Prevalence of Pulmonary Arterial Thrombosis in Adults With Eisenmenger Syndrome

Patients with Eisenmenger syndrome (ES) are at increased risk of thrombotic events, especially in pulmonary vessels. However, both the prevalence and risk factors of pulmonary arterial thrombosis (PAT) have been varied greatly. In this study we sought to examine the prevalence of PAT in adult patients with ES and to identify risk factors. A cross-section descriptive study examining 57 adult patients with ES. All patients underwent computed tomography pulmonary angiography (CTPA) and echocardiography. Echocardiographic parameters and laboratory data were analysed from 57 patients. PAT prevalence was 22.8% (13/57), with all thrombi localized to dilated proximal pulmonary arteries (main pulmonary artery diameter: 52.6 ± 6.2 vs. 40.1 ± 6.9 mm in non-thrombosis group, <i>p</i> < 0.05). Thrombotic patients exhibited higher D-dimer (0.7 [IQR: 0.5-1.9] vs. 0.3 [IQR: 0.2-0.6] mg/L, <i>p</i> < 0.05) and NT-proBNP levels (2561.0 [1389.0-5904.3] vs. 695.4 [180.6-2452.7] pg/mL, <i>p</i> < 0.05), alongside reduced right ventricular fractional area change (RV FAC: 23.9 ± 5.5% vs. 32.4 ± 10.0%, <i>p</i> < 0.05). No differences were observed in age, oxygen saturation, hemoglobin, coagulation profiles, or right heart catheterization parameters (mPAP, PVR, mRAP). PAT affects nearly one-quarter of ES patients, routine CTPA screening should be considered even in asymptomatic cases. The lack of association with conventional risk factors underscores the need for thrombosis risk stratification integrating anatomical and biomarker criteria.