INTRODUCTION: Ambrisentan, a selective endothelin receptor antagonist has been approved in several countries for pulmonary arterial hypertension. No data have been published on the efficacy of ambrisentan on improvement of exercise capacity in patients with portopulmonary hypertension (PoPH).

PATIENTS AND METHODS: We retrospectively analyzed the safety and efficacy of ambrisentan in patients with PoPH in four German university hospitals.

RESULTS: 14 patients with moderate to severe PoPH were included. The median follow-up was 16 months (IQR, 12 - 21). 6 minute walk tests after 6 and 12 months improved from 376 meters (IQR, 207 - 440) at baseline to 415 meters (IQR, 393 - 475; p = 0.011) and 413 meters (IQR, 362 - 473, p = 0.005), respectively. WHO- functional class after 1 year of therapy with ambrisentan also improved significantly (p = 0.014). No significant changes in blood gas analysis and liver function tests (aspartate aminotransferase, alanine aminotransferase, total bilirubin, and international normalized ratio) during therapy with ambrisentan were detectable.

CONCLUSIONS: The present study demonstrates significant improvement of exercise capacity and clinical symptoms without relevant safety concerns during ambrisentan treatment in patients with PoPH.