Bosentan and Pulmonary Endothelial Function

Pulmonary Artery Remodelling With Bosentan

6 months therapy of Bosentan, an endothelin antagonist, will lead to improvement in pulmonary microvascular endothelial function.

Inclusion Criteria:

• Pulmonary arterial hypertension; idiopathic and connective tissue disease associated
• Confirmed or invasive haemodynamic:
• Mean pulmonary arterial pressure greater than or equal to 25 millimeters of mercury
• Pulmonary capillary wedge pressure less than 15 millimeters of mercury
• No prior pulmonary hypertension specific therapy
• Ability to provide informed consent

Exclusion Criteria:

• Contra-indications to medications used to test endothelial function; acetylcholine, sodium nitroprusside, NG-Monomethyl-L-Arginine, L-arginine
• Advanced renal disease
• Previous allergic reaction to contrast agents