Long-term efficacy of bosentan in inoperable chronic thromboembolic pulmonary hypertension

Background. Inoperable chronic thromboembolic pulmonary hypertension (CTEPH) is associated with a poor survival.

Objectives. To evaluate the long-term response to a dual endothelin receptor antagonist in patients with inoperable CTEPH.

Methods. All consecutive 18 patients (mean age 63±14 years) treated with bosentan for symptomatic inoperable CTEPH were included. Efficacy was evaluated by the log value of serum levels of N-terminal-pro brain natriuretic peptide (log NTpro BNP), New York Heart Association functional class (NYHA), and the six-minute walk test (6-MWT). All follow-up data (median 31 months) were compared with baseline and divided into: short-term (<12 months), mid-term (between 12 and 24 months), and long-term follow-up (>24 months).

Results. At baseline, 15 patients were in NYHA class III and three in NYHA class IV, mean log NT-pro BNP level was 7.2±1.4 log pg/ml, and mean 6-MWT distance was 404±125 m. During short-term follow-up (n=18), the NYHA class improved (p=0.001), 6-MWT distance increased by 33 m (p=0.03), and log NT-pro BNP decreased to 6.9±1.4 log pg/ml (p=0.007). During mid-term follow-up (n=17), the NYHA class improved (p<0.001), the mean 6-MWT distance increased by 41 m (p=0.01), and log NT-pro BNP was 6.9±1.4 log pg/ml (p=0.31). During late followup (n=14) the NYHA class was still improved (p=0.03), the 6-MWT distance decreased by 9 m (p=0.73), and log NT-pro BNP was 7.1±1.5 log pg/ml (p=0.91). The overall four year survival rate was 88%.