Anticoagulation in Cortical Venous Thrombosis
For patients with cortical venous thrombosis (cerebral vein or venous sinus thrombosis), initiate therapeutic anticoagulation immediately and continue for at least 3 months, using the same regimens as for other venous thromboembolism. 1
Initial Anticoagulation Strategy
Start with parenteral anticoagulation using one of the following options:
- Low-molecular-weight heparin (LMWH) at weight-adjusted therapeutic dose (preferred) 1, 2
- Unfractionated heparin (UFH) via continuous IV infusion if LMWH is contraindicated 1
The strong recommendation for anticoagulation in cerebral venous thrombosis is based on preventing thrombosis extension and reducing mortality, despite the theoretical concern about hemorrhagic transformation. 1 This represents a critical clinical decision where the benefits of anticoagulation clearly outweigh bleeding risks in most patients.
Transition to Oral Anticoagulation
For treatment-phase therapy (first 3 months), transition to a direct oral anticoagulant (DOAC) rather than warfarin:
- Apixaban, rivaroxaban, edoxaban, or dabigatran are all strongly recommended over vitamin K antagonists 1
- Start oral anticoagulation early (within 24 hours of initiating heparin) 1
- Continue parenteral anticoagulation for minimum 5 days AND until therapeutic oral anticoagulation is established 1
If DOACs are contraindicated or unavailable, use warfarin:
- Target INR: 2.5 (range 2.0-3.0) 1, 4
- Continue heparin until INR ≥2.0 for at least 24 hours on 2 consecutive days 1
Minimum Treatment Duration
All patients with cerebral venous thrombosis require at least 3 months of therapeutic anticoagulation. 1 This is a strong recommendation with low-certainty evidence, reflecting the serious nature of this condition and the established benefit of anticoagulation despite limited high-quality trials specific to cerebral venous thrombosis.
Extended-Phase Anticoagulation Considerations
After completing 3 months of treatment, assess for extended anticoagulation:
- If the thrombosis was unprovoked (no clear transient risk factor), strongly consider extended anticoagulation with a DOAC 1, 5
- If associated with a major transient risk factor (e.g., surgery, trauma), stop anticoagulation after 3 months 1
- Reassess bleeding risk and thrombosis risk at least annually if continuing extended therapy 5
Special Populations
For cancer-associated cerebral venous thrombosis:
- Use oral factor Xa inhibitors (apixaban, edoxaban, or rivaroxaban) over LMWH for initial and long-term treatment 1
- Continue anticoagulation indefinitely while cancer remains active 1, 5
For patients with antiphospholipid syndrome:
- Consider warfarin (target INR 2.5) over DOACs due to concerns about DOAC efficacy in this population 1
Critical Monitoring Parameters
During heparin therapy:
- Check aPTT every 4 hours initially when using UFH, then at appropriate intervals once therapeutic 3
- Monitor platelet count, hematocrit, and occult blood throughout therapy 3
- Achieving therapeutic anticoagulation within 24 hours is important, though subtherapeutic aPTT in the first 48 hours with adequate initial dosing (≥1250 U/h) does not dramatically increase recurrence risk 6
Common Pitfalls to Avoid
Do not withhold anticoagulation due to fear of hemorrhagic transformation - the evidence strongly supports anticoagulation even in the presence of hemorrhagic infarction in most cases. 1 The risk of thrombosis progression without anticoagulation exceeds the bleeding risk in the vast majority of patients.
Do not use inadequate initial heparin dosing - subtherapeutic anticoagulation in the first 24 hours historically increased recurrence rates, though modern protocols with higher initial infusion rates (≥1250 U/h) have mitigated this risk. 7, 8, 6
Do not delay oral anticoagulation initiation - start warfarin or DOACs within the first 24 hours of heparin therapy to ensure smooth transition and adequate anticoagulation duration. 1