Comparative Clinical Characteristics of Patients With Various Forms of Pulmonary Arterial Hypertension Associated With Congenital Heart Disease, According to the Clinical Classification

Objective : to conduct a comprehensive analysis of the clinical, functional, hemodynamic profile of patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) according to the Russian Registry. Materials and methods : The study involved 30 patients with Eisenmenger syndrome, 25 patients with PAH associated with prevalent systemic-to-pulmonary shunts and 26 patients with PAH after defect correction. All patients had been entered in the Russian registry (NCT03707561). A comparative analysis of clinical, functional, hemodynamic parameters was held. The diagnosis was established by the algorithm proposed in the Russian guidelines for the diagnosis and treatment of PH (2016). Results: The patients of three subgroups of PAH-CHD were comparable in age and sex. The time from the onset of symptoms to the final diagnosis in the first and second PAH-CHD subgroups was significantly longer: on average, it took three years to establish the diagnosis, whereas in patients with PAH after defect correction, on average, after 9 months the correct diagnosis was made (p=0,0006). Patients with Eisenmenger syndrome were characterized by significantly high values of mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) according to right heart catheterization (mPAP (81,0 [72,0;92,0] mm Hg against 52,0 [41,0;75,0] mm Hg, p=0,001 and PVR 2329,0 [1333,0;2778,0] dyn*sec*cm-5 vs. 954,5 [591,0;1439,0] dyn*sec*cm-5, p=0,02) compared with the second subgroup of PAH-CHD, and significant decrease in arterial blood oxygen saturation (SpO2) (90,0 [85,0;93,0]% vs. 94,5 [92,5;96,0]% and 96,0 [92,0;98;0]%) compared with patients of the other subgroups (p=0,002). Conclusions : Patients with PAH-CHD are a heterogeneous population, the division of which is presented in the clinical classification, and therefore have a different course of the disease. Analyzing the data of patients with PAH-CHD, we found various clinical, functional, physical and hemodynamic features of these patients. With comparable 6MWT and FC (WHO), patients with Eisenmenger syndrome have the highest values of PAP and PVR, as well as lower values of arterial blood oxygen saturation compared to other subgroups of PAH-CHD. In the group of patients with PAH associated with prevalent systemic-to-pulmonary PVR was significantly less compared to other groups of PAH-CHD. In patients with PAH after defect closure, the correlation between 6MWT and FC (WHO) and the area of the right atrium was detected. The obtained data can be useful in the choice of management of these patients