What labs are required for a patient with pulmonary embolism (PE) to discontinue Eliquis (apixaban)?

From the Guidelines

To determine if a patient with pulmonary embolism (PE) can safely discontinue Eliquis (apixaban), a comprehensive evaluation including laboratory tests and clinical factors is necessary. The patient should undergo a comprehensive coagulation panel including prothrombin time (PT), activated partial thromboplastin time (aPTT), complete blood count (CBC) with platelet count, D-dimer, and specialized thrombophilia testing, as recommended by recent guidelines 1. The thrombophilia panel should include Factor V Leiden mutation, prothrombin gene mutation, protein C and S levels, antithrombin III activity, lupus anticoagulant, anticardiolipin antibodies, and beta-2 glycoprotein antibodies. Renal function tests (creatinine, BUN) and liver function tests are also important as they affect anticoagulant metabolism, and should be considered in the evaluation process 1. These tests help determine if the patient has an underlying hypercoagulable condition that would increase risk of recurrent thrombosis after stopping anticoagulation. The decision to discontinue Eliquis should be based on both laboratory results and clinical factors including the provoked/unprovoked nature of the original PE, time elapsed since the event (typically minimum 3-6 months of treatment), and patient-specific bleeding risks, as outlined in the 2019 ESC guidelines for the diagnosis and management of acute pulmonary embolism 1. This evaluation should always be done under physician supervision with a planned transition strategy if discontinuation is deemed appropriate. Some studies suggest that the use of clinical decision tools, such as the Pulmonary Embolism Rule-Out Criteria, can help guide the evaluation process and reduce the need for unnecessary testing 1. However, the most recent and highest quality study, the 2019 ESC guidelines, should be prioritized in making the decision to discontinue Eliquis 1.

From the FDA Drug Label

The pharmacodynamic effect of apixaban tablets can be expected to persist for at least 24 hours after the last dose, i.e., for about two drug half-lives. When PCCs are used, monitoring for the anticoagulation effect of apixaban using a clotting test (PT, INR, or aPTT) or anti-factor Xa (FXa) activity is not useful and is not recommended.

To determine if a patient with Pulmonary Embolism (PE) can come off Eliquis (apixaban), the following labs should be considered:

• Anti-factor Xa (FXa) activity: Although the label states that monitoring for the anticoagulation effect of apixaban using a clotting test (PT, INR, or aPTT) or anti-factor Xa (FXa) activity is not useful when PCCs are used, it may still be considered in other situations to assess the anticoagulant activity of apixaban.
• PT, INR, or aPTT: These tests may not be useful in monitoring the anticoagulation effect of apixaban, but they can be used to assess the patient's overall coagulation status. It is essential to note that the decision to stop anticoagulation therapy should be made based on the individual patient's risk of thromboembolic events and bleeding complications, and not solely on laboratory results 2.

From the Research

Labs to Order for a Patient with PE Coming Off Eliquis

To determine the appropriate labs to order for a patient with pulmonary embolism (PE) who wants to come off Eliquis (apixaban), consider the following:

• The patient's clinical probability of PE and risk of recurrence should be assessed 3
• D-dimer testing can be used to stratify patients with unprovoked venous thromboembolism (VTE) for the risk of recurrence, but its use in this context is not recommended 4
• The decision to extend anticoagulation should not be based on D-dimer testing alone 4
• Apixaban has been shown to be effective and safe for the treatment and secondary prevention of VTE, with a reduced risk of major bleeding compared to warfarin 5, 6, 7

Relevant Lab Tests

Some relevant lab tests to consider in this scenario include:

• D-dimer test: although not recommended for determining the need for extended anticoagulation, it can be used to assess the patient's risk of recurrence 4
• Complete blood count (CBC): to monitor for signs of bleeding or thrombocytopenia
• Renal function tests: to assess the patient's kidney function and adjust the apixaban dose as needed
• Liver function tests: to monitor for signs of liver injury or dysfunction

Considerations for Stopping Anticoagulation

When considering stopping anticoagulation in a patient with PE, it is essential to weigh the risks and benefits of continued treatment. Factors to consider include:

• The patient's risk of recurrence and the potential consequences of another PE event
• The patient's risk of bleeding and the potential consequences of a major bleeding event
• The patient's overall health status and any comorbid conditions that may affect their risk of recurrence or bleeding 3, 6, 7