A novel approach using hand-held echocardiography to guide the diagnosis of heart failure in pregnant women in a low-resource setting; Maternal and Perinatal Health Research Collaboration

Background Point of care imaging devices are promising tools for cardiovascular imaging in low-resource settings. Purpose Our aim was to determine whether hand-held echocardiography scans performed by obstetricians can help to identify the cardiac phenotypes in pregnant women with heart failure in India. Methods In November 2018, eighteen obstetricians from 10 hospitals across the states of Assam, Meghalaya and Uttar Pradesh were given 2 days of hands-on training in image acquisition using Philips Lumify devices. Obstetricians were asked to follow a simplified protocol of image acquisition and optimisation designed by the Oxford Cardiovascular Clinical Research Facility team. The protocol includes 3 key echocardiography views; parasternal long axis, parasternal short axis, and apical four chamber. Remote supervision and constructive feedback on performance was provided to improve image quality. Echocardiographic images of 269 pregnant women (with and without suspected heart failure) were acquired by the trained obstetricians, between February 2018 and January 2020. The first 147 scans were transferred with end-to-end encryption to the University of Oxford Research Echocardiography Core Laboratory (ORECL). Image interpretation and formal quality assessment was performed by 2 experienced echocardiographers. Results Parasternal long axis image quality was assessed as good in 78.3%, and was superior to both the parasternal short axis view (76.5%) and the apical 4-chamber view (61.9%). Image depth and gain optimisation was the main reason for loss of quality. The acquisition quality was related to reported clinical disease severity, and advanced pregnancy status. Left ventricular systolic function was impaired in 32 participants (21.9%), and 23.3% of the cohort had a dilated left atrium. Rheumatic heart disease was found in 12 participants (8.3%), in which the mitral valve was stenotic; 10 severe and 1 moderate. Mitral regurgitation was reported in 29 cases (20.8%); 6 severe, 7 moderate and 16 mild. Tricuspid and aortic valve abnormalities were also detected. Pericardial effusion was reported in 45 participants (30.8%). Conclusion Obstetricians with supervised training, using hand-held echocardiography have demonstrated acceptable image acquisition quality which could be assessed through core laboratory analysis to detect cardiac abnormalities. Such an approach could be useful to guide the diagnosis of heart failure in pregnant women in low-resource settings. Further training for the obstetricians and image quality assurance have been implemented in the ongoing MaatHRI study with plans to conduct a validation analysis. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Medical Research Council (MRC), UK Fellowship for M Nair.

A systematic review of pocket-sized imaging devices: small and mighty?

IntroductionHand-held imaging devices are widely used in clinical practice and are a useful tool. There is no published review examining the diagnostic parameters achieved with these devices in clinical practice.MethodsWe searched three online medical literature databases (PubMed, EMBASE and MEDLINE) for all literature published up until January 2018. We selected studies that (1) were conducted in the adult population; (2) used a truly hand-held device; (3) featured sensitivities and/or specificities on the use of the hand-held scanner. We extracted and summarised the diagnostic metrics from the literature.ResultsTwenty-seven articles were excluded from the initial 56 relevant articles, as the device featured was not truly hand-held. Ultimately a total of 25 studies were analysed. Sixteen studies were carried out by experienced users, seven by users with little previous experience and two studies by nurses. High diagnostic parameters were achieved by all three groups when scanning cardiac pathology and intra-abdominal structures. Training of non-expert users varied, taking a mean of 21.6 h. These hand-held devices can change diagnoses at the bedside and be used as gate-keepers to formal echocardiography. Individual studies show them to be cost-effective.ConclusionHand-held echocardiography is a useful tool in the hands of experts and novices alike. Studies conducted are highly heterogeneous making it difficult to pool data for the diagnostic metrics. Further studies with rigorous methodology are needed to evaluate the true diagnostic potential in the hands of non-experts and in the community as well as to validate training protocols.

A focussed single-view hand-held echocardiography protocol for the detection of rheumatic heart disease

BackgroundEchocardiographic screening represents an opportunity for reduction in the global burden of rheumatic heart disease. A focussed single-view screening protocol could allow for the rapid training of healthcare providers and screening of patients.ObjectiveThe aim of this study was to determine the sensitivity and specificity of a focussed single-view hand-held echocardiographic protocol for the diagnosis of rheumatic heart disease in children.MethodsA total of nine readers were divided into three reading groups; each interpreted 200 hand-held echocardiography studies retrospectively as screen-positive, if mitral regurgitation ⩾1.5 cm and/or any aortic insufficiency were observed, or screen-negative from a pooled study library. The performance of experts receiving focussed hand-held protocols, non-experts receiving focussed hand-held protocols, and experts receiving complete hand-held protocols were determined in comparison with consensus interpretations on fully functional echocardiography machines.ResultsIn all, 587 studies including 76 on definite rheumatic heart disease, 122 on borderline rheumatic heart disease, and 389 on normal cases were available for analysis. The focussed single-view protocol had a sensitivity of 81.1%, specificity of 75.5%, negative predictive value of 88.5%, and a positive predictive value of 63.2%; expert readers had higher specificity (86.1 versus 64.8%, p<0.01) but equal sensitivity. Sensitivity – experts, 96% and non-experts, 95% – and negative predictive value – experts, 99% and non-experts, 98% – were better for definite rheumatic heart disease. False-positive screening studies resulting from erroneous identification of mitral regurgitation and aortic insufficiency colour jets increased with shortened protocols and less experience (p<0.01).ConclusionOur data support a focussed screening protocol limited to parasternal long-axis images. This holds promise in making echocardiographic screening more practical in regions where rheumatic heart disease remains endemic.