Vendor differences in 2D-speckle tracking global longitudinal strain: an update on a 10-year standardization effort

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

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 (GLS_AV) 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 with 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 > 0.05), indicating consistent results across repeated scans.

In this controlled study setting, GLS measurements from companies that provide contemporary semi-automated clinical software have become more consistent, compared with 10 years ago. Mid-/full-wall strain was now available in all but one software.