Replacing a phosphodiesterase-5 inhibitor with riociguat in patients with connective tissue disease-associated pulmonary arterial hypertension: a case series.

Patients with pulmonary arterial hypertension associated with connective tissue disease (PAH-PAH-CTD) such as systemic sclerosis (SSc) have a poorer response to treatment and increased mortality compared with patients with idiopathic PAH. Current treatment options for PAH-CTD include prostanoids, phosphodiesterase type-5 inhibitors (PDE-5i), endothelin receptor antagonists, and the soluble guanylate cyclase stimulator riociguat. In this case series, we describe three patients with PAH-CTD related to limited scleroderma who were switched from a PDE-5i to riociguat due to insufficient clinical response. The switch to riociguat was associated with an improvement in respiratory and hemodynamic parameters and a favorable tolerability profile. These cases demonstrate that switching to riociguat is a therapeutic option in patients with PAH-CTD who have not achieved a satisfactory clinical response to a PDE-5i.