title: Developing pulmonary vasculopathy in systemic sclerosis, detected with non-invasive cardiopulmonary exercise testing.
abstract: BACKGROUND
  Patients with systemic sclerosis (SSc) may develop exercise intolerance due to musculoskeletal involvement, restrictive lung disease, left ventricular dysfunction, or pulmonary vasculopathy (PV). The latter is particularly important since it may lead to lethal pulmonary arterial hypertension (PAH). We hypothesized that abnormalities during cardiopulmonary exercise testing (CPET) in patients with SSc can identify PV leading to overt PAH.
  
  
  METHODS
  Thirty SSc patients from the Harbor-UCLA Rheumatology clinic, not clinically suspected of having significant pulmonary vascular disease, were referred for this prospective study. Resting pulmonary function and exercise gas exchange were assessed, including peakVO2, anaerobic threshold (AT), heart rate-VO2 relationship (O2-pulse), exercise breathing reserve and parameters of ventilation-perfusion mismatching, as evidenced by elevated ventilatory equivalent for CO2 (VE/VCO2) and reduced end-tidal pCO2 (PETCO2) at the AT.
  
  
  RESULTS
  Gas exchange patterns were abnormal in 16 pts with specific cardiopulmonary disease physiology: Eleven patients had findings consistent with PV, while five had findings consistent with left-ventricular dysfunction (LVD). Although both groups had low peak VO2 and AT, a higher VE/VCO2 at AT and decreasing PETCO2 during early exercise distinguished PV from LVD.
  
  
  CONCLUSIONS
  Previously undiagnosed exercise impairments due to LVD or PV were common in our SSc patients. Cardiopulmonary exercise testing may help to differentiate and detect these disorders early in patients with SSc.
authors.affiliation: Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Torrance, California, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Dumitrescu
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Oudiz
authors.forename: George
authors.initials: G
authors.lastname: Karpouzas
authors.forename: Arsen
authors.initials: A
authors.lastname: Hovanesyan
authors.forename: Amali
authors.initials: A
authors.lastname: Jayasinghe
authors.forename: James E
authors.initials: JE
authors.lastname: Hansen
authors.forename: Stephan
authors.initials: S
authors.lastname: Rosenkranz
authors.forename: Karlman
authors.initials: K
authors.lastname: Wasserman
mesh_terms: D000465:Algorithms; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000175:diagnosis; D008171:Lung Diseases / Q000150:complications*; D010100:Oxygen / Q000378:metabolism; D010477:Perfusion; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000473:pathology; D011659:Pulmonary Gas Exchange; D015272:Pulmonary Medicine / Q000379:methods*; D012129:Respiratory Function Tests; D012595:Scleroderma, Systemic / Q000150:complications*; D014652:Vascular Diseases / Q000150:complications*
chemical_list: D010100:Oxygen