title: Conversion to bosentan from prostacyclin infusion therapy in pulmonary arterial hypertension: a pilot study.
abstract: OBJECTIVE
  We assessed the efficacy of bosentan in transitioning from prostacyclin infusions in patients with pulmonary arterial hypertension (PAH).
  
  
  METHODS
  Twenty-two PAH patients were recruited from five PAH centers if they had been clinically stable while receiving therapy with IV epoprostenol or subcutaneous treprostinil for at least 3 months. Patients were observed in an open-label prospective trial while bosentan was added to therapy, and then epoprostenol or treprostinil were tapered after 2 months.
  
  
  RESULTS
  Ten of the 22 patients were transitioned off prostacyclin infusion therapy after a mean (+/- SEM) duration of 6.1 +/- 1.2 months. Of those patients, seven patients have continued not receiving prostacyclin infusion therapy for a mean duration of 17.7 +/- 5.3 months, with no significant changes in pulmonary artery (PA) pressure estimated by echocardiography, World Health Organization (WHO)/New York Heart Association (NYHA) functional class, 6-min walk distance (6MWD), or Borg dyspnea score. The conditions of three patients deteriorated, necessitating the resumption of prostacyclin therapy, and two patients subsequently died. Twelve patients failed to transition or even lower the prostacylin infusion rate and had worsening of their WHO/NYHA functional class and estimated systolic PA pressures, and had a trend toward deterioration in their mean 6MWD (294 +/- 41 to 198 +/- 34 m, respectively; p = 0.2). Of these, two patients subsequently died. The baseline characteristics of those who transitioned successfully vs those who transitioned unsuccessfully were a lower prostacyclin infusion rate, and less severe elevations in the mean and estimated systolic PA pressures.
  
  
  CONCLUSIONS
  Transitioning from therapy with prostacyclin to bosentan is possible in some PAH patients, mainly in those receiving lower prostacyclin doses and having less pulmonary hypertension at baseline. Careful patient selection and close interim monitoring is needed because the conditions of patients can deteriorate, and they may not respond to the resumption of therapy with prostacyclin.
authors.affiliation: Tufts-New England Medical Center, Boston, MA, USA. ksteiner@partners.org
authors.forename: M Kathryn
authors.initials: MK
authors.lastname: Steiner
authors.forename: Ioana R
authors.initials: IR
authors.lastname: Preston
authors.forename: James R
authors.initials: JR
authors.lastname: Klinger
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Criner
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Waxman
authors.forename: Harrison W
authors.initials: HW
authors.lastname: Farber
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Hill
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D000077300:Bosentan; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D007262:Infusions, Intravenous; D008168:Lung / Q000098:blood supply / Q000187:drug effects / Q000503:physiopathology; D008875:Middle Aged; D010807:Physical Endurance / Q000187:drug effects / Q000502:physiology; D010865:Pilot Projects; D012720:Severity of Illness Index; D013449:Sulfonamides / Q000009:adverse effects / Q000627:therapeutic use*; D016138:Walking / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents; D013449:Sulfonamides; D011464:Epoprostenol; D000077300:Bosentan; C427248:treprostinil