title: Global longitudinal strain software upgrade: Implications for intervendor consistency and longitudinal imaging studies.
abstract: BACKGROUND
  Speckle tracking can be used to measure left ventricular global longitudinal strain (GLS).
  
  
  OBJECTIVE
  To study the effect of speckle tracking software product upgrades on GLS values and intervendor consistency.
  
  
  METHODS
  Subjects (patients or healthy volunteers) underwent systematic echocardiography with equipment from Philips and GE, without a change in their position. Off-line post-processing for GLS assessment was performed with the former and most recent upgrades from these two vendors (Philips QLAB 9.0 and 10.2; GE EchoPAC 12.1 and 13.1.1). GLS was obtained in three myocardial layers with EchoPAC 13.1.1. Intersoftware and intervendor consistency was assessed. Interobserver variability was tested in a subset of patients.
  
  
  RESULTS
  Among 73 subjects (65 patients and 8 healthy volunteers), absolute values of GLS were higher with QLAB 10.2 compared with 9.0 (intraclass correlation coefficient [ICC]: 0.88; bias: 2.2%). Agreement between EchoPAC 13.1.1 and 12.1 varied by myocardial layer (13.1.1 only): midwall (ICC: 0.95; bias: -1.1%), endocardium (ICC: 0.93; bias: 1.6%) and epicardial (ICC: 0.80; bias: -3.3%). Although GLS was comparable for QLAB 9.0 versus EchoPAC 12.1 (ICC: 0.95; bias: 0.5%), the agreement was lower between QLAB 10.2 and EchoPAC 13.1.1 endocardial (ICC: 0.91; bias: 1.1%), midwall (ICC: 0.73; bias: 3.9%) and epicardial (ICC: 0.54; bias: 6.0%). Interobserver variability of all software products in a subset of 20 patients was excellent (ICC: 0.97-0.99; bias: -0.8 to 1.0%).
  
  
  CONCLUSIONS
  Upgrades of speckle tracking software may be associated with significant changes in GLS values, which could affect intersoftware and intervendor consistency. This finding has important clinical implications for the longitudinal follow-up of patients with speckle tracking echocardiography.
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Castel
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France; Inserm U 1088, université de Picardie, Amiens, France.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Menet
authors.affiliation: Centre hospitalier universitaire de Grenoble, Grenoble, France.
authors.forename: Pierre-Vladimir
authors.initials: PV
authors.lastname: Ennezat
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France.
authors.forename: François
authors.initials: F
authors.lastname: Delelis
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Le Goffic
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Binda
authors.affiliation: Centre hospitalier universitaire de Grenoble, Grenoble, France.
authors.forename: Raphaëlle-Ashley
authors.initials: RA
authors.lastname: Guerbaai
authors.affiliation: Centre cardiothoracique, Monaco, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Levy
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Graux
authors.affiliation: Inserm U 1088, université de Picardie, Amiens, France; Centre hospitalier universitaire d'Amiens, Amiens, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Tribouilloy
authors.affiliation: Université Lille Nord de France, GCS - Groupement des hôpitaux, institut catholique de Lille, faculté libre de médecine, université catholique de Lille, Lille, France; Inserm U 1088, université de Picardie, Amiens, France. Electronic address: sylvestre.marechaux@yahoo.fr.
authors.forename: Sylvestre
authors.initials: S
authors.lastname: Maréchaux
mesh_terms: D000368:Aged; D001331:Automation; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012984:Software; D013314:Stress, Mechanical; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left; D057188:Workflow
keywords: Echocardiography; Longitudinal strain; Speckle tracking; Strain longitudinal; Échocardiographie