ic ▁mechanism , ▁that ▁ant ico ag ulation ▁should ▁be ▁superior ▁to ▁anti plate let ▁ther apy ▁at ▁reducing ▁risk ▁of ▁rec urrent ▁stroke . ▁A ▁recent ▁review ▁of ▁the ▁literature ▁supports ▁this ▁hypothesis ▁recomm ending ▁ant ico ag ulation ▁over ▁the ▁use ▁of ▁anti plate let ▁ther apy ▁in ▁patients ▁with ▁P FO ▁and ▁crypt ogen ic ▁stroke . ▁However , ▁more ▁evidence ▁is ▁required ▁comparing ▁of ▁P FO ▁closure ▁with ▁ant ico ag ulation ▁or ▁ant ico ag ulation ▁with ▁anti plate let ▁ther apy . ▁ ▁At rial ▁Sept al ▁De fect ▁ ▁Once ▁someone ▁is ▁found ▁to ▁have ▁an ▁at rial ▁sept al ▁defect , ▁a ▁determ ination ▁of ▁whether ▁it ▁should ▁be ▁corrected ▁is ▁typically ▁made . ▁If ▁the ▁at rial ▁sept al ▁defect ▁is ▁causing ▁the ▁right ▁vent ric le ▁to ▁en large ▁a ▁sec und um ▁at rial ▁sept al ▁defect ▁should ▁generally ▁be ▁closed . ▁If ▁the ▁AS D ▁is ▁not ▁causing ▁problems ▁the ▁defect ▁may ▁simply ▁be ▁checked ▁every ▁two ▁or ▁three ▁years . ▁Method s ▁of ▁closure ▁of ▁an ▁AS D ▁include ▁surg ical ▁closure ▁and ▁per cut aneous ▁closure . ▁ ▁E valu ation ▁prior ▁to ▁correction ▁Prior ▁to ▁correction ▁of ▁an ▁AS D , ▁an ▁evaluation ▁is ▁made ▁of ▁the ▁sever ity ▁of ▁the ▁individual ' s ▁pul mon ary ▁hy pert ension ▁( if ▁present ▁at ▁all ) ▁and ▁whether ▁it ▁is ▁revers ible ▁( closure ▁of ▁an ▁AS D ▁may ▁be ▁recommended ▁for ▁prevent ion ▁purposes , ▁to ▁avoid