Study Design
This prospective observational study was carried out between January 2018 to January 2020 at five outpatient sites within the Allina Health system and the main outpatient site within the Minneapolis Heart Institute Foundation. The study protocol was approved by the Institutional Review Board (IRB), following which 180 consecutive patients underwent echocardiographic assessment with the Vscan (GE Medical Systems, Milwaukee, Wisconsin, USA) by 11 previously untrained primary care providers.
The inclusion criteria were: (i) presence of at least one of the following symptoms during a routine visit; shortness of breath or lack of energy; or (ii) the presence of at least one of the following clinical signs: edema or a new cardiac murmur on auscultation. There were no exclusion criteria for patient enrollment.
All 11 primary care providers (including internists and advanced practice providers such as physician assistants) were provided basic instructions and self-directed learning tools on utilizing the Vscan device, and were taught basic image acquisition for the following views: Parasternal long/short axis as well as apical 3- and 4-chamber, and given. The providers were also trained in utilizing the color Doppler exam as needed. Prior to their participation in this study, the providers’ experiences with handheld imaging devices varied from no to minor experience.
Aortic stenosis was assessed using the parasternal long and short axis views: a 2D assessment was performed to assess for leaflet mobility, valve opening. Color Doppler acceleration in the left ventricular outflow tract was added as necessary. Mitral and tricuspid regurgitation was assessed using the parasternal long, apical 4-, and apical 3- chamber views utilizing 2D assessment to identify leaflet coaptation and color Doppler.
Patients underwent evaluation for VHD and LV function using the Vscan, and all data were collected using a simple data collection sheet (supplement 1). The providers recorded the following findings: (i) Presence of Pericardial or Pleural Effusion, (ii) Presence of mild, moderate or severe Aortic stenosis, Mitral regurgitation, and Tricuspid regurgitation, (iii) LVEF using semi-quantitative analysis as normal (EF>55%), mildly (EF>45 <55%), moderately (EF <45 >35%) or severely (EF <35%) reduced.
Following image acquisition by the outpatient provider, the patients’ echocardiographic Vscan images were read by 3 blinded expert echocardiography readers and results reported on the same collection sheets. Vscan devices for the study were provided through a research grant by GE Healthcare.