title: Longitudinal assessment of right ventricular myocardial strain in relation to transplant-free survival in children with idiopathic pulmonary hypertension.
abstract: BACKGROUND
  Right ventricular (RV) function is an important determinant of mortality in patients with idiopathic pulmonary arterial hypertension (iPAH). The aim of this study was to serially evaluate global and regional RV two-dimensional strain and their relation to transplantation-free survival in children with iPAH.
  
  
  METHODS
  RV regional and global longitudinal strain was retrospectively assessed in children with iPAH. Serial echocardiograms at 3 to 6 months from presentation and then at yearly intervals were analyzed. Results were compared with those from controls and between iPAH survivors (group 1) and those who died or needed transplantation (group 2). Survival stratified by RV global longitudinal strain at presentation was analyzed.
  
  
  RESULTS
  Seventeen patients with iPAH (mean age, 8.4 ± 4.8 years; seven male patients), of whom 11 were alive (group 1) and six had died or undergone transplantation (group 2), and 17 age-matched controls were studied. The median follow-up period was 1.5 years (range, 0.04-7.8 years). RV global longitudinal strain was significantly reduced in patients with iPAH compared with controls (-13.5 ± 5.9% vs -24.4 ± 3.9%, P < .001) and in group 2 compared with group 1 at presentation (-9 ± 2.8% vs -16 ± 5.7%, P < .05) and throughout follow-up. During follow-up, RV global and regional longitudinal strain worsened in group 2, especially in RV apical segments (-6.3 ± 5% vs -1.9 ± 1.6% at presentation compared with the last echocardiographic assessment in group 2, P < .05), but was unchanged in group 1. RV global longitudinal strain > -14% predicted transplantation-free survival with 100% sensitivity and 54.5% specificity.
  
  
  CONCLUSIONS
  RV strain imaging may be useful for serial follow-up and prognostication in children with iPAH.
authors.affiliation: The Labatt Family Heart Center, Division of Cardiology, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Okumura
authors.affiliation: The Labatt Family Heart Center, Division of Cardiology, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tilman
authors.initials: T
authors.lastname: Humpl
authors.affiliation: The Labatt Family Heart Center, Division of Cardiology, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andreea
authors.initials: A
authors.lastname: Dragulescu
authors.affiliation: The Labatt Family Heart Center, Division of Cardiology, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Mertens
authors.affiliation: The Labatt Family Heart Center, Division of Cardiology, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada. Electronic address: mark.friedberg@sickkids.ca.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Friedberg
mesh_terms: D002648:Child; D018572:Disease-Free Survival; D004452:Echocardiography / Q000379:methods; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods; D065627:Familial Primary Pulmonary Hypertension / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D016027:Heart Transplantation / Q000401:mortality; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D033081:Shear Strength; D013314:Stress, Mechanical; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000601:surgery
keywords: Echocardiography; Idiopathic pulmonary hypertension; Right ventricular performance; Strain echocardiography