Incidence and Risk Factors of Chronic Thromboembolic Pulmonary Hypertension Following Acute Pulmonary Embolism

This study aimed to determine the incidence of chronic thromboembolic pulmonary hypertension (CTEPH) following acute pulmonary embolism (PE) and to identify associated risk factors. A total of 256 adult patients diagnosed with acute PE in 2018 and 2019 at a tertiary care center were retrospectively evaluated. Diagnostic and follow-up procedures included clinical scoring, echocardiography, computed tomography pulmonary angiography (CTPA), and/or ventilation/perfusion (V/Q) scintigraphy. To assess the development of CTEPH, we analyzed baseline characteristics and follow-up data for each cohort over a two-year period: 2018 to 2020 for patients diagnosed in 2018, and 2019 to 2021 for those diagnosed in 2019. Right heart catheterization (RHC) findings and follow-up imaging at the third and sixth months were reviewed. Demographic, clinical, laboratory, and radiological variables were compared between patients with and without CTEPH. The incidence of CTEPH was 7.8% (n=20). Right ventricular (RV) dilatation at initial imaging was significantly more frequent in the CTEPH group (p=0.042). At both the third and sixth months, elevated systolic pulmonary artery pressure (sPAP) >50 mmHg, tricuspid regurgitation (TR), and tricuspid regurgitation velocity (TRV) >2.8 m/s were significantly more common in CTEPH patients (p<0.05). No significant association was found with genetic thrombophilia, whereas antiphospholipid antibodies and lupus anticoagulant were more prevalent but not statistically significant. Although rare, CTEPH is associated with high morbidity and mortality but remains potentially curable if diagnosed early. Early signs such as RV dysfunction may help identify high-risk patients. Therefore, structured follow-up protocols are essential to ensure timely diagnosis and referral to specialized centers.