Accuracy of Cardiac Nurse Acquired and Measured Three-Dimensional Echocardiographic Left Ventricular Ejection Fraction: Comparison to Echosonographer.

BACKGROUND: Three-dimensional echocardiography (3D-Echo) performed by novice health care staff to measure left ventricular ejection fraction (LVEF) could allow cost-effective screening and monitoring for left ventricular systolic dysfunction (LVSD) prior to the development of heart failure. The aim of this study was to determine feasibility and accuracy of cardiac nurses (after completing focussed training) independently acquiring 3D-Echo images, and measuring LVEF using semi-automated software when compared to an echosonographer. METHODS: One echosonographer and three cardiac nurses acquired 3D-Echo images on 73 patients (62 ± 16 years, 62% male) with good image quality, and subsequently measured LVEF using a semi-automated algorithm. RESULTS: Overall feasibility was 89% with the three nurses successfully acquiring 3D-Echo images suitable for LVEF assessment in 65 of the 73 patients. High accuracy (r = 0.82; p < 0.0001) with minimal bias (+0.1, -10.6 to +10.8 limits of agreement; p = 0.91) was observed comparing the nurses to the echosonographer for measuring LVEF. Individual nurses demonstrated high feasibility (86%-92%), accuracy (r = 0.83-0.87; all p < 0.0001) and intra-observer reproducibility (r = 0.96-0.97; all p < 0.0001), with good inter-observer consistency in accuracy compared to the echosonographer (one-way analysis of variance p = 0.559). CONCLUSIONS: We have demonstrated that, following a focussed training protocol, it was feasible for cardiac nurses to acquire 3D-Echo images of sufficient image quality to allow measurement of LVEF using a semi-automated algorithm, with comparable accuracy and intra-observer variability to an expert echosonographer. This could potentially allow the broader application of echocardiography to screen for LVSD in high-risk cohorts.

Evaluation of training nurses to perform semi-automated three-dimensional left ventricular ejection fraction using a customised workstation-based training protocol.

AIMS AND OBJECTIVES: We aimed to determine the feasibility of training cardiac nurses to evaluate left ventricular function utilising a semi-automated, workstation-based protocol on three dimensional echocardiography images. BACKGROUND: Assessment of left ventricular function by nurses is an attractive concept. Recent developments in three dimensional echocardiography coupled with border detection assistance have reduced inter- and intra-observer variability and analysis time. This could allow abbreviated training of nurses to assess cardiac function. DESIGN: A comparative, diagnostic accuracy study evaluating left ventricular ejection fraction assessment utilising a semi-automated, workstation-based protocol performed by echocardiography-naïve nurses on previously acquired three dimensional echocardiography images. METHODS: Nine cardiac nurses underwent two brief lectures about cardiac anatomy, physiology and three dimensional left ventricular ejection fraction assessment, before a hands-on demonstration in 20 cases. We then selected 50 cases from our three dimensional echocardiography library based on optimal image quality with a broad range of left ventricular ejection fractions, which was quantified by two experienced sonographers and the average used as the comparator for the nurses. Nurses independently measured three dimensional left ventricular ejection fraction using the Auto lvq package with semi-automated border detection. RESULTS: The left ventricular ejection fraction range was 25-72% (70% with a left ventricular ejection fraction <55%). All nurses showed excellent agreement with the sonographers. Minimal intra-observer variability was noted on both short-term (same day) and long-term (>2 weeks later) retest. CONCLUSIONS: It is feasible to train nurses to measure left ventricular ejection fraction utilising a semi-automated, workstation-based protocol on previously acquired three dimensional echocardiography images. Further study is needed to determine the feasibility of training nurses to acquire three dimensional echocardiography images on real-world patients to measure left ventricular ejection fraction. RELEVANCE TO CLINICAL PRACTICE: Nurse-performed evaluation of left ventricular function could facilitate the broader application of echocardiography to allow cost-effective screening and monitoring for left ventricular dysfunction in high-risk populations.