Objective: Identification of prognostic factors for survival in systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) is necessary for appropriate monitoring, interventions, and timely referral for lung transplantation. Our objectives were (1) to identify factors associated with survival in SSc-PAH and (2) to evaluate the methodologic quality of prognostic studies against current standards.
Methods: A systematic review was performed to identify studies evaluating factors associated with survival in SSc-PAH. The methodologic quality of each study was evaluated using a methodologic quality index.
Results: HLA-DRw6 (RR 54.52, p = 0.01), HLA-DRw52 (RR not reported, p = 0.02), initial systolic pulmonary artery pressure (sPAP) > 60 mmHg (HR 3.60, 95% CI 1.42, 9.15), elevated mean right atrial pressure (mRAP) (HR 20.7, p = 0.0001), and shorter time between SSc onset and observed PAH (5.24 vs 9.93 yrs, p < 0.01) were associated with decreased survival. Age > 50 years (HR 2.34, 95% CI 0.54, 10.2), male sex (HR 2.02, 95% CI 0.65, 6.20), limited subtype (HR 2.37, 95% CI 0.68, 8.20), pulmonary fibrosis [Kaplan-Meier (KM) curves, p = 0.3], change in pulmonary vascular resistance (KM curves, p = 0.8), anti-centromere (HR 1.67, 95% CI 0.66, 4.26) and anti-ScL-70 (HR 0.28, 95% CI 0.03, 1.99) antibodies were not definitively associated with survival. Attributes of participants, prognostic factors, and outcome measures were well reported. Study attrition, confounding, and analysis were not well reported.
Conclusion: HLA-DRw52 and -DRw6, initial sPAP > 60 mmHg, mRAP, and shorter time between SSc onset and observed PAH were associated with decreased survival; however, methodologic quality of study reporting was variable. Prognostic factor research is needed using current methodologic standards.