ABSTRACT: Aim:To study demographic and clinical characteristics and to give a comparative description of the functional and hemodynamic status, profile of concomitant pathology in patients with various forms of pulmonary arterial hypertension (PAH), and chronic thromboembolic pulmonary hypertension (CTEPH) according to the Russian National Registry. Methods:During the period from January 01, 2012, till January 01, 2019, 1105 patients aged >18 years with verified diagnosis of PAH and CTEPH, who were subsequently observed at 15 PH expert centers of the Russian Federation in the 52 provinces, are included in the Russian registry on the basis of the Federal State Budgetary Institution of Cardiology of the Ministry of Healthcare of Russia. All newly diagnosed patients (n = 727) were entered into the registry database (NCT03707561). A comparative analysis of demographic and clinical characteristics, profile of concomitant pathology, and parameters of a comprehensive examination of patients was performed. Results:Among newly diagnosed patients, 67% had PAH and 28.3% had CTEPH. In the PAH group, 40.9% of patients had idiopathic arterial PAH (IPAH), 36.6% had PAH associated with simple congenital heart disease (PAH-CHD), 19.3% had PAH associated with systemic connective tissue disease (PAH-CTD), 1.8% had portal pulmonary hypertension (PoPH), 0.6% had PAH associated with HIV infection (PAH-HIV), 0.4% had heritable PAH (HPAH), and 0.4% had drug/toxin-induced PAH. At the time of diagnosis, PAH patients were younger than patients with CTEPH (45.2 ± 14.9; 52.6 ± 15.3 years, respectively) (p < 0.05). At the time of diagnosis, 71% PAH and 77% CTEPH patients had WHO FC III/IV. Mean (±SD) 6MWD was significantly less in CTEPH vs. the PAH group 331.3 ± 110.3 vs. 361.8 ± 135.7?m (p = 0.0006). Echo data showed a comparable sPAP between groups; CTEPH population had a more pronounced increase in the area of the right atrium (SRA) (24 [20; 32] cm2 and 19 [15; 26] cm2, respectively), and a significant decrease in FAC (24.7 [22, 4; 29.0] and 29.0 [23.0; 31.0] %, respectively) as compared to the PAH group. RHC showed a comparable increase of sPAP and mPAP in PAH and CTEPH groups. 15.2% of patients with IPAH and HPAH demonstrated positive results in the acute vasoreactivity testing. CTEPH patients were more often obese and suffered from arterial hypertension and right heart failure. Deep venous thrombosis was significantly more often observed in patients with CTEPH (53%). The most common concomitant pathology was erosive-ulcerative lesion of the stomach/duodenum, less often of the esophagus (23.5% and 44.5%, respectively). Conclusion:According to the Russian registry in patients with PAH and IPAH, the diagnosis is established at a younger age in comparison with the European registries. CTEPH patients are characterized by more severe functional status, pronounced signs of right heart failure taking into account the older age and the spectrum of comorbid pathology, which limits the possibility of surgical treatment. An increase in the number of expert centers participating in the registry is the key to improving early diagnosis of PH and optimal follow-up according to common standards in order to timely optimize therapy and reduce mortality of patients.
