Long-term safety, tolerability and efficacy of bosentan in adults with pulmonary arterial hypertension associated with congenital heart disease

Objective: To examine long-term safety and efficacy of bosentan - an oral dual endothelin receptor antagonist - in patients with pulmonary hypertension associated with congenital heart disease or Eisenmenger's syndrome. Design: Retrospective study. Setting: Tertiary cardiology referral centre. Patients: All adult patients with pulmonary arterial hypertension associated with congenital heart disease treated with bosentan at the Royal Brompton Adult Congenital Heart Centre were included. Main outcome measures: Oxygen saturation, functional (WHO) class, 6-minute walk test distance and liver enzymes were analysed. Results: Eighteen patients (14 female) with pulmonary arterial hypertension associated with congenital heart disease (15 patients with Eisenmenger's syndrome) with a mean (SD) age of 41 (9) years (range 23 - 69) were included. Median follow- up was 29 months (range 1 - 39). One patient died during follow-up. Patients tolerated bosentan well and no significant rise in liver transaminases was seen. Arterial oxygen saturation remained stable throughout follow- up. Mean (SD) functional class (p = 0.001) and the 6-minute walk test distance improved compared with baseline (284 (144) vs 363 ( 124) m, 380 (91) m and 408 (114) m at baseline, 0 - 6 months, 6 - 12 months and 1 - 2 years of treatment, respectively; p, 0.05 for each). Conclusions: Bosentan appears to be safe and well tolerated in adults with pulmonary arterial hypertension associated with congenital heart disease or Eisenmenger's syndrome during mid-to long-term follow-up. In addition, functional class and the 6-minute walk test distance improved and this effect was maintained for up to 2 years of bosentan treatment.