What are the conditions for bridging anticoagulation (anticoagulant) therapy?

From the Guidelines

Bridging anticoagulation therapy is recommended for patients at high thrombotic risk who require temporary interruption of their long-term anticoagulant for surgery or procedures, as stated in the 2022 American College of Chest Physicians clinical practice guideline 1. The conditions for bridging anticoagulation therapy include:

• Mechanical heart valves (particularly mitral position)
• Recent venous thromboembolism (within 3 months)
• Atrial fibrillation with CHADS2 score ≥4
• Recent stroke/TIA (within 3 months) The standard bridging protocol involves discontinuing warfarin 5 days before the procedure and starting therapeutic-dose low molecular weight heparin (LMWH) such as enoxaparin 1 mg/kg twice daily when the INR falls below 2.0, as defined in the 2022 guideline 1. Some key points to consider when deciding on bridging anticoagulation therapy include:
• The risk of thromboembolism during interruption of VKA anticoagulation, as discussed in the 2021 ACC/AHA guideline 1
• The risk of bleeding complications, as mentioned in the 2017 AHA/ACC focused update 1
• The use of alternative agents, such as intravenous UFH or subcutaneous LMWH, to minimize the risk of adverse events, as recommended in the 2014 AHA/ACC guideline 1 The decision to use bridging anticoagulation therapy should be individualized and based on the patient's specific risk factors and clinical context, as emphasized in the 2022 guideline 1.

From the FDA Drug Label

5.2 Hemorrhage Avoid using heparin in the presence of major bleeding, except when the benefits of heparin therapy outweigh the potential risks.

Use heparin sodium with caution in disease states in which there is increased risk of hemorrhage, including: • Cardiovascular - Subacute bacterial endocarditis, severe hypertension • Surgical - During and immediately following (a) spinal tap or spinal anesthesia or (b) major surgery, especially involving the brain, spinal cord, or eye. • Hematologic - Conditions associated with increased bleeding tendencies, such as hemophilia, thrombocytopenia and some vascular purpuras • Patients with hereditary antithrombin III deficiency receiving concurrent antithrombin III therapy • Gastrointestinal - Ulcerative lesions and continuous tube drainage of the stomach or small intestine. • Other - Menstruation, liver disease with impaired hemostasis.

The conditions for bridging anticoagulation therapy are not explicitly stated in the provided drug label. However, the label does provide information on when to avoid or use with caution heparin therapy due to an increased risk of hemorrhage.

• Bridging is typically considered when a patient is at a high risk of thromboembolism and is being transitioned from one anticoagulant to another, or when anticoagulation needs to be temporarily interrupted for a procedure.
• The decision to bridge should be made on a case-by-case basis, taking into account the individual patient's risk factors for thromboembolism and bleeding.
• Key considerations include the patient's underlying medical condition, the reason for anticoagulation, and the potential risks and benefits of bridging therapy 2.

From the Research

Conditions for Bridging Anticoagulation Therapy

The conditions for bridging anticoagulation therapy are as follows:

• Patients who require oral anticoagulation (OAC) after cardiac surgery due to an increased risk for thromboembolic events should receive bridging therapy with heparin until the INR is in a therapeutic range 3.
• Bridging therapy with low-molecular-weight heparin is usually recommended in patients who must stop oral anticoagulants before surgical or invasive procedures 4.
• The decision to provide bridging therapy requires careful consideration of the relative risks of thromboembolism and bleeding in each patient 5.
• Patients at intermediate-to-high thromboembolic risk requiring interruption of vitamin K antagonists (VKAs) should receive a therapeutic dose of unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) 5.

Patient-Specific Factors

Patient-specific factors that influence the decision for bridging anticoagulation therapy include:

• Thromboembolic risk: patients with mechanical heart valves, atrial fibrillation, or other conditions that increase the risk of thromboembolism may require bridging therapy 3, 4.
• Bleeding risk: patients with a high risk of bleeding may require a lower dose or a different type of anticoagulant 3, 4.
• Renal function: patients with renal insufficiency may require dose adjustments 3.

Anticoagulant Options

The following anticoagulants can be used for bridging therapy:

• Unfractionated heparin (UFH) 3, 5, 6.
• Low-molecular-weight heparin (LMWH) 3, 4, 5, 6, 7.
• The choice of anticoagulant depends on the patient's specific needs and the procedure being performed 3, 4, 5, 6.