Long-Term Outcomes in Systemic Sclerosis-Associated Pulmonary Arterial Hypertension From the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma Registry (PHAROS)

Background: Pulmonary arterial hypertension (PAH) is a leading cause of death in patients with systemic sclerosis (SSc). The purpose of this study was to assess long-term outcomes in patients with SSc-PAH.

Methods: Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma is a prospective registry of patients with SSc at high risk for or with incident pulmonary hypertension from right heart catheterization. Incident World Health Organization group I PAH patients were analyzed. Kaplan-Meier survival curves were generated for the overall cohort and those who died of PAH. Multivariate Cox regression models identified predictors of mortality.

Results: Survival in 160 patients with incident SSc-PAH at 1, 3, 5, and 8 years was 95%, 75%, 63%, and 49%, respectively. PAH accounted for 52% of all deaths. When restricted to deaths from PAH, respective survival rates were 97%, 83%, 76%, and 76%, with 93% of PAH-related deaths occurring within 4 years of diagnosis. Men (hazard ratio [HR], 3.11; 95% CI, 1.38-6.98), diffuse disease (HR, 2.12; 95% CI, 1.13-3.93), systolic pulmonary artery pressure (PAP) on ECG (HR, 1.06 95% CI, 1.01-1.11), mean PAP on right heart catheterization (HR, 1.03; 95% CI, 1.001-1.07), 6-min walk distance (HR, 0.92; 95% CI, 0.86-0.99), and diffusing capacity for carbon monoxide (HR, 0.65; 95% CI, 0.46-0.92) significantly affected survival on multivariate analysis.

Conclusions: Overall survival in PHAROS was higher than other SSc-PAH cohorts. PAH accounted for more than one-half of deaths and primarily within the first few years after PAH diagnosis. Optimization of treatment for those at greatest risk of early PAH-related death is crucial.