Survival in patients with systemic sclerosis (SSc)-associated pulmonary hypertension (PH) and interstitial lung disease (ILD) is poor. Evidence supporting the efficacy of aggressive pulmonary arterial hypertension (PAH)-targeted therapy in this population is limited. The aim of this study was to investigate transplant-free survival in patients with isolated SSc-related PAH or SSc-related PH-ILD who were treated with aggressive PAH-targeted therapy.
SSc patients with right-sided heart catheterization (RHC)-diagnosed precapillary PH (mean pulmonary artery pressure ≥25 mm Hg, pulmonary capillary wedge pressure ≤15 mm Hg, and pulmonary vascular resistance ≥240 dynes × second/cm(5) ) were included. Patients were classified as having ILD based on review of high-resolution computed tomography (CT) chest imaging and spirometry. The Kaplan-Meier method was applied and Cox proportional hazards models were constructed to analyze survival and identify predictive variables.
Of 99 patients with SSc-related precapillary PH, 28% had SSc-related PAH and 72% had SSc-related PH-ILD. The 1- and 2-year survival estimates were, respectively, 72% and 59% in the SSc-related PH-ILD group versus 82% and 66% in the SSc-related PAH group (P = 0.5). Within 6 months of the diagnostic RHC, 24% of all patients were started on prostanoid therapy; an additional 24% were started on prostanoid therapy after 6 months. In the multivariate model, male sex (hazard ratio [HR] 0.7, P = 0.01) and prostanoid therapy initiation within 6 months of the RHC (HR 1.4, P = 0.01) were the only factors significantly associated with transplant-free survival, after accounting for the presence of ILD and severity of PH.
In this study, survival of patients with SSc-related PH-ILD was modestly improved relative to historical series. While these findings may not be generalizable, improved survival may be due partly to aggressive PAH-targeted therapy.