Background/Purpose: Pulmonary hypertension (PH) (defined as a mean pulmonary arterial pressure ≥ 25 mmHg on right heart catheterization) is a leading cause of death in patients with systemic sclerosis (SSc).  Pericardial effusions (PEf) have been shown to be a poor prognostic indicator in patients with idiopathic pulmonary arterial hypertension (PAH).  The World Health Organization (WHO) classifies PH into 5 groups based on etiology.  SSc patients most commonly fall into groups 1 (PAH), 2 (PH due to left heart disease), and 3 (PH due to lung disease or hypoxemia).  Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma (PHAROS) is a multicenter, prospective registry of SSc patients with PH (SSc-PH) or at high risk for the development of PH.  The aim of this study was to compare the survival of SSc-PH patients with PEf to the survival of SSc-PH patients without PEf, and to describe the frequency and associations of PEf in SSc-PH patients.

Methods: This is a prospective cohort study of 260 SSc-PH patients who were enrolled in the PHAROS registry between 2006 and 2012.  Statistical analysis was performed using the Kaplan-Meier method and chi-square test.

Results: The mean age of subjects was 60 years (± 11); 81.6% were female, 65.0% had limited cutaneous (lc) SSc, 29.5% were anti-centromere antibody (ACA) positive, and 65.8% had WHO group 1 PH.  The mean duration of follow-up in PHAROS was 2.3 years (± 1.9) (see Table).  The 3-year cumulative survival rate was 74.8%.  Fifty-nine (22.7%) patients died during the course of follow-up.  Forty-eight percent of all SSc-PH patients had a PEf at some point in their disease course – 53.0% in group 1, 37.2% in group 2, and 39.5% in group 3 (p=0.086).  There was no statistically significant difference in survival between the SSc-PH patients with PEf and those without across the entire cohort, or when analyzing WHO groups 1, 2, and 3 separately.  Patients with ACA were statistically significantly more likely to have had a PEf than patients with anti-Scl-70 antibody or other SSc-specific autoantibodies (58% vs. 31% vs. 47%, respectively, p<0.04).  The frequency of PEf was not statistically significantly different between patients with lcSSc and diffuse cutaneous SSc; between patients of different races; or between patients who died from SSc-related causes and those who died from non-SSc-related causes. 

Conclusion: Unlike in idiopathic PAH, there was no difference in survival between SSc-PH patients with PEf and those without.  Thus, although PEf are common in SSc patients as a whole (19% in SSc patients at high risk for PH) – and even more common in SSc-PH patients – they are not a poor prognostic sign in SSc patients with WHO groups 1, 2, or 3 PH.  SSc-PH patients with ACA were more likely to have PEf than those with anti-Scl-70 or other SSc-specific autoantibodies.  The clinical significance of this association will continue to be examined via long-term follow-up of this cohort.