What is the best anticoagulation strategy for a patient with a progressing thrombus on Eliquis (apixaban)?

From the Guidelines

For a patient with a progressing thrombus despite being on Eliquis (apixaban), the best approach is to switch to therapeutic-dose low molecular weight heparin (LMWH) such as Lovenox (enoxaparin) 1 mg/kg twice daily, as indicated by the most recent guidelines 1. When considering the management of a patient with atrial fibrillation (AFib) on apixaban who develops a new partially occluded thrombus, the primary concern is the failure of the current anticoagulation strategy to prevent thrombus progression.

• The patient's current anticoagulation regimen with Eliquis (apixaban) 5mg bid has not been effective in preventing thrombus progression, suggesting a need for an alternative approach.
• According to the 2020 ACC expert consensus decision pathway for anticoagulant and antiplatelet therapy in patients with atrial fibrillation or venous thromboembolism 1, bridging with low molecular weight heparin (LMWH) is recommended in certain scenarios, particularly when there is a need for more intense anticoagulation.
• LMWH, such as Lovenox (enoxaparin), offers a more predictable anticoagulation effect and a different mechanism of action compared to direct oral anticoagulants (DOACs) like apixaban, making it a suitable option for patients who have failed DOAC therapy.
• The decision to discontinue Eliquis and start Lovenox is based on the principle of switching to a therapeutic strategy that provides more reliable anticoagulation in the setting of treatment failure, as suggested by the guidelines 1. Key considerations in this approach include:
• Close monitoring of the patient after initiating LMWH, with repeat imaging in 1-2 weeks to assess the response of the thrombus to the new anticoagulation regimen.
• Investigation into the underlying cause of apixaban failure, including potential issues with medication adherence, drug interactions, or underlying conditions that may affect the efficacy of DOACs.
• The potential need for long-term anticoagulation and the choice of anticoagulant, balancing the risks of thrombosis and bleeding, as outlined in the consensus decision pathway 1.

From the FDA Drug Label

1. 1 Increased Risk of Thrombotic Events after Premature Discontinuation Premature discontinuation of any oral anticoagulant, including apixaban tablets, in the absence of adequate alternative anticoagulation increases the risk of thrombotic events.

The patient is already on Eliquis (apixaban) for atrial fibrillation (AFib) and has developed a new partially occluded thrombus in the proximal superficial femoral vein.

• The drug label does not provide direct guidance on managing a progressing thrombus in a patient already on apixaban.
• However, it does warn against premature discontinuation of apixaban, which increases the risk of thrombotic events.
• There is no clear recommendation to discontinue apixaban and start Lovenox in this scenario.
• Given the lack of direct guidance, a conservative approach would be to consider alternative anticoagulation strategies under the guidance of a specialist, while being cautious of the risks associated with premature discontinuation of apixaban 2.

From the Research

Anticoagulation Strategy for Progressing Thrombus on Eliquis

• The patient is currently taking Eliquis (apixaban) 5mg bid for atrial fibrillation and has a new partially occluded thrombus noted within the proximal superficial femoral vein.
• The optimal anticoagulation strategy for a patient with a progressing thrombus on Eliquis is unclear, but studies suggest that switching to a different anticoagulant may be necessary 3.
• A study published in the Journal of Thrombosis and Thrombolysis found that there was no difference in recurrent thrombosis-free survival or major bleeding event among patients treated with dabigatran, warfarin, or enoxaparin after failure of initial direct oral anticoagulation (DOAC) therapy 3.

Bridging Therapy with Enoxaparin

• Enoxaparin may be a suitable option for bridging therapy in patients with a high risk of thromboembolic events 4.
• A study published in VASA found that a half-therapeutic dose regimen of enoxaparin was safe and effective for bridging in patients with a target INR of 2.0 to 3.0 4.
• However, the decision to switch to enoxaparin should be made on a case-by-case basis, taking into account the patient's individual risk factors and medical history.

Selecting the Right Anticoagulant

• The choice of anticoagulant should be based on the patient's individual needs and risk factors 5, 6.
• A study published in the European Review for Medical and Pharmacological Sciences found that apixaban had a lower rate of stroke and thromboembolic events compared to acenocumarol in patients with non-valvular atrial fibrillation 5.
• Another study published in Expert Opinion on Pharmacotherapy found that once-daily versus twice-daily regimens of direct oral anticoagulants had practical implications for patient adherence and persistence to therapy 6.

Platelet Cut-off for Anticoagulant Therapy

• In patients with thrombocytopenia, the platelet cut-off for safe administration of low molecular weight heparin (LMWH) is an important consideration 7.
• An expert consensus published in Blood Transfusion found that LMWH at therapeutic doses may be safe for patients with platelet counts between 50-100 x 10^9/L, but dose reduction or alternative therapies may be necessary for patients with lower platelet counts 7.