When is anticoagulant therapy indicated in pediatric stroke?

Anticoagulant Therapy Indications in Pediatric Stroke

Anticoagulant therapy in pediatric stroke is indicated for specific etiologies and stroke types, with treatment decisions based on the underlying cause, presence of hemorrhage, and risk of recurrence.

Cerebral Sinovenous Thrombosis (CSVT)

• For CSVT without significant intracranial hemorrhage:

  • Anticoagulation is recommended initially with unfractionated heparin (UFH) or low molecular weight heparin (LMWH) and subsequently with LMWH or vitamin K antagonist (VKA) for a minimum of 3 months 1
  • For neonates with CSVT without significant hemorrhage, treatment duration should be between 6 weeks and 3 months 1

• For CSVT with significant hemorrhage:

  • Either anticoagulation or supportive care with radiologic monitoring at 5-7 days and anticoagulation if thrombus extension is noted 1
  • If ongoing symptoms or occlusion persists after 3 months, an additional 3 months of anticoagulation is suggested 1

Arterial Ischemic Stroke (AIS)

• Initial management:

  • UFH, LMWH, or aspirin is recommended as initial therapy until dissection and embolic causes have been excluded 1
  • Safety data shows anticoagulant therapy carries approximately 4% risk of symptomatic intracranial hemorrhage in children with AIS 2

• For AIS with cardioembolic source:

  • Anticoagulant therapy with LMWH or VKAs for at least 3 months 1
  • For neonates with first AIS and documented cardioembolic source, anticoagulation with UFH or LMWH is suggested 1

• For AIS secondary to arterial dissection:

  • Anticoagulant therapy with LMWH or VKAs for at least 6 weeks 1
  • Ongoing treatment guided by radiologic assessment of stenosis and evidence of recurrent events 1

• For non-cardioembolic, non-dissection AIS:

  • Once cardioembolic and dissection causes are excluded, daily aspirin prophylaxis for a minimum of 2 years is suggested 1
  • For children with recurrent AIS or TIAs while on aspirin, changing to clopidogrel or anticoagulant therapy with LMWH or VKA is suggested 1

Special Considerations

• Moyamoya disease:

  • Aspirin is suggested over no treatment as initial therapy 1
  • Patients should be referred to specialized centers for revascularization consideration 1

• Non-Moyamoya vasculopathy:

  • UFH, LMWH, or aspirin for 3 months as initial therapy 1
  • Ongoing antithrombotic therapy should be guided by repeat cerebrovascular imaging 1

• Recurrent AIS in neonates:

  • Anticoagulant or aspirin therapy is suggested 1

Important Caveats

• Thrombolysis (tPA) or mechanical thrombectomy is not recommended outside specific research protocols 1

• Combination therapy with aspirin and clopidogrel may increase risk of intracranial bleeding 3

• Children with arteriopathies have a 5-fold increased risk of stroke recurrence compared to those with idiopathic AIS, with 1-year recurrence rates of 32% for moyamoya, 25% for transient cerebral arteriopathy, and 19% for arterial dissection 4

• Pediatric dosing for heparin requires careful monitoring with adjusted doses:

  • Initial dose: 75-100 units/kg IV bolus over 10 minutes
  • Maintenance dose varies by age:
    • Infants: 25-30 units/kg/hour (infants <2 months have highest requirements)
    • Children >1 year: 18-20 units/kg/hour
  • Adjust heparin to maintain aPTT of 60-85 seconds 5

The decision to use anticoagulation in pediatric stroke must carefully weigh the benefits of preventing recurrence against the risks of hemorrhagic complications, with treatment decisions guided by stroke etiology, presence of arteriopathy, and risk factors for recurrence.