The purpose of this study was to investigate intervendor variability when measuring multilayer strain in cancer patients treated with oral chemotherapy. Patients enrolled to receive oral chemotherapy were prospectively included. Firstly, a same operator performed a 2 dimensional echocardiography within a delay of 10 minutes using Vivid 9 (Vendor A) and SC 2000 Siemens (Vendor B) ultrasound systems for each patient. Thereafter, we assessed myocardial deformation by using their respective speckle tracking softwares for strain multilayer measurement. Thus, we compared GLS multilayer values for the 2 vendors in each apical view (4c, 3c and 2c) and for each layer (endocardial, mid and epicardial layer). Comparisons between the 2 vendors were evaluated using intra class correlation coefficient. Eighty patients planned to receive chemotherapy were prospectively included between February and June 2015. Mean age was 55.3±16.3 years and 61% were female. Median left ventricular ejection fraction was 62% (57-66). Results of GLS multilayer values according to vendor, incidence, layer and their comparison are summarized in Table 1 There was a poor agreement between GLS multilayer as measured with GE system and Siemens system, whatever the layers, the incidence and the vendor. We found a poor agreement for layer specific strain evaluation between GE and Siemens system using their dedicated softwares for strain multilayer assessment. These results suggest that in patient receiving chemotherapy the same system and software from the same vendor should be used for a longitudinal follow-up. The author hereby declares no conflict of interest Table Values of GLS according to vendor, layer and views Vendor A Vendor B ICC±SD 4c GLS endo 20.7 (18.5-23.5) 18.8 (17.1-21.0) 0.315±0.089 4c GLS mid 18.2 (16.1-20.5) 15.5 (13.6-17.2) 0.222±0.075 4c GLS epi 15.9 (14.1-17.9) 11.8 (10.6-14.2) 0.125±0.055 3c GLS endo 22.2 (19.8-25.7) 18.5 (16.6-21.4) 0.310±0.078 3c GLS mid 19.2 (17.3-22.3) 15.1 (13.6-17.5) 0.291±0.061 3c GLS epi 16.9 (15.2-14.2) 12.0 (9.6-13.5) 0.189±0.045 2c GLS endo 21.7 (19.0-24.1) 18.0 (16.7-20.9) 0.234±0.075 2c GLS mid 19.3 (17.0-21.8) 15.3 (13.2-17.1) 0.180±0.057 2c GLS epi 17.3 (15.1-19.4) 12.0 (10.3-14.0) 0.042±0.040 GLS: Global longitudinal strain, 4c: 4 chamber view, 3c: 3 chamber view, 2c: 2 chamber view, endo: endocardial layer, mid: mid layer, epi: epicardial layer, ICC: intraclass correlation coefficient, SD: Standard deviation.