Predictors of Favorable Responses to Immunosuppressive Treatment in Pulmonary Arterial Hypertension Associated With Connective Tissue Disease

Background: The potential efficacy of immunosuppressive (IS) treatment has been reported in patients with pulmonary arterial hypertension (PAH) associated with connective tissue disease (CTD), but its positioning in the treatment algorithm remains uncertain. The aim of this study was to identify predictors of favorable responses to first-line IS treatment. Methods and Results: This single-center retrospective study included 30 patients with PAH accompanied by systemic lupus erythematosus (SLE), mixed CTD (MCTD), or primary Sjogren's syndrome (SS) who received first-line IS treatment alone or in combination with pulmonary vasodilators. When short-term treatment response was defined as an improvement in World Health Organization functional class at 3 months, 16 patients (53%) were short-term responders. Simultaneous diagnosis of PAH and CTD, and the use of immunosuppressants, especially intravenous cyclophosphamide, in addition to glucocorticoids were identified as independent predictors of a short-term response (P=0.004 and 0.0002, respectively). Cumulative rates free of PAH-related death were better in short-term responders than non-responders (P=0.04), and were best in patients with a simultaneous diagnosis of PAH and CTD who were treated initially with a combination of glucocorticoids and immunosuppressants. Conclusions: Patients with a simultaneous diagnosis of PAH and CTD, including SLE, MCTD, and primary SS, should receive intensive IS treatment regimens to achieve better short-and long-term outcomes.