title: Beneficial Outcome of Losartan Therapy Depends on Type of FBN1 Mutation in Marfan Syndrome.
abstract: BACKGROUND
  It has been shown that losartan reduces aortic dilatation in patients with Marfan syndrome. However, treatment response is highly variable. This study investigates losartan effectiveness in genetically classified subgroups.
  
  
  RESULTS
  In this predefined substudy of COMPARE, Marfan patients were randomized to daily receive losartan 100 mg or no losartan. Aortic root dimensions were measured by MRI at baseline and after 3 years. FBN1 mutations were classified based on fibrillin-1 protein effect into (1) haploinsufficiency, decreased amount of normal fibrillin-1, or (2) dominant negative, normal fibrillin-1 abundance with mutant fibrillin-1 incorporated in the matrix. A pathogenic FBN1 mutation was found in 117 patients, of whom 79 patients were positive for a dominant negative mutation (67.5%) and 38 for a mutation causing haploinsufficiency (32.5%). Baseline characteristics between treatment groups were similar. Overall, losartan significantly reduced aortic root dilatation rate (no losartan, 1.3±1.5 mm/3 years, n=59 versus losartan, 0.8±1.4 mm/3 years, n=58; P=0.009). However, losartan reduced only aortic root dilatation rate in haploinsufficient patients (no losartan, 1.8±1.5 mm/3 years, n=21 versus losartan 0.5±0.8 mm/3 years, n=17; P=0.001) and not in dominant negative patients (no losartan, 1.2±1.7 mm/3 years, n=38 versus losartan 0.8±1.3 mm/3 years, n=41; P=0.197).
  
  
  CONCLUSIONS
  Marfan patients with haploinsufficient FBN1 mutations seem to be more responsive to losartan therapy for inhibition of aortic root dilatation rate compared with dominant negative patients. Additional treatment strategies are needed in Marfan patients with dominant negative FBN1 mutations.
  
  
  BACKGROUND
  http://www.trialregister.nl/trialreg/index.asp; Unique Identifier: NTR1423.
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Romy
authors.initials: R
authors.lastname: Franken
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Alexander W
authors.initials: AW
authors.lastname: den Hartog
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Teodora
authors.initials: T
authors.lastname: Radonic
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Dimitra
authors.initials: D
authors.lastname: Micha
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Alessandra
authors.initials: A
authors.lastname: Maugeri
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Fleur S
authors.initials: FS
authors.lastname: van Dijk
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Hanne E
authors.initials: HE
authors.lastname: Meijers-Heijboer
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Janneke
authors.initials: J
authors.lastname: Timmermans
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Scholte
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Maarten P
authors.initials: MP
authors.lastname: van den Berg
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Maarten
authors.initials: M
authors.lastname: Groenink
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Barbara J M
authors.initials: BJ
authors.lastname: Mulder
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Aeilko H
authors.initials: AH
authors.lastname: Zwinderman
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.).
authors.forename: Vivian
authors.initials: V
authors.lastname: de Waard
authors.affiliation: From the Departments of Cardiology (R.F., A.W.d.H., M.G., B.J.M.M.), Radiology (M.G.), Clinical Epidemiology and Biostatistics (A.H.Z.), and Medical Biochemistry (V.d.W.), Academic Medical Center Amsterdam, Amsterdam; Interuniversity Cardiology Institute of the Netherlands, Utrecht (R.F., A.W.d.H., M.G., B.J.M.M.); Departments of Pathology (T.R.) and Clinical Genetics (D.M., A.M., F.S.v.D., H.E.M.-H., G.P.), VU University Medical Center, Amsterdam; Department of Cardiology, Radboud University Nijmegen Medical Center, Nijmegen (J.T.); Department of Cardiology, Leiden University Medical Center, Leiden (A.J.S.); and Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands (M.P.v.d.B.). g.pals@vumc.nl.
authors.forename: Gerard
authors.initials: G
authors.lastname: Pals
mesh_terms: D000328:Adult; D005260:Female; D000071838:Fibrillin-1; D000071837:Fibrillins; D005799:Genes, Dominant; D057895:Haploinsufficiency; D006801:Humans; D019808:Losartan / Q000008:administration & dosage*; D008297:Male; D008382:Marfan Syndrome / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D008840:Microfilament Proteins; D008875:Middle Aged; D054392:Adipokines
chemical_list: D000071838:Fibrillin-1; D000071837:Fibrillins; D019808:Losartan; D008840:Microfilament Proteins; C000605722:FBN1 protein, human; D054392:Adipokines
keywords: FBN1 mutation; Losartan; MRI; Marfan syndrome; aneurysm; aortic root; heterogeneity