perioperative/post operative ventricular clot

My husband developed a ventricular clot after knee surgery. He was post MI ( STEMI ) which had occurred two years earlier and was on Plavix which had been stopped for surgery. TEE showed evidence of old apical ventricular clot, presumably at the time of the MI. It was theorized that new clot formed after the Plavix was stopped and embolized when it was resumed since he suffered a right MCA stroke 21 days post op. He is now on Coumadin and needs right hip replacement.  Bridging with Lovenox pre and post op is planned.  Should he have TEE during or after this surgery? If clot is detected how would it be treated? Would Pradaxa be considered instead of Coumadin post op? Thank you for your input.