Is heparin an option for bridging anticoagulation in a 65-year-old male with a history of Deep Vein Thrombosis (DVT) and prior stroke when transitioning off Coumadin (warfarin)?

From the Guidelines

Heparin bridging is a viable option for this patient, and low molecular weight heparin (LMWH) such as enoxaparin is typically the preferred choice. For bridging, the standard regimen would be enoxaparin 1 mg/kg twice daily subcutaneously, or 1.5 mg/kg once daily, as defined by the American College of Chest Physicians clinical practice guideline 1. This patient's history of DVT and stroke when off Coumadin suggests he is at high risk for thromboembolism, making bridging particularly important.

Key Considerations

• Bridging should begin when the INR falls below 2.0, typically 3-5 days before a procedure, and should continue until the INR is therapeutic (2.0-3.0) when restarting warfarin.
• Weight-based dosing is essential, and renal function should be assessed before prescribing LMWH since dose adjustments are needed for patients with kidney impairment.
• The decision to bridge should balance the risk of thromboembolism and bleeding, as bridging increases bleeding risk.

Bridging Regimen

• Therapeutic-dose LMWH, such as enoxaparin 1 mg/kg bid or 1.5 mg/kg daily, is the recommended bridging regimen 1.
• Unfractionated heparin (UFH) can also be used, but it is less often preferred due to the need for monitoring and administration in a clinical setting.

Patient-Specific Factors

• This patient's history of stroke when off anticoagulation suggests he is at high risk for thromboembolism, making bridging particularly important.
• The increased cost of bridging anticoagulation should be weighed against the potential benefits of preventing thromboembolic events.

From the FDA Drug Label

2.7 Converting to Warfarin To ensure continuous anticoagulation when converting from Heparin Sodium Injection to warfarin, continue full heparin therapy for several days until the INR (prothrombin time) has reached a stable therapeutic range. Heparin therapy may then be discontinued without tapering [see Drug Interactions (7.1)].

Bridging with heparin is an option for patients transitioning from warfarin to another anticoagulant or when warfarin needs to be temporarily discontinued.

• Key considerations:
  • The patient has a history of DVT and prior stroke, indicating a need for anticoagulation.
  • Heparin can be used for bridging anticoagulation when warfarin is discontinued.
  • The dosage and administration of heparin should be guided by the patient's clinical condition and laboratory results, as outlined in the drug label 2.
• Clinical decision: Heparin can be considered for bridging anticoagulation in this patient, but the decision should be made on a case-by-case basis, taking into account the patient's individual risk factors and clinical condition.

From the Research

Heparin as a Bridging Option

• The patient has a history of DVT and prior stroke, and is inquiring about heparin for bridging when going off Coumadin 3.
• Heparin can be used for bridging in patients with an increased risk of DVT, such as those with a history of DVT or stroke 4.
• Low-molecular-weight heparin (LMWH) is preferred over unfractionated heparin due to its greater ease of administration, fewer laboratory monitoring requirements, and feasibility of use on an outpatient basis 4.

Safety and Efficacy of Heparin

• Fondaparinux, a type of LMWH, has been shown to be safe and effective for VTE prophylaxis in patients with ischemic stroke, with no significant difference in major hemorrhage rates compared to unfractionated heparin 5.
• The absolute major bleeding risk of LMWH agents is low, with once-daily dosing associated with a lower bleeding risk compared to twice-daily dosing 6.
• Low-dose heparin, LMWH, and heparinoids have been shown to be safe and effective in preventing DVT in stroke patients, with the heparinoid danaparoid providing solid evidence for efficacy 7.

Cost Considerations

• The use of LMWH instead of warfarin for VTE prophylaxis increases costs, but is more effective for preventing DVT and death at a relatively small incremental cost per DVT event avoided and cost per death averted 4.
• Fondaparinux is more cost-effective than enoxaparin for VTE prophylaxis, with a cost saving that increases progressively over time 4.