During the recent years, catheter-based closure of atrial septal defect (ASD) or patent foramen ovale (PFO) has become an effective and safe therapy for the curative treatment of patients with hemodynamically significant inter-atrial shunts [1]. Patients receiving this therapy present a peri-procedural risk of symptomatic thrombo-embolism of 1% to 2% [2] which raises to higher figures for asymptomatic episodes [3] and appears to be independent of the closure device used. In these patients, thrombus formation occurs more commonly in the setting of the procedure (through the delivery sheath or within the closure device).
