P590Right ventricular longitudinal strain assessed by cMR feature-tracking in comparison with 2D speckle-tracking echography in HFpEF patients and controls
Authors: Lejeune S , Ciocea V , Roy C , Slimani A , Amzulescu M , Pasquet A , Vancraeynest D , Beauloye C , Vanoverschelde J L , Gerber B , Pouleur A C 
Published: October 2019

Abstract

Background
The importance of right ventricular remodeling in a wide range of cardiovascular diseases has recently been highlighted. Cardiovascular magnetic resonance (cMR) is currently the gold standard to evaluate RV function and is emerging as an important modality to assess myocardial deformation parameters.

Purpose
We sought to analyze RV longitudinal strain (RVLS) by cMR feature-tracking (cMR-FT) and 2D speckle-tracking echocardiography (STE) in controls and HFpEF patients, and to evaluate feasibility of both techniques.

Methods
Between January 2015 and June 2017, we prospectively enrolled 163 consecutive patients with HFpEF (78±9 years, 62% women) and 27 age and sex matched controls (76±5 years, 67% women). All underwent complete 2D echography. Of those, 99 patients and 25 controls underwent a 3Tesla cMR. Right ventricular myocardial deformation was assessed using dedicated feature-tracking (Segment) and speckle-tracking softwares on cMR and echographic images respectively.

Results
Due to insufficient tracking quality, STE RVLS was not feasible in 14 patients (7.4%) and 19 HFpEF patients (19%) and 5 controls (20%) were excluded from the cMR-FT analysis.
Mean RVLS was significantly altered in HFpEF patients compared to controls with both STE (−21.7±5% vs −25.9±4%; p<0.001) and cMR-FT (−14.6±5% vs −18.2±4%; p<0.001) techniques.
RVLS by cMR-FT was moderately correlated to RVLS by STE (r=0.44, p<0.001) with an important bias of 7.6±4.7 (Figure).
In univariate linear regression analysis, history of atrial fibrillation (r=0.23, p=0.002 and r=0.24, p=0.018), NTproBNP (r=0.34, p<0.001 and r=0.31, p=0.002), E wave velocity (r=0.18, p=0.02 and r=0.33, p=0.001), E/e'(r=0.15, p=0.05 and r=0.38, p<0.001), RV fractional area change (r=−0.61, p<0.001 and r=−0.35, p<0.001), TAPSE (r=−0.57, p<0.001 and r=−0.33, p=0.001), indexed left atrium volume (r=0.27, p=0.001 and r=0.32, p=0.001), LVEF (r=−0.23, p=0.004 and r=−0.34, p=0.001), index LV mass (r=0.24, p=0.003 and r=0.41, p<0.001), RVEF (r=−0.35, p<0.001 and r=−0.45, p<0.001) were associated with RVLS by both STE and cMR-FT. Extracellular volume was only correlated to RVLS by cMR-FT (r=0.26, p=0.01).
Multiple regression analysis showed that RV FAC and NTproBNP (B −29.9 [−38.4; −21.5], p≤0.001 and B 0.613 [0.12; 1.12], p=0.018 respectively) were significant predictors of RV strain when evaluated by STE. On the other hand, only the cMR parameters RVEF (B −0.17 [−0.289; −0.057], p=0.004) and index LV mass (B 0.09 [0.02; 0.15], p=0.008) were independent predictors of RV strain by cMR-FT.

Conclusion
While cMR-FT is an emerging technique to measure RVLS, it could only be done in 80% of the study population because of insufficient tracking quality. Furthermore, it showed a moderate correlation with RVLS by STE, showing similar trends but an important bias. Further studies are needed to assess if cMR–FT has an additional diagnostic or prognostic value over classical parameters of RV function.