Long-term outcomes with ambrisentan monotherapy in pulmonary arterial hypertension

J Card Fail. 2010 Feb;16(2):121-7. doi: 10.1016/j.cardfail.2009.09.008. Epub 2009 Nov 20.


Background: This study evaluated long-term outcomes in patients with pulmonary arterial hypertension (PAH) undergoing treatment with ambrisentan monotherapy, a selective oral endothelin-1 receptor antagonist.

Methods and results: Patients who participated in the Ambrisentan in Pulmonary Arterial Hypertension: A Phase 3, Randomized, Double-Blind, Placebo-Controlled Multicenter Efficacy Study (ARIES-1) clinical trial and extension phase at our institution were included. Cardiac catheterization, 6-minute walk distance (6MWD), and cardiac magnetic resonance (MRI) data were retrospectively reviewed. Twelve patients with PAH (11 idiopathic, 1 fenfluramine) had follow-up from 3 to 5.5 years from the initiation of ARIES-1. Patients received ambrisentan therapy throughout the study period and were on ambrisentan monotherapy for the first 2 years. At year 1, improvements in median mean pulmonary arterial pressure (PA), cardiac output, and pulmonary vascular resistance (PVR) were seen (P = .02, P = .03, P < .01), and the improvement in PVR persisted at 2 years. 6MWD also improved significantly between baseline (350 m) and 1 and 2 years (397 m, P < .01 and 393 m, P = .01). Cardiac MRI results were more varied, with an increase in RV ejection fraction from 29% at baseline to 46% at 2 years (P = .02), but other MRI variables did not improve.

Conclusions: Ambrisentan monotherapy led to improvements in catheterization, 6MWD, and RV ejection fraction, and shows promise as a long-term treatment for pulmonary arterial hypertension.

Publication types

  • Clinical Trial, Phase III
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Double-Blind Method
  • Exercise Test / methods
  • Female
  • Follow-Up Studies
  • Humans
  • Hypertension, Pulmonary / drug therapy*
  • Hypertension, Pulmonary / mortality*
  • Hypertension, Pulmonary / physiopathology
  • Male
  • Middle Aged
  • Phenylpropionates / administration & dosage*
  • Pyridazines / administration & dosage*
  • Survival Rate / trends
  • Time Factors
  • Treatment Outcome
  • Young Adult


  • Phenylpropionates
  • Pyridazines
  • ambrisentan