Tricuspid annular plane systolic excursion assessed using MRI for semi-quantification of right ventricular ejection fraction

Abstract

Accurate determination of right ventricular volume and ejection fraction (RVEF) is established using MRI. Automatic contour detection of the right ventricular endocardial border is not established in clinical practice, resulting in considerable manual efforts to quantify RVEF. Using transthoracic echocardiography (TTE), the tricuspid annular plane systolic excursion (TAPSE) has proved its worth for quantification of RVEF and risk prediction. Therefore, the aim of this study was to clarify whether TAPSE assessed with MRI as a fast and easily obtainable parameter correlated with volumetric quantification of RVEF. Right ventricular volumes and RVEF were measured with the standardised slice-summation method at MRI. MRI-TAPSE was defined as maximum apical excursion of lateral tricuspid annular plane and measured in a four-chamber view using steady-state free precession sequences. Additionally, MRI-TAPSE was compared with TAPSE assessed using TTE. 76 consecutive patients (aged 58±17 years) were examined. At MRI, right end-diastolic volumes were 97±36 ml, right end-systolic volumes were 57±27 ml and the mean RVEF was 42±14%. MRI-TAPSE was determined with 19±6 mm and correlated well at linear regression analysis with volumetric RVEF (r=0.72, p<0.001). Furthermore, MRI-TAPSE discriminated sufficiently between patients with impaired and normal RVEF. Multiplying MRI-TAPSE by 2.5 led to values close to the RVEF by volumetry. Additionally, MRI-TAPSE correlated well with TAPSE determined using TTE. The inter- and intra-observer variabilities of MRI-TAPSE determination were low (3.1% and 1.8%). TAPSE assessed with MRI is a fast and easily obtainable parameter which correlates well with volumetric quantification of RVEF.