of Cardiac Output and Left Heart Morphological...

Area of Science:

• Fetal Cardiology
• Diagnostic Imaging
• Congenital Heart Disease

Background:

• Redundant foramen ovale flap (RFOF) can present similar echocardiographic findings to coarctation of the aorta (CoA).
• Existing methods lack comprehensive indicators to reliably distinguish between RFOF and CoA prenatally.
• Hemodynamic and left heart morphological parameters are crucial for accurate prenatal diagnosis.

Purpose of the Study:

• To investigate the impact of RFOF on cardiac output.
• To evaluate novel left cardiac parameters for differentiating RFOF from CoA.
• To establish specific markers for distinguishing these two fetal cardiac conditions.

Main Methods:

• Prospective diagnostic cohort study of fetuses with suspected CoA and controls.
• Comprehensive echocardiography including cardiac output and novel parameters (RCO/LCO, FOFd/LAd, aortic arch angle, LIOA).
• Receiver operating characteristic (ROC) curve analysis to assess predictive values of indicators.

Main Results:

• In RFOF cases, FOFd/LAd ratio showed the highest AUC, followed by RCO/LCO.
• In CoA cases, aortic isthmus/ductus arteriosus diameter (Aoi/DA) and aortic arch angle had the highest AUC.
• Specific thresholds for FOFd/LAd and RCO/LCO indicate RFOF, while aortic arch angle and Aoi/DA suggest CoA.

Conclusions:

• FOFd/LAd > 0.65 is a specific marker for RFOF, with RCO/LCO > 1.60 providing supportive evidence.
• Aortic arch angle > 75.84° and Aoi/DA < 0.75 strongly suggest CoA.
• Combined use of FOFd/LAd, aortic arch angle, and LIOA improves differentiation between RFOF and CoA.