Chronic Thromboembolic Pulmonary Hypertension in Latvia: Epidemiological Insights and Diagnostic Challenges From 2024.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but serious disease caused by persistent thromboembolic obstruction or narrowing of the pulmonary arteries. Its prevalence varies, and many cases remain undiagnosed, contributing to a substantial clinical burden. This study aimed to summarize all CTEPH cases diagnosed in Latvia in 2024, calculate the annual incidence, and present additional epidemiological data from Latvian pulmonary hypertension (PH) registry. Additionally, we sought to document the presence of risk factors in individual patients and analyze their diagnostic pathways leading to a diagnosis of CTEPH. This observational study aimed to analyze diagnostic pathways and identify risk factors in all patients diagnosed with CTEPH in Latvia in 2024. Diagnosis was confirmed at Pauls Stradins Clinical University Hospital according to ESC guideline criteria. Patients completed the emPHasis-10 questionnaire and underwent a structured interview. In 2024, 15 patients were diagnosed with CTEPH in Latvia, corresponding to an annual incidence of 8.01 cases per million. Prevalence was 31.51 per million, and mortality-3.74 per 100 person-years. Patients diagnosed within 2 years of symptom onset had lower pulmonary vascular resistance compared to those diagnosed later. The most common risk factor was prior acute pulmonary embolism (80%). In 60% of cases, diagnosis was delayed by more than 2 years, reflecting late referral to a PH centre. CTEPH remains frequently misdiagnosed and undertreated. Improved recognition of risk factors and stronger collaboration with specialized PH centres are essential to optimize patient management and outcomes.