Assessment of LV ejection fraction using real-time 3D echocardiography in daily practice: direct comparison of the volumetric and speckle tracking methodologies to CMR

Aims This study is the first to directly compare two widely used real-time 3D echocardiography (RT3DE) methods of cardiac magnetic resonance imaging (CMR) and assess their reproducibility in experienced and less experienced observers. Methods Consecutive patients planned for CMR underwent RT3DE within 8 h of CMR with Philips (volumetric method) and Toshiba Artida (speckle tracking method). Left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were measured using RT3DE, by four trained observers, and compared with CMR values. Results Thirty-five patients were included (49.7+/-15.7 years; 55 % male), 30 (85.7 %) volumetric and 27 (77.1 %) speckle tracking datasets could be analysed. CMR derived LVEDV, LVESV and LVEF were 198+/-58 ml, 106+/-53 ml and 49+/-15 %, respectively. LVEF derived from speckle tracking was accurate and reproducible in all observers (all intra-class correlation coefficients (ICC)>0.86). LVEF derived from the volumetric method correlated well to CMR in experienced observers (ICC 0.85 and 0.86) but only moderately in less experienced observers (ICC 0.58 and 0.77) and was less reproducible in these observers (ICC=0.55). Volumes were significantly underestimated compared with CMR (p<0.001). Conclusion This study demonstrates that both RT3DE methodologies are sufficiently accurate and reproducible for use in daily practice. However, experience importantly influences the accuracy and reproducibility of the volumetric method, which should be considered when introducing this technique into clinical practice.