Diagnosis and Treatment Patterns of Chronic Thromboembolic Pulmonary Hypertension in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia: A Registry Study

Abstract

Abstract Background Patients with chronic thromboembolic pulmonary hypertension (CTEPH) in countries with limited resources have, to date, been poorly represented in registries. Objective This work assesses the epidemiology, diagnosis, hemodynamic and functional parameters, and treatment of CTEPH in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia. Methods A prospective, cohort, phase IV, observational registry with 3-year follow-up (n = 212) in patients aged ≥ 18 years diagnosed with CTEPH was created. Clinical, hemodynamic, and functional parameters were obtained at an initial visit, follow-up visits, and a final visit at the end of 3 years’ observation or end of follow-up. Data were recorded on electronic case report forms. Parameters evaluated included 6-minute walking distance (6MWD), use of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), pulmonary hypertension (PH)-targeted therapy, and survival. All statistical analyses were exploratory and descriptive, and were performed in the overall population. Results The most common symptoms were typical of those expected for CTEPH. Almost 90% of patients underwent right heart catheterization at diagnosis or initial study visit. In total, 66 patients (31%) underwent PEA before the initial visit; 95 patients (45%) were considered operable, 115 (54%) were inoperable, and two (1%) had no operability data. Only 26 patients (12%) had been assessed for BPA at their initial visit. PH-targeted therapy was documented at diagnosis for 77 patients (36%), most commonly a phosphodiesterase type 5 inhibitor (23%). Use of PH-targeted therapy increased to 142 patients (67%) at the initial visit, remaining similar after 3 years. Use of riociguat increased from 6% of patients at diagnosis to 38% at 3 years. Between baseline and end of observation, results for patients with paired data showed an increase in 6MWD. Survival at the end of observation was 88%. Conclusions These data highlight the current diagnosis and management of CTEPH in the participating countries. They show that early CTEPH diagnosis remains challenging, and use of off-label PH-targeted therapy is common. ClinicalTrials.gov: NCT02637050; registered December 2015. Graphical Abstract