RESUMO
BACKGROUND: Intravenous (IV) epoprostenol has been the mainstay of therapy in advanced pulmonary arterial hypertension (PAH). Continuous IV treprostinil has several potential advantages over IV epoprostenol; however, there has been a lack of published long-term efficacy and safety data on IV treprostinil in PAH. METHODS: We conducted a 48-week, multicenter, prospective, open-label, uncontrolled, study of continuous IV treprostinil in 16 patients on no prior PAH specific therapy at baseline (de novo), or 31 patients transitioned at baseline from IV epoprostenol (transition). The primary end point was change in exercise capacity assessed by the 6-minute walk distance (6MWD) test. RESULTS: In de novo patients, IV treprostinil increased the mean ± standard error 6MWD by 125 m from 332 ± 21 m at baseline to 457 ± 26 m at Week 48. There were also improvements in the secondary end points of Naughton-Balke treadmill time, Borg Dyspnea Score, and hemodynamics at Week 48 compared with baseline. In 23 patients transitioned from IV epoprostenol with 48-week follow-up data, 6MWD, hemodynamic measures, and World Health Organization functional class at Week 48 were all stable compared with baseline. Side effects were generally mild and consistent with those reported with prostacyclin treatment. During the study, 5 patients died of causes not considered related to the therapy, and 7 discontinued due to adverse events. CONCLUSIONS: In this open-label trial, continuous IV treprostinil for 1 year appears to be safe and effective in de novo PAH patients and those transitioned from IV epoprostenol.