The contribution of the soluble guanylate cyclase stimulator riociguat to changes in functional status and hemodynamic parameters in the combined approach to treating patients with inoperable chronic thromboembolic pulmonary hypertension

Objective: to study the contribution of the soluble guanylate cyclase stimulator riociguate to the overall effect of combined treatment of patients with inoperable chronic thromboembolic pulmonary hypertension. Material and methods. The study included patients with an inoperable form of CTEPH who were treated with riociguat and underwent balloon pulmonary angioplasty (BPA). The patients were divided into 2 groups of 50 people "Riociguat+BPA" and "BPA+Riociguat". Patients of the "Riociguat+BPA" group received PAH-specific therapy with riociguat at the first stage of treatment, after which they underwent several sessions of BPA. Patients of the "BPA+Riociguat" group recieved a series of BPA, and then riociguat was initiated. Patients took riociguat for 6 months at a target dose of 7.5 mg/day in both groups. The average number of completed BPA sessions was 4. A control invasive measurement of hemodynamic parameters was performed at three points: before the start of treatment, after the first stage of treatment, and 6 months after the completion of the entire course of treatment. Results. Following the administration of riociguat, there was a statistically significant increase in the 6MWT distance by 36 m in the “Riociguat+BPA” group and by 17 m in the “BPA+Riociguat” group. Improvement in key hemodynamic parameters was observed: in particular, after initiation of riociguat therapy, a decrease in mPAP by 6 mmHg and PVR by 1,97 Wood units was observed in the “Riociguat+BPA” group, while in the “BPA+Riociguat” group, a decrease in mPAP by 5 mmHg and PVR by 1,7 Wood units was observed. A smaller influence of riociguat was found with respect to gas exchange parameters. When comparing the results achieved at the end of the course of treatment, both groups demonstrated a good effect from the combined approach, regardless of which type of treatment was initiated first. Conclusion. The contribution of riociguat is manifested in the improvement of the functional status and hemodynamic parameters both when prescribing the drug before a series of BPA sessions, and when adding the drug after endovascular treatment. The sequence of initiation of treatment methods within the framework of the combined approach should be determined individually.