What are the guidelines for antiplatelet and fibrinolytic therapy in a 60-year-old man with acute ischemic stroke, who meets criteria for fibrinolytic (tPA) therapy and has a computed tomography (CT) scan of the brain?

Guidelines for Antiplatelet and Fibrinolytic Therapy in Acute Ischemic Stroke

For a 60-year-old man with acute ischemic stroke who meets criteria for fibrinolytic therapy, administer IV recombinant tissue plasminogen activator (rtPA) at 0.9 mg/kg (maximum 90 mg) over 60 minutes with 10% given as a bolus over 1 minute, and delay antiplatelet therapy until 24 hours after fibrinolysis and confirmation of absence of hemorrhage on follow-up imaging. 1, 2

Fibrinolytic (tPA) Therapy Administration

Eligibility and Timing

• Treatment must be initiated within 4.5 hours of symptom onset
  • Strong recommendation for treatment within 3 hours 2
  • More cautious recommendation for 3-4.5 hour window 2
  • Not recommended beyond 4.5 hours 1, 2

Pre-Treatment Requirements

• Emergency brain imaging (CT or MRI) must be performed to exclude intracranial hemorrhage 1
• Brain imaging should be interpreted within 45 minutes of ED arrival by a physician with expertise in reading CT/MRI 1
• Ensure blood pressure is below 185/110 mmHg before initiating thrombolysis 2
• Check blood glucose (hypoglycemia with glucose <50 mg/dL is a contraindication) 1

Contraindications to Fibrinolytic Therapy

• Absolute contraindications include:
  • Evidence of intracranial hemorrhage on pre-treatment imaging
  • Current use of anticoagulants with INR >1.7 or PT >15 seconds
  • Use of direct thrombin inhibitors or factor Xa inhibitors with elevated lab tests
  • CT showing multilobar infarction (hypodensity >1/3 cerebral hemisphere)
  • Frank hypodensity involving more than one-third of MCA territory 1

Administration Protocol

1. Administer 0.9 mg/kg (maximum dose 90 mg) over 60 minutes
2. Give 10% of the dose as a bolus over 1 minute
3. Admit patient to intensive care or stroke unit for monitoring 1, 2

Post-Fibrinolytic Monitoring and Care

Neurological Assessment

• Perform neurological assessments:
  • Every 15 minutes during and after IV rtPA infusion for 2 hours
  • Every 30 minutes for the next 6 hours
  • Hourly until 24 hours after treatment 1, 2

Blood Pressure Management

• Monitor blood pressure with the same frequency as neurological assessments
• Increase frequency if systolic BP >180 mmHg or diastolic BP >105 mmHg
• Administer antihypertensive medications to maintain BP below these levels 1

Complications Management

• If patient develops severe headache, acute hypertension, nausea, vomiting, or worsening neurological status:
  • Discontinue rtPA infusion immediately
  • Obtain emergent CT scan 1
• Monitor closely for signs of intracranial hemorrhage, especially within first 12 hours 2

Antiplatelet Therapy

Timing After Fibrinolysis

• Do not administer antiplatelet agents until 24 hours after fibrinolysis 2
• Obtain follow-up CT or MRI scan at 24 hours post-treatment before starting antiplatelet therapy 1, 2
• Delay aspirin until after the 24-hour post-thrombolysis scan has excluded intracranial hemorrhage 2

Antiplatelet Options After 24 Hours

• Options include:
  • Aspirin (75-100 mg once daily)
  • Clopidogrel (75 mg once daily)
  • Aspirin/extended-release dipyridamole (25 mg/200 mg twice daily) 2
• For non-cardioembolic stroke, combination of aspirin and extended-release dipyridamole is recommended over aspirin alone 2

Additional Considerations

Procedural Precautions

• Delay placement of nasogastric tubes, indwelling bladder catheters, or intra-arterial pressure catheters if patient can be safely managed without them 1
• Consider venous thromboembolism prophylaxis with prophylactic-dose subcutaneous heparin for patients with restricted mobility 2

Special Circumstances

• If mechanical thrombectomy is being considered, do not delay IV rtPA administration while waiting for thrombectomy preparation 2
• For patients with atrial fibrillation and stroke, long-term oral anticoagulation should be considered after the acute phase 2

This approach prioritizes rapid assessment, appropriate administration of fibrinolytic therapy, careful post-treatment monitoring, and properly timed introduction of antiplatelet therapy to maximize benefit while minimizing the risk of hemorrhagic complications.