Survey of echocardiography practice across five continents.

BACKGROUND AND AIM: The term echocardiography refers to a diverse range of cardiovascular ultrasound imaging methods, both inside and outside specialist cardiology practice. While guidelines exist, we hypothesized that there are significant worldwide differences in the way echocardiography is practiced. We surveyed echocardiography practitioners around the world to characterize the workforce and their practice. METHOD: Social media and word of mouth were used in an explosive sampling approach to recruit echo users, who then completed an online survey that included personal demographics and questions about their practice, their resources, and daily use of echocardiography. RESULTS: In total, 594 participants completed the survey: 54.9% sonographers; 30% cardiologists, with the remainder other physicians or trainees. Significant variation in the number of echoes performed and the time allocated to scanning was observed. There were also differences in the gathering of adjunct measures such as blood pressure and body size. CONCLUSION: There is wide variation in echocardiography practices across the world. Differences are likely to be both clinician- and healthcare system-driven. Guidelines for practice developed in well-resourced western countries and intended for use in cardiology-based echocardiography laboratories may not be applicable to other countries or indeed to new echo users.

Abbreviated Echocardiographic Screening for Rheumatic Heart Disease by Nonexperts with and without Offsite Expert Review: A Diagnostic Accuracy Study.

BACKGROUND: Early detection of rheumatic heart disease (RHD) through echocardiographic screening can facilitate early access to effective treatment, which reduces the risk for progression. Accurate, feasible approaches to echocardiographic screening that can be incorporated into routine health services are needed. The authors hypothesized that offsite expert review could improve the diagnostic accuracy of nonexpert-obtained echocardiographic images. METHODS: This prospective cross-sectional study was performed to evaluate the diagnostic accuracy of health worker-conducted single parasternal long-axis view with a sweep of the heart using hand-carried ultrasound for the detection of RHD in high-risk populations in Timor-Leste and Australia. In the primary analysis, the presence of any mitral or aortic regurgitation met the criteria for a positive screening result. Sensitivity and specificity were calculated for a screen-and-refer approach based on nonexpert practitioner assessment (approach 1) and for an approach using offsite expert review of nonexpert practitioner-obtained images to decide onward referral (approach 2). Each participant had a reference test performed by an expert echocardiographer on the same day as the index test. Diagnosis of RHD was determined by a panel of three experts, using 2012 World Heart Federation criteria. RESULTS: The prevalence of borderline or definite RHD among 3,329 participants was 4.0% (95% CI, 3.4%-4.7%). The sensitivity of approach 1 for borderline or definite RHD was 86.5% (95% CI, 79.5%-91.8%), and the specificity was 61.4% (95% CI, 59.7%-63.1%). Approach 2 achieved similar sensitivity (88.4%; 95% CI, 81.5%-93.3%) and improved specificity (77.1%; 95% CI, 75.6%-78.6%). CONCLUSION: Nonexpert practitioner-obtained single parasternal long-axis view with a sweep of the heart images, reviewed by an offsite expert, can detect borderline and definite RHD on screening with reasonable sensitivity and specificity. Brief training of nonexpert practitioners with ongoing support could be used as an effective strategy for scaling up echocardiographic screening for RHD in high-risk settings.

Adjunct Methods for the Detection of Patent Foramen Ovale: The Contribution of Transcranial Doppler and the Valsalva Manoeuvre.

A patent foramen ovale (PFO) is present in 25% of the population. In some patients, especially those without traditional stroke risk factors and with no immediately apparent cause, a cryptogenic stroke may be caused by an embolus passing through the PFO to the systemic circulation. The identification, or indeed exclusion, of a PFO is sought in these patients, most commonly using contrast-enhanced transthoracic or transoesophageal echocardiography. Another method for detecting a PFO is transcranial Doppler, which allows the detection of PFO possibly without the need for an echo laboratory, and with arguably improved sensitivity. This review will focus on transcranial Doppler detection of PFO, with a brief summary of echocardiographic techniques and the use of ultrasound contrast agents, and the role of provocations to increase diagnostic accuracy, specifically the Valsalva manoeuvre. We discuss the phases alongside the direct and indirect signs of an adequate Valsalva manoeuvre.

New Echocardiography Reference Ranges for Aotearoa (NewERA) Study: the application of international echocardiographic reference values to linear measurements of the hearts of healthy, young Maori and Pacific adults may not detect cardiac enlargement.

AIMS: To develop ethnic-specific echocardiography reference ranges for Aotearoa, and to investigate the impact of indexation to body surface area (BSA). Current reference international ranges are derived from people of mostly NZ European ethnicity and may not be appropriate for Maori and New Zealanders of Pacific ethnicity, who both experience high rates of cardiovascular disease. METHODS: Echocardiography was performed in a cross-sectional study of 263 healthy adults (18-50 years): Maori (N=71, 43 female), Pacific (N=53, 28 female), European (N=139, 74 female). Linear measurements of the left heart are reported and indexed to BSA. The upper/lower limit of normal (ULN/LLN) by ethnicity and sex were derived (quantile regression). Ethnic- and sex-specific differences were examined using ANOVA. RESULTS: The ULN was higher for all un-indexed dimensions in men compared to women, and for most indices the ULN was smallest in NZ Europeans and largest in Maori and Pacific peoples. Indexation reversed these relationships: NZ Europeans had higher ULN for many measurements. CONCLUSIONS: Indexing to BSA introduced bias that preferences the NZ European ethnicity by creating an upper limit reference threshold that far exceeds this sample's upper range. As a result, this may lead to under-recognition of cardiac enlargement in Maori and Pacific patients, and in particular for women. Unique reference ranges for all ethnic groups and sexes are required to optimally detect and manage cardiovascular diseases (CVD) in Aotearoa.

Estimating heart mass from heart volume as measured from post-mortem computed tomography.

Heart mass can be predicted from heart volume as measured from post-mortem computed tomography (PMCT), but with limited accuracy. Although related to heart mass, age, sex, and body dimensions have not been included in previous studies using heart volume to estimate heart mass. This study aimed to determine whether heart mass estimation can be improved when age, sex, and body dimensions are used as well as heart volume. Eighty-seven (24 female) adult post-mortem cases were investigated. Univariable predictors of heart mass were determined by Spearman correlation and simple linear regression. Stepwise linear regression was used to generate heart mass prediction equations. Heart mass estimate performance was tested using median mass comparison, linear regression, and Bland-Altman plots. Median heart mass (P = 0.0008) and heart volume (P = 0.008) were significantly greater in male relative to female cases. Alongside female sex and body surface area (BSA), heart mass was univariably associated with heart volume in all cases (R2 = 0.72) and in male (R2 = 0.70) and female cases (R2 = 0.64) when segregated. In multivariable regression, heart mass was independently associated with age and BSA (R2 adjusted = 0.46-0.54). Addition of heart volume improved multivariable heart mass prediction in the total cohort (R2 adjusted = 0.78), and in male (R2 adjusted = 0.74) and female (R2 adjusted = 0.74) cases. Heart mass estimated from multivariable models incorporating heart volume, age, sex, and BSA was more predictive of actual heart mass (R2 = 0.75-0.79) than models incorporating either age, sex, and BSA only (R2 = 0.48-0.57) or heart volume only (R2 = 0.64-0.73). Heart mass can be more accurately predicted from heart volume measured from PMCT when combined with the classical predictors, age, sex, and BSA.

Single-View Echocardiography by Nonexpert Practitioners to Detect Rheumatic Heart Disease: A Prospective Study of Diagnostic Accuracy.

BACKGROUND: Echocardiographic screening can detect asymptomatic cases of rheumatic heart disease (RHD), facilitating access to treatment. Barriers to implementation of echocardiographic screening include the requirement for expensive equipment and expert practitioners. We aimed to evaluate the diagnostic accuracy of an abbreviated echocardiographic screening protocol (single parasternal-long-axis view with a sweep of the heart) performed by briefly trained, nonexpert practitioners using handheld ultrasound devices. METHODS: Participants aged 5 to 20 years in Timor-Leste and the Northern Territory of Australia had 2 echocardiograms: one performed by an expert echocardiographer using a GE Vivid I or Vivid Q portable ultrasound device (reference test), and one performed by a nonexpert practitioner using a GE Vscan handheld ultrasound device (index test). The accuracy of the index test, compared with the reference test, for identifying cases with definite or borderline RHD was determined. RESULTS: There were 3111 enrolled participants; 2573 had both an index test and reference test. Median age was 12 years (interquartile range, 10-15); 58.2% were female. Proportion with definite or borderline RHD was 5.52% (95% CI, 4.70-6.47); proportion with definite RHD was 3.23% (95% CI, 2.61-3.98). Compared with the reference test, sensitivity of the index test for definite or borderline RHD was 70.4% (95% CI, 62.2-77.8), specificity was 78.1% (95% CI, 76.4-79.8). CONCLUSIONS: Nonexpert practitioners can be trained to perform single parasternal-long-axis view with a sweep of the heart echocardiography. However, the specificity and sensitivity are inadequate for echocardiographic screening. Improved training for nonexpert practitioners should be investigated.

Sex Disparity in Cardiovascular Disease Outcomes: Do Our Current Echocardiographic Reference Ranges Measure Up?

Reducing inequity in access to health care and disparity in health outcomes remain key objectives in cardiovascular medicine. Echocardiography is often the primary diagnostic tool used to detect cardiovascular disease (CVD), and relies on comparison with published reference ranges to appropriately detect pathology. Our understanding of the contribution of age, sex and ethnicity to quantification of cardiac size is improving, but cardiovascular disease management guidelines have yet to evolve. While recently, sex, age and ethnicity-specific reference values have been produced, treatment thresholds in many clinical guidelines do not differentiate between sexes. As a result, in order to reach management thresholds, women are often required to have more severe pathology. In order to reduce potential disadvantage to women, future research efforts should be directed to develop more personalised treatment approaches by identification of sex-appropriate management thresholds.

Correlation between epicardial adipose tissue and body mass index in New Zealand ethnic populations.

AIM: We aimed to investigate the correlation between epicardial adipose tissue (EAT) and body mass index (BMI) in different ethnic groups in New Zealand. METHODS: The study included 205 individuals undergoing open heart surgery. Maori and Pacific groups were combined to increase statistical power. EAT was measured using 2D echocardiography. RESULTS: There were 164 New Zealand Europeans (NZE) and 41 Maori/Pacific participants. The mean (SD) age of the study group was 67.9 (10.1) years, 69.1 (9.5) for NZE and 63.5 (11.4) for Maori/Pacific. BMI was 29.6 (5.5) kg/m2 for NZE and 31.8 (6.2) for Maori/Pacific. EAT thickness was 6.2 (2.2) mm and 6.0 (1.8) mm for NZE and Maori/Pacific, respectively. Using univariate linear regression, BMI showed moderate correlation with EAT in NZE (R2=0.26, p<0.001); however, there was no significant correlation between BMI and EAT in Maori/Pacific patients (R2=0.05, p=0.17). Using multivariate analysis, BMI remained a significant predictor of EAT thickness in NZE (R2 =0.27, p<0.001). CONCLUSIONS: BMI was associated with EAT thickness in NZE patients, but not in Maori/Pacific patients. The same level of BMI can carry different connotations of risk in different ethnic groups, with BMI likely being an inconsistent measure of obesity in in Maori/Pacific patients.

Review: Detection of patient foramen ovale using transcranial Doppler or standard echocardiography.

A patent foramen ovale (PFO) is a common remnant of fetal circulation present in up to 25% of the worldwide adult population. Paradoxical embolism occurs when venous blood crosses the PFO into the arterial system, bypassing the pulmonary circulation. This allows for the direct passage of microemboli into cerebral blood vessels, increasing the risk of cryptogenic stroke. This review investigates the current diagnostic procedures used to detect and grade a PFO, including transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE) and transcranial Doppler (TCD). Only a few studies have directly compared the use of TTE with TCD for PFO detection but several have compared TTE and TCD independently against the clinical gold standard TOE. Known pitfalls of TTE and TCD are also discussed, including the difficulty of differentiating between intracardiac shunts and intrapulmonary shunts. This review also discusses methods to optimise imaging, such as performing an adequate Valsalva manoeuvre, the role of abdominal compression and the choice of the injection site for the contrast agent and how these may increase the diagnostic success of detecting a right-to-left shunt when prompted by a clinician.

The 21st Century Echocardiography Laboratory in Australia and New Zealand: Rapid Evolution of Training and Workforce, Practice and Technology.

Echocardiography is a common and increasingly used noninvasive imaging tool in medicine. In this paper, we imagine the echocardiography laboratory of the future and consider the challenges we face currently, and may face in the future, and how these might be overcome; challenges such as training enough sonographers to meet the increasing demands of the ageing population living with chronic cardiovascular disease and the need for surveillance in other clinical scenarios. We consider the changing qualification framework and the requirements for accreditation and registration in Australia and New Zealand and the potential for migrant sonographers to meet some of the increasing demand. Advanced scopes of practice are likely to be a feature of the future workforce and we consider some of the ways these may evolve. Lastly, we consider how the evolving clinical landscape and technology may change the way echocardiography is delivered.

Plasma levels of soluble VEGF receptor isoforms, circulating pterins and VEGF system SNPs as prognostic biomarkers in patients with acute coronary syndromes.

BACKGROUND: Development of collateral circulation in coronary artery disease is cardio-protective. A key process in forming new blood vessels is attraction to occluded arteries of monocytes with their subsequent activation as macrophages. In patients from a prospectively recruited post-acute coronary syndromes cohort we investigated the prognostic performance of three products of activated macrophages, soluble vascular endothelial growth factor (VEGF) receptors (sFlt-1 and sKDR) and pterins, alongside genetic variants in VEGF receptor genes, VEGFR-1 and VEGFR-2. METHODS: Baseline levels of sFlt-1 (VEGFR1), sKDR (VEGFR2) and pterins were measured in plasma samples from subgroups (n = 513; 211; 144, respectively) of the Coronary Disease Cohort Study (CDCS, n = 2067). DNA samples from the cohort were genotyped for polymorphisms from the VEGFR-1 gene SNPs (rs748252 n = 2027, rs9513070 n = 2048) and VEGFR-2 gene SNPs (rs2071559 n = 2050, rs2305948 n = 2066, rs1870377 n = 2042). RESULTS: At baseline, levels of sFlt-1 were significantly correlated with age, alcohol consumption, NTproBNP, BNP and other covariates relevant to cardiovascular pathophysiology. Total neopterin levels were associated with alcohol consumption at baseline. 7,8 dihydroneopterin was associated with BMI. The A allele of VEGFR-2 variant rs1870377 was associated with higher plasma sFlt-1 and lower levels of sKDR at baseline. Baseline plasma sFlt-1 was univariately associated with all cause mortality with (p < 0.001) and in a Cox's proportional hazards regression model sFlt-1 and pterins were both associated with mortality independent of established predictors (p < 0.027). CONCLUSIONS: sFlt-1 and pterins may have potential as prognostic biomarkers in acute coronary syndromes patients. Genetic markers from VEGF system genes warrant further investigation as markers of levels of VEGF system components in these patients. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry. ACTRN12605000431628 . 16 September 2005, Retrospectively registered.

Diastolic Dysfunction Assessed Using Contemporary Guidelines and Prognosis Following Myocardial Infarction.

BACKGROUND: Recent American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines for the assessment of diastolic dysfunction (DD) recommend a simplified approach with four key variables incorporated into a novel diagnostic algorithm. The aim of this study was to assess the prognostic value of significant DD assessed using the algorithm recommended in the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines (DD2016) in comparison with the prognostic value of significant DD assessed using the 2009 guidelines (DD2009) as well as the individual parameters incorporated in the 2016 algorithm. METHODS: Retrospective data on 419 consecutive patients with first ever myocardial infarction were included. Doppler echocardiography was performed within 24 hours of admission in all patients. Significant DD was defined as grade 2 or 3 DD. The primary outcome measure was composite major adverse cardiovascular events (MACEs), comprising death, myocardial infarction, and heart failure. RESULTS: At a median follow-up of 24 months, there were 61 MACEs. On Kaplan-Meier analysis, DD2016 showed a better association with MACEs than DD2009 (log-rank χ2 = 21.01 [P < .001] vs 13.13 [P = .001]). On Cox proportional-hazards multivariate analysis incorporating significant clinical predictors and left ventricular ejection fraction, DD2016 (hazard ratio, 2.22; 95% CI, 1.25-3.98; P = .007) was the strongest independent predictor of MACEs, whereas DD2009 (hazard ratio, 1.63; 95% CI, 0.95-2.80; P = .074) was not a significant predictor. Of the four key diastolic parameters, only left atrial volume index was independently associated with MACEs (hazard ratio, 1.79; 95% CI, 1.02-3.14; P = .041) when included in a Cox proportional-hazards multivariate model incorporating significant clinical predictors and left ventricular ejection fraction, although the association was weaker than DD2016. Intermodel comparisons with model χ2 and Harrell's C statistic were satisfactory for DD2016. CONCLUSIONS: Significant DD assessed using the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines is a robust independent predictor of clinical outcomes following myocardial infarction and compares favorably with DD2009 as well as the individual parameters incorporated in the novel 2016 algorithm.

Snack bar compositions and their acute glycaemic and satiety effects.

BACKGROUND AND OBJECTIVES: Maintaining blood glucose within homeostatic limits and eating foods that sup-press hunger and promote satiety have beneficial impacts for health. This study investigated the glycaemic re-sponse and satiety effects of a serving size of a healthier snack bar, branded Nothing Else, that met the required nutrient profiling score criteria for a health claim, in comparison to two top-selling commercial snack bars. METHODS AND STUDY DESIGN: In an experimental study, 24 participants aged >=50 years were recruited. On three different days blood glucose concentration was measured twice at baseline and 15, 30, 45, 60, 90 and 120 minutes after consumption of a serving size of each bar. Satiety effects were self-reported hunger, fullness, desire to eat, and amount could eat ratings on visual analogue scales. RESULTS: The incremental area under the blood glucose response curve (iAUC) over two hours for the Nothing Else bar was 30% lower than commercial Bar 2 (p<0.001). At 45 minutes after eating, the Nothing Else bar induced the highest fullness rating and lowest hunger rating among the three snack bars. At two hours, fullness induced by the Nothing Else bar was twice that of Bar 2 (p=0.019), but not different to Bar 1 (p=0.212). CONCLUSIONS: The Nothing Else snack bar developed using the nutrient profiling scheme as a guideline, with its high protein and dietary fibre contents, had a lower glycaemic impact and induced a higher subjective satiety than the two commercial snack bars of equal weight.