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

Abstract

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.

Keywords: connective tissue disease; pulmonary hypertension; scleroderma.

Figure 1

Kaplan-Meier survival curve for all patients with systemic sclerosis-associated pulmonary arterial hypertension (SSc-APAH) in the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma (PHAROS) registry (blue line) and for the subset of patients who died of pulmonary arterial hypertension related causes during follow up (red line).

Figure 2

Kaplan-Meier survival curves for patients with SSc-APAH in the PHAROS registry divided by initial pulmonary arterial hypertension therapy. The prostacyclin group included only patients who received parenteral administration of the medication. See Figure 1 legend for expansion of abbreviations.