Thrombus formation on an atrial septal defect closure device: a case report and review of the literature.

We report on a case of a mobile left atrial thrombus formation on an atrial septal defect occluder system (28 mm StarFLEX-Occluder) despite 6 months of postprocedural anticoagulation with phenprocoumon and platelet antiaggregation with aspirin in a 69-year-old woman. The closure was performed because of a significant left to right atrial shunt (Qp/Qs 1.8) with enlargement of the right atrial and ventricular cavities and impairment of right ventricular function in the presence of persistent atrial fibrillation and chronic heart failure (NYHA II-III). The 6-month follow up by transoesophageal echocardiography (TEE) revealed the floating thrombus located at the left atrial side of the occluder.