title: Effects of the dual endothelin receptor antagonist bosentan in patients with pulmonary arterial hypertension: a 1-year follow-up study.
abstract: OBJECTIVE
  We report on the long-term safety and efficacy of bosentan treatment in patients with pulmonary arterial hypertension (PAH).
  
  
  BACKGROUND
  In a preceding study, bosentan was well tolerated and significantly improved the exercise capacity and hemodynamics of patients with PAH after 12 weeks of treatment.
  
  
  METHODS
  The present study was an open-label extension to the preceding double-blind, placebo-controlled study of 32 patients with PAH (primary or associated with scleroderma) who received bosentan or placebo at 125 mg bid for 3 to 7 months.
  
  
  METHODS
  Twenty-nine of the original 32 patients received bosentan for an additional year (62.5 mg bid for 4 weeks and then 125 mg bid).
  
  
  METHODS
  Study end points included long-term safety, 6-min walk distance at week 4, modified New York Heart Association (NYHA) functional class of PAH at month 12, and the occurrence of withdrawal due to clinical worsening. Additional exploratory analyses included a walk test at month 6 for 19 patients and hemodynamic assessment at month 12 for 11 patients.
  
  
  RESULTS
  At month 6, assessed patients continuing bosentan treatment maintained the improvement in walk distance observed at the end of the previous study (mean +/- SEM, 60 +/- 11 m), and patients starting bosentan treatment improved their walk distance by 45 +/- 13 m. Long-term treatment with bosentan for > 1 year was associated with an improvement in hemodynamic parameters and modified NYHA functional class. Overall, bosentan treatment was well tolerated. No patient underwent transplantation or died.
  
  
  CONCLUSIONS
  Long-term treatment with bosentan is safe and has sustained benefits on exercise capacity and hemodynamics in patients with PAH.
authors.affiliation: Service de Pneumologie Réanimation Respiratoire, Hôpital Antoine Béclère, 157, Avenue de la Porte Trivaux, F-92141 Clamart Cedex, France. olivier.sitbon@abc.ap-hop-paris.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Sitbon
authors.forename: David B
authors.initials: DB
authors.lastname: Badesch
authors.forename: Richard N
authors.initials: RN
authors.lastname: Channick
authors.forename: Adaani
authors.initials: A
authors.lastname: Frost
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Robbins
authors.forename: Gérald
authors.initials: G
authors.lastname: Simonneau
authors.forename: Victor F
authors.initials: VF
authors.lastname: Tapson
authors.forename: Lewis J
authors.initials: LJ
authors.lastname: Rubin
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D000077300:Bosentan; D004311:Double-Blind Method; D065128:Endothelin Receptor Antagonists; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D013449:Sulfonamides / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D065128:Endothelin Receptor Antagonists; D013449:Sulfonamides; D000077300:Bosentan