Should warfarin (anticoagulant) for antiphospholipid syndrome be bridged with enoxaparin (Lovenox, low molecular weight heparin)?

From the Guidelines

Warfarin therapy for antiphospholipid syndrome should not be bridged with enoxaparin in most patients, but may be considered in high-risk patients with recurrent thrombotic events, triple-positive antibody status, or recent thrombosis. When bridging is necessary, enoxaparin can be used at therapeutic doses (1 mg/kg twice daily or 1.5 mg/kg once daily) when the INR falls below 2.0, stopping 24 hours before the procedure, and resuming 24-72 hours after the procedure depending on bleeding risk, as suggested by 1. The decision to bridge should be individualized based on thrombotic risk, and warfarin should be restarted as soon as hemostasis is adequate. This approach is supported by the most recent guidelines, which recommend against routine bridging with low-molecular-weight heparin, except in patients with high thrombotic risk, as stated in 1. Key considerations include:

• Thrombotic risk assessment to determine the need for bridging
• Use of therapeutic doses of enoxaparin when bridging is necessary
• Timing of enoxaparin administration in relation to the procedure
• Resumption of warfarin therapy as soon as possible after the procedure
• Balancing the risks of thrombosis and bleeding in the perioperative period, as discussed in 1 and 1.

From the Research

Anticoagulation Management in Antiphospholipid Syndrome

• The use of warfarin as an anticoagulant in antiphospholipid syndrome (APS) is well-established, but there are situations where bridging with enoxaparin (a low molecular weight heparin) may be necessary 2.
• A study published in 2004 investigated the efficacy and safety of a standardized periprocedural anticoagulation regimen with low-molecular-weight heparin in patients at increased risk for arterial thromboembolism who required temporary interruption of warfarin therapy 2.
• The results of this study showed that a standardized periprocedural anticoagulant regimen with low-molecular-weight heparin is associated with a low risk of thromboembolic and major bleeding complications 2.

Role of Low Molecular Weight Heparin in APS

• Low molecular weight heparin (LMWH) may be a safe and effective alternative to warfarin for APS patients, particularly those who have not responded to or tolerated oral vitamin K antagonists 3.
• A study published in 2011 evaluated the effectiveness and safety of long-term LMWH in patients with APS and found that most patients showed good quality of life with no evidence of recurrent thrombotic events 3.
• However, the use of LMWH in APS patients requires careful monitoring of anticoagulation intensity, as lupus anticoagulant can affect phospholipid-dependent coagulation monitoring tests 4, 5.

Monitoring of Anticoagulation in APS

• Accurate assessment of anticoagulation intensity is essential to optimize anticoagulant dosing and minimize the risk of recurrent thrombosis or bleeding in APS patients 4, 5.
• The international normalized ratio (INR) may not be representative of anticoagulation intensity in patients with APS on warfarin due to an interaction between lupus anticoagulant and the thromboplastin reagent used in the INR determination 5.
• The role of direct oral anticoagulants in APS is not established, and their use requires further study 4, 6.