2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults.

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Improved interobserver variability and accuracy of echocardiographic visual left ventricular ejection fraction assessment through a self-directed learning program using cardiac magnetic resonance images.

BACKGROUND: Although not recommended in isolation, visual estimation of echocardiographic ejection fraction (EF) is widely applied to confirm quantitative EF. However, interobserver variability for EF estimation has been reported to be as high as 14%. The aim of this study was to determine whether self-directed education could improve the accuracy and interobserver variability of visual estimation of EF and whether a multireader estimate improves measurement precision. METHODS: Thirty-one participants provided single-point EF estimates for 30 echocardiograms with a spectrum of EFs, image quality, and clinical contexts in patients undergoing cardiac magnetic resonance (CMR) within 48 hours. Participants received their own case-by-case variance from CMR EF, and the 10 cases with the largest reader variability were discussed along with corresponding CMR images. Self-directed learning was undertaken by side-by-side review of echocardiographic and CMR images. Two months later, 20 new cases were shown to the same 31 participants, using the same methodology. RESULTS: The baseline interobserver variability of ±0.120 improved to ±0.097 after the intervention. EF misclassification (defined as ±0.05 of CMR EF) was reduced from 56% to 47% (P < .001), and the intervention also resulted in a decrease in the absolute difference between CMR and echocardiography for all cases and all readers (from 0.07 ± 0.01 to 0.06 ± 0.01, P = .0001). This improvement was most prominent for the readers with lower baseline accuracy. A combined physician-sonographer EF estimate improved the precision of EF determination by 25% compared with individual reads. CONCLUSIONS: In readers with varying levels of experience, a simple, mostly self-directed intervention modestly decreased interobserver variability and improved the accuracy of EF measurements. Combined physician-sonographer EF reporting improved the precision of EF estimates.

Assessment of left atrial mechanics in patients with atrial fibrillation: comparison between two-dimensional speckle-based strain and velocity vector imaging.

BACKGROUND: Two-dimensional (2D) speckle tracking-derived left atrial (LA) strain (ε) facilitates comprehensive evaluation of LA contractile, reservoir, and conduit function; however, its dependence on the individual software used for assessment has not been evaluated. The aim of this study was to compare LA ε derived from two different speckle-tracking software technologies, Velocity Vector Imaging (VVI) and 2D speckle-tracking echocardiography (STE). METHODS: VVI-derived and 2D STE-derived global longitudinal LA ε and ε rate (SR) were directly compared in 127 patients (mean age, 62 ± 10 years) with atrial fibrillation. Peak negative, peak positive, and total ε (corresponding to LA contractile, conduit, and reservoir function) were measured during sinus rhythm. Late negative (LA contraction), peak positive (left ventricular systole), and early negative (left ventricular early diastole) SR were also measured. RESULTS: The measurement of LA ε and SR by both software was feasible in high proportions of patients (93% with VVI and 93% with 2D STE). The average analysis of ε(negative) was -7.24 ± 3.87% by VVI and -7.30 ± 3.37% by 2D STE (P = .84). The average analysis of ε(positive) was 14.52 ± 5.82% by VVI and 10.74 ± 4.51% by 2D STE (P < .01). The average analysis of ε(total) was 21.76 ± 7.39% by VVI and 18.04 ± 5.98% by 2D STE (P < .01). VVI-derived and 2D STE-derived ε(positive), ε(negative), and ε(total) had good correlations with one another (R = 0.79, R = 0.75, and R = 0.80), with low mean differences. Late negative, peak positive, and early negative SR were correlated less well (R = 0.78, R = 0.71, and R = 0.67). CONCLUSIONS: LA ε measurement using both VVI and 2D STE is feasible in a large proportion of patients in clinical practice. VVI and 2D STE provide comparable LA ε and SR measurements for LA contractile function.

Echocardiographic assessment of raised pulmonary vascular resistance: application to diagnosis and follow-up of pulmonary hypertension.

OBJECTIVE: To optimise an echocardiographic estimation of pulmonary vascular resistance (PVR(e)) for diagnosis and follow-up of pulmonary hypertension (PHT). DESIGN: Cross-sectional study. SETTING: Tertiary referral centre. PATIENTS: Patients undergoing right heart catheterisation and echocardiography for assessment of suspected PHT. METHODS: PVR(e) ([tricuspid regurgitation velocity ×10/(right ventricular outflow tract velocity-time integral+0.16) and invasive PVR(i) ((mean pulmonary artery systolic pressure-wedge pressure)/cardiac output) were compared in 72 patients. Other echo data included right ventricular systolic pressure (RVSP), estimated right atrial pressure, and E/e' ratio. Difference between PVR(e) and PVR(i) at various levels of PVR was sought using Bland-Altman analysis. Corrected PVR(c) ((RVSP-E/e')/RVOT(VTI)) (RVOT, RV outflow time; VTI, velocity time integral) was developed in the training group and tested in a separate validation group of 42 patients with established PHT. RESULTS: PVR(e)>2.0 had high sensitivity (93%) and specificity (91%) for recognition of PVR(i)>2.0, and PVR(c) provided similar sensitivities and specificities. PVR(e) and PVR(i) correlated well (r=0.77, p<0.01), but PVR(e) underestimated marked elevation of PVR(i)-a trend avoided by PVR(c). PVR(c) and PVR(e) were tested against PVR(i) in a separate validation group (n=42). The mean difference between PVR(e) and PVR(i) exceeded that between PVR(c) and PVR(i) (2.8±2.7 vs 0.8±3.0 Wood units; p<0.001). A drop in PVR(i) by at least one SD occurred in 10 patients over 6 months; this was detected in one patient by PVR(e) and eight patients by PVR(c) (p=0.002). CONCLUSION: PVR(e) distinguishes normal from abnormal PVR(i) but underestimates high PVR(i). PVR(c) identifies the severity of PHT and may be used to assess treatment response.