Image arena 4

Speckle tracking echocardiography was performed by an experienced cardiologist blinded to clinical data, using a vendor-independent software package (TomTec software; Image Arena 4.6, Munich, Germany). All echocardiograms were uploaded in the Digital Imaging and Communications in Medicine format to the software package. For myocardial deformation analysis, the endocardial border was traced on the end-systolic frame in each selected image. The end-systolic frame (≥ 50 frames per second) was defined by the QRS complex or based on the smallest ventricular volume during a cardiac cycle. The software automatically tracked speckles along the endocardial border and myocardium throughout the cardiac cycle. The myocardium of the right ventricle was divided into six segments (basal, mid, and apical segments) of the RV free wall and septum. For the assessment of RV strain, we evaluated the average value of the longitudinal peak systolic strain from all segments of the free and septal walls of the right ventricle (RV GLS) in the RV-focused apical view. For the assessment of left ventricular global longitudinal strain (LV GLS), the value for LV GLS was obtained by averaging all segmental strain values from the 18 LV segments in the apical four-, three-, and two-chamber views. The absolute value of RV GLS and LV GLS was expressed as |RV GLS| and |LV GLS|, respectively.

Echocardiographic analysis of LV E/A and E/e′ ratios was completed using Philips IntelliSpace Cardiovascular 2.1 (Philips Healthcare Informatics) in accordance with standard guidelines (23 ). The E and A waves were calculated from the pulsed-wave Doppler with blood flow as the peak modal velocities in early and late diastole, respectively, at the leading edge of the spectral waveform, while e′ was calculated from the tissue Doppler imaging as the peak modal velocity in early diastole at the leading edge of the spectral waveform. Echocardiographic myocardial deformation was measured using Image Arena 4.6 (TomTec). LV longitudinal strain parameters were measured from apical 4-, 2-, and 3-chamber views and LV circumferential strain parameters from the midventricular short-axis view.

Echocardiography was performed following contemporary guidelines^{27 (link)}, and the details are described in Supplementary Methods. The median time interval between HF admission and echocardiography was 1 day (IQR, 0–2 days).
Echocardiography images were subsequently analyzed for strain measurement at the strain core laboratory. Briefly, images qualified for the strain analysis were uploaded to TomTec software (Image Arena 4.6, Munich, Germany) for deformation analysis. Speckles were automatically tracked frame by frame, aligning to the endocardial border of the myocardium, and LV-GLS was calculated as the averaged values from 3 apical views of the entire LV. All strain measurements were performed by independent observers blinded to participants’ clinical information. We used the absolute value of LV-GLS for a straightforward interpretation.

Images were evaluated by two radiologists (J.A.L. and A.I., with 8 and 3 years of experience in CMR, respectively) using dedicated software (IntelliSpace Portal Version 10.1, Philips Medical Systems, Hamburg, Germany). Ventricular and atrial volume and mass parameters were calculated according to recent guidelines and indexed to body surface area using the Mosteller method [19 (link)]. The presence of high signal intensities on T2 STIR and on LGE images was assessed visually by consensus agreement of the two readers. The semiquantitative T2 signal intensity ratio [20 (link)] and semiquantitative enhanced volume percentage (performed in short-axis LGE images) using the full-width half-maximum technique were calculated [19 (link)]. Myocardial relaxation maps were motion-corrected using FEIR (fast elastic image registration) software (IntelliSpace Portal Version 10.1, Philips Medical Systems, Hamburg, Germany). T1 and T2 relaxation times and hematocrit-corrected ECV values (using pre- and postcontrast T1 values) were calculated as previously described [20 (link)]. Dedicated software (Image-Arena 4.6, TomTec Imaging Systems, Unterschleißheim, Germany) was used to perform feature tracking strain measurements derived from cine images in four-chamber and short-axis views to assess LV global longitudinal (GLS), circumferential (GCS), and radial strain (GRS) [10 (link)].