title: Duration of right ventricular contraction predicts the efficacy of bosentan treatment in patients with pulmonary hypertension.
abstract: OBJECTIVE
  In patients with pulmonary hypertension (PH), elevated endothelin-1 levels are associated with prolonged duration of right ventricular (RV) contraction, which induces leftward ventricular septal bowing with impaired left diastolic filling. We hypothesized that baseline RV contraction duration predicts efficacy of endothelin receptor antagonist, bosentan.
  
  
  RESULTS
  Eighteen PH patients (age 57, range 35-79 years, 33% male) received bosentan. Six minute walk distance (6-MWD) and echocardiography were performed at baseline and after 1 year follow-up. After 1 year of treatment, 6-MWD increased (mean 60 +/- 41 m) in 67% of patients (responders). Baseline RV contraction duration was longer in responders, compared with non-responders (612 +/- 66 vs. 514 +/- 23 ms; P < 0.01). A baseline RV contraction duration >550 ms was associated with improved 6-MWD (sensitivity 83%, specificity 83%; P < 0.01).
  
  
  CONCLUSIONS
  An improvement of 6-MWD during bosentan treatment was associated with a decrease in RV contraction duration and could be predicted by a baseline RV contraction duration >550 ms.
authors.affiliation: Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Mariëlle G J
authors.initials: MG
authors.lastname: Duffels
authors.forename: Maxim
authors.initials: M
authors.lastname: Hardziyenka
authors.forename: Sulaiman
authors.initials: S
authors.lastname: Surie
authors.forename: Rianne H A C M
authors.initials: RH
authors.lastname: de Bruin-Bon
authors.forename: Elke S
authors.initials: ES
authors.lastname: Hoendermis
authors.forename: Arie P J
authors.initials: AP
authors.lastname: van Dijk
authors.forename: Berto J
authors.initials: BJ
authors.lastname: Bouma
authors.forename: Hanno L
authors.initials: HL
authors.lastname: Tan
authors.forename: Rolf M F
authors.initials: RM
authors.lastname: Berger
authors.forename: Paul
authors.initials: P
authors.lastname: Bresser
authors.forename: Barbara J M
authors.initials: BJ
authors.lastname: Mulder
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D000077300:Bosentan; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D012189:Retrospective Studies; D013449:Sulfonamides / Q000627:therapeutic use*; D016896:Treatment Outcome; D014463:Ultrasonography; D016278:Ventricular Function, Right / Q000187:drug effects*; D016138:Walking
chemical_list: D000959:Antihypertensive Agents; D013449:Sulfonamides; D000077300:Bosentan