Long-term Outcome in Pulmonary Arterial Hypertension Patients Treated with Subcutaneous Treprostinil

Pulmonary arterial hypertension (PAH) is fatal if untreated. Intravenous epoprostenol improves exercise capacity and haemodynamics in PAH, and increases survival in idiopathic PAH (IPAH). To evaluate the effects of subcutaneous (SC) treprostinil, a longer-acting prostacyclin analogue, followed by the addition of other PAH therapies if needed, 860 PAH patients treated with SC treprostinil for up to 4 yrs were followed. Survival is reported as Kaplan-Meier estimates. For 332 IPAH patients with baseline haemodynamics, observed survival is also compared with predicted survival using the National Institute of Health formula. Out of the 860 patients, 199 (23%) discontinued due to adverse events, 136 (16%) died, 117 (14%) discontinued due to deterioration, 29 (3%) withdrew consent and 11 (1%) underwent transplantation. In total, 97 patients (11%) switched from SC treprostinil to an alternative prostacyclin analogue; bosentan was added in 105 patients (12%) and sildenafil in 25 (3%). In conclusion, survival was 87-68% over 1-4 yrs for all 860 patients and 88-70% over 1-4 yrs with subcutaneous treprostinil monotherapy. For the idiopathic pulmonary arterial hypertension subset with baseline haemodynamics (n = 332), survival was 91-72% over 1-4 yrs. In contrast, predicted survival was 69-38% over 1-4 yrs. The safety profile for long-term subcutaneous treprostinil was consistent with previous short-term trials with no unexpected adverse events.