after a heart attack 2 years ago, my husband had 2 stents put in his artery known as "the widow-maker". now he is suffering from severe knee, calf and foot swelling in his left leg. he has just be treated for a blod clot and is on a cumadin, plavix, aspirin regime. arthritis, as well as gout has been ruled out. what could be the root cause of his swelling?