Reserve capabilities of the cardiovascular and respiratory systems in patients with chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious disease associated with thrombotic lesions of the pulmonary arteries and secondary microvasculopathy, leading to the progression of pulmonary hypertension and heart failure. Pulmonary endarterectomy (PEA) is the preferred treatment for CTEPH. Aim: To study the reserve capabilities of the cardiovascular and respiratory systems in patients with CTEPH. Material and Methods. The retrospective cohort observational study included 403 patients aged 19 to 77 years with CTEPH who underwent PEA at the National Medical Research Center named after. ak. E.N. Meshalkin from 2004 to 2021. Parameters of transthoracic echocardiography, pulmonary circulation tensiometry, pulmonary function tests, six-minute walk test and Borg scale were assessed before surgery, after PEA before discharge and after surgery 12 months later. Results. When comparing transthoracic echocardiography data at the hospital stage after PEA, a decrease in right ventricular systolic pressure was revealed from 82.2 ± 23.1 to 44.9 ± 16.2 mm Hg, leading to an improvement in intracardiac hemodynamics, characterizing the right heart function. These improvements continued into the long-term follow-up. Analysis of pulmonary circulation tensiometry in CTEPH patients after PEA showed that all patients had a significant decrease in mean pulmonary artery pressure from 48.3 ± 14.5 to 27.1 ± 10.7 mmHg (by 1.8 times), which was accompanied by a decrease in pulmonary vascular resistance by 2.8 times and an increase in cardiac output. In the long-term follow-up improvements in the pulmonary circulation tensiometry indicators also persisted. When comparing the indicators of pulmonary function tests, a statistically significant decrease in tidal and minute respiratory volumes was revealed. After PEA six-minute walk test distance increased by 19.0 meters, in the long-term follow-up by 60.6 meters; shortness of breath according to the Borg scale decreased from “severe” to “moderate”, in the long-term follow-up to “mild”. Conclusion. The results obtained demonstrate the continuation of the cardiovascular and respiratory systems recovery processes in the immediate postoperative period, and further during the year of observation after PEA, indicate significant reserve capabilities of the cardiovascular and respiratory systems, and the potential cure of patients with CTEPH.