What are the absolute contraindications for stroke thrombolysis with intravenous tissue plasminogen activator (tPA)?

Absolute Contraindications for Stroke Thrombolysis

The absolute contraindications for intravenous tissue plasminogen activator (tPA) in acute ischemic stroke include evidence of intracranial hemorrhage, active bleeding, and recent major surgery or trauma within the past 3 weeks. 1

Key Absolute Contraindications

Based on established guidelines, the following are absolute contraindications for IV thrombolysis in acute ischemic stroke:

1. Intracranial Hemorrhage

   • Evidence of intracranial hemorrhage on pretreatment imaging 1
   • History of intracranial hemorrhage 1
   • Suspected subarachnoid hemorrhage 1

2. Bleeding Risk

   • Active or recent severe bleeding within the past 21 days 1
   • Known bleeding disorder 1
   • Platelet count < 100,000/mm³ 1
   • INR > 1.7 in patients on oral anticoagulants 1
   • Heparin use within 48 hours with elevated aPTT 1

3. Neurological Conditions

   • Ischemic stroke within the previous 3 months 1
   • Hemorrhagic stroke at any time in the past 1
   • Intracranial neoplasm, arteriovenous malformation, or aneurysm 1
   • Severe head trauma within the previous 3 weeks 1

4. Recent Procedures/Trauma

   • Major surgery within the previous 3 weeks 1
   • Recent puncture of a non-compressible blood vessel (within past 7 days) 1
   • Traumatic external cardiac massage within the past 10 days 1

5. Other Systemic Conditions

   • Systolic blood pressure >185 mmHg or diastolic blood pressure >110 mmHg that cannot be safely reduced 1
   • Bacterial endocarditis 1
   • Acute pancreatitis 1
   • Severe liver disease (hepatic failure, cirrhosis, portal hypertension) 1

Important Considerations

Time Window

• Treatment beyond 4.5 hours from symptom onset is generally contraindicated 1, 2
• The benefit of thrombolysis decreases with time, with greatest benefit within 90 minutes of symptom onset 3

Relative Contraindications

Some conditions previously considered absolute contraindications may now be considered relative contraindications in certain circumstances 1:

• Minor or rapidly improving symptoms
• Seizure at onset with postictal residual neurological impairments (if appropriate intracranial occlusion is documented)
• Recent gastrointestinal or urinary tract hemorrhage (within previous 21 days)
• Recent acute myocardial infarction (within previous 3 months)

Special Populations

1. Pregnancy

   • While traditionally considered a contraindication, limited evidence suggests tPA may be used in pregnant patients after carefully weighing risks and benefits 1
   • tPA does not cross the placenta 1

2. Elderly Patients

   • Advanced age alone (>80 years) should not be considered an absolute contraindication 4
   • Elderly patients can benefit from thrombolysis, though with potentially higher bleeding risk 3

3. Recent TIA

   • Recent TIA is not an absolute contraindication 5
   • Evidence suggests patients with prior ipsilateral TIA do not have higher bleeding risk after thrombolysis 5

Clinical Pitfalls to Avoid

1. Delaying Treatment

   • Do not delay treatment for laboratory results in patients without suspicion of coagulopathy 1
   • Aim to complete initial imaging within 45 minutes of emergency department arrival 1

2. Overestimating Contraindications

   • Some traditional contraindications may be reconsidered in patients with severe, disabling stroke when the potential benefit outweighs the risk 4
   • Patients with contraindications who received thrombolysis still showed favorable outcomes in some studies 4

3. Misinterpreting Imaging

   • Early ischemic changes on CT are not absolute contraindications within the 3-hour window 1
   • Ensure proper imaging interpretation to exclude hemorrhage before treatment 1

The decision to administer IV tPA must balance the potential benefits of improved functional outcomes against the risks of hemorrhagic complications, with consideration of the individual patient's clinical situation and time from symptom onset.