Q. A 58-year-old man underwent a coronary artery bypass graft (CABG) with an internal mammary graft four days ago and is now under observation in ICU for the complication of anesthesia. Following the surgery, he receives an antibiotic (Imipenem), analgesic (acetaminophen), and anticoagulant (enoxaparin). He had coronary angiography and stenting six years ago and a right hip replacement three years ago. He has hypertension and hypercholesterolemia, and both are controlled with medications. Today morning, he developed severe edema and pain in his right leg. Elevation and compression dressing was not effective. The right leg is swollen and tender to palpation. Distal pulses are palpable. Passive stretching of the toes is not painful, but passive dorsiflexion of the right ankle is painful. Today’s lab tests show platelet count 95,000/microL (in the last test, it was 210,000/microL), PT 14 sec, aPTT 52 sec, and D-Dimer 340 ng/mL. Other findings in the lab tests are unremarkable. Ultrasound of the leg shows thrombosis in the deep vein of the right leg. What is the best plan for anticoagulation therapy for him?