From the Guidelines
Heparin therapy in vertebral artery dissection should be approached with caution due to high-risk features that may increase the risk of hemorrhagic complications. The primary concern is the risk of hemorrhagic complications, particularly extension of intramural hematoma or conversion to subarachnoid hemorrhage. Specific high-risk features that warrant extra caution with heparin include:
- Presence of subarachnoid hemorrhage
- Intracranial extension of the dissection
- Pseudoaneurysm formation
- Large or expanding intramural hematoma
- Uncontrolled hypertension
- Recent stroke (especially hemorrhagic transformation) Patients with multiple dissections or underlying coagulopathies also represent higher-risk groups. According to the 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease 1, antithrombotic treatment with either an anticoagulant (heparin, low-molecular-weight heparin, or warfarin) or a platelet inhibitor (aspirin, clopidogrel, or the combination of extended-release dipyridamole plus aspirin) for at least 3 to 6 months is reasonable for patients with extracranial carotid or vertebral arterial dissection associated with ischemic stroke or TIA. When anticoagulation is deemed necessary despite these risks, consider using a lower target aPTT range (50-70 seconds rather than 70-90 seconds), more frequent neurological monitoring, and earlier transition to oral anticoagulants. In many cases, antiplatelet therapy (aspirin 81-325mg daily) may be preferred as first-line treatment due to its more favorable risk profile in the setting of arterial dissection. The rationale for these precautions stems from heparin's mechanism as an anticoagulant, which while preventing thromboembolic complications, may simultaneously increase bleeding risk within the damaged arterial wall.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
High-Risk Features for Heparin Therapy in Vertebral Artery Dissection
The following are high-risk features for heparin (unfractionated heparin) therapy in vertebral artery dissection:
- Hemorrhagic transformation of a cerebral infarction 2, 3
- Ineffective prevention of symptoms or dissection progression 2, 3
- Contra-indications to anticoagulation 2, 3
- High risk of stroke in a younger population 4
- Possible low-impact mechanisms that can cause vertebral artery dissection 4
Anticoagulation Therapy
Anticoagulation with intravenous heparin followed by oral warfarin has been recommended for all patients with acute dissections, regardless of the type of symptoms, unless there are contra-indications 2, 3.
- Intravenous heparin may be associated with hemorrhagic transformation of a cerebral infarction or may be ineffective to prevent symptoms or dissection progression 2, 3
- Oral warfarin may be used as an alternative to heparin 2, 3, 5
Alternative Therapies
Alternative therapies such as endovascular management, stent-assisted angioplasty, and emboli protection device may be considered in selected cases of vertebral artery dissection 2, 3.
- Protected stent-assisted VA angioplasty has not been previously reported and appears to be a safe, effective and immediate method of restoring vessel lumen integrity 2
- Stent-assisted VA angioplasty has rarely been reported in the management of spontaneous dissections and appears to be a safe, effective and immediate method of restoring vessel lumen integrity 3