Can hospital rounds with pocket ultrasound by cardiologists reduce standard echocardiography?

Abstract

Background: Frequently, hospitalized patients are referred for transthoracic echocardiograms. The availability of a pocket mobile echocardiography device that can be incorporated on bedside rounds by cardiologists may be a useful and frugal alternative.

Methods: This was a cross-sectional study designed to compare the accuracy of pocket mobile echocardiography images with those acquired by transthoracic echocardiography in a sample of hospitalized patients. Each patient referred for echocardiography underwent pocket mobile echocardiography acquisition and interpretation by a senior cardiology fellow with level II training in echocardiography. Subsequently, transthoracic echocardiography was performed by skilled ultrasonographers and interpreted by experienced echocardiographers. Both groups were blinded to the results of the alternative imaging modality. Visualizability and accuracy for all key echocardiographic parameters (ejection fraction, wall motion abnormalities, left ventricular end-diastolic dimension, inferior vena cava size, aortic and mitral valve pathology, and pericardial effusion) were determined and compared between imaging modalities.

Results: A total of 240 hospitalized patients underwent echocardiography with pocket mobile echocardiography and transthoracic echocardiography. The mean age was 71 ± 17 years. Pocket mobile echocardiography imaging time was 6.3 ± 1.5 minutes. Sensitivity of pocket mobile echocardiography varied by parameter and was highest for aortic stenosis (97%) and lowest for aortic insufficiency (76%). Specificity also varied by parameter and was highest for mitral regurgitation (100%) and lowest for left ventricular ejection fraction (92%). Equivalence testing revealed the pocket mobile echocardiography outcomes to be significantly equivalent to the transthoracic echocardiography outcomes with no discernible differences in image quality between pocket mobile echocardiography and transthoracic echocardiography (P = 7.22 × 10(-7)). All outcomes remain significant after correcting for multiple testing using the false discovery rate.

Conclusions: The results from rapid bedside pocket mobile echocardiography examinations performed by experienced cardiology fellows compared favorably with those from formal transthoracic echocardiography studies. For hospitalized patients, this finding could shift the burden of performing and interpreting the echocardiogram to the examining physician and reduce the number and cost associated with formal echocardiography studies.

Keywords: Bedside echocardiography; Echocardiography; Handheld echocardiography; Pocket mobile echocardiography.