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.

Myocardial work and left ventricular contractile reserve during stress echocardiography: An angiographic validation.

OBJECTIVE: This study sought to determine the contractile reserve (CR) response to exercise stress echocardiography (ESE) quantified by the novel parameter, non-invasive myocardial work (MW), in subjects with angiographically proven coronary artery disease (CAD). METHODS: CR was measured by the relative change in ejection fraction (EF), global longitudinal strain (GLS) and MW indices from rest to peak exercise in 304 patients referred for clinically indicated ESE. Positive ESE patients proceeded to coronary angiography and further risk stratified based on either percutaneous or surgical intervention. RESULTS: CRGLS and global work index (CRGWI ) significantly decreased with exercise induced ischemia and angiographically proven significant CAD (CRGLS -1.6±3.5%; CRGWI -8.6±511 mm Hg% decrement, p < 0.001) compared to non-ischemic patients (CRGLS 1.4±2.2%; CRGWI 398±404 mm Hg% improvement). Global constructive work (CRGCW ) was significantly higher (p < 0.0001) in non-ischemic (818±457 mm Hg%) and blunted in ischemic patients (208±550 mm Hg%). CRGCW (AUC .81; 95%CI:.75-.86) demonstrated the most association for inducible ischemia followed by CRGLS (AUC .75; 95%CI:.69-.80), CRGWI (AUC .73, 95%CI:.67-.79) and CREF (AUC .71; 95%CI:.65-.77, p < 0.001). Subgroup analysis showed patients requiring surgical revascularization demonstrated a significantly lower CRGWE (-11.5±7.6%, p < 0.05) as a result of reduced CRGCW (281±573 mm Hg%, p < 0.05) and increased global wasted work (CRGWW , 289±151 mm Hg%, p = 0.09). CONCLUSION: Multivessel disease requiring surgical revascularization have the greatest reduction in CR. MW may potentially improve detection of ischemia and further risk stratification during ESE to maximize the benefits of revascularization.

CSANZ Imaging Council Position Statement on Echocardiography Services During the COVID-19 Pandemic.

This Cardiac Society of Australia and New Zealand (CSANZ) Imaging Council Position Statement aims to guide local, regional and national clinical practice, and facilitate resource and echocardiographic service planning appropriately during the current COVID-19 global pandemic. General considerations include workforce arrangements and contingency plans, patient risk assessment for COVID-19 and level of care (personal protective equipment) for staff. Both outpatient and inpatient settings are addressed, including specific considerations in the in-patient setting including scanning protocols, screening modalities and indications for echocardiograms in the context of COVID-19 infection.

The use of computerised simulators for training of transthoracic and transoesophageal echocardiography. The future of echocardiographic training?

BACKGROUND: Echocardiography is the commonest form of non-invasive cardiac imaging but due to its methodology, it is operator dependent. Numerous advances in technology have resulted in the development of interactive programs and simulators to teach trainees the skills to perform particular procedures, including transthoracic and transoesophageal echocardiography. METHODS: Forty trainee sonographers assessed a computerised mannequin echocardiographic simulator and were taught how to obtain an apical two-chamber (A2C) view and image the superior vena cava (SVC). Forty-two attendees at a TOE simulator workshop assessed its utility and commented on perceived future use, using defined criteria. RESULTS: One hundred percent and 88% of sonographers found the simulator useful in obtaining the SVC or A2C view respectively. All users found it easy to use and the majority found it helped with image acquisition and interpretation. Attendees of the TOE training day assessed the simulator with 100% finding it easy to use, as well as the augmented reality graphics benefiting image acquisition. Ninety percent felt that it was realistic. CONCLUSIONS: This study revealed that both trainee sonographers and TOE proceduralists found the simulation process was realistic, helped in image acquisition and improved assessment of spatial relationships. Echocardiographic simulators may play an important role in the future training of echocardiographic skills.

The Prognostic Value of Echocardiographic Wall Motion Score Index in ST-Segment Elevation Myocardial Infarction.

Background: When compared to left ventricular ejection fraction (LVEF), previous studies have suggested the superiority of wall motion score index (WMSI) in predicting cardiac events in patients who have suffered acute myocardial infarction. However, there are limited studies assessing WMSI and mortality in ST-segment elevation myocardial infarction (STEMI). We aimed to compare the prognostic value of WMSI in a cohort of STEMI patients treated with primary percutaneous coronary intervention (PCI). Methods: A comparison of WMSI, LVEF, and all-cause mortality in STEMI patients treated with primary PCI between January 2008 and December 2020 was performed. The prognostic value of WMSI, LVEF, and traditional risk scores (TIMI, GRACE) were compared using multivariable logistic regression modelling. Results: Among 1181 patients, 27 died within 30-days (2.3%) and 49 died within 12 months (4.2%). WMSI ≥1.8 was associated with poorer survival at 12-months (9.2% vs 1.5%; p < 0.001). When used as the only classifier for predicting 12-month mortality, the discriminatory ability of WMSI (area under the curve (AUC): 0.77; 95% CI: 0.68-0.84) was significantly better than LVEF (AUC: 0.71; 95% CI: 0.61-0.79; p=0.034). After multivariable modelling, the AUC was comparable between models with either WMSI (AUC: 0.89; 95% CI: 0.85-0.94) or LVEF (AUC: 0.87; 95% CI: 0.83-0.92; p < 0.08) yet performed significantly better than TIMI (AUC: 0.71; 95% CI: 0.62-0.79; p < 0.001), or GRACE (AUC: 0.63; 95% CI: 0.54-0.71; p < 0.001) risk scores. Conclusions: When examined individually, WMSI is a superior predictor of 12-month mortality over LVEF in STEMI patients treated with primary PCI. When examined in multivariable predictive models, WMSI and LVEF perform very well at predicting 12-month mortality, especially when compared to existing STEMI risk scores.

Resting global myocardial work can improve interpretation of exercise stress echocardiography.

Sensitivity and specificity of ESE to determine hemodynamically significant coronary artery disease (CAD) is limited by subjective qualitative interpretation resulting in false-positive results. The objective of this study was to determine whether resting myocardial work estimated from non-invasive left ventricular pressure-strain loops can help improve the interpretation of exercise stress echocardiography (ESE). Resting global myocardial work was performed on 288 patients referred for clinically indicated ESE with no resting regional wall motion abnormalities and normal ejection fraction (≥ 55%). Coronary angiography was used to validate the presence of significant CAD in those with a positive ESE. Resting global myocardial work index (GWI) was significantly reduced (p < 0.001) in patients with true-positive (1544 ± 354 mmHg%) compared to negative (1819 ± 317 mmHg%) and false-positive (1857 ± 344 mmHg%) ESE. A GWI of ≤ 1391 mmHg (AUC 0.73; sensitivity 94%; specificity 73%) predicted true-positive ESE. Predictors of a true-positive ESE were (1) lower myocardial work efficiency (odds ratio 0.731, 95% CI 0.58-0.92, p = 0.007), (2) lower GWI (odds ratio 0.997, 95% CI 0.996-0.999, p = 0.006) (3) male gender (odds ratio 5.47, 95% CI 1.84-16.31, p = 0.002) and (4) E/e' ratio (odds ratio 1.15, CI 1.01-1.31, p = 0.032). Myocardial work is a potentially valuable quantitative parameter that provides incremental value over qualitative ESE interpretation and improves appropriate patient selection for coronary angiography.

Global Myocardial Work Is Superior to Global Longitudinal Strain to Predict Significant Coronary Artery Disease in Patients With Normal Left Ventricular Function and Wall Motion.

BACKGROUND: Noninvasive detection of functionally significant coronary artery disease (CAD) by echocardiography remains challenging, with the need to perform stress imaging to detect ischemia. The aim of this study was to determine whether global myocardial work (MW), derived from noninvasive left ventricular (LV) pressure-strain loops at rest, can predict significant CAD in patients without regional wall motion abnormalities and preserved LV ejection fraction (EF). METHODS: One hundred and fifteen patients referred for coronary angiography who had EF ≥ 55%, no resting regional wall motion abnormalities, and no chest pain were assessed using echocardiography. Global MW was derived from noninvasive LV pressure-strain loops constructed from speckle-tracking echocardiography indexed to brachial systolic blood pressure. Global constructive work represented the sum of positive work due to myocardial shortening during systole and negative work due to lengthening during isovolumic relaxation. Global wasted work represented energy loss by myocardial lengthening in systole and shortening in isovolumic relaxation. Global MW efficiency was derived from the percentage ratio of constructive work to the sum of constructive work and wasted work. RESULTS: Patients with significant CAD demonstrated a significantly reduced global MW (P < .001) compared with those without CAD. Global longitudinal strain was significantly reduced (P < .001) in patients with multivessel CAD but not those with single-vessel CAD (P = .47). Receiver operating characteristic curve analysis demonstrated that global MW was the most powerful predictor of significant CAD (area under the curve = 0.786) and was superior to global longitudinal strain (area under the curve = 0.693). The optimal cutoff global MW value to predict significant CAD was 1,810 mm Hg% (sensitivity, 92%; specificity, 51%). CONCLUSIONS: Noninvasive global MW derived using LV pressure-strain loops at rest is a more sensitive index than global longitudinal strain to detect significant CAD in patients with no regional wall motion abnormalities and normal EF. This is a potential valuable clinical tool to assist in the early diagnosis of CAD.

A new approach to assess myocardial work by non-invasive left ventricular pressure-strain relations in hypertension and dilated cardiomyopathy.

Aims: Non-invasive left ventricular (LV) pressure-strain loop (PSL) provides a novel method of quantifying myocardial work (MW) with potential advantages over conventional global longitudinal strain (GLS) by incorporating measurements of myocardial deformation and LV pressure. We investigated different patterns of LV PSL and global MW index (GWI) in patients with hypertension (HTN) and dilated cardiomyopathy (CMP). Methods and results: Seventy-four patients underwent transthoracic echocardiography and strain analysis before coronary angiography. Patients were divided into three groups: control, HTN, and CMP. GWI was calculated as the area of the LV PSL as a product of strain × systolic blood pressure. MW efficiency (GWE) is derived from the percentage ratio of constructive work (GCW) to sum of constructive work (GCW) and wasted work (GWW). Influences of HTN and LV function on its relationship with MW were evaluated. GLS and LV ejection fraction were preserved in the HTN group with no difference from controls. GWI was significantly higher in moderate to severe HTN patients (P = 0.004) as a compensatory mechanism to preserve LV contractility and function against an increase in afterload. GWE was preserved in HTN patients due to the proportional increase in GCW and GWW. GLS, GWI, and GWE were significantly reduced in CMP (P < 0.05), with a trend in rightward shift and reduction in the LV PSL. Conclusion: GWI is a potential new technique that allows better understanding of the relationship between LV remodelling and increased wall stress under different loading conditions.

Accuracy of quantitative echocardiographic measures of right ventricular function as compared to cardiovascular magnetic resonance.

BACKGROUND: Many echocardiographic parameters have been proposed to evaluate right ventricular (RV) systolic function. We comprehensively assessed a wide range of quantitative echocardiographic parameters in a single cohort compared with same-day cardiovascular magnetic resonance (CMR). METHODS AND RESULTS: 92 subjects were examined prospectively: Group 1 consisted of 46 healthy controls (21 males, 33.4 ± 11.4 years), Group 2 consisted of 46 patients (20 males, 38.5 ± 18.9 years) undergoing RV functional assessment by CMR (1.5 T). Echocardiography was performed on the same day as CMR; fractional area change (RVFAC), myocardial performance index via spectral Doppler (RVMPI), RVMPI via Doppler tissue imaging (RVMPI-DTI), peak systolic myocardial velocity by DTI (RVSm), tricuspid annular plane systolic excursion (TAPSE), speckle tracking strain, and three dimensional right ventricular ejection fraction (3DE-RV). Linear regression, Bland-Altman and receiver-operator-characteristic (ROC) analyses were performed. At ROC analysis, the most predictive echocardiographic methods were; RVFAC (AUC = 0.892), RVMPI (AUC 0.785), TAPSE (AUC 0.849) and 3DE-RV (AUC 0.909). 3DE-RV appeared the most accurate compared to CMR, although underestimated true RV volumes. CONCLUSION: As compared to CMR; 3DE-RV, RVFAC, TAPSE and RVMPI were the most reliable predictors of RV function. These parameters can be recommended for clinical use.

Echocardiographic assessment of cardiac structure and function in rats.

BACKGROUND: Echocardiography is used in humans to characterise the structure and function of the heart, yet is relatively uncommon in studies on the rat, the most commonly used model of human cardiovascular disease. The aim of this study was to show that echocardiography in rats provides useful information on cardiac changes occurring in thyroid dysfunction and can also be used to characterise cardiac abnormalities. METHODS: Transthoracic echocardiography and Doppler techniques with high frequency, high frame rate imaging were used to define cardiac dimensions and function in 240 Wistar rats and cardiac abnormalities in Wistar and spontaneously hypertensive rats (SHR). RESULTS: Echocardiographic assessment of left ventricular dimensions and function and aortic flows was technically feasible in almost all adult Wistar rats and SHR, including those with thyroid dysfunction and cardiac abnormalities. Pulsed-wave Doppler profiles of mitral inflows to estimate diastolic function were less reliably obtained. CONCLUSIONS: Echocardiography is a powerful technique for non-invasive and serial determination of cardiac structure and function in rat models of human cardiovascular disease.