Rationale: Intravenous epoprostenol improves exercise capacity and survival in patients with pulmonary arterial hypertension. The prostacyclin analog treprostinil is also efficacious by subcutaneous infusion, is easier to administer, and has a longer half-life. With the demonstration of bioequivalence between subcutaneous and intravenous treprostinil, intravenous treprostinil may have an overall better risk-benefit profile than intravenous epoprostenol.
Objective: To evaluate the safety and efficacy of transitioning patients with pulmonary arterial hypertension from intravenous epoprostenol to intravenous treprostinil.
Methods: Patients enrolled in a 12-wk prospective open label study were switched from intravenous epoprostenol to intravenous treprostinil over 24 to 48 h. The intravenous treprostinil dose was adjusted to minimize symptoms/side effects.
Results: Thirty-one patients (mean age, 43 yr; 22 women) were enrolled. Twenty-seven patients completed the protocol; 4 patients transitioned back to epoprostenol. Six-minute walk distance (n = 27; baseline, 438 +/- 16 m; Week 12, 439 +/- 16 m), Naughton-Balke treadmill test time (n = 26; baseline, 582 +/- 50 s; Week 12, 622 +/- 48 s), functional class, and Borg score were maintained with intravenous treprostinil at Week 12 versus intravenous epoprostenol before transition. At Week 12, mean pulmonary artery pressure increased 4 +/- 1 mm Hg (n = 27, p < 0.01), cardiac index decreased 0.4 +/- 0.1 L/min/m2 (n = 27, p = 0.01), and pulmonary vascular resistance increased 3 +/- 1 Wood units x m2 (n = 26, p < 0.01). No serious adverse events were attributed to treprostinil.
Conclusions: These data suggest that transition from intravenous epoprostenol to intravenous treprostinil is safe and effective; whether the hemodynamic differences associated with intravenous treprostinil are clinically important requires longer follow-up.