Novel handheld ultrasound technology to enhance non-expert screening for rheumatic heart disease in the Republic of Palau: A descriptive study

Handheld echocardiography for the screening and diagnosis of rheumatic heart disease: a systematic review to inform WHO guidelines

BACKGROUND

Early detection and diagnosis of acute rheumatic fever and rheumatic heart disease are key to preventing progression, and echocardiography has an important diagnostic role. Standard echocardiography might not be feasible in high-prevalence regions due to its high cost, complexity, and time requirement. Handheld echocardiography might be an easy-to-use, low-cost alternative, but its performance in screening for and diagnosing acute rheumatic fever and rheumatic heart disease needs further investigation.

METHODS

In this systematic review and meta-analysis, we searched Embase, MEDLINE, LILACS, and Conference Proceedings Citation Index-Science up to Feb 9, 2024, for studies on the screening and diagnosis of acute rheumatic fever and rheumatic heart disease using handheld echocardiography (index test) or standard echocardiography or auscultation (reference tests) in high-prevalence areas. We included all studies with useable data in which the diagnostic performance of the index test was assessed against a reference test. Data on test accuracy in diagnosing rheumatic heart disease, acute rheumatic fever, or carditis with acute rheumatic fever (primary outcomes) were extracted from published articles or calculated, with authors contacted as necessary. Quality of evidence was appraised using GRADE and QUADAS-2 criteria. We summarised diagnostic accuracy statistics (including sensitivity and specificity) and estimated 95% CIs using a bivariate random-effects model (or univariate random-effects models for analyses including three or fewer studies). Area under the curve (AUC) was calculated from summary receiver operating characteristic curves. Heterogeneity was assessed by visual inspection of plots. This study was registered with PROSPERO (CRD42022344081).

FINDINGS

Out of 4868 records we identified 11 studies, and two additional reports, comprising 15 578 unique participants. Pooled data showed that handheld echocardiography had high sensitivity (0·87 [95% CI 0·76-0·93]), specificity (0·98 [0·71-1·00]), and overall high accuracy (AUC 0·94 [0·84-1·00]) for diagnosing rheumatic heart disease when compared with standard echocardiography (two studies; moderate certainty of evidence), with better performance for diagnosing definite compared with borderline rheumatic heart disease. High sensitivity (0·79 [0·73-0·84]), specificity (0·85 [0·80-0·89]), and overall accuracy (AUC 0·90 [0·85-0·94]) for screening rheumatic heart disease was observed when pooling data of handheld echocardiography versus standard echocardiography (seven studies; high certainty of evidence). Most studies had a low risk of bias overall. Some heterogeneity was observed for sensitivity and specificity across studies, possibly driven by differences in the prevalence and severity of rheumatic heart disease, and level of training or expertise of non-expert operators.

INTERPRETATION

Handheld echocardiography has a high accuracy and diagnostic performance when compared with standard echocardiography for diagnosing and screening of rheumatic heart disease in high-prevalence areas.

FUNDING

World Health Organization.

TRANSLATIONS

For the Chinese, French, Italian, Persian, Portuguese, Spanish and Urdu translations of the abstract see Supplementary Materials section.

2023 World Heart Federation guidelines for the echocardiographic diagnosis of rheumatic heart disease

Rheumatic heart disease (RHD) is an important and preventable cause of morbidity and mortality among children and young adults in low-income and middle-income countries, as well as among certain at-risk populations living in high-income countries. The 2012 World Heart Federation echocardiographic criteria provided a standardized approach for the identification of RHD and facilitated an improvement in early case detection. The 2012 criteria were used to define disease burden in numerous epidemiological studies, but researchers and clinicians have since highlighted limitations that have prompted a revision. In this updated version of the guidelines, we incorporate evidence from a scoping review, an expert panel and end-user feedback and present an approach for active case finding for RHD, including the use of screening and confirmatory criteria. These guidelines also introduce a new stage-based classification for RHD to identify the risk of disease progression. They describe the latest evidence and recommendations on population-based echocardiographic active case finding and risk stratification. Secondary antibiotic prophylaxis, echocardiography equipment and task sharing for RHD active case finding are also discussed. These World Heart Federation 2023 guidelines provide a concise and updated resource for clinical and research applications in RHD-endemic regions.

Self-administered at-home lung ultrasound with remote guidance in patients without clinical training

BACKGROUND

Access to timely and accurate diagnostic imaging is essential for high-quality healthcare. Point-of-care ultrasound has been shown to be accessible and effective in many aspects of healthcare, including assessing changes in lung pathology. However, few studies have examined self-administered at-home lung ultrasound (SAAH-LUS), in particular performed by non-clinical patients (NCPs).

RESEARCH QUESTION

Are NCPs able to perform SAAH-LUS using remote teleguidance and produce interpretable images?

STUDY DESIGN

Patients were enrolled to the study in a mix of in-person and virtual recruitment, and shipped a smartphone as well as a point of care ultrasound device. Tele-guidance was provided by a remote physician using software integrated with the point of care ultrasound device, allowing real-time remote visualization and guidance of a patient scanning their own chest. A post-intervention survey was conducted to assess patient satisfaction, feasibility, and acceptability of SAAH-LUS. Two POCUS expert reviewers reviewed the scans for interpretability, and inter-rater agreement between the two reviewers was also computed.

RESULTS

Eighteen patients successfully underwent 7-14 days of daily telemedicine in parallel to daily SAAH-LUS. Across 1339 scans obtained from ten different lung zones, the average proportion of interpretability was 96% with a chance-corrected agreement, or Cohen's kappa, reported as κ = 0.67 (significant agreement). 100% of NCPs surveyed found SAAH-LUS to be a positive experience, particularly for its ease of operation and ability to increase access to healthcare services.

INTERPRETATION

This study demonstrates that NCPs can obtain interpretable LUS images at home, highlighting the potential for SAAH-LUS to increase diagnostic capacity, particularly for rural and remote regions where complex imaging and healthcare providers are difficult to obtain. Trial registration The clinical trials has been registered (clinicaltrials.gov).

REGISTRATION NUMBER

NCT04967729.

Rheumatic Heart Disease in the Developing World

Despite recent public policy initiatives, rheumatic heart disease (RHD) remains a major source of morbidity worldwide. Rheumatic heart disease occurs as a sequela of Streptococcus pyogenes (group A streptococcal [GAS]) infection in patients with genetic susceptibility. Strategies for prevention of RHD or progression of RHD include prevention of GAS infection with community initiatives, effective treatment of GAS infection, and secondary prophylaxis with intramuscular penicillin. The cardiac surgical community has attempted to improve the availability of surgery in RHD-endemic areas with some success, and operative techniques and outcomes of valve repair continue to improve, potentially offering patients a safer, more durable operation. Innovation offers hope for a more scalable solution with improved biomaterials and transcatheter delivery technology; however, cost remains a barrier.

Cardiac POCUS in Pediatric Emergency Medicine: A Narrative Review

PURPOSE OF THIS REVIEW

The cardiac point of care ultrasound (POCUS) is among the most impactful examinations in the evaluation of an ill child. This paper will review the English-language literature on cardiac POCUS in the pediatric emergency department (PED), the adult emergency literature with relevance to pediatric emergency, and other pediatric cardiac studies outside pediatric emergency with relevance to PED detection of potentially emergent pediatric cardiac pathology.

RECENT FINDINGS

Pediatric emergency physicians can reliably detect decreased left-sided systolic function and pericardial effusion using POCUS. Case reports show that pediatric emergency physicians have detected right-sided outflow tract obstruction, aortic root dilatation, and congenital cardiac disease using POCUS. Training for pediatric cardiac POCUS competency is feasible, and cardiac POCUS does not increase the burden on cardiology resources to the PED.

SUMMARY

While cardiac pathology in children is relatively rare, pediatric cardiac POCUS can incorporate a broad curriculum beyond systolic function and the presence of pericardial fluid. Further research should assess pediatric emergency physician performance in the identification of a broader range of cardiac pathology.

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.

Hocus POCUS! Parental Quantification of Left-Ventricular Ejection Fraction Using Point of Care Ultrasound: Fiction or Reality?

Point of care ultrasound has become increasingly utilized in pediatric settings. The assessment of cardiac function is one such implementation of this. This study aimed to determine the feasibility of parents in acquiring images to assess function using a handheld ultrasound probe and the correlation of fractional shortening measurements by handheld ultrasound with hospital acquired echocardiography. This was a single-center prospective study of parents of pediatric patients admitted to the hospital. Parents underwent a 25-min education session on how to use the handheld ultrasound probe and then were asked to acquire a parasternal short-axis and apical four-chamber image on their own. Acquired images were reviewed by two physicians to determine adequacy of images to assess systolic cardiac function subjectively and objectively. Fractional shortening was measured using parent-acquired images and then compared to recent hospital acquired fractional shortening. A total of 25 parents of 21 patients enrolled and completed the study. Of the enrolled parents, 96% of both parasternal short-axis and apical four-chamber images acquired were deemed appropriate for subjective assessment of systolic function. Inter-reader variability of fractional shortening was moderate between two readers. Correlation of fractional shortening measured from parent-acquired images versus hospital acquired images was moderate. Parents were able to successfully obtain a parasternal short-axis and apical four-chamber image adequate to assess function and quantify fractional shortening after a 25-min education session. This pilot data demonstrate that further exploration of parent-performed point of care cardiac assessment may be warranted.

Focused Cardiac Ultrasound to Guide the Diagnosis of Heart Failure in Pregnant Women in India

BACKGROUND

Cardiac complications are a leading cause of maternal death. Cardiac imaging with echocardiography is important for prompt diagnosis, but it is not available in many low-resource settings. The aim of this study was to determine whether focused cardiac ultrasound performed by trained obstetricians and interpreted remotely by experts can identify cardiac abnormalities in pregnant women in low-resource settings.

METHODS

A cross-sectional study was conducted among 301 pregnant and postpartum women recruited from 10 hospitals across three states in India. Twenty-two obstetricians were trained in image acquisition using a portable cardiac ultrasound device following a simplified protocol adapted from focus-assessed transthoracic echocardiography protocol. It included parasternal long-axis, parasternal short-axis, and apical four-chamber views on two-dimensional and color Doppler. Independent image interpretation was performed remotely by two experts, in the United Kingdom and India, using a standard semiquantitative assessment protocol. Interrater agreement between the experts was examined using Cohen's κ. Diagnostic accuracy of the method was examined in a subsample for whom both focused and conventional scans were available.

RESULTS

Cardiac abnormalities identified using the focused method included valvular abnormalities (27%), rheumatic heart disease (6.6%), derangements in left ventricular size (4.7%) and function (22%), atrial dilatation (19.5%), and pericardial effusion (30%). There was substantial agreement on the cardiac parameters between the two experts, ranging from 93.6% (κ = 0.84) for left ventricular ejection fraction to 100% (κ = 1) for valvular disease. Image quality was graded as good in 79% of parasternal long-axis, 77% of parasternal short-axis and 64% of apical four-chamber views. The chance-corrected κ coefficients indicated fair to moderate agreement (κ = 0.28-0.51) for the image quality parameters. There was good agreement on diagnosis between the focused method and standard echocardiography (78% agreement), compared in 36 participants.

CONCLUSIONS

The focused method accurately identified cardiac abnormalities in pregnant women and could be used for screening cardiac problems in obstetric settings.

Task shifting for point of care ultrasound in primary healthcare in low- and middle-income countries-a systematic review

Low-and middle-income countries (LMIC) are faced with healthcare challenges including lack of specialized healthcare workforce and limited diagnostic infrastructure. Task shifting for point-of-care ultrasound (POCUS) can overcome both shortcomings. This review aimed at identifying benefits and challenges of task shifting for POCUS in primary healthcare settings in LMIC. Medline and Embase were searched up to November 22nd, 2021. Publications reporting original data on POCUS performed by local ultrasound naïve healthcare providers in any medical field at primary healthcare were included. Data were analyzed descriptively. PROSPERO registration number CRD42021223302. Overall, 36 publications were included, most (n = 35) were prospective observational studies. Medical fields of POCUS application included obstetrics, gynecology, emergency medicine, infectious diseases, and cardiac, abdominal, and pulmonary conditions. POCUS was performed by midwives, nurses, clinical officers, physicians, technicians, and community health workers following varying periods of short-term training and using different ultrasound devices. Benefits of POCUS were yields of diagnostic images with adequate interpretation impacting patient management and outcome. High cost of face-to-face training, poor internet connectivity hindering telemedicine components, and unstable electrici'ty were among reported drawbacks for successful implementation of task shifting POCUS. At the primary care level in resource-limited settings task shifting for POCUS has the potential to expand diagnostic imaging capacity and impact patient management leading to meaningful health outcomes.