Review Question - QID 108415

A 79-year-old female presents to the emergency department with shortness of breath. The patient is tachycardic and complains of pleuritic chest pain. The patient has a blood pressure of 130/75 mmHg, pulse of 100/min, and is afebrile. The patient has a past medical history of hypertension, dyslipidemia, spontaneous hemorrhagic stroke treated two weeks ago in the emergency department, obesity and a significant smoking history of 15 pack-years. Current medications include lisinopril, hydrochlorothiazide, and zolpidem for sleep. An EKG performed in the emergency department demonstrates the findings in Figure A. A chest radiograph is performed demonstrating the findings in Figure B. Lab studies are performed demonstrating an elevated D-dimer. A follow-up ultrasound with Doppler demonstrates several thrombi within the veins of the lower extremity. Which of the following represents the best next step in management for this patient?