From the Guidelines
Tissue Plasminogen Activator (tPA) Administration for Delayed Catheterization
tPA should be administered within 4.5 hours of ischemic stroke onset.
- The main consideration for administering tPA is the time elapsed since the onset of stroke symptoms, not the timing of catheterization.
- According to the guidelines, intravenous recombinant tissue-type plasminogen activator (r-tPA) improves functional outcomes at 3 to 6 months when given within 4.5 hours of ischemic stroke onset 1.
- The American College of Emergency Physicians and the American Academy of Neurology recommend intravenous tPA for acute ischemic stroke patients if given within 3 hours of symptom onset, and also consider it safe and effective between 3 to 4.5 hours after symptom onset 1.
- The American College of Chest Physicians suggests IV recombinant tissue plasminogen activator (r-tPA) if treatment can be initiated within 3 hours (Grade 1A) or 4.5 hours (Grade 2C) of symptom onset 1.
- Earlier treatment, such as within 90 minutes, may result in more favorable outcomes, but treatment between 90 to 180 minutes is also beneficial 1.
- The use of tPA is associated with improved outcomes for a broad spectrum of carefully selected patients who can be treated within the recommended time frame 1.
From the Research
Tissue Plasminogen Activator (tPA) Administration
- The administration of tPA within 4.5 hours from the time last known well (LKW) improves outcomes in ischemic stroke patients, with better outcomes seen with earlier administration 2.
- The average code-to-tPA time was 80 minutes in patients with LKW-to-code time of 0-59 minutes, 67 minutes in patients with LKW-to-code time of 60-119 minutes, and 52 minutes in patients with LKW-to-code time of 120 minutes or more 2.
- Door-to-needle time of 60 minutes or less is recommended for tPA administration, but less than 30% of US patients are treated within this time window 3, 4.
Delayed Catheterization and tPA Administration
- There is no direct evidence on when tPA is given for delayed catheterization, but studies suggest that delays in tPA administration can occur due to various factors, including hospital factors and patient characteristics 3, 4.
- Delays in starting the infusion after the bolus can result in lower serum concentrations of tPA, which could decrease the effectiveness of thrombolysis 5.
- Interruptions in the infusion of tPA can also occur, and rebolusing with tPA may be needed to rapidly restore TPA levels to target concentrations 5, 6.
Clinical Outcomes and tPA Administration
- Improved timeliness of tPA administration is associated with lower in-hospital mortality and intracranial hemorrhage, along with an increase in the percentage of patients discharged home 4.
- Door-to-needle times of 60 minutes or less are associated with better clinical outcomes, including lower in-hospital mortality and symptomatic intracranial hemorrhage 3, 4.