Is tissue plasminogen activator (tPA) contraindicated in a patient with a history of a recent, resolved stroke-like episode that occurred one week ago and has now presented with similar symptoms?

tPA Administration After Recent Transient Stroke-Like Episode

A prior stroke-like episode that resolved spontaneously one week ago is NOT an absolute contraindication to tPA, but requires careful assessment of whether the current presentation represents a new acute ischemic stroke versus recurrent symptoms from the prior event.

Critical Decision Points

Determine if Current Event is a New Stroke

The key question is whether this represents:

• A new acute ischemic stroke (tPA eligible if within time window) 1
• Recurrent symptoms from the prior event without new infarction (tPA not indicated)

Obtain immediate non-contrast CT to exclude:

• Hemorrhagic transformation of the prior event 1
• Extensive early ischemic changes from the prior stroke 1
• New acute infarction distinct from prior territory

Time-Based Treatment Algorithm for New Stroke

If imaging confirms a new acute ischemic stroke distinct from the prior event:

Within 0-3 hours of current symptom onset:

• Administer IV tPA at 0.9 mg/kg (maximum 90 mg) with strongest evidence (Grade 1A) 1, 2
• NNT = 8 for minimal or no disability 1
• This time window provides greatest absolute benefit 1, 2

Within 3-4.5 hours of current symptom onset:

• Offer IV tPA using ECASS III criteria (Grade 2C) 1, 2
• NNT = 14 for improved functional outcome 1
• Smaller but clinically meaningful benefit 3

Beyond 4.5 hours:

• Do NOT administer tPA (Grade 1B recommendation against) 1, 2

Assessment of the Prior Episode

If the Prior Event Was a TIA (Transient Ischemic Attack)

A prior TIA one week ago is NOT a contraindication to tPA for a new acute ischemic stroke. 1, 2

• TIA patients were included in the landmark NINDS trial that established tPA efficacy 3
• The spontaneous resolution suggests the prior event was likely a TIA rather than completed stroke 4
• Proceed with standard tPA protocol if current event meets eligibility criteria 1

If the Prior Event Was a Minor Stroke

A prior minor stroke one week ago that resolved is NOT listed as an absolute contraindication in current guidelines. 1, 2

However, assess for:

• Hemorrhagic transformation risk on current CT imaging 1
• Extent of prior infarction - if >1/3 MCA territory, this increases bleeding risk 1
• Current anticoagulation status - if started after prior event, this IS a contraindication 5

Absolute Contraindications to Verify

Even with a new acute stroke, do NOT give tPA if:

• Patient is on DOACs (rivaroxaban, apixaban, etc.) - this is an absolute contraindication 1, 5
• Blood pressure cannot be reduced to <185/110 mmHg despite treatment 1, 2
• CT shows hemorrhagic transformation of the prior stroke 1
• CT shows extensive early ischemic changes >1/3 MCA territory from either event 1
• Less than 24 hours since prior tPA administration (though this doesn't apply at one week) 1

Risk-Benefit Considerations

Increased Hemorrhagic Risk Factors

The baseline symptomatic intracranial hemorrhage (sICH) rate is 6.4% with tPA versus 0.6% with placebo (NNH = 17) 3, 1, 6

Risk may be higher if:

• Prior stroke had significant edema or mass effect (OR 7.8 for sICH) 6
• Current NIHSS score is high (OR 1.8 per category increase) 6
• Patient was started on antiplatelet therapy after prior event (3% absolute increased ICH risk) 1, 2

Clinical Pitfall to Avoid

Do not assume the current presentation is "just recurrent symptoms" without imaging confirmation. 4

• 32% of patients initially deemed "too mild" or "rapidly improving" were ultimately left dependent or dead 4
• The one-week interval makes a new thrombotic event entirely plausible 1
• Obtain urgent neurology consultation if uncertainty exists 2

Management Protocol if tPA is Administered

Pre-treatment:

• Reduce BP to <185/110 mmHg using labetalol or nicardipine 1, 2

During infusion:

• Monitor BP every 15 minutes during infusion and for 2 hours after 2
• Maintain BP <180/105 mmHg 2

Post-treatment:

• Do NOT give anticoagulants or antiplatelets for 24 hours 1, 2
• After 24-48 hours, initiate aspirin 160-325 mg if not anticoagulated 1

Alternative if tPA is Contraindicated

If the prior stroke creates contraindications (hemorrhagic transformation, anticoagulation started, etc.):

• Consider mechanical thrombectomy for large vessel occlusion 5
• Initiate aspirin 160-325 mg within 24-48 hours 1, 5
• Urgent stroke neurology consultation 2