BACKGROUND: In PATENT-1, riociguat significantly improved 6-minute walking distance (6MWD) pulmonary arterial and a range of secondary end-points in patients with pulmonary arterial hypertension (PAH). We hypertension; investigated whether riociguat increased the proportion of patients achieving clinically relevant riociguat; responder thresholds compared with placebo during PATENT-1. soluble guanylate

METHODS: In PATENT-1, a randomized, double-blind study, treatment-nave patients or patients on cyclase stimulator; background PAR-targeted therapy with symptomatic PAR received 12 weeks of treatment with placebo, treatment response; riociguat up to 2.5 mg 3 times daily, or riociguat up to 1.5 mg 3 times daily. Increases in 6MWD 40 responder threshold m, 6MWD >= 380 m, cardiac index >= 2.5 liter/min/m(2), mixed venous oxygen saturation >= 65%, World criteria Health Organization functional class I/II, N-terminal pro-brain nattiuretic peptide <1,800 pg/ml, and right atrial pressure <8 mm Hg were chosen as threshold criteria of a positive response.

RESULTS: Riociguat increased the proportion of treatment-naive patients and patients on background PAH-targeted therapy with 61VIWD >= 380 m at Week 12 (+21% and +15%, respectively), whereas there was a small reduction in 6MWD in placebo-treated patients for both sub-groups. Riociguat also increased the proportion of treatment-naive patients and patients on background PAR-targeted therapy achieving World Health Organization functional class I/II (+12% and +19%, respectively) and cardiac index >= 2.5 liter/min/m(2) (+30% and +33%, respectively) at Week 12, whereas there was little change in the respective placebo groups.

CONCLUSIONS: Compared with placebo, riociguat increased the proportion of treatment-naive patients and patients on background PAR-targeted therapy who fulfilled criteria defining a positive response to therapy. (C) 2015 International Society for Heart and Lung Transplantation. All rights reserved.