Bosentan treatment in chronic pulmonary venous hypertension with significant right heart dysfunction

Background: Pulmonary venous hypertension (PVH) is very common. The mechanism of PVH is still under discussion and might constitute a 'hyperactive' form of pulmonary vascular remodelling which leads to an inappropriate increase in pulmonary vascular resistance and subsequent significant right heart dysfunction. According to current opinion, the oral dual endothelin (ETA/ETB) antagonist bosentan is not indicated for PVH. We investigated prospectively bosentan in two patients with postcapillary venous hypertension (PVH) to resolve right heart failure. Methods: One patient presented with high-grade aortic stenosis, judged inoperable due to severe congestive liver, pancreatic and bowel disease; the other had a mitral valve replacement 14 years ago. Invasive evaluation of reversibility of pulmonary hypertension with intravenous epoprostenol was performed, and subsequently a test administration of bosentan was given to exclude a significant increase in left ventricular filling pressure. Thereafter bosentan therapy twice daily was administered. Clinical and echocardiographic follow-up was for 5 months. Results: In patient 1, PVH decreased dramatically over 5 months of bosentan treatment. 6-minute walk distance improved from 225 to 525 meters. In patient 2 right ventricular pressure decreased from 60 to 40 mmHg + right atrial pressure (echocardiographic measurements) and his 6-minute walk distance increased from 242 m to 477 m during follow-up of 5 months. Conclusion: Bosentan might lead to improvement in patients with PVH. Invasive haemodynamic testing to confirm pulmonary reagibility and exclude increasing pulmonary capillary wedge pressure is warranted before administration of bosentan.