Hemodynamic Response to Oral Vasodilator Therapy in Systemic Sclerosis-Related Pulmonary Hypertension.

Abstract

Although classified as group 1 pulmonary arterial hypertension (PAH), patients with systemic sclerosis-related pulmonary hypertension (SSc-PH) experience poorer clinical response to PAH therapy and increased mortality compared to those with idiopathic PAH. Due to heterogeneity in phenotypes, identifying patients likely to respond to therapy is challenging. The goal of this study was to determine clinical factors associated with hemodynamic response, defined by a > 20% reduction in pulmonary vascular resistance on repeat right heart catheterization. We applied a time-to-event model using a retrospective cohort of 39 patients with precapillary SSc-PH, defined by a mean pulmonary artery pressure of ≥ 25mmHg and pulmonary arterial wedge pressure (PAWP) ≤ 15mmHg on right heart catheterization. Patients with PAWP ≤ 8mmHg were nearly fourfold more likely to achieve a hemodynamic response compared to those with PAWP > 8mmHg (HR 3.88; 95% CI: 1.20, 12.57); each 1mmHg increase in PAWP was associated with a decreased hazard for hemodynamic response (HR 0.84; 95% CI: 0.70, 1.00). In patients with precapillary SSc-PH, PAWP was associated with time to hemodynamic response, suggesting the importance of subclinical cardiac disease in determining hemodynamic response to oral vasodilator therapy.