title: Echocardiographic methods, quality review, and measurement accuracy in a randomized multicenter clinical trial of Marfan syndrome.
abstract: BACKGROUND
  The Pediatric Heart Network is conducting a large international randomized trial to compare aortic root growth and other cardiovascular outcomes in 608 subjects with Marfan syndrome randomized to receive atenolol or losartan for 3 years. The authors report here the echocardiographic methods and baseline echocardiographic characteristics of the randomized subjects, describe the interobserver agreement of aortic measurements, and identify factors influencing agreement.
  
  
  METHODS
  Individuals aged 6 months to 25 years who met the original Ghent criteria and had body surface area-adjusted maximum aortic root diameter (ROOTmax) Z scores > 3 were eligible for inclusion. The primary outcome measure for the trial is the change over time in ROOTmaxZ score. A detailed echocardiographic protocol was established and implemented across 22 centers, with an extensive training and quality review process.
  
  
  RESULTS
  Interobserver agreement for the aortic measurements was excellent, with intraclass correlation coefficients ranging from 0.921 to 0.989. Lower interobserver percentage error in ROOTmax measurements was independently associated (model R(2) = 0.15) with better image quality (P = .002) and later study reading date (P < .001). Echocardiographic characteristics of the randomized subjects did not differ by treatment arm. Subjects with ROOTmaxZ scores ≥ 4.5 (36%) were more likely to have mitral valve prolapse and dilation of the main pulmonary artery and left ventricle, but there were no differences in aortic regurgitation, aortic stiffness indices, mitral regurgitation, or left ventricular function compared with subjects with ROOTmaxZ scores < 4.5.
  
  
  CONCLUSIONS
  The echocardiographic methodology, training, and quality review process resulted in a robust evaluation of aortic root dimensions, with excellent reproducibility.
authors.affiliation: Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA. tierneys@stanford.edu
authors.forename: Elif Seda
authors.initials: ES
authors.lastname: Selamet Tierney
authors.forename: Jami C
authors.initials: JC
authors.lastname: Levine
authors.forename: Shan
authors.initials: S
authors.lastname: Chen
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Bradley
authors.forename: Gail D
authors.initials: GD
authors.lastname: Pearson
authors.forename: Steven D
authors.initials: SD
authors.lastname: Colan
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Sleeper
authors.forename: M Jay
authors.initials: MJ
authors.lastname: Campbell
authors.forename: Meryl S
authors.initials: MS
authors.lastname: Cohen
authors.forename: Julie
authors.initials: J
authors.lastname: De Backer
authors.forename: Lin T
authors.initials: LT
authors.lastname: Guey
authors.forename: Haleh
authors.initials: H
authors.lastname: Heydarian
authors.forename: Wyman W
authors.initials: WW
authors.lastname: Lai
authors.forename: Mark B
authors.initials: MB
authors.lastname: Lewin
authors.forename: Edward
authors.initials: E
authors.lastname: Marcus
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Mart
authors.forename: Ricardo H
authors.initials: RH
authors.lastname: Pignatelli
authors.forename: Beth F
authors.initials: BF
authors.lastname: Printz
authors.forename: Angela M
authors.initials: AM
authors.lastname: Sharkey
authors.forename: Girish S
authors.initials: GS
authors.lastname: Shirali
authors.forename: Shubhika
authors.initials: S
authors.lastname: Srivastava
authors.forename: Ronald V
authors.initials: RV
authors.lastname: Lacro
mesh_terms: D000293:Adolescent; D058671:Adrenergic beta-1 Receptor Antagonists / Q000627:therapeutic use; D000328:Adult; D000704:Analysis of Variance; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy; D001262:Atenolol / Q000627:therapeutic use; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D019808:Losartan / Q000627:therapeutic use; D008297:Male; D008382:Marfan Syndrome / Q000000981:diagnostic imaging* / Q000188:drug therapy; D015203:Reproducibility of Results
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D047228:Angiotensin II Type 1 Receptor Blockers; D001262:Atenolol; D019808:Losartan