Study Evaluating the Addition of Sildenafil to Bosentan Therapy in Pulmonary Arterial Hypertension

Addition of Sildenafil to Bosentan Monotherapy in Patients With Pulmonary Arterial Hypertension (PAH)

This study will examine the effects of add-on sildenafil to bosentan monotherapy in patients with Pulmonary Arterial Hypertension. Patients on bosentan monotherapy will be followed every 6 months to assess if they have met the pre-defined treatment goals. If a patient fails to achieve these treatment goals or fails to maintain them, sildenafil will be added to their existing bosentan monotherapy. Patients will be assessed 6 months after start of combination therapy for changes in 6MWT, Borg dyspnea scale, WHO functional class, quality of life.

Inclusion & Exclusion Criteria