Comparative Reproducibility of Myocardial Work and Left Ventricular Ejection Fraction in Patients After an Acute Coronary Syndrome

To assess reproducibility (interobserver variability and agreement) of global work efficiency (GWE) and left ventricular ejection fraction (LVEF), assessed by 2D-echocardiography (2-DE) and 3D-echocardiography (3-DE), in patients with acute coronary syndrome (ACS), through measurements performed by operators with different levels of experience. Echocardiographers with three levels of experience were involved in offline processing: advanced, who performed image acquisition-Reader 1 (5 years of training in 2-DE, 3 years in 3-DE); intermediate-Reader 2 (3 years of training in 2-DE, 1 year in 3-DE); and beginner-Reader 3 (1 year of training in 2-DE, 3 months in 3-DE). Measurements of GWE and LVEF were performed independently. Intraobserver and interobserver variability and agreement between readers were compared using Bland-Altman plots, as bias and limits of agreement (LOA), and Pearson correlations. 90 patients (54 ± 9 years, 75 males) with ACS were analyzed. Comparing measurements of GWE, the following bias and LOA were obtained: R1 versus R2: bias -0.6, LOA -3-2 (r = 0.98, p < 0.001); R2 versus R3: bias -0.3, LOA -3-5 (r = 0.96, p < 0.001); R1 versus R3: bias -1, LOA -5-4 (r = 0.94, p < 0.001). Interobserver variability and agreement of GWE were comparable with LVEF by 3-DE: R1 versus R2: bias 0.6, -2, and -1.4; LOA -3-4, -7-4, and -6-4, respectively (r = 0.96, 0.91, and 0.94, respectively, all p < 0.001); however, for LVEF by 2-DE, interobserver variability was higher, while agreement was lower. Reproducibility of GWE in patients after an ACS is independent of the experience of the operator and similar to the reproducibility of LVEF by 3-DE.