Haemodynamic effects of riociguat in inoperable/recurrent chronic thromboembolic pulmonary hypertension.

OBJECTIVE: We compared the haemodynamic effects of riociguat in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or persistent/recurrent CTEPH after pulmonary endarterectomy in the Chronic Thromboembolic Pulmonary Hypertension Soluble Guanylate Cyclase-Stimulator Trial 1 study. METHODS: Patients with inoperable or persistent/recurrent CTEPH (n=261; mean± SD age 59±14 years; 66% women) were randomised to riociguat (up to 2.5 mg three times daily) or placebo. Haemodynamic parameters were assessed at baseline and week 16. RESULTS: Riociguat decreased pulmonary vascular resistance (PVR) in inoperable (n=189; least-squares mean difference: -285 dyn s/cm5 (95% CI -357 to -213); p<0.0001) and persistent/recurrent (n=72; -131 dyn s/cm5 (95% CI -214 to -48); p=0.0025) patients. Cardiac index improved in inoperable patients by a least-squares mean difference of +0.6 L/min/m2 (95% CI 0.4 to 0.7; p<0.0001), while in persistent/recurrent patients the change was +0.2 L/min/m2 (95% CI -0.1 to 0.5; p=0.17). Mean pulmonary artery pressure decreased in inoperable and persistent/recurrent patients(-4.7 mm Hg (95% CI -6.9 to -2.6; p<0.0001 and -4.8 mm Hg (-8.2 to -1.5; p=0.0055), respectively). For all patients, changes in 6 min walk distance correlated with changes in PVR (r=-0.29 (95% CI -0.41 to -0.17); p<0.0001) and cardiac index (r=0.23 (95% CI 0.10 to 0.35); p=0.0004). CONCLUSIONS: Riociguat improved haemodynamics in patients with inoperable CTEPH or persistent/recurrent CTEPH.