Relationship Between Right Atrium Area and Right Ventricular Ejection Fraction on Magnetic Resonance Imaging: Comparison with Other Prognostic Markers in Patients with Pulmonary Arterial Hypertension.

OBJECTIVE:To compare the right atrium (RA) area and right ventricular ejection fraction (RVEF) with other known prognostic markers in patients with pulmonary arterial hypertension (PAH).MATERIALS AND METHODS:This was a retrospective study of 74 patients diagnosed with PAH by right heart catheterization at a referral center between January 2018 and May 2018. All of the patients underwent cardiac magnetic resonance imaging (MRI) within 3 months of the right heart catheterization (RHC), as well as undergoing echocardiography, a 6-minute walk test, and determination of the level of N-terminal pro-brain natriuretic peptide (NT-proBNP) within a month of the RHC. We attempted to determine whether the cardiac MRI-derived RA area correlated with ions between RVEF and RA area measured by that determined by echocardiography, as well as whether the cardiac MRI-derived RA area and RVEF correlated with the 6-minute walk distance and NT-proBNP level.RESULTS:The MRI-derived RA area demonstrated a weak correlation with the pulmonary vascular resistance measured by RHC (r = 0.268; p = 0.055) and a moderate correlation with the NT-proBNP (r = 0.429; p = 0.003). All correlations between clinical characteristics and the RVEF were statistically significant. In the univariate linear analysis, the RVEF showed stronger correlations with the clinical characteristics than did the RA area.CONCLUSION:In patients with PAH, cardiac MRI-derived RVEF appears to correlate more strongly with other prognostic factors than does RA area.