Clinical Influence of Handheld Ultrasound, Supported by Automatic Quantification and Telemedicine, in Suspected Heart Failure.

Early and correct heart failure (HF) diagnosis is essential to improvement of patient care. We aimed to evaluate the clinical influence of handheld ultrasound device (HUD) examinations by general practitioners (GPs) in patients with suspected HF with or without the use of automatic measurement of left ventricular (LV) ejection fraction (autoEF), mitral annular plane systolic excursion (autoMAPSE) and telemedical support. Five GPs with limited ultrasound experience examined 166 patients with suspected HF (median interquartile range = 70 (63-78) y; mean ± SD EF = 53 ± 10%). They first performed a clinical examination. Second, they added an examination with HUD, automatic quantification tools and, finally, telemedical support by an external cardiologist. At all stages, the GPs considered whether the patients had HF. The final diagnosis was made by one of five cardiologists using medical history and clinical evaluation including a standard echocardiography. Compared with the cardiologists' decision, the GPs correctly classified 54% by clinical evaluation. The proportion increased to 71% after adding HUDs, and to 74 % after telemedical evaluation. Net reclassification improvement was highest for HUD with telemedicine. There was no significant benefit of the automatic tools (p ≥ 0.58). Addition of HUD and telemedicine improved the GPs' diagnostic precision in suspected HF. Automatic LV quantification added no benefit. Refined algorithms and more training may be needed before inexperienced users benefit from automatic quantification of cardiac function by HUDs.

Real-time automatic quantification of left ventricular function by hand-held ultrasound devices in patients with suspected heart failure: a feasibility study of a diagnostic test with data from general practitioners, nurses and cardiologists.

OBJECTIVES: To evaluate the feasibility and reliability of hand-held ultrasound (HUD) examinations with real-time automatic decision-making software for ejection fraction (autoEF) and mitral annular plane systolic excursion (autoMAPSE) by novices (general practitioners), intermediate users (registered cardiac nurses) and expert users (cardiologists), respectively, compared to reference echocardiography by cardiologists in an outpatient cohort with suspected heart failure (HF). DESIGN: Feasibility study of a diagnostic test. SETTING AND PARTICIPANTS: 166 patients with suspected HF underwent HUD examinations with autoEF and autoMAPSE measurements by five novices, three intermediate-skilled users and five experts. HUD results were compared with a reference echocardiography by experts. A blinded cardiologist scored all HUD recordings with automatic measurements as (1) discard, (2) accept, but adjust the measurement or (3) accept the measurement as it is. PRIMARY OUTCOME MEASURE: The feasibility of automatic decision-making software for quantification of left ventricular function. RESULTS: The users were able to run autoEF and autoMAPSE in most patients. The feasibility for obtaining accepted images (score of ≥2) with automatic measurements ranged from 50% to 91%. The feasibility was lowest for novices and highest for experts for both autoEF and autoMAPSE (p≤0.001). Large coefficients of variation and wide coefficients of repeatability indicate moderate agreement. The corresponding intraclass correlations (ICC) were moderate to good (ICC 0.51-0.85) for intra-rater and poor (ICC 0.35-0.51) for inter-rater analyses. The findings of modest to poor agreement and reliability were not explained by the experience of the users alone. CONCLUSION: Novices, intermediate and expert users were able to record four-chamber views for automatic assessment of autoEF and autoMAPSE using HUD devices. The modest feasibility, agreement and reliability suggest this should not be implemented into clinical practice without further refinement and clinical evaluation. TRIAL REGISTRATION NUMBER: NCT03547076.

Feasibility and Accuracy of Tele-Echocardiography, With Examinations by Nurses and Interpretation by an Expert via Telemedicine, in an Outpatient Heart Failure Clinic.

OBJECTIVES: To study the feasibility and accuracy of focused echocardiography by nurses supported by near-real-time interpretation via telemedicine by an experienced cardiologist. METHODS: Fifty consecutive patients were included from an outpatient heart failure (HF) clinic. Limited echocardiography was performed by 1 of 3 specialized nurses. The echocardiograms were transferred by a secure transfer model for near-real-time interpretation to 1 out-of-hospital cardiologist, assessing, among others, the left ventricular (LV) internal diameter, end-diastolic volume, ejection fraction, left atrial (LA) indexed end-systolic volume, mitral early inflow velocity (E), the ratio of E to mitral late inflow, and the ratio of E to the mitral annular early diastolic velocity. The reference method was echocardiography by 1 of 4 experienced cardiologists. RESULTS: The median age of the population (46% women) was 79 (range, 33-95) years. The assessment and quantification of LA and LV dimensions, volumes, and functional indices were feasible in 94% or more via the telemedical approach. The agreement with reference measurements was very high by the telemedical approach. The mean duration ± SD of the complete telemedical approach from the start of echocardiography until the cardiologist's report was received by the caregiving nurse was 1.32 ± 0.36 (range, 1.58) hours. The correlations with reference to the above-specified indices were r = 0.75 to 0.94. CONCLUSIONS: Limited echocardiography by nurses in an outpatient heart failure clinic, supported by interpretation by an out-of-hospital cardiologist, was feasible and reliable. This may reduce geographic disparities and allow more patients to benefit from the advantages of implementing focused echocardiography by noncardiologists in diagnostics and follow-up.