Systemic sclerosis-related pulmonary hypertension associated with interstitial lung disease: Impact of pulmonary arterial hypertension therapies

Objective Precapillary pulmonary hypertension (PH) is an important cause of death in patients with systemic sclerosis (SSc). It can occur in isolation (pulmonary arterial hypertension [PAH]) or in association with interstitial lung disease (ILD). Importantly, the outcomes and efficacy of PAH therapies in patients with SSc-related PH complicating ILD (PH-ILD) remain unknown. This study was undertaken to evaluate our experience with PH-ILD with regard to the efficacy and safety of PAH therapies in this patient cohort. Methods We conducted a retrospective analysis of consecutive SSc patients from 2 large referral centers who had PH-ILD confirmed by right-sided heart catheterization and who received targeted PAH therapies. World Health Organization (WHO) functional class, 6-minute walk distance, and hemodynamic parameters were assessed at baseline and after a mean ± SD of 7.7 ± 6.2 months of treatment for PAH. Kaplan-Meier and Cox proportional hazards models were used to analyze survival and to identify prognostic factors. Results Seventy patients were included in the study. No significant changes were observed in WHO functional class, 6-minute walk distance, or hemodynamic parameters after therapy. The 1-, 2-, and 3-year survival estimates were 71%, 39%, and 21%, respectively. In the multivariate model, worsening oxygenation during followup and reduced renal function were the only significant risk factors for death. Conclusion This study represents the largest series to date in which the impact of PAH therapies in SSc-related PH-ILD was examined. In this cohort, PAH therapies were associated with no clear benefits. Deterioration in oxygenation was an important determinant of long-term survival. Prospective clinical trials focusing on this group of patients are warranted.