Transcatheter closure of atrial septal defect and patent foramen ovale in adult patients using the Amplatzer occlusion device: no evidence for thrombus deposition with antiplatelet agents.

Transcatheter closure of atrial septal defect (ASD) and patent foramen ovale (PFO) using the Amplatzer septal occluder (AGA Medical, Minneapolis, Minn) is an alternative to surgical closure. There are only limited data on the thrombogenic potential of the device. Thirty-seven patients (14 men, 23 women) underwent device closure of their ASD (n = 21) or PFO (n = 16) at a mean age of 47 +/- 14 years (range, 18-72). The device was successfully deployed in all patients. Thirty-three of 37 patients received antiplatelet therapy with clopidogrel bisulfate and aspirin for a total of 6 months. Four patients in atrial fibrillation were also anticoagulated (international normalized ratio 2.0 to 3.0). No thrombus was detected in any patient on either side of the device by transthoracic and transesophageal echocardiography and there were no cases of symptomatic thromboembolism. Right-to-left interatrial shunting was diagnosed by contrast transesophageal echocardiography with the Valsalva's maneuver. At 1-month follow-up, minimal right-to-left shunting was detected in 6 patients (2 PFO, 4 ASD). Two patients (PFO) had minimal shunting at 1 month but not at 6 months. In 3 patients (ASD), inducible right-to-left shunting persisted at 6 months. In conclusion, our results obtained from a modest number of patients indicate that antiplatelet therapy is safe and effective in preventing thrombus formation on the septal occluder surface.