FOCUSED READING SESSIONS IMPROVE CORRELATION OF ECHOCARDIOGRAPHIC ASSESSMENT OF RIGHT VENTRICULAR SYSTOLIC FUNCTION WITH RIGHT VENTRICULAR EJECTION FRACTION BY CARDIAC MAGNETIC RESONANCE IMAGING
Bo Xu, M.D., Heart and Vascular Institute, Cleveland Clinic, OH, USA
Background: Echocardiographic assessment of right ventricular (RV) systolic function is limited by the complex geometric shape of the right ventricle. Reliance on conventional longitudinal measures of RV systolic function (tricuspid annular plane systolic excursion (TAPSE), systolic tissue velocity (Sí) may lead to inaccurate assessment of global RV systolic function. The incremental benefit of RV strain in the assessment of RV systolic function is unclear.
Aims: We investigated whether focussed reading sessions would improve correlation of echocardiographic assessment of RV systolic function with right ventricular ejection fraction (RVEF), as quantified by cardiac magnetic resonance imaging (CMR). We also assessed whether incorporating RV strain would incrementally improve echocardiographic assessment of RV systolic function.
Methods: 20 echocardiography readers (7 echocardiologists, 5 fellows, 8 technologists) evaluated 19 randomly selected cases. During the first reading session, standard RV views (parasternal long-axis, parasternal short-axis, apical four-chamber, dedicated RV apical view, subcostal), TAPSE and Sí were shown. The readers categorized RV systolic function into normal, mild, moderate or severe dysfunction. Three weeks later, the readers assessed the same cases again, with the addition of RV global and free wall strain parameters.
Results: RVEF by CMR: 21% to 62% (normal: n=6; mild dysfunction: n=8; moderate dysfunction: n=3; severe dysfunction: n=2). TAPSE: 9 to 32 mm. Sí: 5 to 16 cm/second. RV global and free wall strains: -24.5 to -7.7%, and -31.7% to -9.7%, respectively. The original reported grades of RV systolic function: normal (n=15); mild dysfunction (n=2); moderate dysfunction: (n=2); severe dysfunction: (n=0). Correlation of initial grades of RV systolic function with CMR RVEF by Spearmanís rho: -0.59. Following the first focussed reading session, correlation with RVEF by Spearmanís rho: -0.67 Ī 0.19 (p=0.04). Following the second focussed reading session, correlation with RVEF by Spearmanís rho: -0.61 Ī 0.10 (p>0.05).
Conclusion: Reading sessions focussed on the right ventricle improved correlation of echocardiographic assessment of RV systolic function with RVEF by CMR. Routine incorporation of right ventricular strain parameters did not improve correlation with RVEF by CMR further.