Pulmonary Regurgitation: Determining Severity by Echocardiography and Magnetic Resonance Imaging

Objective. Pulmonary regurgitation (PR) is common after repair of congenital heart disease involving the right ventricular outflow tract. Because PR results in chronic right ventricular volume overload and associated morbidity and mortality, accurate assessment of its severity is important. The aim of this study was to compare echocardiography with the gold standard of PR quantitation by magnetic resonance imaging (MRI) in a young population with repaired congenital heart disease. Design/Methods. Patients with congenital heart disease who had undergone right ventricular outflow tract reconstruction and/or pulmonary valve replacement and had an MRI within 3 months of an echocardiogram formed the study group. Echocardiographic indices were compared with MRI‐determined pulmonary regurgitant fraction (PRF) to determine the most accurate measurements to quantitate PR. Results. Of the 69 MRI/echocardiography pairs in 64 patients, 53 data sets were complete and used in the analysis. For the prediction of MRI PRF ≥20%, PR jet width/annulus ratio ≥0.5 demonstrated excellent sensitivity (94%), specificity (100%), positive predictive value (PPV 100%), and negative predictive value (NPV 82%). For the prediction of MRI PRF ≥40%, jet width/annulus ratio ≥0.7 and diastolic flow reversal in the branch pulmonary arteries showed useful sensitivity (92%), specificity (68%), PPV (76%), and NPV (88%). Conclusion. Pulmonary regurgitation jet width/annulus ratio combined with diastolic flow reversal is the most valuable echocardiographic measure for assessing PR severity after right ventricular outflow tract reconstruction or pulmonary valve replacement; however, this surrogate measure does not replace the importance of MRI evaluation.