Long-Term Anticoagulation for Submassive Pulmonary Embolism
A 75-year-old woman presents to the emergency department after experiencing sudden onset, progressive dyspnea over the past 24 hours. She had a right-sided open reduction internal fixation of a stress ankle fracture without complication three days ago. On presentation she is afebrile with blood pressure 110/84 mm Hg, heart rate 123 bpm, respiratory rate 26 bpm, and oxygen saturation is 86% on ambient air, which improves to 96% with three liters of supplemental oxygen via nasal cannula. Troponin T is 0.16 ng/mL (normal <0.04 mg/mL), N-terminal prohormone brain natriuretic peptide (NT-proBNP) is 2,155 pg/mL, and creatinine is 0.8. Her weight is 150 lbs and creatinine clearance is 65 mL/min. Computed tomography angiography (CTA) of the chest reveals large filling defects in the proximal right and left pulmonary arteries and a right to left ventricular ratio of 1.2. Transthoracic echocardiography is remarkable for acute right ventricular strain.
She is placed on an intravenous heparin infusion, and taken to the cardiac catheterization lab for placement of two ultrasound-facilitated infusion catheters in the bilateral pulmonary arteries for low-dose catheter-directed thrombolysis. The procedure is uncomplicated and she receives a total of 24 mg of tPA over 12 hours. The catheters are then removed.
After five more days of parenteral anticoagulation, which of the following long-term anticoagulation strategies would be preferred for this patient?