Objective The objective of this report is to compare baseline, management and survival characteristics in idiopathic pulmonary arterial hypertension (IPAH) with systemic sclerosis-associated pulmonary arterial hypertension (SSc-APAH) using data from the prospectively enrolled PAH Quality Enhancement Research Initiative.

Methods Between August 2005 and July 2007, patients with IPAH and SSc-APAH were enrolled across 60 US sites and followed up for 3 years. Data on diagnostic tests, clinical variables, pulmonary arterial hypertension (PAH) medication and outcomes were recorded.

Results With some exceptions, baseline clinical and laboratory characteristics were similar between the 279 patients with IPAH and the 228 with SSc-APAH. Patients with SSc-APAH were older at the time of PAH diagnosis, were more likely to be female and were antinuclear antibody positive. Patients with SSc-APAH had poorer spirometric results. During the 3-year follow-up, both groups were managed with prostacyclin and prostacyclin analogue treatment, endothelin receptor antagonists and phosphodiesterase type 5 inhibitors (PDE5i) singly or in combination. At 3 years, patients with SSc-APAH were more likely to be treated with PDE5i alone or with an endothelin receptor antagonist. Patients with SSc-APAH had a significantly lower survival rate compared to patients with IPAH (60% vs 77%, p<0.0001).

Conclusions The cohort with SSc-APAH was older, was more severely ill, was more likely to be female, was managed with PDE5i and had reduced 3-year survival compared with the cohort with IPAH.