BACKGROUND Prevalence of patent foramen ovale (PFO) is higher in patients with paradoxical embolism and associated with increased risk for recurrent thromboembolic events. By percutaneous closure of PFO, surgical closure or permanent oral anticoagulation can be avoided. So far, published series included different occluder systems and various indications and regimens of postprocedural anticoagulation. The aim of the present study was to evaluate the short- and long-term results after implantation of the Starflex occluder in patients with PFO using an intensified anticoagulation regimen. METHODS AND RESULTS 154 patients with PFO (94 men; age: 44 +/- 13 years) and >or=1 thromboembolic event were included. Other causes for embolism were excluded. PFO closure was successful in 147 patients (95.5%). All patients were treated with phenprocoumon (INR 2.5) and aspirin (100 mg/die) for 6 months. Transesophageal echocardiography (TEE) was repeated at 6 months. Mean clinical follow-up period was 26 +/- 18 months. After 6 months, five patients had a significant residual shunt, and five patients had suspected thrombus formation on the occluder. In three of these five patients, the occluder was surgically removed and foreign body reaction was noted. During follow-up, nine patients suffered from neurological events (two strokes, seven transient ischemic attacks [TIA]), though complete closure of the PFO was documented by TEE. Two patients died during follow-up; three patients had bleeding complications. CONCLUSION Percutaneous closure of PFO in symptomatic patients by Starflex occluder represents an effective therapy with a low incidence of periinterventional complications and recurrent thromboembolism. However, thrombus formation at the occluder system may occur in some patients despite an aggressive anticoagulation regimen.