TREATMENT OF PULMONARY ARTERIAL HYPERTENSION ASSOCIATED WITH CONGENITAL HEART DEFECTS
Authors: Vasilyeva L. I. , Kalashnykova O. S. 
Published: October 2024

Patients with pulmonary arterial hypertension, associated with congenital heart disease (PAH-CHD) are a heterogeneous population with a varied course of PH. Improvements in pediatric cardiac surgery have changed the epidemiology and survival rate of patients with CHD, of which 90% reach adulthood. Progress in terms of prognosis has also been observed among patients with PAH-CHD. Better survival was observed in ES compared with PAH after defect correction. Advances in surgical treatment of CHD and an increase in life expectancy have led to the study of PAH-CHD and the need to create recommendations for drug treatment of this category of patients. In most of studies, the evaluation of drug treatment of group 1 PAH was carried out without identifying its subgroups. And thus, according to existing recommendations, treatment algorhithms for patients with PAH-CHD are similar to approaches to other forms of PAH. However, various clinical, functional, physical and hemodynamic characteristics of patients with PAH-CHD call into question of correct risk stratification approaches development. Multicenter randomized clinical trials included predominantly a small number of patients with corrected defects, which does not allow the results to be interpreted for the entire population of patients with PAH-CHD. Data from single-center observational studies, expert opinion, and several randomized trials primarily involving patients with Eisenmenger syndrome (ES) indicate the effectiveness and safety of PAH-specific therapy in patients with PAH-CHD. In this literature review, we examined and showed the results of studies involving patients with PAH-CHD and their response to specific therapy. The results obtained significantly expanded the possibilities of using bosentan, sildenafil, epoprostenol, riociguat, ralinepag, sotatercept as they lead to improvement of functional capacity and hemodynamic parameters in patients with PAH-CHD, and only epoprostenol demonstrated an effect on prognosis. Combination PAH-specific therapy, initial or sequential administration of two or more drugs with different mechanisms of action, is an important treatment strategy for patients with PAH. The role of such therapy has increased in recent years. Based on the results of the AMBITION, SERAPHIN, GRIPHON, COMPASS-2 studies, initial or sequential oral combination PAH-specific therapy is recommended for patients with WHO FC II or III. At the same time, there is little evidence to support the effectiveness of this approach in ES patients. The use of anticoagulants in PAH-CHD remains controversial. Low-flow oxygen therapy should be considered individually and continued when there is a significant predominance of subjective or objective benefit. Iron deficiency is associated with poor survival in ES. It is important to note that microcytosis is rare in patients with iron deficiency cyanosis and a normal mean red cell volume does not indicate the absence of anemia. In cases of intolerance to oral iron, intravenous drugs should be used.
Currently, based on existing guidelines, most centers follow a consistent symptom-based approach in the treatment of patients with PAH-CHD. Therapy begins with oral ERAs or PDE-5 inhibitors and is escalated if symptoms persist or clinical worsening occurs. If there is no effect of oral PAH-specific therapy, it is recommended to consider parenteral drugs.