Clinical utility of semi-automated estimation of ejection fraction at the point-of-care

INTRODUCTION: To compare estimation of ejection fraction at the bedside by AutoEF compared with conventional methods and to assess feasibility and time consumption. METHODS: A total of 102 relatively hemodynanically stable mixed medical and surgical patients were included. All patients underwent ultrasonography of the heart at the bedside performed by a novice examiner. Three assessments of ejection fraction were made: 1) Expert eyeballing by a single specialist in cardiology and expert in echocardiography; 2) Manual planimetry by an experienced examiner; 3) AutoEF by a novice examiner with limited experience in echocardiography. RESULTS: Expert eyeballing of ejection fraction was performed in 100% of cases. Manual planimetry was possible in 89% of cases and AutoEF was possible in 83% of cases. The correlation between expert eyeballing and AutoEF was r=0.82, p < 0.001, for manual planimetry and for AutoEF it was r=0.82, p < 0.001; for expert eyeballing and manual planimetry it was r=0.80, p < 0.001. The mean time consumption for manual planimetry was 98 ( 90-106 ) seconds; correspondingly the mean time spent for AutoEF was 41 ( 36-46 ) seconds, which was significantly less (p < 0.001). CONCLUSIONS: AutoEF seems to be a valid supplement to the clinical assessment of ejection fraction in the hands of less experienced examiners, yielding result similar to manual planimetry with less time consumption and less intra-observer variability. However, manual editing may be required and training is thus recommended before AutoEF is applicable for use by novices.