What are the options for systemic anticoagulation in the setting of femoral occlusion?

Systemic Anticoagulation for Femoral Occlusion

For acute femoral artery occlusion, immediately initiate unfractionated heparin (UFH) as the first-line systemic anticoagulant unless contraindicated by active bleeding or high bleeding risk. 1

Immediate Anticoagulation Protocol

Unfractionated heparin is the preferred agent for acute limb ischemia from femoral occlusion because of its short half-life, titratability, and ability to limit thrombus propagation while revascularization plans are determined. 1

UFH Dosing for Acute Femoral Occlusion

• Initial bolus: 50-100 units/kg IV (maximum 5,000 units for adults) 1, 2
• Maintenance infusion: 20,000-40,000 units/24 hours (approximately 1,000-2,000 units/hour) 2
• Target ACT: >200 seconds during procedures; for prolonged anticoagulation, target aPTT 1.5-2 times normal or 60-85 seconds 1, 2
• Monitoring: Check aPTT every 4 hours initially, then at appropriate intervals; monitor platelet counts, hematocrit, and occult blood throughout therapy 2

Alternative Parenteral Anticoagulants

If UFH is contraindicated (e.g., heparin-induced thrombocytopenia):

• Direct thrombin inhibitors (argatroban or bivalirudin) can be substituted 1
• Argatroban dosing: 200 mcg/kg IV bolus, then 15 mcg/kg/min infusion (adjust for prior anticoagulation) 1
• Bivalirudin dosing: 0.75 mg/kg bolus, then 1.75 mg/kg/hour infusion 1

Low-molecular-weight heparin (LMWH) is NOT recommended for acute femoral occlusion management because it lacks the rapid titratability needed in this emergency setting and cannot be easily reversed. 1

Transition to Oral Anticoagulation

Once the acute phase is managed and revascularization completed:

Warfarin Transition

• Continue full-dose UFH for several days until INR reaches stable therapeutic range (2.0-3.0) 2, 3
• Target INR: 2.5 (range 2.0-3.0) for most indications 3
• Do not taper heparin—discontinue abruptly once INR is therapeutic 2
• Initial warfarin dose: 2-5 mg daily (lower doses for elderly/debilitated patients) 3

Direct Oral Anticoagulant (DOAC) Transition

• Stop UFH infusion immediately after administering first DOAC dose 2
• No bridging required with DOACs due to rapid onset of action 1
• Preferred over warfarin in most post-revascularization scenarios for ease of management 1

Post-Catheterization Femoral Artery Thrombosis

For iatrogenic femoral artery thrombosis after cardiac catheterization in pediatric patients:

Initial Management

• UFH bolus: 100 units/kg (maximum 5,000 units) at time of arterial access 1
• Continue UFH infusion: 17-20 units/kg/hour for 24-48 hours if pulse loss occurs 1
• Monitor ACT: Target >200 seconds (250-300 seconds for high-risk procedures) 1

Escalation to Thrombolytic Therapy

If pulse remains absent after 24-48 hours of heparinization:

• tPA regimen: 0.5 mg/kg/hour for 1 hour, then 0.25 mg/kg/hour until improvement (typically 4-11 hours) 1
• Alternative short-duration protocol: 0.1 mg/kg bolus followed by 0.5 mg/kg/hour for 6 hours 1
• Success rate: 71% improve with heparin alone; 85% of remaining cases respond to thrombolytics 1
• Requires monitored setting with trained personnel due to bleeding risk (approximately 30% minor bleeding at puncture site) 1

Critical Pitfalls to Avoid

• Never administer UFH to patients already on therapeutic subcutaneous enoxaparin—this "stacking" significantly increases bleeding risk 1
• Do not use fondaparinux alone for acute arterial occlusion—it requires supplementation with an agent possessing anti-IIa activity 1
• Avoid bridging with LMWH when transitioning to oral anticoagulation for most patients—this increases bleeding 20-fold without reducing thromboembolism 4
• Do not resume therapeutic anticoagulation within 24 hours post-procedure in high bleeding-risk scenarios 4, 5
• For patients on chronic anticoagulation undergoing intervention, assess access site hemostasis before restarting therapy and consider body habitus, recent bleeding history, and coagulation abnormalities 1, 5

Special Considerations

For patients with atrial fibrillation or mechanical heart valves requiring long-term anticoagulation after femoral revascularization, oral anticoagulation can typically be resumed within 24 hours post-procedure after careful bleeding risk assessment. 1, 5

Radial access is strongly preferred over femoral access when feasible to minimize vascular complications, particularly in patients requiring ongoing anticoagulation. 1