Early-Diastolic Right Ventricle-Pulmonary Artery Pressure Gradient by Doppler Echocardiography to Guide Cardiac Magnetic Resonance Assessment of Pulmonary Regurgitation after Right Ventricular Outflow Tract Reconstruction.
Abstract
Background
Pulmonary regurgitation (PR) after right ventricular outflow tract (RVOT) reconstruction is a major driver of right ventricular (RV) remodeling. Cardiac magnetic resonance (CMR) is the reference standard for quantifying PR but is not routinely feasible in many pediatric follow-up settings. We evaluated whether an echocardiographic early-diastolic RV-pulmonary artery (PA) pressure gradient (Echo-EaDPG), derived from early-diastolic peak PR velocity (ΔP = 4v2), can serve as a practical complementary hemodynamic marker to guide CMR assessment.
Methods
We retrospectively analyzed patients with repaired tetralogy of Fallot or related conditions who underwent echocardiography, CMR, and cardiac catheterization within a 6-month interval of each other after RVOT reconstruction. Echo-EaDPG was compared with CMR-derived PR fraction (CMR-PRF) and catheter-measured early-diastolic RV-PA pressure gradient (Cathe-EaDPG). Clinically significant PR was operationally defined as CMR-PRF ≥ 25%. Correlation, multivariable analyses, receiver operating characteristic (ROC) analysis, and bootstrap internal validation were performed.
Results
Forty patients were included. Echo-EaDPG correlated with CMR-PRF (r = 0.65, p < 0.001) and Cathe-EaDPG (r = 0.55, p < 0.001) and was independently associated with CMR-PRF ≥ 25% among tested echocardiographic indices. Echo-EaDPG demonstrated good discrimination for identifying CMR-PRF ≥ 25% on ROC analysis (AUC = 0.90), with bootstrap-supported robustness. Interobserver agreement for Echo-EaDPG was excellent (ICC = 0.96, 95% CI 0.82-0.99, p < 0.001).
Conclusions
Echo-EaDPG is a simple Doppler-derived parameter associated with CMR-quantified PR and invasive early-diastolic RV-PA gradients after RVOT reconstruction. As an adjunct to integrated echocardiographic assessment, Echo-EaDPG may help identify patients who warrant CMR for quantitative PR evaluation, particularly when routine CMR is difficult to obtain.