The most important factors associated with device-related erosion have been reported to be the implantation of an oversized device and the moving of the device relative to the heart.22,23 Transcatheter PFO closure has been reported to be safe and effective in these patients due to the increased risk for paradoxical embolism.24 Recent reports have suggested that even in patients with mutations in factor V Leiden, factor X, factor VIII, protein C, protein S, and MTHFR as well as those with positive antiphospholipid/anticardiolipin antibodies, transcatheter PFO closure may be beneficial.24 This evidence concerns the gene MTHFR and Embolism, Paradoxical.