What is the recommended treatment for thrombolysis after an ischemic Cerebrovascular Accident (CVA)?

Thrombolysis for Ischemic Cerebrovascular Accident (CVA)

Intravenous alteplase (0.9 mg/kg, maximum dose 90 mg over 60 minutes with initial 10% of dose given as bolus over 1 minute) is recommended for eligible patients who can be treated within 4.5 hours of ischemic stroke symptom onset or last known well. 1

Time Windows for Thrombolysis

• Within 3 hours: Strong recommendation for IV alteplase (Grade 1A) 1
• 3-4.5 hours: Suggested use of IV alteplase (Grade 2C) 1
• Beyond 4.5 hours: Not recommended (Grade 1B) 1, except in specific scenarios:
  • Patients with wake-up stroke who have MRI DWI-FLAIR mismatch within 4.5 hours of symptom recognition 1
  • Patients with core/perfusion mismatch on CT or MRI between 4.5-9 hours from symptom onset 1

Patient Selection and Pre-treatment Assessment

1. Immediate evaluation:

   • Use validated stroke screening tool 1
   • Check blood glucose (only test required before initiating IV alteplase) 1
   • Perform brain imaging (CT or MRI) without delay 1
   • Assess stroke severity using a rating scale (e.g., NIHSS) 1

2. Blood pressure management:

   • Lower BP below 185/110 mmHg before initiating IV thrombolysis 1
   • Continue BP monitoring during and after treatment 2

Contraindications for IV Alteplase

• Symptom onset >4.5 hours (unless specific imaging criteria are met) 2
• Unknown time of symptom onset (unless DWI-FLAIR mismatch is present) 2
• Stroke or serious head injury within preceding 3 months 2
• Major surgery within prior 14 days 2
• History of intracranial hemorrhage 2
• Gastrointestinal or genitourinary hemorrhage within previous 21 days 2
• Evidence of intracranial hemorrhage on pre-treatment imaging 2

Post-thrombolysis Management

1. Neurological monitoring:

   • Assess every 15 minutes during and after IV alteplase infusion for 2 hours
   • Every 30 minutes for the next 6 hours
   • Hourly until 24 hours after treatment 2

2. Imaging follow-up:

   • Obtain follow-up CT or MRI scan at 24 hours post-treatment
   • Delay antiplatelet therapy until after the 24-hour scan has excluded intracranial hemorrhage 2

3. Blood pressure management:

   • Maintain BP below 180/105 mmHg 2

Special Considerations

Mechanical Thrombectomy

• Eligible patients should receive IV thrombolysis even if mechanical thrombectomy is being considered 1
• Do NOT wait to evaluate responses to IV thrombolysis before proceeding with catheter angiography for mechanical thrombectomy 1
• For patients with suspected large vessel occlusion (LVO), obtain non-invasive angiography (e.g., CTA) 1

Intraarterial (IA) Thrombolysis

• Consider IA r-tPA within 6 hours of symptom onset for patients with proximal cerebral artery occlusions who do not meet eligibility criteria for IV r-tPA (Grade 2C) 1
• IV r-tPA is preferred over combination IV/IA r-tPA (Grade 2C) 1

Complications and Safety

• Symptomatic intracranial hemorrhage occurs in approximately 2.4% of patients treated with alteplase (vs. 0.2% with placebo) 3
• Overall mortality does not significantly differ between alteplase and placebo groups (7.7% vs. 8.4%) 3

Emerging Treatments

• Tenecteplase is being studied as an alternative to alteplase with potential advantages including lower cost and ease of administration 4, but alteplase remains the standard of care based on current guidelines 1

Pitfalls to Avoid

• Delaying treatment - efficacy decreases and risk increases with time from symptom onset 2
• Failing to check blood glucose before administration 1
• Administering thrombolysis without controlling hypertension (>185/110 mmHg) 1
• Withholding IV thrombolysis in eligible patients who are also candidates for mechanical thrombectomy 1
• Starting antiplatelet therapy before obtaining post-thrombolysis imaging at 24 hours 2

Remember that "time is brain" - every minute counts in acute stroke management, with earlier treatment associated with better outcomes.