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Updated: Aug 7, 2026
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Optimized Management of Endovascular Treatment for Acute Ischemic Stroke
Published on: January 18, 2018
Intravenous Thrombolysis Beyond the Conventional Time Window for Acute Ischemic Stroke: A Systematic Review and
Shaan Patel1, Shiva A Nischal2, Kush M Kale2
1Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.
JAMA Network Open
|August 6, 2026
Summary
Intravenous thrombolysis (IVT) for acute ischemic stroke improves functional outcomes when given over 4.5 hours after symptom onset. However, this extended treatment increases the risk of symptomatic intracerebral hemorrhage.
Area of Science:
- Neurology
- Cardiovascular Medicine
- Medical Imaging
Background:
- Intravenous thrombolysis (IVT) is a standard treatment for acute ischemic stroke within 4.5 hours of symptom onset.
- Many patients present outside this time window or have unknown symptom onset times.
- Recent trials explore IVT benefits in extended windows for select patients.
Purpose of the Study:
- To evaluate functional and safety outcomes of IVT administered 4.5 hours or more after stroke onset.
- To determine if extended IVT improves patient outcomes in acute ischemic stroke.
Main Methods:
- Systematic search of PubMed, Embase, and Cochrane Central Register of Controlled Trials.
- Included randomized clinical trials (RCTs) of adults with acute ischemic stroke treated with IVT beyond 4.5 hours.
- Extracted data and performed meta-analysis using random-effects models.
Main Results:
- Analyzed 14 RCTs with 4174 patients; 9 published in the last 5 years.
- IVT beyond 4.5 hours improved excellent (RR 1.22) and good (RR 1.12) functional outcomes at 90 days.
- Increased risk of symptomatic intracerebral hemorrhage (RR 2.44) observed, with no difference in mortality.
Conclusions:
- IVT beyond 4.5 hours improves functional outcomes in acute ischemic stroke.
- Increased risk of symptomatic intracerebral hemorrhage necessitates careful patient selection.
- Supports extending thrombolytic therapy in imaging-selected patients beyond the conventional window.
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