Incremenal Value of Cardiac Magnetic Resonance for Assessing Pulmonic Valve Regurgitation.

BACKGROUND AND AIM OF THE STUDY: Cardiac magnetic resonance (CMR) is the 'gold standard' for quantifying pulmonic regurgitation (PR) in adults with congenital heart disease, but remains costly and is less readily available than echocardiography. Qualitative echocardiographic assessment of PR is challenging, and guiding criteria are limited. It is unknown if echocardiography is sufficient to screen for significant PR. The study aim was to determine whether cardiac MRI provides additional benefit in the assessment of PR in adults with congenital heart disease. METHODS: Patients with repaired tetralogy of Fallot or congenital pulmonic stenosis after valvotomy undergoing transthoracic echocardiography and CMR with no interval intervention were identified from a prospective registry. Patients with greater than mild pulmonic stenosis, residual ventricular septal defect or poor echocardiographic windows were excluded. Whole-cohort and subgroup (tetralogy of Fallot versus pulmonic stenosis) analyses for inter-modality agreement were performed. RESULTS: A total of 48 patients (24 men, 24 women; mean age 43 +/- 12 years) was included in the analysis. The unweighted kappa value for the two modalities was 0.30, suggesting 'fair' agreement, though only 52% had matching PR assessments. The indexed right ventricular end-systolic volume (RVESVi) correlated closely with cardiac MRI-monitored PR (p = 0.011 by analysis of variance), but not with that monitored with echocardiography (p = 0.081). Subgroup analysis demonstrated less inter-modality agreement in the tetralogy of Fallot population (kappa 0.25) than in the pulmonic stenosis population (kappa 0.35). CONCLUSION: CMR measurement of PR correlates closely with the RVESVi, and appears superior to echocardiography when assessing patients at risk for PR. The study results suggest a vital role for CMR whenever significant PR is suspected in the adult congenital heart disease population.