Pocket-sized ultrasound, a new method for point-of-care diagnosis of heart failure

Purpose and goal

To be able to diagnose heart failure (HF) in patients with a reduced left ventricular ejection fraction (LVEF) in the primary care setting would be of clinical value. Few studies on this subject have been conducted. Therefore, we designed a trial of cardiac ultrasound by a handheld device (Vscan, GE-Healthcare) as a part of a training programme for primary care physicians. Study patients were recruited among primary care patients that were evaluated in primary care and referred to a comprehensive cardiac ultrasound examination (reference method).

Expected results and effects

158 patients were enrolled: 58 examined only supervised in the training period, and 100 patients were examined independently. The agreement in LVEF by the study method and reference was evaluated at the cut-off level LVEF< 50%: False positive rate 19,0 %, false negative rate 52,6%, sensitivity 47,4% (95% CI 27,3-68,3), specificity 81% (95% CI 73,1-87,0), Cohen´s Kappa value =0,22 (95% CI 0,03-0,40); i.e. low agreement wit the reference method. In patients with a false negative study examination, only 1/7 patients met full criteria of HF with reduced ejection fraction (LVEF<40%).>

Planned approach and implementation

A trial of focused cardiac ultrasound (FCU) performed by primary care physicians taking part in a FCU-training programme for evaluation of LVEF. Comprehensive cardiac ultrasound by specialized staff was used as reference. Six examiners taking part in the training programme conducted 20 individually supervised examinations, before commencing with independent examinations. Evaluation of LVEF was done by visual assessment and graded as normal (LVEF> 50%), reduced, or severely reduced (LVEF< 30%).