Switching Strategy in the Management of Patients with Pulmonary Arterial Hypertension. The REPLACE Study Results

Abstract

The article is devoted to topical issues of management of patients with pulmonary arterial hypertension and strategies for switching to riociguat therapy in patients with insufficient clinical response against the background of phosphodiesterase type 5 (PDE-5) inhibitors. The role of the NO metabolic pathway in the development of pulmonary arterial hypertension (PAH) was shown. From the standpoint of pathogenesis, the importance of the effect of medication on this pathway through soluble guanylate cyclase (sGC) has been assessed. The effects of the drug riociguat, the only member of the sGC stimulant class approved for the treatment of PAH, are associated with a dual mechanism of action: riociguat sensitizes the sGC enzyme to endogenous NO by stabilizing the NO-sGC bond, and also directly stimulates the latter through another site of the bond, regardless of NO. The favorable efficacy and safety profile of riociguat has been demonstrated in the PATENT-1,2 studies. During therapy, patients showed an improvement in exercise tolerance, functional class, and a number of other indicators. Studies that indicate the feasibility of using a change in therapy in clinical practice are reviewed. In particular, the article provides a detailed analysis of the REPLACE study. It demonstrated a significantly greater likelihood of achieving clinical improvement and a significant decrease in the rate of development of clinical deterioration when switching patients with PAH from PDE-5 inhibitors to riociguat. This therapy was well tolerated and can be considered as a strategy for managing patients at intermediate risk with insufficient patient response to PDE-5 inhibitors. In conclusion, the need to plan the need for specific therapy for pulmonary arterial hypertension in the region is noted in order to rapidly escalate therapy to achieve a low risk of mortality in these patients.