title: Segmental Aortic Stiffness in Children and Young Adults With Connective Tissue Disorders: Relationships With Age, Aortic Size, Rate of Dilation, and Surgical Root Replacement.
abstract: BACKGROUND
  Aortic diameter is an imperfect predictor of aortic complications in connective tissue disorders (CTDs). Novel indicators of vascular phenotype severity such as aortic stiffness and vertebral tortuosity index have been proposed. We assessed the relation between aortic stiffness by cardiac MRI, surgical root replacement, and rates of aortic root dilation in children and young adults with CTDs.
  
  
  RESULTS
  Retrospective analysis of cardiac MRI data on children and young adults with a CTD was performed to derive aortic stiffness measures (strain, distensibility, and β-stiffness index) at the aortic root, ascending aorta, and descending aorta. Vertebral tortuosity index was calculated as previously described. Rate of aortic root dilation before cardiac MRI was calculated as change in echocardiographic aortic root diameter z score per year. In 83 CTD patients (median age, 24 years; range, 1-55; 17% <18 years of age; 60% male), ascending aorta distensibility was reduced in comparison with published normative values: median z score, -1.93 (range, -8.7 to 1.3; P<0.0001 versus normals). Over a median follow-up period of 2.7 years, there were no aortic dissections or deaths, but 16 of 83 (19%) patients underwent surgical aortic root replacement. In multivariable analysis, lower aortic root strain (P=0.05) and higher vertebral tortuosity index (P=0.01) were independently associated with aortic root replacement. Lower ascending aorta strain (P=0.02) was associated with a higher rate of aortic root dilation.
  
  
  CONCLUSIONS
  Higher aortic stiffness is associated with higher rates of surgical aortic replacement and aortic root dilation in children and young adults with CTDs.
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.). ashwin.prakash@cardio.chboston.org.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Prakash
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Himanshu
authors.initials: H
authors.lastname: Adlakha
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Nicole
authors.initials: N
authors.lastname: Rabideau
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Cara J
authors.initials: CJ
authors.lastname: Hass
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Shaine A
authors.initials: SA
authors.lastname: Morris
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Tal
authors.initials: T
authors.lastname: Geva
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Kimberlee
authors.initials: K
authors.lastname: Gauvreau
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Michael N
authors.initials: MN
authors.lastname: Singh
authors.affiliation: From Department of Cardiology, Boston Children's Hospital, MA (A.P., H.A., N.R., C.J.H., S.A.M., T.G., K.G., M.N.S., R.V.L); and Department of Pediatrics, Harvard Medical School, Boston, MA (A.P., T.G., M.N.S., R.V.L.).
authors.forename: Ronald V
authors.initials: RV
authors.lastname: Lacro
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001011:Aorta / Q000473:pathology* / Q000601:surgery; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003240:Connective Tissue Diseases / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D018810:Magnetic Resonance Angiography; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D059289:Vascular Stiffness / Q000502:physiology*; D055815:Young Adult
keywords: aortic dilation; aortic replacement; cardiac MRI; connective tissue diseases; vascular stiffness