apy ▁only . ▁Pre vious ▁studies ▁did ▁not ▁identify ▁a ▁clear ▁benefit ▁of ▁P FO ▁closure ▁over ▁anti plate let ▁ther apy ▁in ▁reducing ▁rec urrent ▁is chem ic ▁stroke . ▁However , ▁based ▁on ▁new ▁evidence ▁ ▁and ▁system atic ▁review ▁in ▁the ▁field , ▁per cut aneous ▁P FO ▁closure ▁in ▁addition ▁to ▁anti plate let ▁ther apy ▁is ▁suggested ▁for ▁all ▁who ▁meet ▁all ▁the ▁following ▁criteria : ▁▁ ▁Age ▁ ≤ ▁ 6 0 ▁years ▁at ▁on set ▁of ▁first ▁stroke , ▁Em bol ic - app ear ing ▁crypt ogen ic ▁is chem ic ▁stroke ▁( i . e ., ▁no ▁evident ▁source ▁of ▁stroke ▁despite ▁a ▁compreh ensive ▁evaluation ), ▁and ▁ ▁P FO ▁with ▁a ▁right - to - left ▁inter at rial ▁sh unt ▁detected ▁by ▁b ubble ▁study ▁( ech oc ardi ogram ) ▁ ▁A ▁variety ▁of ▁P FO ▁closure ▁devices ▁may ▁be ▁impl anted ▁via ▁c ath eter - based ▁procedures . ▁ ▁Medical ▁Ther apy ▁ ▁Based ▁on ▁the ▁most ▁up ▁to ▁date ▁evidence , ▁P FO ▁closure ▁is ▁more ▁effective ▁at ▁reducing ▁rec urrent ▁is chem ic ▁stroke ▁when ▁compared ▁to ▁medical ▁ther apy . ▁In ▁most ▁of ▁these ▁studies , ▁anti plate let ▁and ▁ant ico ag ulation ▁were ▁combined ▁in ▁the ▁medical ▁ther apy ▁arm . ▁Although ▁there ▁is ▁limited ▁data ▁on ▁the ▁effect iveness ▁of ▁ant ico ag ulation ▁in ▁reducing ▁stroke ▁in ▁this ▁population , ▁it ▁is ▁hypoth es ized ▁that ▁based ▁on ▁the ▁em bol