Objectives: This study investigated the long-term effects of bosentan, an oral endothelin ETA/ETB receptor antagonist, in patients with pulmonary arterial hypertension (PAH) exclusively related to connective tissue diseases (CTD).
Methods: Fifty-three patients with PAH related to connective tissue diseases (PAH-CTD) in WHO functional class III received bosentan 62.5 mg b.i.d. for 4 weeks and then 125 mg b.i.d. for 44 weeks in this open non-comparative study. Assessments at Weeks 16 and 48 included WHO class, clinical worsening, quality of life (Short-Form Health Survey (SF-36) and health assessment questionnaire (HAQ) modified for scleroderma), and survival (Week 48 only). Safety and tolerability were monitored throughout the study.
Results: At Week 48, WHO class improved in 27% of patients (95% CI: [16%:42%]) and worsened in 16% (95% CI: [7%:29%]). Kaplan-Meier estimates were 68% (95% CI: [55%:82%]) for absence of clinical worsening and 92% (95% CI: [85%:100%]) for survival. Overall changes in quality of life were minimal. There were no unexpected side effects observed during the study.
Conclusions: In most patients, bosentan was associated with improvement or stability of clinical status. The 92% estimate for survival at 48 weeks is a significant achievement in this patient population.
- connective tissue diseases
- endothelin receptors
- pulmonary arterial hypertension