Predicting Regurgitant Fraction in Pediatric Patients with Repaired Fallot Using Right Ventricular Strain

Area of Science:

• Cardiology
• Medical Imaging
• Echocardiography

Background:

• Pulmonary regurgitation is a primary reason for re-intervention in Tetralogy of Fallot (TOF) patients.
• Current criteria for pulmonary valve replacement (PVR) rely on cardiac magnetic resonance (CMR) imaging.
• Novel echocardiographic methods are needed to assess PVR indications.

Purpose of the Study:

• To evaluate three-dimensional (3D) echocardiography-derived right ventricular (RV) indices, specifically RV global longitudinal strain (GLS), as predictors of pulmonary regurgitation (PR).
• To determine if RV GLS can facilitate timely referral for PVR in repaired TOF patients.

Main Methods:

• 3D speckle tracking echocardiography and 3D volumetry were performed on TOF patients with recent CMR data.
• 42 controls were included for benchmarking echocardiographic measurements.
• Echocardiography-derived RV and left ventricle (LV) volumes and longitudinal strain were analyzed for diagnostic accuracy in predicting PR.

Main Results:

• Good correlation was observed between CMR and echocardiography-derived ventricular volumes (Bland-Altmann analysis).
• RV GLS <11% demonstrated high sensitivity and specificity in predicting severe pulmonary regurgitation.
• Volume differences between CMR and echocardiography were less pronounced in the LV than in the RV.

Conclusions:

• RV GLS shows promise as a non-invasive imaging biomarker for assessing PR severity in repaired TOF.
• A cutoff of RV GLS <11% may aid in identifying patients requiring PVR.
• While limited by sample size, this study offers a new diagnostic approach for TOF management.