LAUSR

ABSTRACT Introduction Pulmonary arterial hypertension (PAH) is still a chronic disorder characterized by high morbidity and mortality. Chronic thromboembolic pulmonary hypertension (CTEPH) is another form of pulmonary hypertension (PH) for which pulmonary endarterectomy (PEA) is the treatment of choice. However, not all patients are operable, while PH is often recurrent or persistent. Thus, for both disorders novel treatment options are urgently needed. Areas covered This review describes the mechanism of action of riociguat, a soluble guanylate cyclase (sGC) stimulator, with a dual mode of action. The most relevant publications are presented regarding the efficacy of riociguat in PAH and CTEPH, and also data regarding its potential effect on other forms of PH. Expert opinion Riociguat is a first-in-class drug approved for the treatment of PAH as a monotherapy or added to endothelin-receptor antagonists as a sequential combination therapy, and for the treatment of inoperable CTEPH or persistent/recurrent PH after PEA. As it can stimulate sGC independently of NO, it could be beneficial in PAH patients with inadequate response to phosphodiesterase 5 inhibitors (PDE5i). Future studies are needed to evaluate whether drug switching is beneficial in PAH and which baseline markers could guide the optimal initial treatment selection.