Intravenous (IV) epoprostenol improves exercise tolerance, symptoms, hemodynamics, and survival in PAH. IV treprostinil, a prostacyclin analogue, may have similar clinical benefits and a better safety profile with a longer (4 hour) elimination half-life. Previous reports from this investigator initiated study have demonstrated favorable 12 week results. The purpose of this study was to assess the clinical efficacy of IV treprostinil after one year of therapy.
In this open label, multicenter study, PAH patients were treated with IV treprostinil either as initial therapy for PAH (de novo) or transitioned to treprostinil from epoprostenol (transition). The goal of therapy was improvement in de novo patients and maintenance of functional capacity and symptoms in the transition patients. Patients were assessed with six minute walk distance (6MWD) and right heart catheterization at baseline and 1 year using a paired t-test.
Forty-seven patients (16 de novo, 31 transition), mean age 43.4 years, (81% female) were enrolled. PAH was idiopathic in 62%, related to connective tissue disease 25%, and related to congenital heart disease in 13%. At baseline 49% were FC II, 47% were FC III and 4% were FC IV. Transition patients were on epoprostenol for 55 ± 44 months at a mean dose of 40 ± 23 ng/kg/min. At one year, the mean treprostinil dose was 111 ± 29 ng/kg/min in de novo patients and 124 ± 57 ng/kg/min in transition patients. One year data was available in 16 patients. Data was not available in the remaining 31 for the following reasons: death (4), discontinuation of IV treprostinil (7), and duration of IV treprostinil therapy <1 year (20). 6MWD and hemodynamic results are displayed in the table. Side effects associated with treprostinil were typical of prostacyclins, eg. headache, jaw pain, leg pain, and diarrhea.
The clinical efficacy of IV treprostinil appears to be maintained at one year.
IV Treprostinil may be an effective alternative to IV epoprostenol in selected PAH patients.
Vallerie McLaughlin, Grant monies (from industry related sources) United Therapeutics; Consultant fee, speaker bureau, advisory committee, etc. United Therapeutics.ParameterDe Novo (n=5)Transition (n=11)Baseline1 yearP valueBaseline1 yearP value6MWD (meters)323±35454±430.06482±18482±120.96PAPm (mmHg)66±948±70.00645±450±30.08CI (L/min/m2)1.5±0.12.5±0.20.042.9±0.23.0±0.20.71PVRI (Wood units•m2)37±516±40.0113±214±20.5
M ± SE