Vendor Differences in 2D-Speckle Tracking Global Longitudinal Strain: An Update on a Ten-Year Standardization Effort.

Aims: To assess the inter-vendor differences in global longitudinal strain measurements and determine a potential improvement compared to the situation 10 years ago.

Methods and results: 372 echocardiographic exams were performed in 62 subjects (50 male, age 56 ± 17) with LV ejection fraction ranging from 30% to 68%, using ultrasound systems from six manufacturers: GE, Philips, Canon, Siemens, Fujifilm and Esaote. Each subject was scanned consecutively on all machines by the same assigned sonographer, with two image sets per subject to assess test-retest setting reproducibility. Average peak systolic global strain from the three apical views (GLSAV) was measured on three vendor-specific (Canon, Siemens and Fujifilm) and six vendor-agnostic (GE, Philips, US2.AI, Caas Qardia, Medis and Epsilon) software solutions (SWS). Endocardial and mid-/full-wall GLS were measured and compared to the mean GLS of contemporary semi-automated clinical software: GE, Philips, Canon, Fujifilm, and Caas Qardia.Endocardial and mid-/full-wall GLS measurements from contemporary semi-automated clinical software showed minimal inter-vendor differences, with an average maximum bias of 0.6% strain units. There was a remaining inter-vendor bias with and among some other vendors.The average minimal detectable change with contemporary semi-automated clinical software was 2.5 and 2.4 strain% for endocardial and mid-/full-wall GLS, resp. These values were higher for and among some other vendors.Test-retest variability of GLS measurements was good and similar to that of LV ejection fraction (6.6% vs. 6.5%, p > .05), indicating consistent results across repeated scans.

Conclusion: In this controlled study setting, GLS measurements from companies that provide contemporary semi-automated clinical software have become more consistent, compared to ten years ago. Mid-/full-wall strain was now available in all but one software.