Prospective, multicenter observational study, of the effectiveness of a standard of care protocol implemented to enhance home treatment of VTE. Study population will be selected as part of usual care as eligible for home treatment. Study personnel will travel to participating institutions to qualify the sites, deliver a Powerpoint® lecture to introduce the protocol, meet and train site principal investigators, emergency physicians and research personnel on the implementation of the protocol as part of usual clinical care, and data collection methods for a quality assurance registry with plans to use the data collected in this registry in future publications. Follow-up will be 30 days using medical records and/or telephone interview to assess for primary outcomes of bleeding or VTE recurrence.

Inclusion Criteria:

1. Patients must be low risk, as defined by either A or B below:

   A. The modified Hestia criteria:

   • Systolic blood pressure > 100 mm Hg
   • No thrombolysis needed
   • No active bleeding
   • SaO2 >94% while breathing room air
   • Not already anticoagulated
   • No more than two doses of IV narcotics in the emergency department
   • Other medical or social reasons to admit
   • Creatinine clearance >30mL/min
   • Not pregnant, severe liver disease or heparin induced thrombocytopenia OR

   B. The physician opinion that a patients' overall social and medical situation is favorable for home treatment and the patient has a zero score on the simplified pulmonary embolism severity index (sPESI).

   All of the following must true:

   • Age < 81 years
   • No history of cancer
   • No history of heart failure or chronic lung disease
   • Pulse < 110 beats/min
   • SBP > 99 mm Hg
   • O2 sat >89%%

   We have chosen either criteria because both have been found equal in terms of safety for outpatient treatment of PE.6,22 Hestia includes implicit questions that most emergency physicians would use as criteria for discharge (e.g., overall medical status and social situation), whereas sPESI does not. For that reason, we have added the additional gestalt assessment question about physician discretion.

2. Patients must be discharged in <24 hours after triage in an ED visit with diagnosis of VTE using objective criteria in the emergency department.

Exclusion Criteria:

• VTE diagnosis while taking anticoagulants with evidence of compliance (e.g., physician opinion that patient is taking a Eliquis®, Xarelto® or Pradaxa®, low molecular weight heparin injections or warfarin as prescribed for any condition)
• Sensitivity or contraindication to use of apixaban
• Troponin assay value, drawn as part of usual care and found to be positive, using local standards
• High risk for hemorrhage defined by a score>1.5 using the method of Ruiz Gimenez.3 (Note that several criteria are already excluded by Hestia):

Recent major bleeding, 2 points Creatinine levels >1.2 mg/dl, 1.5 points Anemia, 1.5 points Cancer, 1 point Clinically overt PE, 1 point Age >75 years, 1 point

Emergency department patients with new or recurrent VTE deemed low-risk by modified Hestia or clinician discretion and sPESI (-).