Agreement of two vendor-independent strain analysis software platforms in assessing left ventricular global longitudinal strain.

Purpose: The new version of EchoPAC platform was recently developed by General Electronics (GE) to provide 'vendor-independent' full-myocardial-layer left ventricular (LV) global longitudinal strain (LV-GLS). The agreement of the LV-GLS by two vendor-independent software platforms was investigated under diverse clinical situations.

Methods: Two-dimensional speckle-tracking LV-GLS was separately measured by two software platforms. LV-GLS values were compared as default setting of each software platform (GE full-myocardial-layer [GE-Full], and TomTec endocardial-layer [TomTec-Endo]). Agreements according to various conditions and type of echocardiography vendors were evaluated using Bland-Altman analysis and intraclass correlation coefficients (ICC). Inter-observer reproducibility of each software platform was assessed, and agreements were further evaluated in various subgroups.

Results: One hundred five subjects were initial candidates for the current study (normal LV function without any cardiac pathology [n = 25], hypertrophic cardiomyopathy [n = 40], dilated cardiomyopathy [n = 25], or restrictive cardiomyopathy [n = 15]). After excluding seven subjects with inadequate tracking quality, 98 subjects were finally analyzed. The average LV-GLS was lower in GE-Full than in TomTec-Endo. Agreement between GE-Full and TomTec-Endo was excellent in general; while the greatest bias was observed in the hypertrophic cardiomyopathy group, with TomTec-Endo exhibiting greater LV-GLS values than GE-Full (bias -1.71, limits of agreement -6.02 to 2.59). Both platforms showed excellent inter-observer reproducibility (GE-Full, ICC 0.99; TomTec-Endo, ICC 0.91), and were in good agreements regardless of the echocardiography vendors or subgroups according to age, heart rate, myocardial wall thickness, or LV ejection fraction.

Conclusions: LV-GLS by GE-Full showed excellent agreement with that by TomTec-Endo under various cardiac conditions.