Dynamics of the clinical functional and hemodynamic profile of patients with pulmonary arterial hypertension with initial monotherapy with endothelin receptor antagonists: bosentan vs. macitentan

Abstract

Aim To compare results of 24-h treatments with bosentan and macitentan by the clinical functional status and indexes of pulmonary hemodynamics in patients with pulmonary arterial hypertension (PAH).Materials and methods Based on the Russian National Registry (NCT03707561), 44 patients older than 18 years with PAH (34 patients with idiopathic pulmonary hypertension (IPH) and 10 patients with Eisenmenger syndrome) were retrospectively included into this study. Based on the statistical method of pairwise comparison, two groups were formed and matched by age, gender, WHO functional class (FC), and 6-min walk distance (6MWD). 22 patients of group 1 (17 with IPH and 5 with Eisenmenger syndrome) were treated with macitentan 10 mg/day, and 22 patients of group 2 (17 with IPH and 5 with Eisenmenger syndrome) were treated with bosentan 250 mg/day. Clinical instrumental data (6MWD, Borg dyspnea score, chest X-ray, transthoracic echocardiography (EchoCG), and right heart catheterization (RHC)) were evaluated at baseline and after 24 weeks of therapy.Results By week 24 of the treatment, FC and 6MWD improved in both groups. The macitentan treatment was associated with a significant decrease in Borg score. Significant intergroup differences in EchoCG data were not observed. The bosentan treatment was associated with a decrease in right ventricular (RV) dimension and a tendency towards a decrease in calculated pulmonary artery systolic pressure (PASP). By week 24, the macitentan treatment as compared to the bosentan treatment, was associated with a decrease in cardiothoracic ratio (CTR). In both groups, RHC showed decreases in PASP, mean pulmonary artery pressure and pulmonary vascular resistance, and improvements in cardiac output (CO), cardiac index, and stroke volume (SV) values. By week 24, the increase in SV was greater in the macitentan treatment group than in the bosentan treatment group (р=0.05).Conclusion The 24-week treatment with bosentan or macitentan provided significant and comparable improvement of the functional profile in PAH patients with FC II (WHO) at baseline. The decrease in CTR was significantly more pronounced in the macitental treatment group compared to the bosentan treatment group. The 24-week bosentan treatment resulted in a decrease in RV anterior-posterior dimension, a tendency towards a decrease in PASP according to EchoCG data. Macitentan provided more pronounced dynamics of dyspnea than bosentan according to the results of 6MWD test and the increase in SV according to RHC data.