Sleep-related breathing disorders in patients with chronic thromboembolic pulmonary hypertension

Relevance. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare severe form of pulmonary hypertension due to pulmonary artery obstruction. According to a number of previously published studies, sleep-disordered breathing (SDB) was frequently observed in patients with CTEPH. However, despite the high incidence both in the general population and in this group of patients, the aggravating effect of SDB on the clinical picture of CTEPH has not been sufficiently studied. Aim: to analyze the occurrence of various sleep-disordered breathing, as well as to study the aspects and relationships of identified disorders with the parameters of the clinical and hemodynamic status in patients with chronic thromboembolic pulmonary hypertension. Materials and methods. It was included 67 patients with a verified diagnosis of CTEPH, hospitalized from February 2021 to December 2023. The general clinical condition (anamnesis, examination, anthropometric data), echocardiography and right heart catheterization (RHC) data were assessed. Questionnaire survey was conducted using international questionnaires (STOP-Bang, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index) and one of the methods of multifunctional sleep study was performed. Statistical data processing was performed using MedCalc Statistical Software and Microsoft Office Excel. Results. In the sample, the median age was 59.0 years, 48 (71.6%) people were overweight, the incidence of any sleep-disordered breathing was 83.6%. A significant relationship (classical correlation) was determined between the distance in the six-minute walking distance and apnea-hypopnea index (AHI) (r=−0.447; p=0.0015), minimum night saturation (r=0.373; p=0.009) and average night saturation (r=0.341; p=0.0176). The total score on the STOP-Bang scale ≥3 shows a sensitivity of 52.2% and a specificity of 69.1% (AUC=0.653; p=0.02;), that doesn’t allow considering the STOP-Bang scale as an effective screening method in this category of patients. Сonclusion. The revealed reliable correlations between the apnea-hypopnea index and the six-minute walking distance, daytime saturation at rest and after exercise in patients with CTEPH may indicate the influence of various SDB severity on the clinical picture of the underlying disease.