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Updated: Aug 15, 2026

Catheter-based Endovascular Angioplasty for Fibrosing Mediastinitis-associated Pulmonary Vein Stenosis
Published on: August 26, 2025
Bosentan therapy for inoperable chronic thromboembolic pulmonary hypertension
Marius M Hoeper1, Thorsten Kramm, Heinrike Wilkens
1Department of Respiratory Medicine, Hannover Medical School, 30623 Hannover, Germany. hoeper.marius@mh-hannover.de
Study Objectives:
We performed an open-label multicenter study to evaluate the safety and efficacy of the dual endothelin receptor antagonist bosentan in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).
Patients:
Nineteen patients with inoperable CTEPH were enrolled.
Measurements:
The primary end point was a change in pulmonary vascular resistance (PVR). Secondary end points included 6-min walk test, peak oxygen uptake (V(O2)), New York Heart Association functional class, serum levels of N-terminal-pro brain natriuretic peptide (NT-pro-BNP), and various other hemodynamic parameters.
Results:
After 3 months of treatment with bosentan, PVR decreased from 914 +/- 329 to 611 +/- 220 dyne.s.cm(-5) (p < 0.001). Functional class and peak V(O2) remained unchanged, but 6-min walk distance increased from 340 +/- 102 to 413 +/- 130 m (p = 0.009), and serum NT-pro BNP levels improved from 2,895 +/- 2,620 to 2,179 +/- 2,301 (p = 0.027). One patient died, presumably from influenza A infection, and another patient experienced progressive fluid retention despite reduction of PVR. Other than that, treatment was well tolerated by all patients.
Conclusions:
This open-label pilot trial suggests that bosentan may offer a therapeutic option for patients with inoperable CTEPH. Randomized controlled trials are warranted to confirm these findings.
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