title: Pulmonary arterial hypertension in systemic sclerosis is associated with profound impairment of microvascular endothelium-dependent vasodilatation.
abstract: OBJECTIVE
  Impaired microvascular function may contribute to organ complications in patients with systemic sclerosis (SSc). We investigated whether SSc patients with and without pulmonary arterial hypertension (PAH) show a graded impairment of microvascular function compared to healthy controls.
  
  
  METHODS
  Twenty-two patients with SSc and 22 controls were studied. All patients underwent right heart catheterization; 6 had no PAH (SSc-nonPAH) and 16 had PAH (SSc-PAH). Acetylcholine (ACh)-mediated endothelium-dependent vasodilatation and sodium nitroprusside (SNP)-mediated endothelium-independent vasodilatation were assessed by iontophoresis combined with laser Doppler flowmetry.
  
  
  RESULTS
  Compared to sex- and age-matched controls, ACh-mediated vasodilatation was reduced in SSc-PAH (340.4% vs 79.5%, respectively; p < 0.01), but not in SSc-nonPAH (340.4% vs 397.9%; p = 0.90). No significant differences were present between the groups in SNP-mediated vasodilatation.
  
  
  CONCLUSIONS
  Systemic microvascular endothelium-dependent vasodilatation is markedly reduced in SSc complicated by PAH.
authors.affiliation: Department of Internal Medicine, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands. hma.hofstee@vumc.nl
authors.forename: Herman M A
authors.initials: HM
authors.lastname: Hofstee
authors.forename: Alexandre E
authors.initials: AE
authors.lastname: Voskuyl
authors.forename: Anton
authors.initials: A
authors.lastname: Vonk Noordegraaf
authors.forename: Yvo M
authors.initials: YM
authors.lastname: Smulders
authors.forename: Piet E
authors.initials: PE
authors.lastname: Postmus
authors.forename: Ben A C
authors.initials: BA
authors.lastname: Dijkmans
authors.forename: Erik H
authors.initials: EH
authors.lastname: Serné
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry; D008833:Microcirculation / Q000187:drug effects* / Q000502:physiology; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D012595:Scleroderma, Systemic / Q000503:physiopathology*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine