Bosentan in pulmonary arterial hypertension secondary to scleroderma

Objective. To assess the efficacy and tolerability of bosentan in pulmonary arterial hypertension secondary to systemic sclerosis (SSc-PAH) including patients with restrictive lung disease. Methods. We retrospectively reviewed 23 SSc-PAH patients with PAH at baseline [PA systolic pressure (PASP) >= 45 mm, Hg by echocardiogram or mean PA pressure > 25 mm Hg at rest by cardiac catheterization], World Health Organization (WHO) functional classes II-IV, and with data available for 18 months. Bosentan dose was 62.5 mg twice daily for 1 month then 125 mg twice daily. Outcomes were WHO functional class, PASP, and pulmonary function tests (PFT) at 3-month intervals for 18 months. Results. WHO class at baseline 3.1 +/- 0.1 (mean +/- SE); 3 months, 2.5 +/- 0.2*; 6 months, 2.4 +/- 0.2*; 9 months, 2.5 0.2* (*p < 0.02 vs baseline, n = 21 to 23), indicating clinical improvement at 9 months. After 9 months, results were not significant versus baseline. Reduction in WHO class by at least one rank was 57% at 3 months; none worsened. After 9 months, WHO class tended to worsen compared to baseline. Baseline PASP was 54 2 mm Hg (n = 23) and did not change significantly with therapy. Restriction (total lung capacity 76% +/- 4% of predicted) and reduced diffusing capacity (39% 3% of predicted) were unchanged during therapy. Abnormal transaminases in 2 patients (9%) necessitated discontinuing drug in both. Conclusion. Bosentan is clinically beneficial in patients with SSc-PAH including patients with restrictive lung disease, but pulmonary hemodynamics and PFT results remained stable during treatment.