Pulmonary Thrombosis in Adults with Eisenmenger Syndrome

OBJECTIVES: We sought to determine the prevalence of pulmonary artery thrombosis in patients with Eisenmenger syndrome and to identify individuals at highest risk. BACKGROUND: Eisenmenger syndrome is associated with pulmonary arterial thrombus formation. Both the prevalence and the determinants of pulmonary arterial thrombosis are unknown. METHODS: This is a review of patients with Eisenmenger syndrome seen at the Toronto Congenital Cardiac Centre for Adults, Canada. Patients underwent a contrast-enhanced computed tomographic (CT) scan of the thorax. RESULTS: Forty-nine consecutive patients with Eisenmenger syndrome were seen in our hospital. Fifteen patients did not undergo CT angiograms; therefore, 34 patients (mean age 42 ± 10 years) were included in the study. Responsible shunts included ventricular septal defect (65%), atrial septal defect (15%), patent ductus arteriosus (9%), and other (11%). The prevalence of proximal pulmonary artery thrombus was 21% (7/34) of patients. Evidence of more distal vessel thrombosis was observed in 43% (3/7) of the patients who had visible thrombus in the proximal pulmonary arteries. Patients with thrombus were more likely to be female (86% vs. 37%, p = 0.04) and to have lower oxygen saturations (72% ± 9% vs. 85% ± 6%, p = 0.01). Differences in functional status did not identify patients at highest risk for thrombosis. CONCLUSIONS: Patients with Eisenmenger syndrome have a substantial risk of pulmonary artery thrombus formation. Women and patients with lower oxygen saturations are at the highest risk of developing thrombosis. In the context of an increased bleeding tendency in these patients, the role of anticoagulation treatment needs to be determined.