Does automated left ventricular ejection fraction assessment available on handheld ultrasound devices represent improvement in the diagnostic accuracy?

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Purpose To assess the accuracy of an algorithm for automated measurement of the left ventricular ejection fraction (LVEF) available on handheld ultrasound device (HUD). Methods 112 patients admitted to the cardiology department, who were referred for the conventional echocardiographic examination, underwent additional assessment performed with HUD (Vscan Extend, GE Vingmed Ultrasound, Horten, Norway). In each case 4 – chamber apical view was obtained and LVEF was calculated by means of the LVivo software. Imaging quality was assessed in a 4-grade scale. Subsequently, during the examination performed with the use of the stationary echocardiograph the three-dimensional (3D) measurement of LVEF was recorded. Results Ultimately 96 (53 men, mean age 63 ± 11) patients were enrolled into the study group In the remaining 16 cases (14%) 3D image quality was not sufficient to allow the calculation of the LVEF. LVivo software was unsuccessful in calculating LVEF in all these 16 patients and in additional 20 patients, who remained in the study group due to satisfactory 3D image quality. The quality of images acquired with the use of HUD was assessed as optimal in 25 (26%) patients, good in 37 (39%), acceptable in 24 (25%), poor in 10 (10%). The average LVEF value was 46%±14 with the 3D LVQ measurements and 48%±14 using the LVivo software. The correlation coefficient between the LVEF values obtained with the two methods was r = 0,92; (P < 0,0001). Using paired samples t-test we found that the difference between these two techniques was not significant (mean difference 4,5± 3,4%; P = 0,35). LVivo software EF assessment is based on a single apical view and for this reason we have assumed that the differences in EF can be larger in patients with regional wall motion abnormalities, in whom LVEF values derived from different apical views can significantly vary. For this reason the group of patients with history of myocardial infarction (40pts, 42%) was analysed separately and we found that the difference between LVivo and 3D LVEF was also not statistically significant (mean difference 6,1± 3,3%; P= 0,14). The correlation coefficient equalled r = 0,78; (P < 0,0001). Conclusion The LVivo software despite its limitations is capable of the accurate LVEF measurement when the acquired views are of at least good imaging quality. Such expanded capabilities of HUDs can potentially lead to the overall improvements of the diagnostic accuracy of the ultrasonographic examinations, particularly when in hands of the non-expert echocardiographers.